WO2004031831A1 - Methods and systems for improved boundary contrast - Google Patents
Methods and systems for improved boundary contrast Download PDFInfo
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- WO2004031831A1 WO2004031831A1 PCT/SE2003/001509 SE0301509W WO2004031831A1 WO 2004031831 A1 WO2004031831 A1 WO 2004031831A1 SE 0301509 W SE0301509 W SE 0301509W WO 2004031831 A1 WO2004031831 A1 WO 2004031831A1
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- micromirrors
- tilting
- tilt
- tilting axis
- output intensity
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Classifications
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70425—Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning
- G03F7/70433—Layout for increasing efficiency or for compensating imaging errors, e.g. layout of exposure fields for reducing focus errors; Use of mask features for increasing efficiency or for compensating imaging errors
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70216—Mask projection systems
- G03F7/70283—Mask effects on the imaging process
- G03F7/70291—Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70425—Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning
- G03F7/70433—Layout for increasing efficiency or for compensating imaging errors, e.g. layout of exposure fields for reducing focus errors; Use of mask features for increasing efficiency or for compensating imaging errors
- G03F7/70441—Optical proximity correction [OPC]
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
- G03F7/70491—Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring processes
- G03F7/70516—Calibration of components of the microlithographic apparatus, e.g. light sources, addressable masks or detectors
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S359/00—Optical: systems and elements
- Y10S359/904—Micromirror
Definitions
- the present invention relates to methods and systems that define feature boundaries in a radiation sensitive medium on a workpiece using a diffraction- type micromirror array, extending to production of patterns and structures on a semiconductor substrate.
- Workpieces include lithographic masks, integrated circuits and other electronic and optical devices. Particular aspects of the present invention are described in the claims, specification and drawings.
- Photon beam(s) and electron beam(s) Two main types of radiant energy used to generate patterns for integrated circuit or device production are photon beam(s) and electron beam(s). Systems using multiple scanned photon beams are more generally available than systems using multiple electron beams. Photon or laser pattern generator systems usually are faster but less precise than e-beam systems. Multiple, relatively wide beams in a laser scanning system have different characteristics, than a single electron beam in a vector-driven e-beam system. Embellishments can be used in mask writing with a laser scanning system to compensate partially for the larger beam width of the photon beam. [0003] For direct writing applications, photon-exposing radiation may be preferred, because an electron beam may adversely affect layer properties of the integrated circuit.
- Photon-based writing devices have the further advantage of generally being faster than electron beam devices.
- the new kind of pattern generator uses a micromirror array, in one embodiment, a spatial light modulator ("SLM”), and a pulsed illumination source to print so-called stamps across the face of a workpiece.
- SLM spatial light modulator
- the Graphics Engine application referenced above is one of several applications with overlapping inventors that disclose aspects of this new kind of pattern generator. These co-pending applications also teach that other kinds of micromirror arrays that may be used with pulsed illumination to print stamps.
- micromirror array under development relies on diffraction, rather than deflection, to produce contrast in the radiation sensitive medium.
- diffraction small movements of micromirrors induce scattering of radiation.
- the scattering corresponds to so-called destructive interference among components of radiation relayed from a single micro-mirror in an object plane.
- Apertures and other optical components translate the scattering into gray-scaled intensity variations in an image plane corresponding to the radiation sensitive medium on the workpiece.
- a single micromirror in the object plane produces a Gaussian distribution of intensity in the image plane.
- the intensity distribution of a single micromirror affects an area generally corresponding to a 3 x 3 or 5 x 5 grid of micromirrors.
- the intensity of exposing radiation at a spot in the image plane may depend on the orientation of 9 or 25 micromirrors in the object plane.
- a radiation sensitive medium, such as resist, at the image plane has some thickness and some opacity.
- the top and bottom of the medium respond somewhat differently to the exposing radiation. This depends on the characteristics of the medium and the contrast at boundaries between areas intended to be exposed and unexposed. Poor contrast typically produces a trench with a wide top and a narrow bottom or a non-vertical sidewall, corresponding to an iso-exposure profile through the thickness of the medium.
- a non- vertical sidewall compromises the placement of a boundary, due to variations in medium thickness, in particular, after erosion in etch processes. The variations in medium thickness are large, compared to the allowed critical dimension variations.
- the sine of a 10 or 15 degree angle is .1736 or .2588, respectively, which indicates the degree to which non-vertical sidewalls make boundary placement is sensitive to medium thickness.
- a range of micromirror operation may influence boundary placement, as may a transfer function between boundary placement and micromirror tilt.
- Calibration methods also may improve placement and / or contrast at boundaries.
- the present invention relates to methods and systems that define feature boundaries in a radiation sensitive medium on a workpiece using a diffraction- type micromirror array, extending to production of patterns and structures on a semiconductor substrate.
- Workpieces include lithographic masks, integrated circuits and other electronic and optical devices. Particular aspects of the present invention are described in the claims, specification and drawings.
- FIG. 1 depicts the general layout of a micromirror pattern generator.
- FIG. 2 illustrates a range of mirror tilts.
- FIG. 3A illustrates complex amplitude and intensity curves.
- FIG. 3B depicts complex amplitudes that may be generated by various mirror configurations.
- FIGs. 3C-3E depict SLM pixel values, aerial image is in resist image is corresponding to various complex amplitude ranges.
- FIG. 4 illustrates the impact of using a negative black tilt on imperfect mirror tilt.
- FIG. 5 illustrates production of side lobes.
- FIG. 6 illustrates different mirror shapes, array configurations and surface profiles that influence sidelobe production.
- FIG. 7 depicts variations on placement of phase interference structures on the surface of a mirror, individually and as part of a micromirror array.
- FIG. 8 depicts a transfer function
- FIG. 9 is a block diagram of an optical system.
- FIG. 10 depicts various patterns that can be used with calibration techniques.
- FIG. 1 1 depicts an imperfect edge and influence of neighboring pixels on a local edge placement.
- FIG. 12 illustrates varying line placements useful for calibration.
- FIGs. 13 and 14 depict aspects of calibration.
- FIG. 15 is a flow chart for one calibration algorithm.
- FIG. 16 illustrates multipass writing
- FIG. 17 illustrates calibration in anticipation of multipass writing.
- FIG. 1 depicts the general layout of a micromirror array pattern generator, in one embodiment employing a spatial light modulator ("SLM"). Aspects of an SLM pattern generator are disclosed in the related pending patent applications identified above. The workpiece to be exposed sits on a stage 112. The position of the stage is controlled by precise positioning device, such as paired interferometers 1 13.
- SLM spatial light modulator
- the workpiece may be a mask with a layer of resist or other exposure sensitive material or, for direct writing, it may be an integrated circuit with a layer of resist or other exposure sensitive material.
- the stage moves continuously.
- the stage In the other direction, generally perpendicular to the first direction, the stage either moves slowly or moves in steps, so that stripes of stamps are exposed on the workpiece.
- a flash command 108 is received at a pulsed excimer laser source 107, which generates a laser pulse.
- This laser pulse may be in the deep ultraviolet (DUV) or extreme ultraviolet (EUV) spectrum range.
- the laser pulse is converted into an illuminating light 106 by a beam conditioner or homogenizer.
- a beam splitter 105 directs at least a portion of the illuminating light to an SLM 104.
- the pulses are brief, such as only 20 ns long, so any stage movement is frozen during the flash.
- the SLM 104 is responsive to the datastream 101, which is processed by a pattern rasterizer 102.
- the SLM has 2048 x 512 mirrors that are 16 x 16 ⁇ m each and have a projected image of 80 x 80 nm. It includes a CMOS analog memory with a micro-mechanical mirror formed half a micron above each storage node. The electrostatic forces between the storage nodes and the mirrors actuate the mirrors.
- the device works in diffraction mode, not specular reflectance, and needs to deflect the edge of the mirrors by only a quarter of the wavelength (62 nm at 248 nm) to go from the fully on state to the fully off state.
- To create a fine address grid the mirrors are driven to on, off and 63 inte ⁇ iediate values.
- the pattern is stitched together from millions of images of the SLM chip. Flashing and stitching proceed at a rate of 1000 stamps per second. To eliminate stitching and other errors, the pattern is written four times with offset grids and fields. Furthermore, the fields are blended along the edges.
- the mirrors are individually calibrated.
- a CCD camera sensitive to the excimer light, is placed in the optical path in a position equivalent to the image under the final lens.
- the SLM mirrors are driven through a sequence of known voltages and the camera measures the response.
- a calibration function is determined for each mirror, to be used for real-time correction of the grey-scale data during writing.
- the vector format pattern is rasterized into grey-scale images, with grey levels corresponding to dose levels on the individual pixels in the four writing passes. This image can then be processed using image processing.
- the final step is to convert the image to drive voltages for the SLM.
- the image processing functions are done in real time using programmable logic. Through various steps that have been disclosed in the related patent applications, rasterized pattern data is converted into values 103 that are used to drive the SLM 104. [0026] In this configuration, the SLM is a diffractive mode micromirror device.
- FIG. 2A depicts a mirror 212 perpendicular to exposing radiation.
- a beam splitter is used to allow the input and output from the micromirror array to traverse the same path.
- the input radiation might be at an angle to the mirror surface, so that the output was collected along a path different than the input.
- the complex amplitude of output from any one point on the mirror 212 can be depicted as a point on a unit circle representing its real and imaginary (phase) amplitude components.
- the reference position of the mirror is considered to have a real part of +1 and an imaginaiy part of 0.
- This reference position 210 is the same for all points on the mirror 212, because it is perpendicular to the input radiation.
- FIG. 2B depicts a tilt angle that is approximately one-third of a quarter wave tilt. (The tilt in the diagram is illustrative, not scaled.)
- the tilt of mirror 222 from the reference line 224 provides a comparison of the mirror position at the edge and the mirror position in the middle.
- a quarter wave tilt induces a 180 degree phase difference between light reflected from the edge and middle of the mirror.
- the complex amplitude of the one side of the mirror 225 is graphed on the unit circle as an arc 221.
- the arc 221 represents the complex amplitude of points across the face of the mirror 222, from the center to the outside edge. It should be understood that the complex amplitude of the whole mirror surface would be graphed with a second arch, reflected across the x-axis from arc 221. Only one side of the mirror is graphed in this set of figures, for clarity.
- the projection optics illustrated in FIG. 9 and discussed below act as a low-pass filter. In the image, the mechanical structure of the mirror is removed by the low pass filter. What remains is the average complex amplitude over the mirror surface, which may be translated into an intensity distribution. For a surface, the average complex amplitude of the surface can be expressed by a surface integral:
- the resulting complex amplitude depends on an initial complex amplitude.
- the complex reflectance r can sometimes be taken as 1 , to simplify the analysis.
- the deflection h is at the edge of the mirror.
- the wavelength ⁇ is for one mode of the illumination.
- Simplifications apply to various cases.
- the surface integral dS can be simplified to a one dimensional integration clx from the right edge to the left edge of the mirror.
- the cross-section of the mirror varies as a function of x
- a simplification is: i right edge i
- A A 0 ⁇ ? " rj 1 clx , where " is the angle at the mirror surface, which is constant for lefi edge a mirror that has a flat surface.
- A A r left edge
- the real part of the complex integral is indicated by 220. It is in the range of the arc 221. Recall that the arc 221 also exists on the mirror side of the x-axis for a center-tilting mirror, in which case the counterclockwise and clockwise arcs have complementary imaginary parts.
- FIG. 2C a quarter wave tilt is represented. The distance that the edge of the minOr 232 has tilted away from the reference line 234 is one-quarter wavelength. Light traveling perpendicular to the mirror travels one-half wavelength less distance at the raised edge than at the mirror center, which is what gives rise to destructive interference and diffraction.
- the arc 231 depicts contributions to the complex amplitude of the mirror from one side of the mirror.
- the resulting complex amplitude 230 is graphed at the origin, which coincides with destructive interference.
- over-tilting of the mirror 242 from the reference line corresponds to what can be called a "negative black.”
- This negative black tilt angle has been analyzed and determined to have favorable properties for contrast at feature boundaries, as well as implications for mirror design, transfer functions, calibration and semi-conductor device manufacturing that are explained below.
- the arc 241 describes approximately 257 degrees phase difference between input and output waves, which is between a quarter wave tilt and a half wave tilt. For a mirror 16 microns wide, this corresponds to a tilt of approximately 87.5 oi ⁇ 88 nm at the edge and illuminated by a 248 nm source. This is a new range of tilts.
- Complex amplitude and intensity curves are depicted in FIG. 3A.
- FIG. 3A resembles the present FIG. 3A.
- that application teaches setting a lower bound for a dynamic range that corresponds in FIG. 3 A to a quarter wave tilt of some mirror, where the amplitude 310 and intensity 312 curves intersect at the x-axis.
- this inventor and his colleague suggested calibrating all mirrors in a micromirror array so that they would produce a similar maximum reflected output and a similar minimum reflected output.
- the control signal for Blanket Gray Calibration would drive a particular mirror tilt to a point typically short of a quarter wave tilt, at which the particular mirror produced a low output level that all micromirrors could attain. In this way, a consistent dynamic range could be produced and a minimum output intensity as close to zero as practical could be attained.
- FIGs. 3A-3B depict output resulting from the new range of tilts for a mirror, for which different transfer functions and calibration strategies are proposed in this disclosure.
- the new range of tilts is illustrated in FIGs. 2A-2D.
- the complex amplitude curve 310 has a minimum real part that is below the x- axis. This minimum corresponds to the real part of the complex amplitude 240 and to the angle of the arc 241 in FIG. 2D.
- the curve 306 is approximated by the function sin(x)/x.
- FIG. 3B-3E illustrate how negative black exposure can be used to improve contrast in positive and negative resists.
- FIG. 3B is a unit circle 1600 labeled to match FIGs. 2A-D.
- Point A corresponds to 210 in FIG. 2A.
- Points B, C and D correspond to 220, 230 and 240 in FIGs. 2B-2D.
- Point E is added.
- certain mirror configurations that have more effective reflecting surface away from the tilting axis, as opposed to near the tilting axis (e.g., FIG.
- 3C-3E include coded pixel values for diffracting elements (such as mirrors,) with reference to the points marked on the unit circle.
- the pattern of pixel values is DDAAAADD.
- A is a bright mirror and D a dark mirror with zero complex amplitude.
- on and off mirrors are adjacent, with no negative black applied.
- the pattern is BBAAAABB.
- a "B" mirror produces a negative amplitude, for instance a rectangular mirror tilted 87 nm. The negative amplitude is small relative to the positive amplitude.
- the pattern is EEAAAAEE.
- FIG. 3C illustrates the impact of the DDAAAADD pixel pattern, both in terms of an aerial image and a resist image.
- zero intensity exposure is the base line or axis and an exposure that activates the resist is a varying dashed line 301.
- the real part of the respective complex amplitudes are represented by a dashed line that sometimes is negative (FIGs. 3D-3E).
- the complex amplitude and intensity curves are similar.
- the relative position of three points 326 indicates the sharpness of the contrast, with a vertical stack of dots representing high contrast. These dots may represent how the image is viewed by adjacent pixels of a sensor or camera. More vertical dots would correspond to more variation of readings taken from adjacent pixels of a sensor array.
- the stack of dots in 3C is less vertical than in the other figures, which corresponds to relatively slanted sidewalls in the resist image 322 on the substrate 324.
- FIG. 3D illustrates a higher contrast at the sidewalls of the resist 332, corresponding to a more nearly vertical stack of dots 336.
- the dashed curve of the aerial image includes some negative complex amplitude.
- the solid intensity curve has a small positive value in the area where the developed resist is supposed to be removed.
- the small positive intensity at the outside edges of the curve is below the threshold 301 at which the resist is triggered, so the resist image 322 has the desired shape and more nearly vertical sidewalls than in FIG. 3C.
- 3E is different from the preceding figures, because it assumes a negative resist or radiation sensitive layer. That is, the resist images 342, 343 remain where there is minimal exposure below the threshold 301 , instead of maximal exposure above the threshold. Radiation intensity above the threshold 301 triggers the negative resist, but to make removable by etching instead of hardening it against etching.
- the dashed complex amplitude curve extends about as far below the axis as above it, so the solid intensity curve has similar or equal heights in each of the three nodes.
- the stack of points 348 is more nearly vertical than in the preceding figures, corresponding to more nearly vertical sidewalls of the resist images 342, 343.
- FIG. 4 illustrates the impact of using a negative black tilt on imperfect mirror tilt. This figure assumes that the same mirror tilt is desired, but not attained for all dark mirrors. That is, in the rows 402, the desired quarter wave minOr tilt is 62 nm (for a 248 nm wavelength.) However, the actual mirror tilt attained may range from 61 to 64 nm. As a result, the boundaries 412 & 414 between dark and bright (0 tilt) miiTors undulate, are not straight.
- FIG. 5 illustrates production of side lobes that can result from use of negative black. Side lobes are a phenomenon sometimes discussed in the context of attenuated phase shift masks. Suppose that exposures intended at targets 502. Small groups of minors, or single mi rors, produce a Gaussian distribution that is partially represented by circles 504. Curve 312 of FIG.
- FIG. 6 illustrates different minor shapes, an'ay configurations and surface profiles that influence sidelobe production.
- Mirror 602 has been shown by sophisticated simulations to produce a residual intensity of approximately 4.77 percent.
- a minor like 604 produces a greater residual intensity, in a range of 6 to 8 percent.
- Minor 606 produces less than 4.77 percent residual intensity.
- minor 608 produces a more difficult printing array than any of the other footprints.
- micromirrors of design 608 are anayed along a pair of offset axes 622 and 624. The approaches describe in the Graphic Engine application do not work as nicely with a diamond shaped mirror and pair of axes as an array that has a single set of axes.
- FIG. 6 depicts an approach that in can obtain the reduced residual intensity of mirror 608 and the regular array configuration of mirrors 602, 604 and 606.
- the minor 632 is a rectangle, but could be another regular shape.
- the surface of the mirror has areas 634 that are at different heights, as illustrated by the cross-section.
- the raised section 644 shown in the cross section are about a quarter wave above the main surface of the mirror 642. These sections cause destructive interference and diffraction through a range of minor tilts.
- a raised surface area of one unit cancels out a lower surface area of the same size and at the same distance from the tilting axis.
- FIG. 7 illustrates various potential placements of raised area, corresponding to 634 in FIG. 6.
- FIG. 7 depicts variations on placement of phase interference structures on the surface of a minor, individually and as part of a micromirror array.
- the interference structures 704 are placed at the comers of the mirror, leaving a diamond-like shape 702 in the middle of the minor.
- the effect of the interference structures 704 is to cancel out twice their surface area in reflected output, in a pattern like 708, leaving an interior area 706 effectively producing reflected output.
- the interference structures 704 yield an interior area 706 that resembles the reflective area of minor 608 in FIG. 6.
- the minor using interference structures 704 is rectangular, so an array can be fonned with mirrors arranged so that centers of reflecting surfaces are aligned in rows and columns, without the need for offset rows and columns on a second set of axes that is depicted in array 618 of FIG. 6.
- substantially all of the arcay can be covered by minors with interference structures. Having a relatively small area of the array either uncovered or open as trenches between mirrors reduces the stray radiation that needs to be dealt with. This stray radiation might otherwise be reflected along the optical path in undesirable directions, absorbed by the array, or channeled under the minors where damage can result to minor actuating components.
- the 7A has a substantially central tilting axis and similar reflecting areas on opposing sides of the tilting axis.
- the reflecting areas on opposite sides of the tilting axis are symmetrically reflected across the tilting axis.
- the reflecting surface could be twice reflected (across the tilting axis and then along the tilting axis) or symmetrical about a center point of the minor.
- the interference sfructures on opposing sides of the tilting axis produce less reflect output intensity away from the tilting axis than at or near the tilting axis.
- the effective reflecting surface is a triangle with its base along the tilting axis and its apex at the edge away from the tilting axis.
- the interference structures are positioned closer to the opposing edges of the minor than to the tilting axis.
- the interference sfructures 704 preferably are offset above or below the level of the main reflecting structure 702 by an odd multiple of a quarter wavelength. Any odd multiple of a quarter wavelength will produce a 180 degree phase difference between light reflected from the interference structures 704 and the reflecting surface 702.
- FIG. 7B depicts another arrangement of phase-shifted interference structures.
- the interference structures 714 are larger near the tilting axis than away from the tilting axis.
- the reflecting surface 712 produces more reflected output intensity 716 (proportional to effective reflecting area) away from near the tilting axis than at or near from the tilting axis.
- the effectively diffracted area 718 is again approximately twice as large as the interference structure 714. Removing effective reflecting area close to the tilting axis makes the minimum complex amplitude more negative. Thus, it increase the amount of "negative black,” giving higher contrast and edge acuity and at the same time more potential sidelobes. The eventuality of sidelobes leads to use of negative resist when the curve resembles FIG. 3E. [0047] Taken together, FIGs.
- FIG. 7C depicts using phase interference structures 724 around the perimeter of the reflecting surface 722 to produce effectively smaller minors.
- the effectively diffracted area 728 gives a smaller mirror profile 726 which may project smaller intensity distribution, thereby increasing the spatial resolution, especially with multiple writing passes.
- the effective radius of distribution might be reduced by half, for instance, by perimeter interference structures. This effective reflecting area reduction could be duplicated on adjacent minors or on alternating rows of minors or on a checkerboard pattern of minors.
- Two sides (FIG.
- each minor 7D or two comers (FIG. 7E) of each minor could have perimeter interference structures, such that the array would have complementary interference sfructures, when adjacent minors and their interference structures were considered.
- the perimeter interference structures may be set back a short distance from the edge of the minor, to establish an interference effect along the boundaiy between two bright minors, instead of in-phase constructive interference between adjacent interference sfructures.
- One or more transfer functions translate a desired feature displacement into a mirror deflection.
- One needed transfer function translates a feature displacement into a minor tilt.
- a gray scale value can be used as a short hand for feature displacement, though the relationship between photographic grays may not translate linearly to feature displacement.
- a displacement-to-tilt function can be combined with a driving voltage function or other transfer functions that realize a desired feature displacement in the operation of micromirror array hardware.
- FIG. 8 depicts a transfer function.
- the y-axis 802 corresponds to feature edge displacement. In other words, where in the exposure sensitive medium will the exposure be sufficient to set (in a positive medium) the medium?
- the x-axis 804 corresponds to minor deflection.
- the curve 806 relates one to the other.
- the output intensity of a micromirror among other similarly tilted micromirrors would actually increase (e.g., as tilt increased from 62 to 87.6 nm.)
- the function is monotonic because the resulting intensity in the image plane of a negative black microminor near a bright micromirror is reduced by destructive interference and diffraction resulting from interaction between the negative black and bright minors.
- a transfer function relating feature edge displacement to minor deflection or its proxy, such as deflection actuation voltage) is a practical way to improve contrast at a feature boundaiy using negative deflection.
- Calibration is required to take into account the performance individual minors, as explained in other commonly owned applications and patent, including the Blanket Gray Calibration application. Ongoing development has included new calibration methods, some of which are particularly useful in calibrating mirrors with a negative black max-tilt.
- An optical system that can be used for calibration is depicted in FIG. 9. Those of skill in the art will appreciate that orientations of the components can be changed and additional optical components can be added or substituted for use with the calibration methods described above.
- an illuminating radiation 901 is projected onto a micromirror array 902. This radiation typically is pulsed, either from a pulsed source or by interrupting a continuous source.
- the array in the object plane, is actuated to generate a pattern.
- Light reflected from the array is directed to a partially reflecting surface, such as a beam splitter 906 and relayed to a first lens assembly or an equivalent focusing minor.
- An aperture 908 is positioned in a Fourier plane. This aperture may be smaller (stopped down further than) or larger than aperture 916.
- Exposing radiation is directed through a second lens assembly 910 to another partially reflecting surface 912, which directs part of the radiation to a workpiece 920 and part of the radiation to a calibration sensor 926.
- the radiation directed towards the workpiece 920 passes through a third lens assembly 914, a second aperture 916 and a fourth lens assembly 918. It typically is focused on a radiation sensitive layer on a workpiece 920.
- the radiation directed towards the calibration sensor 926 passes through a fifth and sixth lens assembly 922, 924.
- an additional aperture could be positioned between lens 922 and lens 924. It is expected that the reduction ratio at the workpiece 920 will produce a smaller image than at the calibration sensor 926.
- the calibration sensor may, for instance, be a Charged Coupled Device (CCD) camera, a MOS camera, or a Charged Injection Device (CID).
- CCD-camera is for example a camera from Kodak ® KAF 1600 with approximately 1000*1600 pixels and sensitivity for the wavelength used, e.g. 248nm or 197nm.
- this sensitivity involves converting the radiation to visible light by a fluorescent dye, but camera chips which are directly sensitive to short wavelength, e.g. 248 nm are also available.
- the dose of electromagnetic radiation lies around 0.8*max range of the sensor. With a too low dose projected onto the sensor, the signal to noise ratio will in some cases be unacceptable low. With a too high dose projected onto the sensor, the sensor will be over saturated, with the result of an inaccurate measurement. [0051] Before the SLM can be calibrated, the SLM pixels must be mapped onto the sensor array or camera, so that geometric relationship between the sensor and the pixels is established. An image consisting of a relatively coarse grid of spots, typically bright in a dark background or vice-a-versa, is imaged by the minors.
- FIG. 10 depicts various patterns that can be used with calibration techniques, including new methods.
- FIG. 10A depicts a pattern produced by so-called blanket gray calibration, as described in the Blanket Gray Calibration application. In this method, all of the pixels in a field are nominally set to the produce the same reflected output. Pixels such as 1010 that vary from the others produce a different intensity in portions of the image plane. Iteratively, the output from the pixels found to produce a different intensity is adjusted to match neighboring pixels.
- FIG. 10B presents a checkerboard calibration method. Instead of setting a field of pixels to produce the same reflected output intensity, half of the pixels in a checkerboard pattern 1022 are set to a bright (or dark) value. The other half of the pixels 1024 are varied through a range from somewhat gray to negative black (or bright). This calibration method generates a transfer function like 806 in FIG. 8, because interaction between adjacent pixels in different tilt modes impacts the intensity in the image plane.
- FIG. 10C presents a sparse checkerboard calibration method. This pattern spaces non-bright pixels well apart. By one metric, the non-bright pixels 1032 are separated by three, four or five bright pixels 1034. By another metric, separation between non-bright pixels relates to the image plane intensity profile of a single minor. This intensity profile, more likely generated by simulation than measurement, corresponds to a distribution of intensity generated in the image plane from radiation corresponding to a particular bright pixel, without interference or contribution from other pixels.
- the bright pixel may be fully bright (e.g., at min-tilt) or a selected bright corresponding to a constrained min-tilt for the dynamic range used in operation of the pixel.
- the metric is the root mean square of the intensity distribution. A standard definition of RMS is adapted for this metric:
- r is a position in the image plane at a distance r from the center of an intensity distribution
- E(r) is a measure of the intensity or exposing dose in the image plane at r.
- this value is computed after removing background exposing energy from sources other than the bright pixel using the following, slightly simplified double integral:
- (x, y) coordinates are provided for the point r.
- the limits of integration cover at least the center of the distribution, (x 0 , y 0 ) and a range that includes substantially all of the exposing dose from the bright pixel.
- the integration could be performed using polar coordinates, again over a range that includes substantially all of the exposing dose from the bright pixel.
- the separation of non-bright pixels is k*inte ⁇ sityRMS, measured center-to-center, so that a pair of non-bright pixels are separated by 2*intensityRMS if the centers of their intensity distributions in the image plane are separated by the distance 2*intensityRMS.
- Non- bright pixels have a separation of greater than or equal to 2 ⁇ *i ⁇ ttensityRMS, 3* intensity RMS, or 4*intensityRMS.
- the 2*intensityRMS, 3*intensityRMS, or 4*intensityRMS metric may better apply to microminor configurations with perimeter interference structures, such as in FIGs. 7C-7E, than would a bright minor count metric.
- the separation between non-bright minors is greater than or equal to 4*intensityRMS. Less preferably, the separation may be 2*inte ⁇ tsityRMS or 3*intensityRMS.
- FIGs. 10D-10E illustrate another calibration method in which dark pixel bands are swept across bright pixel fields, bounded by non-bright pixels.
- FIGs. 10A-10E can be used to explain improved calibration methods.
- the micromirrors, and in a more general case any SLM elements modulating the complex amplitude or intensity, can be calibrated using the intensity produced in the image as it is picked up by a sensor or camera.
- all minors are driven to a first approximation of uniform gray, typically by applying the same modulation (voltage) to all elements.
- the measurement of the actually produced gray value and how it varies over the array in the image produced on the camera provides information to refine the modulation of particular elements. Iterating the procedure improves the approximation until a good uniform gray camera image has been produced, as described in the Blanket Gray Calibration application.
- the voltage map is recorded as a calibration map. After several gray values have been calibrated, the maps are condensed into the minor parameter map.
- Improved photometric calibration procedures use a pattern where some minors are bright and others are dark or non-bright and the resulting level of gray is measured, instead of trying to drive the minors to a uniform gray.
- One improved method uses a checkerboard pattern (FIG.
- the improved calibration may include driving the micromirror array with line patterns as illustrated in FIGs. 10D-10E and calibrating pixels along the boundary between bright and dark.
- the photometric calibration produces straight edges if the input data is a straight edge 1 101 in FIG. 1 1.
- the photometric calibration methods leave a residual waviness 1 102 in an edge. As straightness and correctness of edges are important printing parameters, even small improvements in edge control are valuable.
- Modulators are loaded with line pattern data.
- An image is produced from the modulators and the line pattern image 1 102 is recorded.
- the edges of the line are quantified for placement and straightness, and coi ⁇ ections to the neighboring pixels 1106, 1107, 1108 are computed based on line placement 1105 at particular positions 1 104 along the edge.
- Conections to a particular pixel are based line placement and straightness at and near a particular pixel, as illustrated by the line placements in FIG. 12.
- the coixection applied may be a weighted average of several co ⁇ ections co esponding to varying line placements in FIG. 12. At least one and preferably two or more points on the transfer function 806 of FIG. 8 are conected.
- the method can be used iteratively, by itself, or following calibration using with another method.
- the procedure is as follows: A dense line-space pattern parallel to one axis is applied to the SLM.
- the pitch is, in a preferred embodiment, 7 pixels, so the bright and dark areas are 3.5 and 3.5 pixels wide.
- FIGs. 11-14 show only one edge of the line-space pattern, for clarity.
- the SLM is illuminated under conditions similar to those used for writing actual patterns, and the projected radiation is tapped by a semitransparent beam sampler or splitter 912, to produce a second image 1109 at a sensor anay 926.
- the second image is created is identical the image reaching in the exposure sensitive medium on the workpiece, but the scale may be adjusted to the resolution of the sensor anay 1 109 and sensor-related noise 1110 is introduced.
- the captured image is stored in an attached computer for analysis.
- the sensor anay should be is photometrically and geometrically calibrated.
- the geometrical calibration may include outputting a sparse dot-pattern to the SLM and calculating an image distortion map.
- the photometric calibration may be done with uniform illumination. At the same time, other errors such as dark current in the sensor array can be measured and tabulated.
- An image captured by the sensor array may be conected for geometry and sensitivity using the stored calibration data.
- the captured image is analyzed for edges.
- the edge location 1 105 in the central pixel 1 103 is affected by all minors within a radius such as 1104. (The radius illustrated is approximate and various radii can be detemiined to match various intensitvRMS factors.)
- Bright neighboring pixels 1 107 influence a pixel 1 104 with their min-tilt.
- Dark pixels 1105 influence with their max-tilt.
- Gray pixels 1108 influence with their mid-tilt.
- the edge 1101 is, in principle, found by thresholding to a pre-determined level.
- the pixel immediately at the error vector 1304 gets the largest contribution to its correction value; nearest neighbors get a smaller one; second neighbors get only small ones.
- the weight functions can be predetermined, but also may be detemiined or refined empirically during calibration. Changing the voltage on one mirror at a time in a small neighborhood and recording the movement of the edge gives not only the relative sensitivities but also the actual numerical values, e.g. expressed in nm per DAC values.
- the correction value may be expressed in DAC values and scaled so that when the procedure is finished the accumulated correction value is the desired correction in DAC values.
- More than one correction value can be assigned to a pixel.
- correction values can be computed for relative amplitudes of +1, +0.4 and - 0.1 , as illustrated in FIG. 14.
- minors have three correction values, implemented by accumulators.
- the edge position of pixel 5 is affected by the white value of pixels 1 and 4, the middle values of pixels 2 and 5 and the dark values of pixels 3 and 6.
- Computed conections are weighted and accumulated in the accumulator registers.
- the line-space pattern is shifted one-half a pixel and a new image is recorded and processed.
- the line-space pattern can be shifted by another suitable distance before a new image is recorded and processed. More points on the transfer function 806 can be calculated directly when the line-space pattern is shifted a smaller amount.
- 14 images will be a complete set all half-integer pixel positions of the pattern.
- the pattern can be rotated to a different orientation (e.g., from vertical to horizontal) and a new set of images (e.g., 14 images) recorded and processed.
- four sets of orientations such as horizontal, vertical and two diagonals can be recorded as well.
- Calibration can be adapted to the geometry being printed, so that the most important line orientations are presented in a line-space pattern with sets of images recorded and processed. After all images have been acquired and processed there is a mirror correction map with correction for white, black and medium values and the mirror tables can be corrected.
- the minors have been precalibrated photometrically and the new conection map is applied by shifting, scaling or stretching the voltage scale of each minors, depending on the number of points in the conection map. For three or more points the stretching is done by a smooth function. For three points, a second order polynomial can be fit. For more than three points, a cubic spline function going through the computed points.
- FIG. 15 is a flow diagram of the edge calibration, generally as described above and showing multiple levels of potential iteration.
- function weights are detemiined first 1511.
- the function weights may be empirically detemiined at other positions in the process flow or refined during the process.
- a conection process begins with reset accumulators 1512.
- a line pattern is generated 1513 to be applied to the micromirror anay, for instance, by rasterizing a line from vector foimat to rasterized fonnat.
- calibration logic can generate lines for calibration, without rasterization, for instance by storing the simple pattern data used for calibration.
- An image is projected onto a sensor anay 1514. The edges in the projected image are detected 1515. Camera noise is filtered out 1516, for instance by integration over time or by averaging multiple images.
- a placement enor is detemiined for one location along the edge 1517.
- the enor is distributed by a weighting function and accumulated in conection accumulators for neighboring pixels 1518.
- steps 1517 and 1518 could be varied and reordered, so that multiple placement errors were detemiined and a single conection calculated, based on weighting of the multiple placement errors, before accessing the corresponding accumulator. Iteration proceeds of multiple levels. While the iterations across the edge orientations 1502, edge placements 1503 and edge pixels 1504 are depicted in a certain order, the order of iterations can be varied as desired.
- a processor system fast enough to resolve complex patterns in real time and feed them to a microminor anay is most likely to be fast enough to generate patterns in an arbitrary order of edge orientations, placements and pixels.
- the outer iteration loop 1501 indicates that the process can be repeated until it converges on satisfactoiy results.
- the weight function can be empirically detemiined during the process or refined and virtually any level of iteration.
- the edge placement calibration can be used for any SLM and illumination scheme that produces lines.
- the implementation is the same whether the SLM is driven between white and zero amplitude black (e.g., A and D in FIG. 3B), oi ⁇ between gray and negative black (e.g., A and B in FIG. 3B).
- a larger dynamic range makes it more desirable to use more than three points of calibration or to predetermine curve characteristics where a point of inflection is anticipated.
- An SLM used as a strongly phase-shifting mask will have a dynamic amplitude range from -1 through 0 to +1 (e.g., E, D, A in FIG.
- anays that can be calibrated are optical anays or SLMs based on specular reflection (e.g., minor designs taught by TI, Daewoo) grating light valves (e.g., Silicon Light Machines), LCD modulating elements, absorbing anays (e.g., Hank Smith MIT) and on electrooptic (e.g., Xerox), photeelastic, acustooptic, magnetooptic, interferometric, or emissive (e.g., LEDs, VCSELs) properties.
- specular reflection e.g., minor designs taught by TI, Daewoo
- grating light valves e.g., Silicon Light Machines
- LCD modulating elements e.g., absorbing anays (e.g., Hank Smith MIT) and on electrooptic (e.g., Xerox), photeelastic, acustooptic, magnetooptic, interferometric,
- the light can be imaged with a single lens, multiple lenses or with lens anays (e.g., Hank Smith MIT), refractive or diffractive.
- lens anays e.g., Hank Smith MIT
- Other anays are nearfield optical, mechanical (e.g., IBM) and electrical (e.g., carbon naontubes) writing arrays.
- Futhermore it is possible to use these calibration methods for ion or electron beams based on modulator arrays such as aperture plates (e.g., SPIE 2002, Canon), photoemitters (e.g., Mapper), or multiple particle columns (e.g., ETEC, Broody).
- aperture plates e.g., SPIE 2002, Canon
- photoemitters e.g., Mapper
- multiple particle columns e.g., ETEC, Broody
- ETEC ETEC, Broody
- the method needs to be adapted somewhat depending on whether the image is non-interlaced or interlaced.
- the diffractive micromirror SLM in partially coherent light forms a contiguous, non-interlaced image. Adjacency and influence in the image reflect the state of the modulator array.
- Other types of anay modulators e.g., an array of nano-tubes, or the lens array optics from MIT, produce interlaced images. Adjacent pixels are formed by non-adjacent modulator elements and at different times. Interlacing somewhat complicates the calibration software, but does not change any of the principles described above.
- the calibration software needs to be aware of the interlace properties and add the weighted corrections to the proper correction accumulator.
- the calibration process described can be extended to multi-pass writing.
- the goal is to calibrate the anay so that is writes without errors.
- These residuals can be reduced by averaging, when a pattern is printed in multiple passes, as depicted in FIGs. 16A-16C. Two printing passes gives a reduction of random errors by the square root of two.
- One embodiment is a method of defining a feature boundaiy of exposing at least one radiation sensitive medium on a workpiece using a two-dimensional anay of tilting micromirrors.
- this method can be applied to a one-dimensional anay of tilting micromirrors.
- This method includes tilting a first set of micromirrors on one side of the boundary to produce a high reflected output and tilting a second set of micromirrors on an other side of the boundary past a tilt producing minimum reflected output intensity to till producing substantially improved contrast along the boundaiy.
- the high reflected output can be constrained by the maximum output attained by the microminor, by a dynamic range corresponding to values attainable by various micromirrors in the anay, or by a selected dynamic range chosen to enhance the ratio of positive complex amplitude produced by the first set of micromirrors to negative complex amplitude produced by the second set of micromirrors.
- the complex amplitude of reflected output from the second set of micromirrors may have a substantially negative value of the real component of the complex amplitude.
- the ratio of the absolute value of the native complex amplitude to the positive complex amplitude of a particular micromirror can be on the order of approximately 0.218, 0.5 were even 1.0, depending on the selected dynamic range for the high reflected output and the configuration of the iiiicrominOr.
- the desirable ratios may be greater than equal to 0.2, greater than or equal to 0.5, or approximately 1.0, depending on the application. For instance, a mask making application may use a lower ratio and a direct writing application may use a higher ratio.
- Substantially improved contrast along the boundaiy can be detemiined by simulation or by evaluation of latent or developed patterns in resist or another radiation sensitive medium.
- One aspect of this method may being selecting tilt for the first and second sets of micromirrors such the destructive interference between the sets of micromirrors substantially improved contrast.
- the third set of micromirrors may be positioned between the first and second sets of micromirrors, the third set of microminors having an intermediate tilt. Tilting this third set of micromirrors may produce a gray scaling corresponding to a nionotonic function.
- This nionotonic function may range from the high reflected output to the output resulting from the tilt of the second set minors.
- This nionotonic function may relate edge displacement in the radiation sensitive medium to tilt at the edge of the micromirrors.
- the nionotonic function may have an inflection point closer to the tilt of the second set micromirrors than to the tilt of the first set of micromirrors, as can be deduced from the curves shown in the figures.
- Another aspect of this method involves how the micromirrors are tilted. They may be tilted about a substantially central axis or they may be tilted from one side. Tilting may involve defoniiing supporting members of the micromirrors or it may involve defoniiing the micromirrors themselves, as in defo ⁇ nable micromirror devices described by Texas Instruments.
- the various aspects of the method described above may be further combined with repeatedly tilting the micromirrors, illuminating the anay with a partially coherent radiation and directing the reflected output to fonn at least one pattern in the radiation sensitive medium and processing the workpiece to fonn one or more semiconductor structures on the workpiece corresponding to the pattern.
- the workpiece is a reticle
- the method described above may be combined with repeatedly tilling the micromirrors, illuminating the anay with a partially coherent radiation and directing reflected output onto the radiation sensitive medium; developing a pattern on the reticle; and forming one or more semiconductor structures on a semiconductor substrate corresponding to the pattern.
- Another embodiment is a method of defining a feature boundary when exposing a radiation sensitive medium on a workpiece using a one or two-dimensional anay of tilting micromirrors.
- This embodiment may include tilting a first set of micromirrors on one side of the boundary to produce a high reflected output and tilting a second set of micromirrors on an other side of the boundaiy, past a tilt producing maximum destructive interference within reflected output of the second set of micromirrors, to a tilt producing substantial destructive interference between the reflected outputs of the first and second sets of micromirrors.
- a similar embodiment is a method of defining feature boundary when exposing a radiation sensitive medium on a workpiece using a one or two-dimensional anay of tilting micromirrors.
- the similar embodiment includes tilting a first set of micromirrors on one side of the boundary to produce a high reflected output and tilting a second set of micromirrors on hand other side of the boundary past a tilt producing minimum reflected output intensity, to a tilt producing substantial destructive interference between the reflected output of the first and second sets of microminors.
- Substantial destructive interference in these embodiments is more than what would be caused accidentally by misalignment or niiscalibration of mirrors.
- Substantial destructive interference may be detemiined by simulation or by evaluating patterns produced in radiation sensitive medium.
- One device embodiment is a controller for a one or two- dimensional anay of tilting microminors defining a feature boundary when exposing a radiation sensitive medium on a workpiece.
- the controller includes logic and resources operably coupled to the anay adapted to drive a first set of micromirrors on one side of the boundaiy to a first tilt and produce a high reflected output and to drive a second set of micromirrors on an other side of the boundaiy to second tilt, past point of producing minimum reflected output intensity, to a point of producing substantially improved contrast along the boundaiy.
- the tilting micromirror of this embodiment coupled to and controlled by the controller, may include a reflecting surface footprint that has one or more of the following characteristics: a substantially central tilting axis; similar reflecting areas on opposing sides of the tilting axis; and substantially less (or more) reflecting area away from the tilting axis than at or near the tilting axis.
- the preceding controller embodiments may further include pattern generator components.
- the pattern generator components may include an illumination source, projecting radiation on the anay. Optics, relaying the radiation reflected from the anay to the radiation sensitive medium on the workpiece. And, a stage, supporting the workpiece, controlled to move it has feature batteries are defined.
- the device may be further adapted to drive a third set of micromirrors, between the first and second sets of micromirrors, to an intermediate tilt.
- This intermediate tilt may be determined by a transfer function that is nionotonic.
- the range of the nionotonic function may include the tilt producing a high reflected output and a tilt producing substantially improved contrast.
- the nionotonic transfer function may have an inflection point closer to the tilt producing substantially improved contrast than to the tilt producing a high reflected output.
- An article of manufacturer embodiment includes a machine-readable medium impressed with instructions to control defining a feature boundaiy when exposing a radiation sensitive medium on a workpiece with a micromirror anay, including instructions to implement any of the methods and variations on methods described above.
- the present invention further includes several embodiments of the tilting micromirror.
- One tilting microminor embodiment adapted to be used or actually used in a micromirror anay, includes a reflecting surface footprint.
- This reflecting surface footprint has a substantially central tilting axis, similar reflecting areas on opposing signs of the tilting axis and substantially less (or more) reflecting area away from the tilting axis than at or near the tilting axis.
- the similar reflecting areas may be symmetrical across the tilting axis (e.g., minor images) or they may be symmetrical across a point on the tilting access (e.g., an image reflected twice across perpendicular axes.)
- Another embodiment is a reflecting surface of a tilting micromirror ' adapted to be used or actually used in a micromirror anay.
- the reflecting surface includes a reflecting surface footprint that has a substantially central tilting axis, similar reflecting areas on opposing signs of the tilting axis and substantially less (or more) reflecting area away from the tilting axis than at or near the tilting axis.
- the reflecting surface as a range of tilt the includes a first tilt angle that produces a high reflected output and a second tilt angle, beyond a tilt producing minimum reflected output intensity to a tilt producing substantially improved contrast between micromirrors assuming the first and second tilt angles.
- the range of tilt angles in this embodiment may alternatively be as expressed in methods described above.
- a further embodiment also includes a reflecting surface of the tilting microminor adapted to be used or actually used in a micromirror anay.
- the reflecting surface has a footprint that has a substantially centi-al tilting axis and similar reflecting areas on opposing sides of the tilting axis.
- the reflecting surface footprint further has phase interference structures on opposing signs of the tilting axis, positioned such that the reflecting surface produces less (or more) reflected output intensity away from the tilting axis than an or near the tilting axis.
- the reflecting surface footprint includes opposing edges on opposite sides of the central tilting access and that phase interference structures are positioned closer to the opposing edges and to the tilting axis.
- the reflecting surface footprint includes opposing edges at opposite ends of the central tilting axis and the interference structures are positioned closer to the opposing edges than to a point midway between the opposing edges.
- the interference structures are positioned along outer edges of the reflecting surface footprint. Interference structures positioned along the outer edges may effectively reduce the size of the projected intensity distribution of the microminor.
- the phase interference structures may differ in height from the reflecting surface itself by an odd multiple of a quarter wavelength.
- the method preferably operates parallel to both the first and second access, but could be operated only along one axis.
- This method includes, parallel to a first axis, generating at least one first line of contrast between bright and dark macuOiiiiriOrs.
- the first line of contrast is applied across the anay with gray valued micromirrors between the dark and bright micromirrors for at least some line locations.
- the line may be swept across the anay.
- pattern generating logic may position the first line at various locations across the anay in an arbitrary order. At various first line locations, the reflected output intensity corresponding to the micromirrors is recorded.
- the process of generating a first line of contrast is repeated for a second line of contrast parallel to a section axis that is not parallel to the first axis.
- the first axis might run through the centers of micrometers in the second access also might run through centers of micromirrors. If the niicromirors are arranged in a Cartesian array, the axes are likely to be perpendicular. However, other orientations of axes may be applied.
- the process of generating lines of contrast may be repeated for third and fourth axes that run diagonally. This method further includes calculating conections to individual micromirrors corresponding to the recorded reflected output intensities.
- the first and second lines of contrast between bright and dark micromirrors have a with including at least three consecutive dark micromirrors that are either adjacent to, or separated by at least one gray micromirrors from, at least three consecutive bright micromirrors.
- applying the lines of contrast may include locating lines of contrast so that at least three recording the reflected output intensity from a pixel are made corresponding to each line of contrast.
- Another embodiment is method for calibrating for a two-dimensional anay of micromirrors illuminated by a partially coherent source of electromagnetic radiation having a characteristic wavelength.
- This method includes generating a checkerboard pattern of micromirrors in the anay, with alternating squares the checkerboard set to bright and non-bright values.
- the squares the checkerboard may be individual pixels or small clusters of pixels, such as two by two or three by three pixels.
- the method further includes driving the non-bright microminors in a range between a quarter-and half-wavelength difference between a tilting access and edges of the micromirrors and recording the intensity of output an image claim. It also includes detennining one or more driving values or the non-bright micromirrors to use in setting a response curve the maps the driving values two the recorded output intensity.
- the recorded output intensity is a proxy for edge displacement.
- Another embodiment is method of calibrating a two-dimensional anay of micromirrors illuminated by a partially coherent source electromagnetic radiation. This method includes generating a pattern of micromirrors in the anay. Most of the micromirrors are set to a first output intensity. Other micromirrors are veiy through a range of output intensity values. The other micromirrors are substantially separated from one another. The method includes driving the other micromirrors to range of output intensity values and recording output intensity of the other micromirrors at various drive signals.
- the drive signals may be embodied in a calibration curve or transfer function.
- the separation among the other micromirrors may be at least three micromirrors of the first output intensity value.
- the separation between microminors centers, measured in the image plane may be a factor of the root mean square of the intensity distribution corresponding to a typical bright micromirrors.
- the separation between the centers of the micromin'ors may be measured in me image plane.
- the factor may be two, three or four times through mean square of the intensity distribution.
- a further embodiment is method calibrating a two-dimensional anay of exposing radiation sources.
- This method includes generating a pattern of sources in the array, with most of the sources set to a first output intensity value and other sources. To a range of output intensity value. The other sources are sufficiently separated from one another to be individually resolved by a sensor.
- the method includes driving other the other sources throw a range of output intensity values and recording output intensity of the other sources at various drive signals.
- Drive signals are detemiined for the sources to produce desired output intensity levels.
- a further aspect of this invention is the drive signals may be detemiined for individual sources.
- the present invention further includes logic and resources to implement any of the methods described above. It extends to a pattern generator including such logic and resources. It also includes as an article of manufacturer a memory impressed with digital logic to implement any of the methods described above. It extends to a pattern generator into which the digital logic from the article of manufacturer is loaded.
Abstract
Description
Claims
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006119601A (en) * | 2004-09-24 | 2006-05-11 | Canon Inc | Light modulator and optical apparatus using the same |
JP2006148140A (en) * | 2004-11-24 | 2006-06-08 | Asml Holding Nv | Pattern generator using dual phase step elements, and method of using the same |
JP2009296004A (en) * | 2004-06-08 | 2009-12-17 | Asml Netherlands Bv | Lithographic apparatus and device manufacturing method |
JP2016114832A (en) * | 2014-12-16 | 2016-06-23 | 株式会社リコー | Light beam exposure device, electronic equipment including light beam exposure device, and operation method of light beam exposure device |
Families Citing this family (50)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6627863B2 (en) * | 2000-12-15 | 2003-09-30 | Mitutoyo Corporation | System and methods to determine the settings of multiple light sources in a vision system |
US20030233630A1 (en) * | 2001-12-14 | 2003-12-18 | Torbjorn Sandstrom | Methods and systems for process control of corner feature embellishment |
SE0104238D0 (en) * | 2001-12-14 | 2001-12-14 | Micronic Laser Systems Ab | Method and apparatus for patterning a workpiece |
US7410736B2 (en) * | 2003-09-30 | 2008-08-12 | Asml Holding N.V. | Methods and systems to compensate for a stitching disturbance of a printed pattern in a maskless lithography system not utilizing overlap of the exposure zones |
US7023526B2 (en) * | 2003-09-30 | 2006-04-04 | Asml Holding N.V. | Methods and systems to compensate for a stitching disturbance of a printed pattern in a maskless lithography system utilizing overlap without an explicit attenuation |
US6876440B1 (en) * | 2003-09-30 | 2005-04-05 | Asml Holding N.V. | Methods and systems to compensate for a stitching disturbance of a printed pattern in a maskless lithography system utilizing overlap of exposure zones with attenuation of the aerial image in the overlap region |
US7003758B2 (en) | 2003-10-07 | 2006-02-21 | Brion Technologies, Inc. | System and method for lithography simulation |
US7270942B2 (en) * | 2003-10-22 | 2007-09-18 | Lsi Corporation | Optimized mirror design for optical direct write |
US7215460B2 (en) * | 2003-11-01 | 2007-05-08 | Fusao Ishii | Sequence and timing control of writing and rewriting pixel memories for achieving higher number of gray scales |
JP4095570B2 (en) * | 2004-03-26 | 2008-06-04 | 株式会社東芝 | Ion implantation apparatus and ion implantation method |
US7053981B2 (en) * | 2004-03-31 | 2006-05-30 | Asml Netherlands B.V. | Lithographic apparatus and device manufacturing method |
US7372547B2 (en) * | 2004-04-27 | 2008-05-13 | Lsi Corporation | Process and apparatus for achieving single exposure pattern transfer using maskless optical direct write lithography |
US6963434B1 (en) * | 2004-04-30 | 2005-11-08 | Asml Holding N.V. | System and method for calculating aerial image of a spatial light modulator |
US7177012B2 (en) | 2004-10-18 | 2007-02-13 | Asml Netherlands B.V. | Lithographic apparatus and device manufacturing method |
US7457547B2 (en) * | 2004-11-08 | 2008-11-25 | Optium Australia Pty Limited | Optical calibration system and method |
US7202939B2 (en) * | 2004-12-22 | 2007-04-10 | Asml Netherlands B.V. | Lithographic apparatus and device manufacturing method |
KR20070104444A (en) * | 2005-01-28 | 2007-10-25 | 에이에스엠엘 홀딩 엔.브이. | Method and system for a maskless lithography rasterization technique based on global optimization |
JP2006300981A (en) * | 2005-04-15 | 2006-11-02 | Seiko Epson Corp | Optical scanner, method of controlling optical scanner, and image display device |
US7466394B2 (en) * | 2005-12-21 | 2008-12-16 | Asml Netherlands B.V. | Lithographic apparatus and device manufacturing method using a compensation scheme for a patterning array |
KR20090026116A (en) * | 2006-06-09 | 2009-03-11 | 가부시키가이샤 니콘 | Pattern formation method, pattern formation device, exposure method, exposure device, and device manufacturing method |
US7936445B2 (en) * | 2006-06-19 | 2011-05-03 | Asml Netherlands B.V. | Altering pattern data based on measured optical element characteristics |
US7738077B2 (en) * | 2006-07-31 | 2010-06-15 | Asml Netherlands B.V. | Patterning device utilizing sets of stepped mirrors and method of using same |
JP5073273B2 (en) * | 2006-11-21 | 2012-11-14 | スタンレー電気株式会社 | Perspective determination method and apparatus |
US7768627B2 (en) * | 2007-06-14 | 2010-08-03 | Asml Netherlands B.V. | Illumination of a patterning device based on interference for use in a maskless lithography system |
WO2009008605A2 (en) * | 2007-07-10 | 2009-01-15 | Lg Electronics Inc. | Maskless exposure method |
US7958464B1 (en) * | 2007-09-07 | 2011-06-07 | Kla-Tencor Corporation | Electron beam patterning |
JP5417343B2 (en) * | 2007-12-27 | 2014-02-12 | ラム リサーチ コーポレーション | System and method for calibrating an end effector alignment using at least one light source |
US9269529B2 (en) * | 2007-12-27 | 2016-02-23 | Lam Research Corporation | Systems and methods for dynamic alignment beam calibration |
SG187402A1 (en) * | 2007-12-27 | 2013-02-28 | Lam Res Corp | Systems and methods for calibrating end effector alignment in a plasma processing system |
CN101911277B (en) * | 2007-12-27 | 2012-04-04 | 朗姆研究公司 | Arrangements and methods for determining positions and offsets |
DE102008000589B4 (en) * | 2008-03-11 | 2018-02-01 | Seereal Technologies S.A. | Method for coding computer-generated holograms in pixelated light modulators |
US9025136B2 (en) * | 2008-09-23 | 2015-05-05 | Applied Materials, Inc. | System and method for manufacturing three dimensional integrated circuits |
WO2010063827A1 (en) * | 2008-12-05 | 2010-06-10 | Micronic Laser Systems Ab | Gradient assisted image resampling in micro-lithographic printing |
US9507271B1 (en) * | 2008-12-17 | 2016-11-29 | Applied Materials, Inc. | System and method for manufacturing multiple light emitting diodes in parallel |
US8861066B2 (en) * | 2009-02-16 | 2014-10-14 | Micronic Ab | Oversized micro-mechanical light modulator with redundant elements, device and method |
US8570613B2 (en) * | 2009-03-06 | 2013-10-29 | Micronic Laser Systems Ab | Lithographic printing system with placement corrections |
WO2011107601A1 (en) * | 2010-03-05 | 2011-09-09 | Micronic Mydata AB | 1.5d slm for lithography |
US8743165B2 (en) * | 2010-03-05 | 2014-06-03 | Micronic Laser Systems Ab | Methods and device for laser processing |
US8539395B2 (en) | 2010-03-05 | 2013-09-17 | Micronic Laser Systems Ab | Method and apparatus for merging multiple geometrical pixel images and generating a single modulator pixel image |
DE102010063337B9 (en) * | 2010-12-17 | 2020-05-07 | Carl Zeiss Ag | Process for mask inspection and process for emulating imaging properties |
US20140085426A1 (en) | 2012-09-24 | 2014-03-27 | Alces Technology, Inc. | Structured light systems with static spatial light modulators |
JP6559706B2 (en) | 2014-01-27 | 2019-08-14 | ビーコ インストルメンツ インコーポレイテッド | Wafer carrier with holding pockets with compound radius for chemical vapor deposition systems |
IN2014CH00782A (en) | 2014-02-19 | 2015-08-28 | Kennametal India Ltd | |
KR101577561B1 (en) * | 2015-02-24 | 2015-12-29 | 정용호 | Display apparatus |
US9627239B2 (en) | 2015-05-29 | 2017-04-18 | Veeco Instruments Inc. | Wafer surface 3-D topography mapping based on in-situ tilt measurements in chemical vapor deposition systems |
US9831110B2 (en) | 2015-07-30 | 2017-11-28 | Lam Research Corporation | Vision-based wafer notch position measurement |
DE102016204703B4 (en) * | 2016-03-22 | 2022-08-04 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Device and method for generating an optical pattern from pixels in an image plane |
US11537051B2 (en) | 2017-03-16 | 2022-12-27 | Nikon Corporation | Control apparatus and control method, exposure apparatus and exposure method, device manufacturing method, data generating method and program |
US10761430B2 (en) | 2018-09-13 | 2020-09-01 | Applied Materials, Inc. | Method to enhance the resolution of maskless lithography while maintaining a high image contrast |
DE102020207566B4 (en) | 2020-06-18 | 2023-02-16 | Carl Zeiss Smt Gmbh | Device and method for characterizing a mask for microlithography |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0467076A2 (en) * | 1990-07-17 | 1992-01-22 | Micronic Laser Systems Ab | Method and apparatus for fabricating microstructures on a photosensitively layered substrate by means of focussed laser radiation |
US5148157A (en) * | 1990-09-28 | 1992-09-15 | Texas Instruments Incorporated | Spatial light modulator with full complex light modulation capability |
WO1993009469A1 (en) * | 1991-10-30 | 1993-05-13 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Exposure device |
US6373619B1 (en) * | 1998-03-02 | 2002-04-16 | Micronic Laser Systems Ab | Pattern generator with improved address resolution |
Family Cites Families (45)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4476465A (en) * | 1982-08-30 | 1984-10-09 | Litton Systems, Inc. | Magneto-optic display generator |
US4879605A (en) * | 1988-02-29 | 1989-11-07 | Ateq Corporation | Rasterization system utilizing an overlay of bit-mapped low address resolution databases |
US4945351A (en) | 1988-05-23 | 1990-07-31 | Hewlett-Packard Company | Technique for optimizing grayscale character displays |
US4908780A (en) * | 1988-10-14 | 1990-03-13 | Sun Microsystems, Inc. | Anti-aliasing raster operations utilizing sub-pixel crossing information to control pixel shading |
US6348907B1 (en) * | 1989-08-22 | 2002-02-19 | Lawson A. Wood | Display apparatus with digital micromirror device |
US5123085A (en) * | 1990-03-19 | 1992-06-16 | Sun Microsystems, Inc. | Method and apparatus for rendering anti-aliased polygons |
US5042950A (en) * | 1990-05-22 | 1991-08-27 | The United States Of America As Represented By The United States Department Of Energy | Apparatus and method for laser beam diagnosis |
US5103101A (en) * | 1991-03-04 | 1992-04-07 | Etec Systems, Inc. | Multiphase printing for E-beam lithography |
US5278949A (en) * | 1991-03-12 | 1994-01-11 | Hewlett-Packard Company | Polygon renderer which determines the coordinates of polygon edges to sub-pixel resolution in the X,Y and Z coordinates directions |
EP0558781B1 (en) * | 1992-03-05 | 1998-08-05 | Micronic Laser Systems Ab | Method and apparatus for exposure of substrates |
EP0562424B1 (en) * | 1992-03-25 | 1997-05-28 | Texas Instruments Incorporated | Embedded optical calibration system |
US5673376A (en) * | 1992-05-19 | 1997-09-30 | Eastman Kodak Company | Method and apparatus for graphically generating images of arbitrary size |
DE69331547T2 (en) * | 1992-11-02 | 2003-04-24 | Applied Materials Inc N D Ges | IMAGE FORMATTING FOR A PATTERN GENERATION DEVICE |
GB2278524B (en) * | 1993-05-28 | 1997-12-10 | Nihon Unisys Ltd | Method and apparatus for rendering visual images employing area calculation and blending of fractional pixel lists for anti-aliasing and transparency |
US5684939A (en) * | 1993-07-09 | 1997-11-04 | Silicon Graphics, Inc. | Antialiased imaging with improved pixel supersampling |
US5581292A (en) * | 1993-09-10 | 1996-12-03 | Xerox Corporation | Method and apparatus for enhancing charged area developed regions in a tri-level printing system |
US5467146A (en) * | 1994-03-31 | 1995-11-14 | Texas Instruments Incorporated | Illumination control unit for display system with spatial light modulator |
US5504504A (en) * | 1994-07-13 | 1996-04-02 | Texas Instruments Incorporated | Method of reducing the visual impact of defects present in a spatial light modulator display |
US5684510A (en) * | 1994-07-19 | 1997-11-04 | Microsoft Corporation | Method of font rendering employing grayscale processing of grid fitted fonts |
JP4006478B2 (en) * | 1994-08-04 | 2007-11-14 | テキサス インスツルメンツ インコーポレイテッド | Display system |
US5504614A (en) * | 1995-01-31 | 1996-04-02 | Texas Instruments Incorporated | Method for fabricating a DMD spatial light modulator with a hardened hinge |
US5594854A (en) * | 1995-03-24 | 1997-01-14 | 3Dlabs Inc. Ltd. | Graphics subsystem with coarse subpixel correction |
US5629794A (en) * | 1995-05-31 | 1997-05-13 | Texas Instruments Incorporated | Spatial light modulator having an analog beam for steering light |
US5835256A (en) * | 1995-06-19 | 1998-11-10 | Reflectivity, Inc. | Reflective spatial light modulator with encapsulated micro-mechanical elements |
JP3331822B2 (en) * | 1995-07-17 | 2002-10-07 | ソニー株式会社 | Mask pattern correction method, mask using the same, exposure method, and semiconductor device |
US5701365A (en) | 1996-06-21 | 1997-12-23 | Xerox Corporation | Subpixel character positioning with antialiasing with grey masking techniques |
US5804340A (en) * | 1996-12-23 | 1998-09-08 | Lsi Logic Corporation | Photomask inspection method and inspection tape therefor |
US6148117A (en) | 1996-12-27 | 2000-11-14 | Hewlett-Packard Company | Image processing system with alterable local convolution kernel |
US6188427B1 (en) * | 1997-04-23 | 2001-02-13 | Texas Instruments Incorporated | Illumination system having an intensity calibration system |
US5774254A (en) * | 1997-06-26 | 1998-06-30 | Xerox Corporation | Fault tolerant light modulator display system |
US6201545B1 (en) * | 1997-09-23 | 2001-03-13 | Ati Technologies, Inc. | Method and apparatus for generating sub pixel masks in a three dimensional graphic processing system |
JP3397101B2 (en) * | 1997-10-29 | 2003-04-14 | 株式会社日立製作所 | Defect inspection method and apparatus |
US6088102A (en) * | 1997-10-31 | 2000-07-11 | Silicon Light Machines | Display apparatus including grating light-valve array and interferometric optical system |
US6496187B1 (en) | 1998-02-17 | 2002-12-17 | Sun Microsystems, Inc. | Graphics system configured to perform parallel sample to pixel calculation |
US6142641A (en) * | 1998-06-18 | 2000-11-07 | Ultratech Stepper, Inc. | Four-mirror extreme ultraviolet (EUV) lithography projection system |
US6360134B1 (en) * | 1998-07-20 | 2002-03-19 | Photronics, Inc. | Method for creating and improved image on a photomask by negatively and positively overscanning the boundaries of an image pattern at inside corner locations |
US6261728B1 (en) * | 1998-10-19 | 2001-07-17 | Vanguard International Semiconductor Corporation | Mask image scanning exposure method |
US6356340B1 (en) * | 1998-11-20 | 2002-03-12 | Advanced Micro Devices, Inc. | Piezo programmable reticle for EUV lithography |
JP4057733B2 (en) * | 1999-02-22 | 2008-03-05 | 株式会社東芝 | Transfer pattern simulation method |
SE516914C2 (en) * | 1999-09-09 | 2002-03-19 | Micronic Laser Systems Ab | Methods and grid for high performance pattern generation |
WO2001093303A2 (en) | 2000-06-01 | 2001-12-06 | Applied Materials, Inc. | High throughput multipass printing with lithographic quality |
US6598218B2 (en) * | 2000-12-19 | 2003-07-22 | United Microelectronics Corp. | Optical proximity correction method |
EP1386192A2 (en) * | 2001-04-03 | 2004-02-04 | CiDra Corporation | Dynamic optical filter having a spatial light modulator |
US6618185B2 (en) * | 2001-11-28 | 2003-09-09 | Micronic Laser Systems Ab | Defective pixel compensation method |
US6823101B2 (en) * | 2002-01-14 | 2004-11-23 | Agere Systems Inc. | Method for calibrating a MEMS device |
-
2003
- 2003-06-12 US US10/462,010 patent/US7106490B2/en not_active Expired - Lifetime
- 2003-09-29 DE DE60335475T patent/DE60335475D1/en not_active Expired - Lifetime
- 2003-09-29 EP EP03799230A patent/EP1546788B1/en not_active Expired - Fee Related
- 2003-09-29 WO PCT/SE2003/001509 patent/WO2004031831A1/en active Application Filing
- 2003-09-29 JP JP2005500105A patent/JP4376228B2/en not_active Expired - Lifetime
- 2003-09-29 KR KR1020057005456A patent/KR101052653B1/en active IP Right Grant
- 2003-09-29 AU AU2003265190A patent/AU2003265190A1/en not_active Abandoned
-
2005
- 2005-11-14 US US11/272,925 patent/US7158280B2/en not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0467076A2 (en) * | 1990-07-17 | 1992-01-22 | Micronic Laser Systems Ab | Method and apparatus for fabricating microstructures on a photosensitively layered substrate by means of focussed laser radiation |
US5148157A (en) * | 1990-09-28 | 1992-09-15 | Texas Instruments Incorporated | Spatial light modulator with full complex light modulation capability |
WO1993009469A1 (en) * | 1991-10-30 | 1993-05-13 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Exposure device |
US6373619B1 (en) * | 1998-03-02 | 2002-04-16 | Micronic Laser Systems Ab | Pattern generator with improved address resolution |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009296004A (en) * | 2004-06-08 | 2009-12-17 | Asml Netherlands Bv | Lithographic apparatus and device manufacturing method |
JP2012094917A (en) * | 2004-06-08 | 2012-05-17 | Asml Netherlands Bv | Lithographic apparatus and device manufacturing method |
US9176392B2 (en) | 2004-06-08 | 2015-11-03 | Asml Netherlands B.V. | Lithographic apparatus and device manufacturing method using dose control |
JP2006119601A (en) * | 2004-09-24 | 2006-05-11 | Canon Inc | Light modulator and optical apparatus using the same |
JP2006148140A (en) * | 2004-11-24 | 2006-06-08 | Asml Holding Nv | Pattern generator using dual phase step elements, and method of using the same |
JP2009145904A (en) * | 2004-11-24 | 2009-07-02 | Asml Holding Nv | Patterning device using dual phase step element and using method thereof |
JP2016114832A (en) * | 2014-12-16 | 2016-06-23 | 株式会社リコー | Light beam exposure device, electronic equipment including light beam exposure device, and operation method of light beam exposure device |
Also Published As
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US7106490B2 (en) | 2006-09-12 |
KR101052653B1 (en) | 2011-07-28 |
US7158280B2 (en) | 2007-01-02 |
EP1546788A1 (en) | 2005-06-29 |
JP4376228B2 (en) | 2009-12-02 |
AU2003265190A1 (en) | 2004-04-23 |
EP1546788B1 (en) | 2010-12-22 |
DE60335475D1 (en) | 2011-02-03 |
JP2006501687A (en) | 2006-01-12 |
US20060077506A1 (en) | 2006-04-13 |
KR20050070018A (en) | 2005-07-05 |
US20040053143A1 (en) | 2004-03-18 |
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