CN101424854B - Reflective liquid crystal panel substrate - Google Patents

Abstract

A liquid crystal panel substrate is disclosed, which is composed of the steps that: a pixel region in which reflective electrodes are configured in a shape of matrix is formed on the substrate, and peripheral circuits are arranged on the substrate of the periphery of the pixel region; and which is characterized in that a first passivation film is formed on the reflective electrode by silicon oxide; and a second passivation film composed of silicon oxide is formed on a side of a laminated configuration that is formed by covering the peripheral circuits.

Description

Liquid crystal substrate and liquid crystal panel

The application is that application is 97120489.6, the dividing an application of female case application in October 21 1997 applying date.

Technical field

The present invention relates to liquid crystal panel and reflective liquid crystal panel, particularly relate to utilizing at the on-off element that semiconductor substrate or insulated substrate form and come applicable technology in the active array type liquid crystal panel of switch pixel capacitors.Also relate to the electronic installation and the projecting display that use it.

Background technology

So far, the reflection-type active matrix liquid crystal panel that uses in the light valve as projecting display, what reached degree of being practical is the liquid crystal panel that forms the structure of thin film transistor (TFT) (TFT) array that adopts amorphous silicon at glass substrate.

The active matrix liquid crystal panel of above-mentioned use TFT is the liquid crystal panel of transmission-type, forms pixel capacitors by nesa coating.In the liquid crystal panel of transmission-type, the formation district that is located at the such on-off element of TFT on each pixel is not transmission area, so numerical aperture is certainly very low, and the fatal shortcoming that exists numerical aperture to reduce along with the increase of resolution XGA, the S-VGA of panel.

Therefore, than the little liquid crystal panel of transmission-type active matrix liquid crystal panel, can consider to utilize the transistor that forms at semiconductor substrate or insulated substrate to come switch to consist of the such reflection-type active matrix liquid crystal panel of pixel capacitors of reflecting electrode as size.

So far, in such reflective liquid crystal panel, the necessity of passivating film that is provided as diaphragm at the substrate that forms reflecting electrode is little, so mostly with its omission.Therefore, the present inventor has studied passivating film has been located at reflective liquid crystal panel with the situation on the substrate.

Usually in semiconductor device, mostly use the silicon nitride film that utilizes the formation such as decompression CVD method as passivating film., in the situation of prior art, the deviation of utilizing the thickness of the passivating film that the CVD method forms will avoid producing about 10% is difficult.Yet in reflective liquid crystal panel, reflectivity changes a lot along with the variation of the deviation of passivation film thickness, and the refractive index of liquid crystal also changes thereupon, and this is unfavorable.

Summary of the invention

Even the object of the present invention is to provide a kind of deviation with reflectivity large, substrate and liquid crystal panel that the high reflective liquid crystal panel of reliability of passivating film of the variations in refractive index of liquid crystal is used.

Another object of the present invention is to provide the good reflective liquid crystal panel of a kind of reliability height and image quality and use its electronic installation and projecting display.

In order to achieve the above object, substrate for liquid crystal panel of the present invention is to consist of like this, namely be at substrate and form reflecting electrode rectangularly, simultaneously form each transistor corresponding to each reflecting electrode, by above-mentioned transistor voltage is added on the above-mentioned reflecting electrode, it is characterized in that: form passivating film at above-mentioned reflecting electrode, the thickness of above-mentioned passivating film is to select like this, namely when above-mentioned reflecting electrode during to the characteristic variations of the reflectivity of lambda1-wavelength, the variation of reflectivity can be limited in about 1%, the deviation of thickness is little on the impact of the reflectivity of above-mentioned reflecting electrode.

In addition, because this passivating film is film formed by monox, so the reflectivity of energy inhibitory reflex electrode changes the phenomenon that greatly variation occurs with light wavelength.

In addition, be that to use thickness be the silicon oxide film of 500～2000 dusts as reflective liquid crystal panel with the passivating film of substrate.How much weaker silicon oxide film is as the function ratio silicon nitride film of diaphragm; but because the deviation of thickness is less than silicon nitride film on the impact of the reflectivity of pixel capacitors; simultaneously particularly thickness is that the dependence of the reflectivity of silicon oxide film of 500～2000 dusts and wavelength is little; so by using the silicon oxide film as passivating film, can reduce the variation of reflectivity.

Moreover, corresponding to the incident light wavelength, the thickness of passivating film is set in respectively suitable scope.More particularly, in the pixel capacitors of reflect blue light, the thickness that makes the silicon oxide film that becomes passivating film is 900～1200 dusts, in the pixel capacitors of reflects green, is 1200～1600 dusts, in the pixel capacitors of reflection red light, is 1300～1900 dusts.If will become the thickness setting of silicon oxide film of passivating film in above-mentioned scope, then the deviation to reflectivity of all kinds can be suppressed at below 1%, can improve the reliability of liquid crystal panel, can improve simultaneously such reflective liquid crystal panel as the image quality in the projecting display of light valve use.

Moreover the relation that becomes between the thickness of the alignment films that the thickness of the silicon oxide film of passivating film can use and form on it is set.In addition, at this moment the suitable thickness of alignment films is 300～1400 dusts, is preferably 800～1400 dusts.By with the thickness setting of alignment films in above-mentioned scope, can effectively prevent the variation of liquid-crystal refractive-index.

In addition, be the rectangular pixel region that has disposed pixel capacitors and form in the reflective liquid crystal panel of the peripheral circuits such as shift register or control circuit in its outside at same substrate, also can above pixel region, form the passivating film that is consisted of by silicon oxide film, and above above-mentioned peripheral circuit, form the passivating film that is consisted of by silicon nitride film.Because the thickness of peripheral circuit and the passivating film above it and reflectivity are irrelevant, so by using silicon nitride film, can protect more reliably peripheral circuit, improve reliability.

Moreover, will establish passivating film at reflecting electrode and replace the passivating film that is consisted of by silicon oxide film, perhaps with the passivating film that is consisted of by silicon oxide film and usefulness, also can establish silicon nitride film by the interlayer dielectric between reflecting electrode and the metal level below it.Improve thus moisture-proof, can prevent pixel switch with MOSFET and keep electric capacity by corrosion such as water.

In addition; be provided with the overlapping protection structure that has formed silicon nitride film at the passivating film that is consisted of by silicon oxide film; cover from the end of the overlapping body of interlayer dielectric and metal level until on its sidewall with it, above-mentioned interlayer dielectric is the transistor of switch pixel and consists of the interlayer dielectric of desirable voltage and signal being supplied with this transistorized wiring region.Therefore, improved the water resistance of the liquid crystal panel end of easy water inlet, it becomes reinforcement simultaneously, can improve permanance.

Moreover the light valve usefulness with having adopted the liquid crystal panel of above-mentioned substrate for liquid crystal panel as projecting display has: the look tripping device that the light of light source is divided into 3 primitive color lights; To the 1st above-mentioned reflective liquid crystal panel of being modulated by the red light of this look tripping device separation; To the 2nd above-mentioned reflective liquid crystal panel of being modulated by the green light of this look tripping device separation; And the 3rd above-mentioned reflective liquid crystal panel to being modulated by the blue light of this look tripping device separation, form the thickness of silicon oxide film of passivating film of above-mentioned the 1st reflective liquid crystal panel in the scope of 1300～1900 dusts, form the thickness of silicon oxide film of passivating film of above-mentioned the 2nd reflective liquid crystal panel in the scope of 1200～1600 dusts, form the thickness of silicon oxide film of passivating film of above-mentioned the 3rd reflective liquid crystal panel in the scope of 900～1200 dusts, so each light valve that each coloured light is modulated has the passivation film thickness corresponding with the wavelength of the coloured light of modulating, reduced the deviation of reflectivity, the deviation of synthetic light has also reduced.Therefore, can prevent the different phenomenon of color matching that the colour of projected light in each goods of projecting display shows.

Description of drawings

Fig. 1 (a), (b) are the sectional views that the 1st embodiment of the pixel region on the reflecting electrode side group plate of reflective liquid crystal panel of the present invention has been used in expression.

Fig. 2 is the sectional view of one of the expression structure of having used the peripheral circuit on the reflecting electrode side group plate of reflective liquid crystal panel of the present invention example.

Fig. 3 is the plane figure of having used the 1st embodiment of the pixel region on the reflecting electrode side group plate of reflective liquid crystal panel of the present invention.

Fig. 4 is the sectional view of one of the end construction example of the expression reflecting electrode side group plate of having used reflective liquid crystal panel of the present invention.

Fig. 5 is the sectional view of another embodiment that the reflecting electrode side group plate of reflective liquid crystal panel of the present invention has been used in expression.

Fig. 6 is the planimetric map of the layout structure example on the reflecting electrode side group plate of liquid crystal panel of expression embodiment.

Fig. 7 is the sectional view of one of reflective liquid crystal panel example of the substrate of the expression liquid crystal panel of having used embodiment.

Fig. 8 is pixel capacitors switch the grid drive waveforms of FET and the oscillogram of data line drive waveforms example that reflective liquid crystal panel of the present invention has been used in expression.

Fig. 9 is as with the liquid crystal panel of the embodiment simple structural drawing as the projection TV set of one of the projecting display of light valve example.

Figure 10 is illustrated in the reflecting electrode that is made of aluminium lamination to caused the curve map of the result of study of what kind of variation in the reflectivity of each wavelength of incident direction by the thickness of silicon oxide film.

Figure 11 is the reflectivity that is illustrated in the reflecting electrode that is made of aluminium lamination causes the result of study of what kind of variation because of the thickness of silicon oxide film in each wavelength of incident light curve map.

Figure 12 is the curve map of the reflectivity when the thickness of the change silicon oxide film of drawing by each suitable wavelength in the wavelength coverage centered by blueness.

Figure 13 is the curve map of the reflectivity when the thickness of the change silicon oxide film of drawing by each suitable wavelength in the wavelength coverage centered by green.

Figure 14 is the curve map of the reflectivity when the thickness of the change silicon oxide film of drawing by each suitable wavelength in the wavelength coverage centered by redness.

Figure 15 (a), (b), (c) are the outside drawings that has represented respectively to adopt the electronic installation example of reflective liquid crystal panel of the present invention.

Figure 16 is the sectional view of another embodiment that the reflecting electrode side group plate of reflective liquid crystal panel of the present invention has been used in expression.

Figure 17 is the sectional view of another embodiment that the reflecting electrode side group plate of reflective liquid crystal panel of the present invention has been used in expression.

Embodiment

Below, the preferred embodiments of the present invention are described with reference to the accompanying drawings.

(having adopted the explanation of the substrate for liquid crystal panel of semiconductor substrate)

Fig. 1 and Fig. 3 have represented to use the 1st embodiment of the reflecting electrode side group plate of reflective liquid crystal panel of the present invention.Sectional view and the plane figure of the pixel parts in the pixel that is rectangular configuration have been shown in Fig. 1 and Fig. 3.Fig. 1 (a) expression is along the sectional view of the I-I line among Fig. 3.The same expression of Fig. 1 (b) is along the sectional view of the II-II line among Fig. 3.In addition, Fig. 6 represents all plane figures of reflecting electrode side group plate of reflective liquid crystal panel of the present invention.

In Fig. 1, the 1st, monocrystalline silicon P-type semiconductor substrate (also can be N-type semiconductor substrate (N ^-)), the 2nd, the P type well region that the impurity concentration in the ratio semiconductor substrate that the surface of this semiconductor substrate 1 forms is high, the 3rd, the element that forms on the surface of semiconductor substrate 1 separates with field oxide film (so-called LOCOS).Above-mentioned well region 2 without particular limitation of, but form the general well region of pixel region, it is with rectangular form of configuration of pixels precedent as 768 * 1024.This well region 2 as shown in Figure 6, it is that well region with the part of forming element separates and forms, and this element is formed in pixel and is the peripheral circuits such as the data line drive circuit 21 of periphery configuration of pixel region 2 of rectangular configuration or grid line driving circuit 22, input circuit 23, timing control circuit 24.Above-mentioned field oxide film 3 forms the thickness of 5000～7000 dusts by carrying out selectively thermal oxide.

On above-mentioned field oxide film 3, each pixel is formed 2 peristomes, inboard gate oxidation films (dielectric film) 4b of central authorities by being formed by thermal oxide at a peristome, the grid 4a that formation is made of polysilicon or metal silicide etc., substrate surface in this grid 4a both sides forms source, drain region 5a, the 5b that is made of the high N-type impurity-introduced layer (hereinafter referred to as doped layer) of impurity concentration, consists of thus MOSFET.Grid 4a extends along scan-line direction (pixel rows direction), consists of grid line 4.

In addition, on the substrate surface of the inboard that is formed on another peristome on the above-mentioned field oxide film 3, form P type doped region 8, simultaneously at the dielectric film 9b of the surface of this P type doped region 8 by being formed by thermal oxide, the electrode 9a that formation is made of polysilicon or metal silicide, (sandwich dielectric film 9b) consists of the maintenance electric capacity that keeps being added in the voltage on the pixel between this electrode 9a and above-mentioned P type doped region 8.Above-mentioned electrode 9a can with the same operation of the polysilicon of the grid 4a that consists of above-mentioned MOSFET or metal silicide layer in form, in addition, the dielectric film 9b below the electrode 9a can form in same operation with the dielectric film that consists of gate insulating film 4b.

Above-mentioned dielectric film 4b, 9b form the thickness of 400～800 dusts at the inboard semiconductor substrate surface of above-mentioned peristome by thermal oxide.Above-mentioned electrode 4a, 9a consist of like this, namely form the polysilicon layer that thickness is 1000～2000 dusts after, on it, form again the silicide layer of the such refractory metal of Mo that thickness is 1000～3000 dusts or W.Source, drain region 5a, 5b be with above-mentioned grid 4a as mask, on the substrate surface of its both sides, inject N-type impurity with ion implantation and Self-adjustment forms.In addition, grid 4a under well region consist of the channel region 5c of MOSFET.

In addition, above-mentioned P type doped region 8 can form by the doping treatment that for example special-purpose Implantation and thermal treatment are carried out, and also can form with ion implantation before forming grid.In other words, after forming dielectric film 4b, 9b, inject the impurity identical with the trap conduction type, the surface of trap forms low resistance and is turned to the zone 8 higher than the impurity concentration of trap.The good impurity concentration of above-mentioned well region 2 is 1 * 10 ¹⁷/ cm ³Below, be preferably 1 * 10 ¹⁶～5 * 10 ¹⁶/ cm ³The surface impurity concentration of source, drain region 5a, 5b is preferably 1 * 10 ²⁰～3 * 10 ²⁰/ cm ³, the surface impurity concentration of P type doped region 8 is preferably 1 * 10 ¹⁸～5 * 10 ¹⁹/ cm ³, but from the reliability of the dielectric film that consist of to keep electric capacity and withstand voltage viewpoint, 1 * 10 ¹⁸～1 * 10 ¹⁹/ cm ³Good especially.

Form the 1st interlayer dielectric 6 from above-mentioned electrode 4a and 9a and cover on the field oxide film 3 always, be provided with the data line 7 (with reference to Fig. 3) that consisted of by the metal level take aluminium as main body and stretch out source electrode 7a and the auxiliary coupling wiring 10 that forms from this data line at this dielectric film 6.Source electrode 7a carries out electric conductivity by the contact hole 6a that forms at dielectric film 6 with source region 5a and is connected, in addition, one end of auxiliary coupling wiring 10 carries out electric conductivity by the contact hole 6ba that forms at dielectric film 6 with drain region 5b and is connected, and the other end carries out electric conductivity by the contact hole 6c that forms at dielectric film 6 with electrode 9a and is connected.

After above-mentioned dielectric film 6 was the HTO film (silicon oxide film that forms with high temperature CVD method) on for example deposit 1000 Izod right sides, deposition thickness was that the bpsg film (silicate glass film that comprises boron and phosphorus) of 8000～10000 dusts forms again.The metal level that consists of source electrode 7a (data line 7) and auxiliary coupling wiring 10 begins for example to be 4 layers of structure of Ti/TiN/Al/TiN from lower floor.Each layer thickness is respectively: the Ti of lower floor is 100～600 dusts, and TiN is that 1000 Izods are right, and Al is 4000～10000 dusts, and the TiN on upper strata is 300～600 dusts.

Cover on the interlayer dielectric 6 from above-mentioned source electrode 7a and auxiliary coupling wiring 10 formation the 2nd interlayer dielectric 11 always, form by the 2nd layer of photomask that metal level 12 consists of take aluminium as main body at the 2nd interlayer dielectric 11.As described later, the 2nd layer of metal level 12 that consists of this photomask is that the metal level as the wiring that connects usefulness between composed component forms in the peripheral circuits such as driving circuit that the periphery of pixel region forms.Therefore, owing to only form this photomask 12, so do not need to increase operation, can simplify technique.In addition, with the above-mentioned auxiliary coupling 10 corresponding positions of connecting up, form for hereinafter described pixel capacitors and MOSFET electric conductivity the peristome 12a that passes of the column coupling bar 15 that couples together, in addition, above-mentioned photomask 12 all covers pixel region 20.That is, in planimetric map shown in Figure 3, the rectangle frame of tape symbol 12a represents above-mentioned peristome, and the outside of this peristome 12a all is photomask 12.Therefore, almost all interdicted from the light of Fig. 1 top (liquid crystal layer side) incident, make light by channel region 5c and the well region 2 of pixel switch with MOSFET, can be prevented from flowing through light leakage current.

Above-mentioned the 2nd interlayer dielectric 11 is to form like this, namely take for example TEOS (tetraethyl countenance silicate) as material, behind the silicon oxide film (hereinafter referred to as the TEOS film) with plasma CVD method formation on deposit 3000～6000 Izod right sides, deposit sog film (spin diffusing glass film) again, with interior etching method with its skiving after, deposition thickness is the 2TEOS film on 2000～5000 Izod right sides on it again.Consist of this photomask the 2nd layer of metal level 12 can with above-mentioned the 1st layer of metal level 7 (7a), 10 same structures, for example begin to be 4 layers of structure of Ti/TiN/Al/TiN from lower floor.Each layer thickness is respectively: undermost Ti is 100～600 dusts, and the TiN above it is that 1000 Izods are right, and Al is 4000～10000 dusts, and the TiN of the superiors is 300～600 dusts.

In this embodiment, form the 3rd interlayer dielectric 13 at above-mentioned photomask 12, as shown in Figure 3, form roughly corresponding with the 1 pixel pixel capacitors 14 as the rectangular reflection electrode at the 3rd interlayer dielectric 13.Then, corresponding to the peristome 12a that establishes at above-mentioned photomask 12, be positioned at its inboard and offer the contact hole 16 that connects above-mentioned the 3rd interlayer dielectric 13 and the 2nd interlayer dielectric 11, be used for electric conductivity ground in these contact hole 16 interior fillings and connect the column coupling bar 15 that is consisted of by refractory metals such as tungsten of above-mentioned auxiliary coupling wiring 10 and above-mentioned pixel capacitors 14.In addition, on above-mentioned pixel capacitors 14, form all sidedly passivating film 17.

When consisting of liquid crystal panel, form alignment films at this reflecting electrode side group plate again, with this substrate relatively with the interval of regulation, at inside surface configuration relative (public) electrode, relative with the counter substrate that has formed in the above alignment films, simultaneously in this gap, enclose liquid crystal, consist of liquid crystal panel.

Although without particular limitation of, but will consist of the adhesions such as tungsten of coupling bar 15 with the CVD method after, with CMP (cmp) method, scabble tungsten and the 3rd interlayer dielectric 13, after making it smooth, forming thickness with for example low temperature sputtering method is the aluminium lamination of 300～5000 dusts, forms the foursquare pixel capacitors 14 that every length of side is about 15～20 μ m by forming figure.In addition, as the formation method of above-mentioned coupling bar 15, utilize in addition the CMP method to make 13 planarizations of the 3rd interlayer dielectric, then offer contact hole, tungsten is sticked to wherein.As above-mentioned passivating film 17, adopting thickness in pixel region section is the silicon oxide film of 500～2000 dusts, and partly adopting thickness at neighboring area, hermetic unit and the indentation of substrate is the silicon nitride film of 2000～10000 dusts.In addition, so-called hermetic unit, a pair of substrate that refers to the to consist of liquid crystal panel formation district of encapsulant of usefulness that is adhesively fixed with a gap.In addition, so-called indentation part, refer to form a plurality of reflective liquid crystal panel substrates of the present invention at semiconductor thin plate, when along line of weakness its cutting and separating being become each semi-conductor chip along the part (end of substrate for liquid crystal panel) of scored region.

In addition, owing to use silicon oxide film as the passivating film that covers the pixel region part, so can the inhibitory reflex rate produce large variation or reflectivity produces the phenomenon of large variation with the difference of light wavelength with the deviation of thickness.

On the other hand; the neighboring area of covered substrate, particularly enclosed the passivating film 17 in the zone, the zone outside (outside of sealing) of liquid crystal; since use from the viewpoint of the water tolerance of substrate etc. see than with silicon oxide film as the better silicon nitride film of diaphragm; adopt the single layer structure of this silicon nitride film or form the diaphragm of the double-layer structure of silicon nitride film at silicon oxide film, so more can improve reliability.That is, although water etc. easily regional from the substrate periphery that contact with extraneous air, particularly indentation partly enters, this part is covered with by the diaphragm that silicon nitride film consists of, so can improve reliability and permanance.

In addition, when passivating film 17 consists of liquid crystal panel, form the alignment films that is consisted of by polyimide at all surfaces, carry out friction treatment.

Moreover the thickness of above-mentioned passivating film 17 can be according to the wavelength set of incident light in each suitable scope.Specifically, becoming the thickness of the silicon oxide film of passivating film, is 900～1200 dusts in the pixel capacitors of reflect blue light, is 1200～1600 dusts in the pixel capacitors of reflects green, is 1300～1900 dusts in the pixel capacitors of reflection red light.The thickness setting of the silicon oxide film by will becoming passivating film is in above-mentioned scope, and the reflecting electrode that can be made of aluminium lamination is suppressed at below 1% the deviation of reflectivity of all kinds.Its reason below is described.

In Figure 10 and Figure 11, show the reflecting electrode that consisted of by aluminium lamination to the reflectivity of each wavelength how with the result of study of the variation in thickness of silicon oxide film.In Figure 10, symbol ◆ the reflectivity the when reflectivity of expression thickness when being 500 dust, symbol represent that thickness is 1000 dust, the reflectivity of symbol ▲ when the expression thickness is 1500 dust, the reflectivity of symbol * when the expression thickness is 2000 dust.In addition, in Figure 11, symbol ◆ the reflectivity the when reflectivity of expression thickness when being 1000 dust, symbol represent that thickness is 2000 dust, the reflectivity of symbol ▲ when the expression thickness is 4000 dust, the reflectivity of symbol * when the expression thickness is 8000 dust.

With reference to Figure 11 as can be known, be in the situation of 4000 dusts at thickness, when wavelength changed between 450～550nm, reflectivity from 0.89 to 0.86 reduced by 3% approximately, and when wavelength changed between 700～800nm, reflectivity from 0.85 to 0.77 reduced by 8% approximately.In addition, be in the situation of 8000 dusts at thickness, when wavelength changed between 500～600nm, reflectivity from 0.89 to 0.86 reduced by 3% approximately, and when wavelength changed between 650～750nm, reflectivity from 0.86 to 0.80 reduced by 6% approximately.Different therewith, when thickness was 500 dusts, 1000 dusts, 1500 dusts, 2000 dust, reflectivity was not found so rapid variation.For the above reasons as can be known, the effective range of silicon oxide film thickness is 500～2000 dusts.

Therefore as can be known, in the situation that consists of reflective liquid crystal panel, as the passivating film that forms at reflecting electrode, if can obtain the thickness of 500～2000 dust scopes, just can consist of the reflectivity reflective liquid crystal panel little to the dependence of wavelength.

Moreover, by Figure 10 and Figure 11 as can be known, if from local wavelength's scope, exist reflectivity to change little scope with the variation of silicon oxide film thickness.In addition, the present inventor considers the different color light corresponding to the incident back reflection, whether has the optimum thickness range of silicon oxide film, and this is studied in great detail.To the results are shown in Figure 12～Figure 14.Wherein, Figure 12 is centered by blueness in its vicinity the wavelength coverage of 420～520nm, the curve of the reflectivity the during thickness of the change silicon oxide film of drawing by each suitable wavelength, Figure 13 is centered by green in its vicinity the wavelength coverage of 500～600nm, the same curve of pressing the reflectivity of each suitable wavelength drafting, Figure 14 is centered by redness in its vicinity the wavelength coverage of 560～660nm, the curve of the reflectivity of drawing by each suitable wavelength equally.

With reference to Figure 12 as can be known, be in the situation of 800 dusts at thickness, when wavelength changed between 440～500nm, reflectivity from 0.896 to 0.882 descended 1.1% approximately.In addition, be in the situation of 1300 dusts at thickness, when wavelength changed between 420～470nm, reflectivity from 0.887 to 0.893 changed 0.6% approximately, and is much lower when simultaneously wavelength is other thickness of luminance factor between 420～450nm.Different therewith, when thickness is 900 dusts or 1000 dusts, 1100 dusts, 1200 dust, do not find the so rapid variation of reflectivity, can obtain the value of enough big or small reflectivity simultaneously.

In addition, with reference to Figure 13 as can be known, be in the situation of 1100 dusts at thickness, when wavelength changed between 550～600nm, reflectivity from 0.882 to 0.866 descended 1.6% approximately.In addition, be in the situation of 1700 dusts at thickness, much lower during other thickness of the luminance factor of wavelength between 500～530nm.Different therewith, when thickness is 1250 dusts or 1400 dusts, 1550 dust, do not find the so rapid variation of reflectivity, can obtain the value of enough big or small reflectivity simultaneously.

In addition, with reference to Figure 14 as can be known, be in the situation of 1200 dusts at thickness, when wavelength changed between 560～660nm, reflectivity from 0.882 to 0.848 descended 3.4% approximately.In addition, be in the situation of 2000 dusts at thickness, much lower during other thickness of the luminance factor of wavelength between 560～610nm.Different therewith, when thickness is 1400 dusts or 1600 dusts, 1800 dust, do not find the so rapid variation of reflectivity, can obtain the value of enough big or small reflectivity simultaneously.

By Figure 12～Figure 14 as can be known, because in the pixel capacitors of reflect blue light, the thickness setting that will become the silicon oxide film of passivating film is the scope of 900～1200 dusts, in the pixel capacitors of reflects green, be set as the scope of 1200～1600 dusts, in the pixel capacitors of reflection red light, be set as the scope of 1300～1900 dusts, so can will be suppressed at the deviation of reflectivity of all kinds below 1%, can obtain enough values of the reflectivity of size simultaneously.

In addition, Figure 12～each curve table shown in Figure 14 is shown on the passivating film and forms thickness the reflectivity when being the alignment films that is made of polyimide of 1100 dusts.If the thickness of alignment films is different, then some is different for the optimum thickness range of silicon oxide film and above-mentioned scope.In addition, from the little viewpoint of variations in refractive index that makes liquid crystal, the thickness range of alignment films is preferably set like this, that is, because the thickness of alignment films is when being lower than 300 dust, just there is not capacity of orientation, if when thick, polyimide will absorb the light of low wavelength and high wavelength than 1400 dusts, as the capacitive component that is connected in series with liquid crystal capacitance in the equivalent electrical circuit, can not ignore polyimide, the thickness range of alignment films preferably is set in the scope of 300～1400 dusts.If will worry that capacity of orientation reduces but alignment films is thin, so the thickness range of alignment films preferably is set in the scope of 800～1400 dusts.

If the thickness of alignment films in above-mentioned scope, and if the thickness of the silicon oxide film of liquid crystal panel of all kinds be set in respectively above-mentioned scope, just the deviation of the reflectivity of reflecting electrode can be suppressed at below 1%.

Therefore, carrying out with a liquid crystal panel in the colored situation about showing, can corresponding to the color of each pixel, make the color of the passivating film on the reflecting electrode different.Namely, on the inside surface of the counter substrate relative with this reflection side substrate, form the RGB colored filter corresponding to pixel capacitors, coloured light by this film is reflected by pixel capacitors, in such structure, if make the thickness of the passivating film that forms on the pixel capacitors of the red light that reflects the colored filter that has passed through red (R) in the scope of 1300～1900 dusts, make the thickness of the passivating film that forms on the pixel capacitors of the green light that reflects the colored filter that has passed through green (G) in the scope of 1200～1600 dusts, make the thickness of the passivating film that forms on the pixel capacitors of the blue light that reflects the colored filter that has passed through blue (B) in the scope of 900～1200 dusts, then can consist of the high monolithic reflective liquid crystal panel of reflectivity.In addition, this liquid crystal panel can also be as the light valve of one chip projection display device.Moreover, even without colored filter, also can change the device (for example dichronic mirror) that makes the light that incides on each pixel capacitors become coloured light into, consist of coloured light.

Moreover, shown in the projection display device as described later, even in the situation of the liquid crystal panel of the liquid crystal panel of the liquid crystal panel that has respectively reflection red light, reflects green, reflect blue light, also can use liquid crystal panel of the present invention.At this moment, in the liquid crystal panel of the light valve of modulated red coloured light, can will become the thickness setting of silicon oxide film of passivating film in the scope of 1300～1900 dusts, equally in the liquid crystal panel of the light valve of modulating green light, to become the thickness setting of silicon oxide film of passivating film in the scope of 1200～1600 dusts, in the liquid crystal panel of light valve of modulation blue light, will become the thickness setting of silicon oxide film of passivating film in the scope of 900～1200 dusts.

Fig. 3 is the plane figure of the substrate for liquid crystal panel of reflection side shown in Figure 1.As shown in the drawing, in this embodiment, the formation that crosses one another of data line 7 and grid line 4.Because grid line 4 doubles as grid 4a, so grid line 4 parts in the place that represents with hacures H among Fig. 3 become grid 4a, the substrate surface below it is provided with the channel region 5c that pixel switch is used MOSFET.Formation source, drain region 5a, 5b on the substrate surface of above-mentioned channel region 5c both sides (upper and lower sides among Fig. 3).In addition, the source electrode 7a that is connected with data line is from data line 7 outstanding formation the along the longitudinal extension of Fig. 3, and is connected with the source region 5a of MOSFET by contact hole 6b.

In addition, consist of keeping the P type doped region 8 of a side terminal of electric capacity connecting along the P type doped region of the pixel of direction (direction of the pixel rows) adjacency parallel with grid line 4 forms.And, connecting the power circuit 70 that is located at the pixel region outside by contact hole 71, be applied in for example such assigned voltage Vss of 0V (earthing potential).This assigned voltage Vss can be current potential or near the current potential it that is configured in the common electrode on the counter substrate, or the amplitude central potential of the picture intelligence of supply data line or near the current potential it, or any one current potential in the intermediate potential of the amplitude central potential of common electrode current potential and picture intelligence.

The outside at pixel region, by P type doped region 8 is connected with utility voltage Vss, make the current potential of a lateral electrode that keeps electric capacity stable, make the maintenance current potential that (when MOSFET is non-conduction) keeps electric capacity to keep between the non-selecting period of pixel stable, can be reduced in the variation that be added in the current potential on the pixel capacitors 1 image duration.In addition, because P type doped region 8 is located near the MOSFET, simultaneously the current potential of P type trap is fixed, so can make the substrate potential of MOSFET stable, can be prevented the variation of the threshold voltage that produced by back of the body matrix effect.

Although not shown, said power road 70 also can be used as the circuit that assigned voltage Vss is supplied with the P type well region (separating with the well region of pixel region) of the peripheral circuit that is located at the pixel region outside as trap potential and uses.Said power road 70 is made of the 1st floor metal level identical with above-mentioned data line 7.

Pixel capacitors 14 is rectangular respectively, and the pixel capacitors 14 of so-called adjacency is to consist of like this, namely for example at a distance of 1 μ m setting closer to each other, in order to reduce from the light quantity of the leakage of the gap between pixel capacitors as far as possible.In addition, in the drawings, there is skew at the center of the center of pixel capacitors and contact hole 16, but preferably makes two unanimous on the whole or coincidences in center.Its reason is because of being provided with opening at the 12a place that has on the 2nd layer of metal level 12 of shade function around the contact hole 16, if so opening 12a is arranged near the end of pixel capacitors 14, then the light from the gap incident of pixel capacitors just carries out diffuse reflection and arrives opening 12a between the back side of the 2nd layer of metal level 12 and pixel capacitors 14, the substrate-side below this opening incides and light leak.Therefore, preferably the center of the center by making pixel capacitors and contact hole 16 is unanimous on the whole or overlap, so that from the light of the gap incident of the pixel capacitors of adjacency arrive from each pixel capacitors end contact hole apart from approximate equality, can make light be difficult for arrival and might make light incide the contact hole of substrate-side.

In addition, in the above-described embodiments, illustrated that making pixel switch MOSFET is the N channel-type, and make the semiconductor region 8 that becomes a lateral electrode that keeps electric capacity become the situation of P type doped layer, but also can make well region 2 be N-type, making pixel switch MOSFET is the P channel-type, and makes the semiconductor region that becomes a lateral electrode that keeps electric capacity become the N-type doped layer.At this moment, preferably will be added on the N-type doped layer that becomes a lateral electrode that keeps electric capacity with the same regulation current potential VDD that is added on the N-type well region.In addition, this regulation current potential VDD is the current potential that is added on the N-type well region, so the on high-tension side current potential of supply voltage preferably.That is, be 5V if be added in pixel switch with the source of MOSFET, the voltage of picture intelligence in the leakage, preferably make this regulation current potential VDD also be 5V.

Moreover, owing to be added on the grid 4a of pixel switch with MOSFET different from the voltage that 15V is large like this, and drive (the parts of peripheral circuit such as logical circuit such as shift register of peripheral circuit with the so little voltage of 5V, such as drive the circuit etc. of sweep signal being supplied with grid line with 15V), so can consider such technology, be about to consisting of gate insulating film with the FET of the peripheral circuit of 5V work forms thinlyyer (with the manufacturing process of gate insulating film as other operation with the gate insulating film of FET than pixel switch, in addition, form the gate insulating film surface of the FET of peripheral circuit by etching etc.), improve the response characteristic of the FET of peripheral circuit, improve the operating rate of peripheral circuit (particularly requiring the shift register of data line one side drive circuit of high-velocity scanning).In the situation that has adopted such technology, according to the withstand voltage situation of gate insulating film, the thickness that can make the gate insulating film of the FET that consists of peripheral circuit is about 1/1/3rd～five (for example 80～200 dusts) that pixel switch is used the thick gate insulating film of FET.

Simultaneously, the drive waveforms among the 1st embodiment becomes appearance shown in Figure 8.Among the figure, VG is the sweep signal that is added on the pixel switch usefulness grid of MOSFET, and cycle tH1 is the selection cycle (scan period) that makes the MOSFET conducting of pixel, and the cycle in addition is the non-selection cycle that makes the not conducting of MOSFET of pixel.In addition, Vd is the peak swing that is added in the picture intelligence on the data line, and Vc is the central potential of picture intelligence, and LC-COM is added public current potential on opposed (public) electrode that the counter substrate relative with reflecting electrode side group plate forms.

The voltage swing that is added between the electrode that keeps electric capacity is determined by the difference that is added in the picture intelligence voltage Vd on the data line and is added in the such assigned voltage Vss of 0V in the P-type semiconductor district 8 shown in Figure 8.; originally namely about 5V (added public current potential LC-COM differs Δ V than Vc on opposed (public) electrode 33 of counter substrate 35 settings of the liquid crystal panel in Fig. 6, but becomes Vd-Δ V after in fact being added in voltage phase difference Δ V on the pixel capacitors) is just enough should to be added in the potential difference (PD) that keeps on the electric capacity and to be the difference of central potential Vc of picture intelligence voltage Vd and picture intelligence.Therefore, in the 1st embodiment, make the polarity opposite (being N-type during P type trap) of doped region 8 with the trap of a side terminal that consists of maintenance electric capacity, near the peripheral part of pixel region can connect Vc or LC-COM current potential also can be the current potential different from trap potential (for example P type trap is Vss).Therefore, can be without the gate insulating film of pixel switch with FET, and form simultaneously the polysilicon that consists of a lateral electrode 9a who keeps electric capacity or the dielectric film 9b under the metal silicide layer with the gate insulating film of the FET that consists of peripheral circuit, compare with above-described embodiment, can make to keep the insulator film thickness of electric capacity to be the former 1/1/3rd～five, therefore make capacitance become 3～5 times.

Fig. 1 (b) is the sectional view of section (along the II-II line among Fig. 3) of peripheral part of the pixel region of expression one embodiment of the invention.Show the direction of scanning (pixel rows direction) doped region 8 that extends and the structure of stipulating the part that current potential (Vss) is connected that make along pixel region.The 80th, the P type contact region that forms with the same operation in the source of the MOSFET that forms peripheral circuit, drain region forms with the impurity that ion implantation is injected same conduction type after grid forms the doped region 8 that forms before grid forms.Contact region 80 is connected with wiring 70 by contact hole 71, is applied in constant voltage Vss.In addition, on this contact region 80, also use by the 3rd layer of photomask that metal level consists of 14 ' shading.

Secondly, Fig. 2 outside of being illustrated in pixel region consists of the sectional view of embodiment of cmos circuit element of the peripheral circuit of driving circuit etc.In Fig. 2 with Fig. 1 in the place of same-sign, expression is with metal level, dielectric film and the semiconductor region of same operation formation.

In Fig. 2,4a, 4a ' are respectively the N-channel MOS FET that consists of the peripheral circuit (cmos circuit) such as driving circuit, the grid of P channel mosfet, 5a (5b), 5a ' (5b ') be respectively N-type doped region, the P type doped region that consists of this source (leakage) district, 5c, 5c ' they are respectively channel regions.Constant voltage Vss being supplied with the contact region 80 of P type doped region 8 of a lateral electrode of the maintenance electric capacity in the pie graph 1, is the same operation formation of P type doped region 5a ' (5b ') with source (leakages) district that consists of above-mentioned P channel mosfet.27a, 27c are made of the 1st layer of metal level, are the source electrodes that connects supply voltage (0V, 5V or 15V any one), and 27b is by the 1st layer of drain electrode that metal level consists of.32a is by the 2nd layer of wiring layer that metal level consists of, and uses as the wiring between the element that connects and composes peripheral circuit.32b also is the power-supply wiring layer that is made of the 2nd layer of metal level, but also has the function as photomask.Photomask 32b also can connect any one in certain voltage such as Vc or LC-COM or supply voltage 0V, can also be indefinite current potential.14 ' is the 3rd layer of metal level, and at peripheral circuit part, the 3rd layer of metal level uses as photomask, is used for preventing that light from by the semiconductor region that consists of peripheral circuit charge carrier occuring, and causes peripheral circuit to delay work so that the current potential of semiconductor region is unstable.In other words, peripheral circuit also carries out shading with the layers 2 and 3 metal level.

As mentioned above, the passivating film 17 of peripheral circuit part can use than the silicon oxide film of the passivating film that consists of pixel region as diaphragm also will be good silicon nitride film consist of, also can be used as the diaphragm that forms the double-layer structure of silicon nitride film at silicon oxide film and consist of.In addition, although be not particularly limited, the source, drain region of MOSFET that consists of the peripheral circuit of this embodiment also can form with the Self-adjustment technology.Moreover the source of MOSFET, drain region both can be LDD (trace doped drain electrode) structure arbitrarily, also can be DDD (double doped-drain) structure.In addition, consider with large voltage to drive pixel switch FET, must the Leakage prevention electric current, can compensate (structure of maintenance certain distance between grid and source, drain region).

Fig. 4 represents the most preferred embodiment as the end construction of reflecting electrode (pixel capacitors) side group plate.In Fig. 4, with Fig. 1, Fig. 2 in the place of same-sign, expression with same operation form layer and semiconductor region.

As shown in Figure 4; the end of the overlapping body of interlayer dielectric and metal level and sidewall thereof are formed in the overlapping protection structure that formed on the passivating film 17 that is made of silicon oxide film that covers pixel region and peripheral circuit behind the silicon nitride film 18 as mentioned above; this end is after silicon chip forms a plurality of substrates of the present invention, the end of each substrate when along line of weakness its cutting and separating being become each substrate (semi-conductor chip).In other words, the downside step part of the step part on right side is scored region among Fig. 4.

Therefore, because the top of substrate end and sidewall sections use silicon nitride film as diaphragm, so water etc. are difficult to enter from the end, can improve permanance, strengthen simultaneously the end, so can improve qualification rate.In addition, in this embodiment, be located on the fully smooth above-mentioned overlapping protection structural portion sealing the encapsulant 36 that liquid crystal uses.Therefore, the thickness deviation that produces with having or not interlayer dielectric or metal level is irrelevant, can make with the interval of counter substrate certain.In addition, if adopt said structure, then because can be with the diaphragm on the reflecting electrode of mono-layer oxidized silicon fiml formation formation pixel capacitors, thus the decline that can reduce reflectivity and reflectivity with the different of wavelength the dependence to wavelength.

As shown in Figure 4, in this embodiment, the 3rd layer of metal level 14 ' is the 14 identical layers of using with the reflecting electrode of the photomask of peripheral circuit region or pixel, connect the wiring layer 19 that impurity forms on the surface of semiconductor substrate 1 by the 2nd layer and the 1st layer of metal level 12 ', 7 ', be fixed in substrate potential.Can certainly replace the 3rd layer of metal level 14 ' with the layer that the following set potential that makes the 2nd layer of metal level 12 ' or the 1st layer of metal level 7 ' extend to encapsulant 36 is used.Therefore, in the forming process of substrate for liquid crystal panel, in the forming process of liquid crystal panel or liquid crystal panel all may carry out the processing of the aspects such as static after forming.By unshowned weld zone in these wiring layer 19 connection layout, also can apply voltage or the signal of regulation in addition.

Fig. 5 represents another embodiment of the present invention.Fig. 5 is same as in figure 1, also is the sectional view along the I-I line in the plane figure shown in Figure 3.In Fig. 5, with Fig. 1, Fig. 2 in the place of same-sign, layer and semiconductor region that expression uses the operation identical with these figure illustrated embodiments to form.This embodiment be above-mentioned reflecting electrode 14 and below it as the metal level of light shield layer 12 between form the interlayer dielectric 13a that is consisted of by above-mentioned TEOS film (after comprising a part of etching remaining sog film), in addition, below it, formed silicon nitride film 13b.Otherwise, also can be on TEOS film 13a formation silicon nitride film 13b.By adopting the structure of such increase silicon nitride film, water etc. are not easy to enter, and can improve moisture resistance properties.

In addition, the thickness of the passivating film on the reflecting electrode is identical with situation embodiment illustrated in fig. 1.

Figure 16 represents another embodiment of the present invention.Figure 16 is same as in figure 1, also is the sectional view along the I-I line in the plane figure shown in Figure 3.In Figure 16, with Fig. 1, Fig. 2 in the place of same-sign, layer and semiconductor region that expression uses the operation identical with the embodiment of these figure to form.This embodiment be above-mentioned reflecting electrode 14 and below it as the metal level of light shield layer 12 between form the interlayer dielectric 13a that is consisted of by above-mentioned TEOS film (after comprising a part of etching remaining sog film), in addition, on it, formed silicon nitride film 13b.At this moment can also make silicon nitride film 13b planarization with CMP method etc.After having formed silicon nitride film like this, because the opening of the embodiment among aperture efficiency Fig. 5 of silicon nitride part is few, enter so water etc. are more difficult, can improve moisture resistance properties.Between the reflecting electrode of reflecting electrode 14 and vicinity thereof, consisted of by protection dielectric film 17 and silicon nitride film 13b simultaneously.Because the refractive index of silicon nitride film is 1.9～2.2; refractive index 1.4～1.6 height than the silicon oxide film of protecting dielectric film 17 to use; so when light incides protection dielectric film 17 from liquid crystal side, reflecting with the interface of silicon nitride film 13b owing to the difference of refractive index.Therefore, the light of injecting interlayer film reduces, and makes the current potential of semiconductor region unstable so charge carrier occurs in the time of preventing light by semiconductor region.

In addition, in the present embodiment, form silicon nitride film 13b after also can making the interlayer dielectric 13a planarization that is consisted of by the TEOS film with CMP method etc.In general, in order to eliminate local step, need to be be equivalent to the thickness of local step, the film of 8000～12000 dusts for example such as deposits such as CMP methods.In addition, in the ordinary course of things, be used for the silicon nitride film of 13b along with the increase of thickness, for lower film, strong stress occur.In the present embodiment, by grinding interlayer dielectric 13a with CMP method etc., carry out planarization, form silicon nitride film 13b again on it, the thickness of deposit when reducing silicon nitride film 13b and adopting CMP method etc. can relax the stress of silicon nitride film 13b.In addition; at this moment owing between the reflecting electrode of reflecting electrode 14 and vicinity thereof, also consist of protection dielectric film 17 and silicon nitride film 13b; reduce so inject the light of interlayer film, make the current potential of semiconductor region unstable so charge carrier occurs in the time of preventing light by semiconductor region.In addition, in the present embodiment, the thickness that preferably makes silicon nitride film 13b for example is 2000～5000 dusts.This is because can improve the moisture resistance properties of silicon nitride film 13b when 2000 dusts are above, and when 5000 dusts are following, has reduced the etching depth of contact hole 16, and etching simultaneously by reducing the thickness of silicon nitride film 13b, can relax the stress that lower film is produced easily.

In addition, the thickness of the passivating film on the reflecting electrode is identical with situation embodiment illustrated in fig. 1.

Fig. 6 has represented to use the general plane layout structure of the liquid crystal panel (substrate of reflecting electrode side) of above-described embodiment.

As shown in Figure 6, in this embodiment, be provided with photomask 25, be used for preventing that light from inciding on the peripheral circuit that the peripheral part at substrate arranges.Peripheral circuit is located on the periphery that is the rectangular pixel region 20 that has disposed above-mentioned pixel capacitors, comprising: will the picture intelligence corresponding with pictorial data supply with the data line drive circuit 21 of above-mentioned data line 7 or scan in order the grid line driving circuit 22 of grid line 4; Be taken into from the input circuit 23 of the pictorial data of outside input by weld zone 26; Control timing control circuit 24 circuit such as grade of these circuit, these circuit be the MOSFET that will form with same operation or the different operation of MOSFET with the pixel capacitors switch as active component or on-off element, and itself and resistance and electric capacity even load elements combination formed.

In this embodiment, above-mentioned photomask 25 is made of the 3rd layer of metal level that the same operation of using with pixel capacitors shown in Figure 1 14 forms, and is applied in the current potential of the regulations such as the central potential Vc of supply voltage or picture intelligence or public current potential LC-COM.Be added on the photomask 25 by the current potential with regulation, compare with the situation of potential fluctuation or other current potential, can reduce reflection.The 26th, the weld zone of the weld zone that uses for supply line voltage or formation terminal.

Fig. 7 has represented to use the cross-section structure of the reflective liquid crystal panel of above-mentioned base plate of liquid crystal panel 31.As shown in Figure 7, the supporting substrate 32 usefulness bonding agents that are made of glass or pottery etc. are bonded in the back side of above-mentioned base plate of liquid crystal panel 31.Meanwhile, at the glass substrate 35 of its surperficial side with suitable arranged spaced light incident side, this glass substrate 35 has the opposite electrode (also claiming common electrode) 33 that is made of the nesa coating that has applied public current potential LC-COM (ITO), filled around well-known TN (Twisted Nematic) type liquid crystal in the gap with encapsulant 36 sealing or under making alive state not SH (Super Homeotropic) the type liquid crystal 37 etc. of liquid crystal molecule approximate vertical orientation, consist of liquid crystal panel 30.In addition, set like this setting position of encapsulant, that is, from external input signal, make weld zone 26 be positioned at the outside of above-mentioned encapsulant 36.

Photomask 25 on the peripheral circuit accompanies liquid crystal 37 therebetween with opposite electrode 33 relative formations.And, if the public current potential of LC is added on the photomask 25, just then the public current potential of LC has been added on the opposite electrode 33, so DC voltage is not added on the intervenient liquid crystal.Therefore, if TN type liquid crystal, then liquid crystal molecule often reverses roughly 90 °, if SH type liquid crystal, then liquid crystal molecule often keeps vertical orientated state.

In this embodiment, because be bonded in the back side of the above-mentioned base plate of liquid crystal panel 31 that is consisted of by semiconductor substrate by the supporting substrate 32 usefulness bonding agents that consist of such as glass or potteries, so its intensity increases significantly.If after consequently being bonded in supporting substrate 32 on the base plate of liquid crystal panel 31, carry out the applying with counter substrate, then have and make liquid crystal layer along whole uniform advantages in gap of panels.

(using the explanation of the substrate for liquid crystal panel of insulated substrate)

In the above description, the reflective liquid crystal panel of using semiconductor substrate has been described with the structure of substrate and has used its liquid crystal panel, and the following structure that the reflective liquid crystal panel usefulness substrate of use insulated substrate will be described.

Figure 17 is the expression reflective liquid crystal panel with the sectional view of the pixel structure on the substrate.This figure is same as in figure 1, also is the sectional view along the I-I line in the plane figure shown in Figure 3.In the present embodiment, the transistor that uses TFT to use as pixel switch.In Figure 17, with Fig. 1, Fig. 2 in the place of same-sign, layer and semiconductor region that expression and these figure have same function.The 1st, quartzy or without the glass substrate of alkalescence, form monocrystalline or polycrystalline or amorphous silicon film (5a, 5b, 5c, 8 form layer) at this insulated substrate, form by the silicon oxide film that forms by thermal oxide and the dielectric film 4b, the 9b that consist of with the double-decker of the silicon nitride of CVD method deposit at this silicon fiml.In addition, before the upper silicon nitride film that forms dielectric film 4b, with N-type impurity mixed in 5a, 5b and 8 districts of silicon fiml, form source region 5a, the drain region 5b of TFT and the electrode district 8 of maintenance electric capacity.In addition, form the grid 4a that consists of TFT and the wiring layers such as the polysilicon of another electrode 9a that keeps electric capacity or metal silicide at dielectric film 4b.As mentioned above, form by grid 4a, gate insulating film 4b, raceway groove 5c, source 5a, leak TFT that 5b consists of and by electrode 8,9 and the maintenance electric capacity that consists of of dielectric film 9b.

In addition, form the 1st interlayer dielectric 6 that is formed by silicon nitride or monox at wiring layer 4a, 9a, the source electrode 7a that is connecting source region 5a at the contact hole of these dielectric film 6 formation is formed by the 1st metal level that aluminium lamination consists of.Form by silicon nitride film or the 2nd interlayer dielectric 13 that formed by the double-decker of silicon oxide film and silicon nitride film at the 1st metal level again.After the 13 usefulness CMP method planarizations of the 2nd interlayer dielectric, on it, each pixel is formed into pixel capacitors for the reflecting electrode that is made of aluminium.In addition, silicon fiml electrode district 8 is connected with pixel capacitors and is carried out electric conductivity by contact hole 16 and connect.This connection is to use the method same with Fig. 1, will be imbedded to realize by the coupling bar 15 that the refractory metals such as tungsten consist of.

As mentioned above, form reflecting electrode owing to reaching above maintenance electric capacity at the TFT that insulated substrate forms, so it is large that the pixel capacitors district becomes, in addition, also the plane figure with shown in Figure 3 is the same owing to keep electric capacity, can form with large tracts of land below reflecting electrode, even so fine (pixel is little) panel, also can obtain large numerical aperture (reflectivity), and can keep fully being added in the voltage on each pixel, drive stable.

In addition, the same with above embodiment, form the passivating film 17 that is consisted of by silicon oxide film at reflecting electrode 14.The thickness of this passivating film 17 is the same with above embodiment, can obtain reflectivity with the little reflective liquid crystal panel substrate of the wavelength variations of incident light.In addition, the structure of the general structure of substrate for liquid crystal panel and liquid crystal panel is identical with Fig. 6 and Fig. 7.

In addition, in Figure 17, although interlayer dielectric 11 and the light shield layer 12 of configuration resemble Fig. 1, the light leakage phenomena for the TFT that prevents from causing from the light of the gap incident of the pixel capacitors 14 of adjacency also can wait with Fig. 1 and similarly dispose these layers.In addition, if supposition light can be from the below incident of substrate, so can also silicon fiml 5a, 5b, 8 below dispose again light shield layer.In addition, the grid among the figure is the top grid formula that is positioned at raceway groove top, but also can form first grid, is configured as the silicon fiml of raceway groove by gate insulating film again, consists of the bottom gate formula.Moreover peripheral circuit region is identical with Fig. 4, owing to form the double-decker of silicon nitride film or silicon oxide film and silicon nitride film, so can improve moisture resistance properties.

(using the explanation of the electronic installation of reflective liquid crystal panel of the present invention)

Fig. 9 is one of the electronic installation example of using liquid crystal panel of the present invention, is the planimetric map of simple structure of the major part of projector's (projecting display) that reflective liquid crystal panel of the present invention is used as light valve.This Fig. 9 is the sectional view along the XZ plane at the center of passing through optical element 130.This routine projector is made of following part: along the light source portion 110 (the 111st, lamp, the 112nd, catoptron) of systematic optical axis L configuration; Integration lens 120; The polarization illuminator 100 that is simply consisted of by polarization 130; With the polarization beam splitter 200 of S light beam reflecting surface 201 reflections from the S light beam of polarization illuminator 100 outgoing; The dichronic mirror 412 of blue light (B) component of separation from the light of S polarized light reflecting surface 201 reflections of polarization beam splitter 200; Separated blue light (B) is carried out the reflection-type liquid crystal light valve 300B of blue light modulation; The dichronic mirror 413 of red light (R) component in the light beam after reflection and separation blue light are separated; The reflection-type liquid crystal light valve 300R that separated red light (R) is modulated; To the reflection-type liquid crystal light valve 300G that modulates through the remaining green light (G) of dichronic mirror 413; And with dichronic mirror 412,413 and 200 pairs of light of being modulated by 3 reflection-type liquid crystal light valve 300R, 300G, 300B of polarization beam splitter synthesize, and will synthesize light and project to the projection optical system 500 that is consisted of by projecting lens on the screen 600.Used respectively above-mentioned liquid crystal panel among above-mentioned 3 reflection-type liquid crystal light valve 300R, 300G, the 300B.

After the random polarization light beam that penetrates from light source portion 110 is divided into many intermediate beam by integration lens 120, be transformed into the basically identical a kind of light beam in polarization direction (S light beam) by the polarization 130 that the 2nd integration lens is arranged at light incident side, then arrive polarization beam splitter 200.Be polarized S polarized light reflecting surface 201 reflections of beam splitter 200 from the light beam of polarization 130 ejaculations, blue light beam in the light beam that is reflected (B) is after the reflection of the blue light reflection horizon of dichronic mirror 412, and 300B modulates by reflection-type liquid crystal light valve.In addition, see through red beam (R) in the light beam in blue light reflection horizon of dichronic mirror 411 after the red reflective layer reflection of dichronic mirror 413,300R modulates by reflection-type liquid crystal light valve.

On the other hand, the green beam (G) that sees through the red reflective layer of dichronic mirror 413 is modulated by reflection-type liquid crystal light valve 300G.So, the coloured light of being modulated by each reflection-type liquid crystal light valve 300R, 300G, 300B with dichronic mirror 412,413 and polarization beam splitter 200 synthesize, carry out projection by 500 pairs of the projection optical systems light after should be synthetic again.

In addition, the reflective liquid crystal panel that consists of reflection-type liquid crystal light valve 300R, 300G, 300B adopts TN type liquid crystal (when making alive not, the major axis of liquid crystal molecule orientation is roughly parallel to the liquid crystal of display panel substrate) or SH type liquid crystal (when making alive not, the major axis orientation of liquid crystal molecule is approximately perpendicular to the liquid crystal of display panel substrate).

In the situation that adopts TN type liquid crystal, be on the pixel (OFF pixel) below the threshold voltage of liquid crystal at the voltage on the liquid crystal layer between the common electrode that is added in the reflecting electrode that is sandwiched in pixel and the substrate relative with it, the coloured light of incident becomes it into elliptically polarized light by liquid crystal layer, after being reflected the electrode reflection, by liquid crystal layer, be reflected and outgoing as the light of many elliptic polarization light state that is similar to polarizing axis with the coloured light of incident and roughly is offset the polarizing axis components of 90 degree.On the other hand, applied at liquid crystal layer on the pixel (ON pixel) of voltage, the coloured light of incident directly arrives reflecting electrode, and after being reflected, same polarizing axis is reflected and outgoing with incident the time.Along with the difference that is added in the voltage on the reflecting electrode, the arrangement angle of TN type liquid crystal molecule changes, thus catoptrical polarizing axis with respect to the angle of incident light along with the voltage that the transistor by pixel is added on the reflecting electrode changes.

In addition, in the situation that adopts SH type liquid crystal, on the pixel (OFF pixel) that is added in below the threshold voltage that voltage on the liquid crystal layer is liquid crystal, the coloured light of incident directly arrives reflecting electrode, after being reflected, same polarizing axis is reflected and outgoing with incident the time.On the other hand, applied at liquid crystal layer on the pixel (ON pixel) of voltage, the coloured light of incident becomes it into elliptically polarized light by liquid crystal layer, after being reflected the electrode reflection, by liquid crystal layer, be reflected and outgoing with respect to many elliptically polarized lights that the polarizing axis of incident light roughly is offset the polarizing axis components of 90 degree as polarizing axis.The same with the situation of TN type liquid crystal, the arrangement angle of SH type liquid crystal molecule changes along with being added in the voltage on the reflecting electrode, thus catoptrical polarizing axis with respect to the angle of incident light along with the voltage that the transistor by pixel is added on the reflecting electrode changes.

In addition, in the pixel (OFF pixel) when adopting the SH liquid crystal below liquid crystal layer institute making alive is the threshold voltage of liquid crystal, the coloured light of incident directly arrives reflecting electrode and is reflected, with incident the time same polarizing axis directly reflect, outgoing.On the other hand, applied in the pixel (ON pixel) of voltage at liquid crystal layer, the coloured light of incident becomes elliptically polarized light and is reflected the electrode reflection at liquid crystal layer, pass through liquid crystal layer, roughly be offset a plurality of elliptically polarized lights of 90 ° polarizing axis component as polarizing axis with respect to the polarizing axis of incident light, reflect, outgoing.Same with TN type liquid crystal phase, because the arrangement angle of the liquid crystal molecule of SH type liquid crystal changes with the voltage that is added on the reflecting electrode, so catoptrical polarizing axis can change with the voltage that the transistor by pixel is added on the reflecting electrode with respect to the angle of incident light.

From the coloured light that the pixel of these liquid crystal panels reflects, the S polarized light component does not see through the polarization beam splitter 200 of reflection S polarized light, and on the other hand, the P polarized light component sees through.Form image by the light that sees through this polarization beam splitter 200.Therefore, when TN type liquid crystal is used for liquid crystal panel, the reflected light of OFF pixel arrives projection optical system 500, the reflected light of ON pixel does not arrive lens, so the image that is projected is normal white displays, in the situation that adopts the SH liquid crystal, the reflected light of OFF pixel does not arrive projection optical system, the reflected light of ON pixel arrives projection optical system 500, so be normal black display.

Reflective liquid crystal panel is compared with transmission-type active array type liquid crystal panel, can obtain large pixel capacitors, so can obtain high reflectance, can with the image of hard contrast projection fine, can make projector's miniaturization simultaneously.

As described in usefulness Fig. 7, the peripheral circuit of liquid crystal panel with shadow shield cover, with together be applied in identical current potential (the public current potential of LC for example at the opposite electrode with respect to the position formation of opposite electrode, if but when not having the public current potential of LC, just become the current potential different from the opposite electrode of pixel section, so at this moment become the peripheral opposite electrode that separates with the opposite electrode of pixel section.), so the voltage that is added on the marginal liquid crystal is roughly 0V, it is identical with the OFF state that liquid crystal becomes.Therefore, can as one man make the periphery of area of image be complete white the demonstration with normal white displays with TN type liquid crystal panel, can as one man make the periphery of area of image be complete black the demonstration with normal black display with SH type liquid crystal panel.

By as the polarization beam splitter 200 of look tripping device the light of above-mentioned light source 110 being divided into 3 primitive color lights, form thickness setting as the silicon oxide film of the passivating film of the light valve 300R of the 1st reflective liquid crystal panel that separated red light is modulated in the scope of 1300～1900 dusts, form thickness setting as the silicon oxide film of the passivating film of the light valve 300G of the 2nd reflective liquid crystal panel that green light is modulated in the scope of 1200～1600 dusts, form thickness setting as the silicon oxide film of the passivating film of the light valve 300B of the 3rd reflective liquid crystal panel that blue light is modulated in the scope of 900～1200 dusts, so just can obtain desirable result.

If abide by above-described embodiment, then can keep fully being added in the voltage on each pixel capacitors of reflective liquid crystal panel 300R, 300G, 300B, simultaneously because the reflectivity of pixel capacitors is very high, so can obtain the image of distinctness.

Figure 15 is the outside drawing that has represented respectively to adopt the electronic installation example of reflective liquid crystal panel of the present invention.In these electronic installations, it or not the light valve that uses as with polarization beam splitter, but use as the reflective liquid crystal panel of direct viewing type, so reflecting electrode does not need to be completely mirror-like, in order to enlarge field angle, certainly be preferably with suitable concavo-convexly, but the situation of main member in addition and light valve is basic identical.

Figure 15 (a) is the oblique view of expression portable phone.1000 expression portable phone bodies, wherein 1001 are the liquid crystal display parts that used reflective liquid crystal panel of the present invention.Figure 15 (b) is the synoptic diagram of expression watch style electronic installation.The 1100th, the oblique view of expression wrist-watch body.The 1101st, used the liquid crystal display part of reflective liquid crystal panel of the present invention.This liquid crystal panel is compared with existing clock and watch display part, has the pixel of fine, so can also show television image, can realize the televisor of Wristwatch-type.

Figure 15 (c) is the synoptic diagram of the portable information processing devices such as expression word processor, personal computer.1200 expression signal conditioning packages, the input parts such as 1202 expression keyboards, the display part of reflective liquid crystal panel of the present invention has been used in 1206 expressions, 1204 expression signal conditioning package bodies.Each electronic installation is to use battery-driven electronic installation, so if use not with the reflective liquid crystal panel of illuminator, then can extending battery life.In addition, as shown in the present, owing to peripheral circuit can be contained in the liquid crystal panel, so can significantly reduce part number, more lightweight and miniaturization.

In addition, in above embodiment, as the liquid crystal in the liquid crystal panel, the SH type of TN type and isotropic orientation has been described, but the liquid crystal that changes other type into can be implemented also certainly.

As mentioned above, the present invention is owing to being provided with passivating film in reflective liquid crystal panel with substrate, so have the effect that improves reliability.And, that to use thickness be the silicon oxide film of 500～2000 dusts as passivating film, so the deviation of thickness is little on the impact of the reflectivity of pixel capacitors, simultaneously particularly since thickness to be the reflectivity of silicon oxide film of 500～2000 dusts little to the dependence of wavelength, so have the effect that can reduce reflectance varies.

Moreover, because according to the incident light wavelength, will be as the thickness setting of the silicon oxide film of passivating film in each suitable scope, for example, pixel capacitors in reflect blue light is 900～1200 dusts, pixel capacitors in reflects green is 1200～1600 dusts, pixel capacitors at reflection red light is 1300～1900 dusts, so can will be suppressed at the deviation of reflection of light rate of all kinds below 1%, can improve the reliability of liquid crystal panel, have simultaneously and can improve the effect of such reflective liquid crystal panel as the image quality of the projecting display of light valve use.

Moreover, according to and the thickness of the alignment films that on it, forms between relation set the thickness of the silicon oxide film that becomes passivating film, simultaneously with the thickness setting of the alignment films scope at 300～1400 dusts, so can effectively prevent the variation of liquid-crystal refractive-index.

In addition; forming pixel capacitors at same substrate is the pixel region of rectangular configuration and forms in the reflective liquid crystal panel of the peripheral circuits such as shift LD reservoir and control circuit in its outside; owing to above pixel region, form the passivating film that is consisted of by silicon oxide film; above above-mentioned peripheral circuit, form the passivating film that is consisted of by silicon nitride film; so by using silicon nitride film at periphery; peripheral circuit can be protected more reliably, reliability can be improved.

Moreover, to establish passivating film at reflecting electrode and replace the passivating film that is consisted of by silicon oxide film, perhaps with the passivating film that is consisted of by silicon oxide film and usefulness, and the interlayer dielectric between reflecting electrode and the metal level below it is established silicon nitride film, therefore can improve moisture-proof, can prevent pixel switch with MOSFET and keep electric capacity by corrosion such as water.

In addition; owing to be provided with the overlapping protection structure that has formed silicon nitride film at the passivating film that is consisted of by silicon oxide film; cover the end of overlapping body of the interlayer dielectric that forms in the surrounding zone from pixel region and the metal level that this surrounding zone is carried out shading until on its sidewall with it; therefore; improved the water resistance of the liquid crystal panel end of easy water inlet; it becomes reinforcement simultaneously, has the effect that can improve permanance.

Claims (5)

1. substrate for liquid crystal panel is at semiconductor substrate and forms reflecting electrode rectangularly, forms each transistor corresponding to each reflecting electrode simultaneously, by described transistor voltage is added on the described reflecting electrode, it is characterized in that, comprising:

P type well region (2) is formed on the surface of described semiconductor substrate, and is higher than the impurity concentration in the described semiconductor substrate;

At the upper on-off element that is consisted of by gate insulating film and the high N-type impurity-introduced layer of impurity concentration of described P type well region (2); And

Keep electric capacity, clip dielectric film (9b) between P type doped region (8) on the described P type well region and the electrode (9a) and consist of by being formed on,

Described semiconductor substrate is the P-type semiconductor substrate,

The surface impurity concentration of described P type doped region (8) is 1 * 10 ¹⁸～5 * 10 ¹⁹/ cm ³,

The impurity concentration of described P type well region (2) is 1 * 10 ¹⁷/ cm ³Below,

Forming thickness at described reflecting electrode is the passivating film of the monox of 500～2000 dusts.

2. substrate for liquid crystal panel claimed in claim 1 is characterized in that,

The thickness of the dielectric film of described maintenance electric capacity (9b) be described on-off element thick gate insulating film 1/3rd to 1/5th.

3. liquid crystal panel comprises:

The substrate for liquid crystal panel of claim 1;

Transparency carrier has opposite electrode and relative with substrate for liquid crystal panel, and described transparency carrier and described substrate for liquid crystal panel are opened by separated; With

Liquid crystal material is used for sealing the gap between described transparency carrier and the described substrate for liquid crystal panel.

4. an electronic installation comprises the liquid crystal panel claimed in claim 3 as the display part.

5. a projecting display comprises: electronic installation claimed in claim 4; Light source; Modulation is from the described liquid crystal panel of the light of described light source; And projecting lens, be used for the light of projection by the modulation of described liquid crystal panel.

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