WO1981003086A1 - Silicon pressure sensor - Google Patents

Silicon pressure sensor Download PDF

Info

Publication number
WO1981003086A1
WO1981003086A1 PCT/US1981/000376 US8100376W WO8103086A1 WO 1981003086 A1 WO1981003086 A1 WO 1981003086A1 US 8100376 W US8100376 W US 8100376W WO 8103086 A1 WO8103086 A1 WO 8103086A1
Authority
WO
WIPO (PCT)
Prior art keywords
diaphragm
transducer
silicon
current
resistor
Prior art date
Application number
PCT/US1981/000376
Other languages
French (fr)
Inventor
J Gragg
Original Assignee
Motorola Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola Inc filed Critical Motorola Inc
Priority to BR8108314A priority Critical patent/BR8108314A/en
Publication of WO1981003086A1 publication Critical patent/WO1981003086A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
    • H01L29/04—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/84—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by variation of applied mechanical force, e.g. of pressure
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
    • G01L9/0051—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance
    • G01L9/0052—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance of piezoresistive elements
    • G01L9/0054—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance of piezoresistive elements integral with a semiconducting diaphragm

Definitions

  • This invention relates in general to a monolithic silicon pressure sensor and more particularly to a single element pressure sensor which utilizes the shear stress piezoresi stive effect in silicon.
  • the resistance value of a properly oriented silicon resistor is known to change in response to a flexing of the silicon crystal. This pi ezoresi sti ve response has been utilized to fabricate pressure transducers. A differential pressure applied across a silicon diaphragm in which a resistor is formed causes a change in the resistor value. Measurements of the resistance change are proportional to changes in the differential pressure.
  • the four resistors must have the same temperature coefficient; that is, the resistance value of each component must change with temperature in the same fashion. While it is possible, although undesirable, to correct for differences in component values which lead to a zero offset, it is very difficult to correct for differences in thermal coefficient. If the temperature coefficients of the four resistors are not identical each component will change in some different manner, changing the zero offset as the temperature changes.
  • the resistor is formed in a silicon membrane having a (100) surface orientation; the edges of the membrane are oriented along [110] crystalline direc tions; and the resistor is provided with current contacts which allow forcing of a current along a current axis oriented at 45° with respect to the membrane edge.
  • a transverse voltage generated in response to pressure induced stresses can be detected at voltage contacts located at the edge of the resistor. The voltage is generated along a line perpendicular to the current axis.
  • FIG. 1 is a plan view of a pressure transducer in accordance with the invention.
  • FIG. 2 illustrates in cross section a portion of a silicon wafer and depicts the fabrication of a pressure transducer.
  • FIG. 3 illustrates output voltage of the sensor in response to applied pressure differential.
  • FIG. 1 illustrates a plan view of a pressure transducer in accordance with the invention.
  • the transducer is formed in a silicon membrane or diaphragm 12 having a (100) surface orientation.
  • the membrane has a rectangular, and preferably a square, shape.
  • the sides of the membrane indicated by the dashed line 14 are oriented parallel to [ 1 10 ] c ry s t a l l i n e d i re ct i o n .
  • Ref e re nce s t o c ry s t a l l ographic orientations and directions are consistent with conventions well known in the semiconductor art.
  • a transducer element 16 is formed in membrane 12 by diffusion, ion implantation, or the like.
  • Transducer element 16 comprises an elongated resistor portion 18 which is oriented along a current axis 20.
  • the current axis is oriented along a [100] crystalline direction and forms a 45° angle with an edge of the membrane.
  • Current contacts 22, 23 make electrical contact to the ends of resistor 18.
  • the current contacts are preferably made by a heavily doped, high conductivity diffusion which provides a low impedance path from the ends of resistor 18 to a location outside diaphragm 12.
  • Voltage taps 26, 27 are positioned along the two sides of resistor 18 approximately midway along the length of the resistor.
  • the voltage taps allow the detection and measurement of a transverse voltage generated in response to a flexing of diaphragm 12 when a current flows along current axis 20.
  • Ohmic contact to voltage taps 26, 27 are made by voltage contacts 29, 30, respectively.
  • the voltage contacts are preferably heavily doped, high conductivity regions which extend from the voltage taps to a position outside diaphragm 12.
  • Transducer element 16 is positioned close to the edge of the diaphragm at a position midway along the diaphragm edge. This position, in combination with the orientation of the current axis along a [100] direction, maximizes shear stress in the resistor while minimizing longitudinal and transverse stresses along the current axis.
  • the coefficients and are the piezoresistive coefficients transformed to a coordinate system defined by the current axis, the perpendicular to the current axis, and the wafer normal. These results assume a state of plane stress, a valid approximation for a thin membrane considered here. As indicated, a shear stress produces a voltage at right angles to the current axis.
  • the orientation and location of transducer element 16 are selected to maximize and to simul aneously minimize and .
  • a pressure differential across the diaphragm will therefore produce a voltage detectible at voltage taps 26, 27 which is proportional to the magnitude of the pressure differential.
  • This can be characterized as a physical analog to a Hall device, where the piezoresistive coefficient replaces the Hall coefficient R H and the shear stress replaces the magnetic field strength B.
  • FIG. 2 illustrates in cross-section a preferred embodiment for implementing a pressure transducer in accordance with the invention.
  • the transducer is formed in an n-type silicon wafer 34 having a resistivity of about 1-10 Ohm-cm and a (100) crystallographic surface orientation.
  • the resistor element is formed, in a preferred embodiment, in the surface 36 of the wafer by conventional photolitho graphic and diffusion techniques.
  • the p-type resistor is diffused to a depth of about 3 micrometers and has a sheet resistivity of about 200-300 Ohms per square.
  • the current contacts and contacts to voltage taps are high concentration p-type diffusions having a resistivity of about 10-20 Ohms per square.
  • the contact diffusion is of sufficiently high conductivity to not appreciably interfere with the operation of the transducer element itself.
  • Contact to the voltage taps and to the current contacts can also be made by means of metallic leads contacting the transducer element itself, but the use of metallization directly on the thin silicon diaphragm can lead to problems relating to temperature coefficient.
  • the metal directly on the silicon diaphragm tends to form a bimetallic structure which results in undesirable perturbations as the temperature environment changes.
  • a recess 38 is etched in the back side of wafer 34 to form the thinned diaphragm region 12.
  • the recess can be etched, for example, using an anisotropic silicon etchant such as an aqueous solution of potassium hydroxide and isopropyl alcohol.
  • the potassium hydroxide mixture rapidly etches (100) planes in preference to (111) planes.
  • a planar diaphragm 12 is formed in the (100) oriented wafer.
  • the recess 38 is bounded at its edges 40 by (111) planes.
  • the thick silicon regions 42 at the edge of the diaphragm serve to bound or constrain the edges of the diaphragm.
  • the thick silicon regions also provide mechanical strength to the transducer.
  • the diaphragm preferably has a thickness of about 25 ⁇ m and is about 1.4 mm on a side.
  • the diffused resistor is located with its closest portion about 80-120 ⁇ m from the edge of the diaphragm.
  • the transducer wafer 34 is joined to a backing wafer 44.
  • the two wafers are sealed together, for example, by a low temperature glass frit sealing process usually carried out in a vacuum. By this process a sealing glass mixture is applied to wafer 44. In an evacuated enclosure the two wafers are pressed together and heated to a temperature sufficient to melt the sealing glass.
  • the transducer so formed is suitable for use as either an absolute or a differential pressure sensor.
  • wafer 44 is provided with a hole 46 which aligns with recess 38.
  • the sensor is then packaged to expose front surface 36 to a first pressure and the underside of the diaphragm, through hole 46, to a second pressure. Differences in those two pressures causes a flexing of diaphragm 12.
  • An absolute pressure sensor is formed by an integral wafer 44 without holes. During the sealing process, accomplished in a vacuum or at other known desired pressure, that pressure is sealed within recess 38 and provides a reference pressure against which pressures proximate the front surface 36 are compared. Pressures different from the reference pressure cause a flexing of the diaphragm which is proportional to that pressure difference. The proportionate flexing, in turn, causes a voltage to appear at the voltage taps which is proportional to the pressure difference.
  • FIG. 2 illustrates the fabrication of a single transducer
  • a plurality of such devices are normally fabricated simultaneously in wafer 34 in a manner well known in the semiconductor industry.
  • the individual devices are then separated, for example, by sawing the wafer into dice, each containing one transducer.
  • FIG. 3 The output response from a pressure sensor fabricated in accordance with the invention is illustrated in FIG. 3.
  • the voltage output measured at the voltage taps is shown as a function of applied pressure differential.
  • the applied exitation voltage is about 3 volts. Measurements taken at two different temperatures are shown, the maximum deviation from linearity is less than about 35 ⁇ v.
  • a silicon pressure transducer which comprises a single, four-contact piezoresistive element sensitive to shear stresses.
  • the resistor element and the diaphragm in which it is formed are oriented to maximize output in response to applied pressure changes.
  • the invention has been described by reference to a particular embodiment, but the invention is not to be interpreted as being so limited.
  • the particular embodiment described is particularly suited to the measurement of pressure differences in the order of zero to fifteen pounds per square inch.
  • a similar sensor can be fabricated for higher or lower nominal pressure differences by increasing or decreasing the thickness and/or size of the diaphragm.
  • diffusion results have been specified by way of illustration. Other resistivities, diffusion depths and doping levels for example, can also be used to optimize the transducer device for a particular application.

Abstract

A monolithic silicon pressure sensor (10) employing a terminal resistive element (16) is formed in a thin monocrystalline silicon diaphragm (12). The resistive element is a diffused resistor (18) having current contacts (22, 23) at the ends and two voltage contacts (26, 27) located midway between the current contacts and on opposite sides of a current axis defined between the two current contacts. The thin silicon diaphragm (12) has a square shape and is oriented in a (100) silicon surface with its sides parallel to a (110) crystal orientation. The resistor (18) is oriented with its current axis parallel to a (100) crystalline direction and at 45 degrees with respect to the edge of the diaphragm to maximize sensitivity of the resistor to shear stresses generated by flexure of the diaphragm resulting from pressure differentials across the diaphragm. With a current flowing between current contacts (22, 23), a shear stress acting on the resistor (18) generates a voltage which appears at the voltage contacts (26, 27) and which is proportional to the magnitude of the shear stress.

Description

SILICON PRESSURE SENSOR
BACKGROUND OF THE INVENTION
This invention relates in general to a monolithic silicon pressure sensor and more particularly to a single element pressure sensor which utilizes the shear stress piezoresi stive effect in silicon.
The resistance value of a properly oriented silicon resistor is known to change in response to a flexing of the silicon crystal. This pi ezoresi sti ve response has been utilized to fabricate pressure transducers. A differential pressure applied across a silicon diaphragm in which a resistor is formed causes a change in the resistor value. Measurements of the resistance change are proportional to changes in the differential pressure.
In the past it has not been found practical to use a single resistor as a pressure sensor. In general, the percentage change in resistance of the single resistor transducer is too low to be practical ; the small signal that is generated requires sensitive amplifiers and engenders problems relating, for example, to noise. A more conventional approach has been, therefore, to arrange four resistors in a Wheatstone bridge configuration. Small changes in the individual resistance values contribute to a significant offset in the bridge and provide an easily detectible signal. A series of other problems, however, confront the Wheatstone bridge approach. The four resistors used for the bridge must be closely matched in value to avoid a zero offset; that is, a non-zero output for zero applied pressure differential. For diffused resistors this requires that both the geometry and diffusion parameters be controlled and uniform. More importantly, the four resistors must have the same temperature coefficient; that is, the resistance value of each component must change with temperature in the same fashion. While it is possible, although undesirable, to correct for differences in component values which lead to a zero offset, it is very difficult to correct for differences in thermal coefficient. If the temperature coefficients of the four resistors are not identical each component will change in some different manner, changing the zero offset as the temperature changes.
In addition, most applications require that the pressure transducer have an output which is approximately linear with changes in pressure. The Wheatstone bridge generally has a relatively low output when designed for linear response, and low outputs are generally characterized by difficulties with noise and need for amplification. Accordingly, in view of the disadvantages associated with Wheatstone bridge and other prior art pressure transducers, a need existed for an improved pressure transducer. It is therefore an object of this invention to provide a silicon pressure transducer which does not require matching of transducer components.
It is a further object of this invention to provide a silicon pressure transducer having improved reproducibility and improved temperature coefficient of response.
It is a still further object of this invention to provide a silicon pressure transducer having a small zero pressure differential offset.
SUMMARY OF THE INVENTION
The foregoing and other objects and advantages of the invention are achieved through the use of a single, four contact resistor element oriented to maximize response to pressure induced stresses through shear stress effects. To maximize these effects the resistor is formed in a silicon membrane having a (100) surface orientation; the edges of the membrane are oriented along [110] crystalline direc tions; and the resistor is provided with current contacts which allow forcing of a current along a current axis oriented at 45° with respect to the membrane edge. A transverse voltage generated in response to pressure induced stresses can be detected at voltage contacts located at the edge of the resistor. The voltage is generated along a line perpendicular to the current axis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a pressure transducer in accordance with the invention.
FIG. 2 illustrates in cross section a portion of a silicon wafer and depicts the fabrication of a pressure transducer.
FIG. 3 illustrates output voltage of the sensor in response to applied pressure differential.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a plan view of a pressure transducer in accordance with the invention. The transducer is formed in a silicon membrane or diaphragm 12 having a (100) surface orientation. The membrane has a rectangular, and preferably a square, shape. The sides of the membrane indicated by the dashed line 14 are oriented parallel to [ 1 10 ] c ry s t a l l i n e d i re ct i o n . Ref e re nce s t o c ry s t a l l ographic orientations and directions are consistent with conventions well known in the semiconductor art. A transducer element 16 is formed in membrane 12 by diffusion, ion implantation, or the like. Transducer element 16 comprises an elongated resistor portion 18 which is oriented along a current axis 20. The current axis is oriented along a [100] crystalline direction and forms a 45° angle with an edge of the membrane. Current contacts 22, 23 make electrical contact to the ends of resistor 18. The current contacts are preferably made by a heavily doped, high conductivity diffusion which provides a low impedance path from the ends of resistor 18 to a location outside diaphragm 12. Voltage taps 26, 27 are positioned along the two sides of resistor 18 approximately midway along the length of the resistor. The voltage taps allow the detection and measurement of a transverse voltage generated in response to a flexing of diaphragm 12 when a current flows along current axis 20. Ohmic contact to voltage taps 26, 27 are made by voltage contacts 29, 30, respectively. The voltage contacts are preferably heavily doped, high conductivity regions which extend from the voltage taps to a position outside diaphragm 12. Transducer element 16 is positioned close to the edge of the diaphragm at a position midway along the diaphragm edge. This position, in combination with the orientation of the current axis along a [100] direction, maximizes shear stress in the resistor while minimizing longitudinal and transverse stresses along the current axis.
Mathematically the response of the transducer element can be described by the equations:
Figure imgf000006_0001
Figure imgf000006_0002
where
Figure imgf000006_0005
is the current density flowing parallel to the applied field ,
Figure imgf000006_0008
Figure imgf000006_0006
is the resistance of the body;
Figure imgf000006_0007
is the voltage perpendicular to the current;
Figure imgf000006_0003
is the stress parallel to the current;
Figure imgf000006_0004
is the stress perpendicular to the current; and
Figure imgf000007_0001
is the shear stress in the plane of the resi stor.
The coefficients
Figure imgf000007_0002
Figure imgf000007_0003
and
Figure imgf000007_0004
are the piezoresistive coefficients transformed to a coordinate system defined by the current axis, the perpendicular to the current axis, and the wafer normal. These results assume a state of plane stress, a valid approximation for a thin membrane considered here. As indicated, a shear stress
Figure imgf000007_0009
produces a voltage
Figure imgf000007_0008
at right angles to the current axis. The orientation and location of transducer element 16 are selected to maximize
Figure imgf000007_0005
and to simul aneously minimize
Figure imgf000007_0007
and
Figure imgf000007_0006
.
A pressure differential across the diaphragm will therefore produce a voltage detectible at voltage taps 26, 27 which is proportional to the magnitude of the pressure differential. This can be characterized as a physical analog to a Hall device, where the piezoresistive coefficient
Figure imgf000007_0011
replaces the Hall coefficient RH and the shear stress replaces the magnetic field
Figure imgf000007_0010
strength B.
Because of symmetries in the silicon crystal, element 16 could equally be placed at any of the locations 32 shown in FIG. 1 by an "X". Each of these locations is crystal lographically equivalent and for a square diaphragm is also mechanically equivalent. The position near but not at the edge of the diaphragm is selected to maximize the shear stress effect without encountering undesirable edge or boundary effects. FIG. 2 illustrates in cross-section a preferred embodiment for implementing a pressure transducer in accordance with the invention. The transducer is formed in an n-type silicon wafer 34 having a resistivity of about 1-10 Ohm-cm and a (100) crystallographic surface orientation. The resistor element is formed, in a preferred embodiment, in the surface 36 of the wafer by conventional photolitho graphic and diffusion techniques. The p-type resistor is diffused to a depth of about 3 micrometers and has a sheet resistivity of about 200-300 Ohms per square.
The current contacts and contacts to voltage taps are high concentration p-type diffusions having a resistivity of about 10-20 Ohms per square. The contact diffusion is of sufficiently high conductivity to not appreciably interfere with the operation of the transducer element itself. Contact to the voltage taps and to the current contacts can also be made by means of metallic leads contacting the transducer element itself, but the use of metallization directly on the thin silicon diaphragm can lead to problems relating to temperature coefficient. The metal directly on the silicon diaphragm tends to form a bimetallic structure which results in undesirable perturbations as the temperature environment changes.
A recess 38 is etched in the back side of wafer 34 to form the thinned diaphragm region 12. The recess can be etched, for example, using an anisotropic silicon etchant such as an aqueous solution of potassium hydroxide and isopropyl alcohol. The potassium hydroxide mixture rapidly etches (100) planes in preference to (111) planes. As a result, a planar diaphragm 12 is formed in the (100) oriented wafer. The recess 38 is bounded at its edges 40 by (111) planes. The thick silicon regions 42 at the edge of the diaphragm serve to bound or constrain the edges of the diaphragm. The thick silicon regions also provide mechanical strength to the transducer. For a transducer useful in the pressure range of about one atmosphere, the diaphragm preferably has a thickness of about 25 μm and is about 1.4 mm on a side. The diffused resistor is located with its closest portion about 80-120 μm from the edge of the diaphragm.
After metallizing the transducer to facilitate contact from heavily diffused regions 22, 23, 29, and 30 to circuitry external to the transducer and the optional passivating of the transducer surface with an insulator layer, the transducer wafer 34 is joined to a backing wafer 44. The two wafers are sealed together, for example, by a low temperature glass frit sealing process usually carried out in a vacuum. By this process a sealing glass mixture is applied to wafer 44. In an evacuated enclosure the two wafers are pressed together and heated to a temperature sufficient to melt the sealing glass.
The transducer so formed is suitable for use as either an absolute or a differential pressure sensor. To form the differential sensor, wafer 44 is provided with a hole 46 which aligns with recess 38. The sensor is then packaged to expose front surface 36 to a first pressure and the underside of the diaphragm, through hole 46, to a second pressure. Differences in those two pressures causes a flexing of diaphragm 12.
An absolute pressure sensor is formed by an integral wafer 44 without holes. During the sealing process, accomplished in a vacuum or at other known desired pressure, that pressure is sealed within recess 38 and provides a reference pressure against which pressures proximate the front surface 36 are compared. Pressures different from the reference pressure cause a flexing of the diaphragm which is proportional to that pressure difference. The proportionate flexing, in turn, causes a voltage to appear at the voltage taps which is proportional to the pressure difference.
While FIG. 2 illustrates the fabrication of a single transducer, a plurality of such devices are normally fabricated simultaneously in wafer 34 in a manner well known in the semiconductor industry. The individual devices are then separated, for example, by sawing the wafer into dice, each containing one transducer.
The output response from a pressure sensor fabricated in accordance with the invention is illustrated in FIG. 3. The voltage output measured at the voltage taps is shown as a function of applied pressure differential. The applied exitation voltage is about 3 volts. Measurements taken at two different temperatures are shown, the maximum deviation from linearity is less than about 35 μv. There has thus been provided, in accordance with the invention, a silicon pressure transducer which comprises a single, four-contact piezoresistive element sensitive to shear stresses. The resistor element and the diaphragm in which it is formed are oriented to maximize output in response to applied pressure changes.
The invention has been described by reference to a particular embodiment, but the invention is not to be interpreted as being so limited. The particular embodiment described is particularly suited to the measurement of pressure differences in the order of zero to fifteen pounds per square inch. A similar sensor can be fabricated for higher or lower nominal pressure differences by increasing or decreasing the thickness and/or size of the diaphragm.
Reference has been made to specific preferred crystalline orientations and directions. It will be appreciated by those skilled in the art that some variation in these directions and orientation still falls within the spirit of the invention. Acceptable results are obtained when the orientations and directions are maintained to within about±10-15 percent of those specified; preferably directions and orientations will be maintained within about ±2-3 percent.
Additionally, specific examples of diffusion results have been specified by way of illustration. Other resistivities, diffusion depths and doping levels for example, can also be used to optimize the transducer device for a particular application.
Accordingly, it is intended that all such alternatives and modifications fall within the scope and spirit of the following claims:

Claims

C LA I MS
1. A silicon pressure transducer comprising: a silicon diaphragm of first conductivity type capable of flexing in response to changes in pressure; a diffused region in said diaphragm of opposite conductivity type; first and second electrical terminals to said diffused region by which a current can be forced through said region in the plane of said diaphragm; third and fourth electrical terminals to said diffused region located on opposite sides of and along a line approximately perpendicul ar to a line between said first and second terminals, said third and fourth electrical terminals permitting the detection and measurement of a voltage generated in response to a pressure being applied to and causing flexure of said diaphragm.
2. The transducer of claim 1 wherein said diaphragm is rectangular in shape.
3. The transducer of claim 1 wherein said diaphragm is approximately square in shape.
4. The transducer of claim 3 wherein said diaphragm is bounded at the edges of the square.
5. The transducer of claim 3 wherein said diaphragm is oriented in a (100) silicon plane.
6. The transducer of claim 5 wherein said diaphragm has an edge oriented in a [110] direction.
7. The transducer of claim 6 wherein said diffused region is cross shaped, having first and second portions oriented approximately perpendicular to each other.
8. The transducer of claim 7 wherein said first and second electrical terminals contact said first portion and said third and fourth terminals contact said second portion.
9. The transducer of claim 7 wherein said first portion is oriented at approximately 45° to an edge of said diaphragm.
10. The transducer of claim 3 wherein said region is located proximate to an edge of said diaphragm.
11. The transducer of claim 1 wherein said diaphragm is n-type and said diffused region is p-type.
12. A silicon pressure sensor comprising: a monocrys talline silicon diaphragm of first conductivity type having a. square shape, said diaphragm having a (100) surface orientation and having sides oriented in [110] crystalline directions; a resistor of opposite conductivity type diffused into said diaphragm having current contact areas at the ends thereof, a line between said current contact areas forming a current axis, and first and second voltage contact areas positioned at opposite sides of said resi stor.
13. The pressure sensor of claim 12 wherein said resistor is positioned in said diaphragm with said current axis oriented in a [100] crystalline direction at approximately 45° with respect to one of said sides.
14. The pressure sensor of claim 12 wherein said diaphragm is n-type and said resistor is p-type.
15. The pressure sensor of claim 12 wherein said diaphragm is formed by etching a cavity in a silicon wafer to leave said diaphragm unetched.
16. The pressure sensor of claim 15 wherein said silicon wafer in which a cavity is etched is sealed to a second silicon wafer.
17. The pressure sensor of claim 16 wherein said second silicon wafer is provided with a hole therein aligned with said cavity in said first wafer.
PCT/US1981/000376 1980-04-14 1981-03-16 Silicon pressure sensor WO1981003086A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
BR8108314A BR8108314A (en) 1980-04-14 1981-03-16 SILICON PRESSURE SENSOR

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US140289 1980-04-14
US06/140,289 US4317126A (en) 1980-04-14 1980-04-14 Silicon pressure sensor

Publications (1)

Publication Number Publication Date
WO1981003086A1 true WO1981003086A1 (en) 1981-10-29

Family

ID=22490586

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1981/000376 WO1981003086A1 (en) 1980-04-14 1981-03-16 Silicon pressure sensor

Country Status (7)

Country Link
US (1) US4317126A (en)
EP (1) EP0050136A4 (en)
JP (1) JPS57500491A (en)
KR (1) KR840002283B1 (en)
BR (1) BR8108314A (en)
IT (1) IT1142466B (en)
WO (1) WO1981003086A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0146709A2 (en) * 1983-12-16 1985-07-03 Hitachi, Ltd. Pressure sensor
EP0195232A2 (en) * 1985-03-20 1986-09-24 Hitachi, Ltd. Piezoresistive strain sensing device
US6474162B1 (en) 1995-08-08 2002-11-05 Eads Deutschland Gmbh Micromechanical rate of rotation sensor (DRS)
EP1785711A2 (en) * 2005-11-10 2007-05-16 Honeywell Inc. Pressure and Temperature Sensing Element

Families Citing this family (77)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4456901A (en) * 1981-08-31 1984-06-26 Kulite Semiconductor Products, Inc. Dielectrically isolated transducer employing single crystal strain gages
US4510671A (en) * 1981-08-31 1985-04-16 Kulite Semiconductor Products, Inc. Dielectrically isolated transducer employing single crystal strain gages
JPS58197780A (en) * 1982-05-14 1983-11-17 Hitachi Ltd Semiconductor pressure converter
JPS5952727A (en) * 1982-09-20 1984-03-27 Hitachi Ltd Semiconductor pressure sensor
US4481497A (en) * 1982-10-27 1984-11-06 Kulite Semiconductor Products, Inc. Transducer structures employing ceramic substrates and diaphragms
USRE33518E (en) * 1983-04-29 1991-01-15 Baxter International, Inc. Pressure transducer assembly
US5220189A (en) * 1983-07-06 1993-06-15 Honeywell Inc. Micromechanical thermoelectric sensor element
US5220188A (en) * 1983-07-06 1993-06-15 Honeywell Inc. Integrated micromechanical sensor element
US4600934A (en) * 1984-01-06 1986-07-15 Harry E. Aine Method of undercut anisotropic etching of semiconductor material
US4651120A (en) * 1985-09-09 1987-03-17 Honeywell Inc. Piezoresistive pressure sensor
US5450053A (en) * 1985-09-30 1995-09-12 Honeywell Inc. Use of vanadium oxide in microbolometer sensors
US4683755A (en) * 1985-11-15 1987-08-04 Imo Delaval Inc. Biaxial strain gage systems
US5300915A (en) * 1986-07-16 1994-04-05 Honeywell Inc. Thermal sensor
JPS6381867A (en) * 1986-09-25 1988-04-12 Yokogawa Electric Corp Semiconductor diffusion strain gauge
US5062302A (en) * 1988-04-29 1991-11-05 Schlumberger Industries, Inc. Laminated semiconductor sensor with overpressure protection
US5286976A (en) * 1988-11-07 1994-02-15 Honeywell Inc. Microstructure design for high IR sensitivity
US4889590A (en) * 1989-04-27 1989-12-26 Motorola Inc. Semiconductor pressure sensor means and method
US5178016A (en) * 1989-11-15 1993-01-12 Sensym, Incorporated Silicon pressure sensor chip with a shear element on a sculptured diaphragm
US5050423A (en) * 1989-12-04 1991-09-24 Motorola, Inc. Multi-variable sensor calibration
US5119166A (en) * 1990-02-06 1992-06-02 Honeywell Inc. Hall effect element aligned to reduce package-induced offsets
US5493248A (en) * 1990-09-04 1996-02-20 Motorola, Inc. Integrated circuit for sensing an environmental condition and producing a high power circuit
US5291607A (en) * 1990-09-05 1994-03-01 Motorola, Inc. Microprocessor having environmental sensing capability
US5218861A (en) * 1991-03-27 1993-06-15 The Goodyear Tire & Rubber Company Pneumatic tire having an integrated circuit transponder and pressure transducer
US5181975A (en) * 1991-03-27 1993-01-26 The Goodyear Tire & Rubber Company Integrated circuit transponder with coil antenna in a pneumatic tire for use in tire identification
US5432372A (en) * 1993-01-14 1995-07-11 Yamatake-Honeywell Co., Ltd. Semiconductor pressure sensor
US5347869A (en) * 1993-03-25 1994-09-20 Opto Tech Corporation Structure of micro-pirani sensor
US6087930A (en) * 1994-02-22 2000-07-11 Computer Methods Corporation Active integrated circuit transponder and sensor apparatus for transmitting vehicle tire parameter data
US5483827A (en) * 1994-06-03 1996-01-16 Computer Methods Corporation Active integrated circuit transponder and sensor apparatus for sensing and transmitting vehicle tire parameter data
US5731754A (en) * 1994-06-03 1998-03-24 Computer Methods Corporation Transponder and sensor apparatus for sensing and transmitting vehicle tire parameter data
US5507090A (en) * 1994-07-20 1996-04-16 Thiokol Corporation Method for making stress sensors
US7386401B2 (en) 1994-11-21 2008-06-10 Phatrat Technology, Llc Helmet that reports impact information, and associated methods
US6539336B1 (en) * 1996-12-12 2003-03-25 Phatrat Technologies, Inc. Sport monitoring system for determining airtime, speed, power absorbed and other factors such as drop distance
US8280682B2 (en) * 2000-12-15 2012-10-02 Tvipr, Llc Device for monitoring movement of shipped goods
US6516284B2 (en) * 1994-11-21 2003-02-04 Phatrat Technology, Inc. Speedometer for a moving sportsman
US6266623B1 (en) 1994-11-21 2001-07-24 Phatrat Technology, Inc. Sport monitoring apparatus for determining loft time, speed, power absorbed and other factors such as height
US5759870A (en) * 1995-08-28 1998-06-02 Bei Electronics, Inc. Method of making a surface micro-machined silicon pressure sensor
US6117086A (en) * 1996-04-18 2000-09-12 Sunscope International, Inc. Pressure transducer apparatus with disposable dome
US5993395A (en) * 1996-04-18 1999-11-30 Sunscope International Inc. Pressure transducer apparatus with disposable dome
US6308577B1 (en) 1996-09-30 2001-10-30 Motorola, Inc. Circuit and method of compensating for membrane stress in a sensor
US5770965A (en) * 1996-09-30 1998-06-23 Motorola, Inc. Circuit and method of compensating for non-linearities in a sensor signal
US20020003274A1 (en) * 1998-08-27 2002-01-10 Janusz Bryzek Piezoresistive sensor with epi-pocket isolation
US6006607A (en) * 1998-08-31 1999-12-28 Maxim Integrated Products, Inc. Piezoresistive pressure sensor with sculpted diaphragm
US6351996B1 (en) 1998-11-12 2002-03-05 Maxim Integrated Products, Inc. Hermetic packaging for semiconductor pressure sensors
US6346742B1 (en) 1998-11-12 2002-02-12 Maxim Integrated Products, Inc. Chip-scale packaged pressure sensor
US6229190B1 (en) 1998-12-18 2001-05-08 Maxim Integrated Products, Inc. Compensated semiconductor pressure sensor
US6297069B1 (en) * 1999-01-28 2001-10-02 Honeywell Inc. Method for supporting during fabrication mechanical members of semi-conductive dies, wafers, and devices and an associated intermediate device assembly
US8266465B2 (en) 2000-07-26 2012-09-11 Bridgestone Americas Tire Operation, LLC System for conserving battery life in a battery operated device
US7161476B2 (en) 2000-07-26 2007-01-09 Bridgestone Firestone North American Tire, Llc Electronic tire management system
US6427539B1 (en) 2000-07-31 2002-08-06 Motorola, Inc. Strain gauge
US6622558B2 (en) 2000-11-30 2003-09-23 Orbital Research Inc. Method and sensor for detecting strain using shape memory alloys
US7171331B2 (en) 2001-12-17 2007-01-30 Phatrat Technology, Llc Shoes employing monitoring devices, and associated methods
US6732422B1 (en) * 2002-01-04 2004-05-11 Taiwan Semiconductor Manufacturing Company Method of forming resistors
US6772509B2 (en) 2002-01-28 2004-08-10 Motorola, Inc. Method of separating and handling a thin semiconductor die on a wafer
US6608370B1 (en) * 2002-01-28 2003-08-19 Motorola, Inc. Semiconductor wafer having a thin die and tethers and methods of making the same
WO2007047889A2 (en) * 2005-10-18 2007-04-26 Phatrat Technology, Llc Shoe wear-out sensor, body-bar sensing system, unitless activity assessment and associated methods
US7284438B2 (en) 2005-11-10 2007-10-23 Honeywell International Inc. Method and system of providing power to a pressure and temperature sensing element
FR2894953B1 (en) * 2005-12-15 2008-03-07 Ecole Polytechnique Etablissem MICROELECTROMECHANICAL SYSTEM COMPRISING A DEFORMABLE PART AND A STRESS DETECTOR
US9137309B2 (en) * 2006-05-22 2015-09-15 Apple Inc. Calibration techniques for activity sensing devices
US20070271116A1 (en) * 2006-05-22 2007-11-22 Apple Computer, Inc. Integrated media jukebox and physiologic data handling application
US20070270663A1 (en) * 2006-05-22 2007-11-22 Apple Computer, Inc. System including portable media player and physiologic data gathering device
US7643895B2 (en) 2006-05-22 2010-01-05 Apple Inc. Portable media device with workout support
US8073984B2 (en) * 2006-05-22 2011-12-06 Apple Inc. Communication protocol for use with portable electronic devices
US7813715B2 (en) 2006-08-30 2010-10-12 Apple Inc. Automated pairing of wireless accessories with host devices
US7913297B2 (en) * 2006-08-30 2011-03-22 Apple Inc. Pairing of wireless devices using a wired medium
US7698101B2 (en) * 2007-03-07 2010-04-13 Apple Inc. Smart garment
US8132465B1 (en) 2007-08-01 2012-03-13 Silicon Microstructures, Inc. Sensor element placement for package stress compensation
US7820485B2 (en) * 2008-09-29 2010-10-26 Freescale Semiconductor, Inc. Method of forming a package with exposed component surfaces
US8415203B2 (en) * 2008-09-29 2013-04-09 Freescale Semiconductor, Inc. Method of forming a semiconductor package including two devices
US8525279B2 (en) * 2009-06-04 2013-09-03 University Of Louisville Research Foundation, Inc. Single element three terminal piezoresistive pressure sensor
US20120211805A1 (en) * 2011-02-22 2012-08-23 Bernhard Winkler Cavity structures for mems devices
DE102012206531B4 (en) 2012-04-17 2015-09-10 Infineon Technologies Ag Method for producing a cavity within a semiconductor substrate
US9136136B2 (en) 2013-09-19 2015-09-15 Infineon Technologies Dresden Gmbh Method and structure for creating cavities with extreme aspect ratios
US9798132B2 (en) * 2014-06-17 2017-10-24 Infineon Technologies Ag Membrane structures for microelectromechanical pixel and display devices and systems, and methods for forming membrane structures and related devices
GB2552025B (en) 2016-07-08 2020-08-12 Sovex Ltd Boom conveyor
US20180180494A1 (en) 2016-12-22 2018-06-28 Honeywell International Inc. High Sensitivity Silicon Piezoresistor Force Sensor
US10352792B2 (en) * 2017-02-15 2019-07-16 Texas Instruments Incorporated Device and method for on-chip mechanical stress sensing
CN113227954A (en) * 2018-12-20 2021-08-06 深圳纽迪瑞科技开发有限公司 Pressure sensing device, pressure sensing method and electronic terminal

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3918019A (en) * 1974-03-11 1975-11-04 Univ Leland Stanford Junior Miniature absolute pressure transducer assembly and method
US3968466A (en) * 1973-10-09 1976-07-06 Kabushiki Kaisha Toyota Chuo Kenkyusho Pressure transducer
US3994009A (en) * 1973-02-12 1976-11-23 Honeywell Inc. Stress sensor diaphragms over recessed substrates
US4204185A (en) * 1977-10-13 1980-05-20 Kulite Semiconductor Products, Inc. Integral transducer assemblies employing thin homogeneous diaphragms
US4275406A (en) * 1978-09-22 1981-06-23 Robert Bosch Gmbh Monolithic semiconductor pressure sensor, and method of its manufacture

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3909924A (en) * 1974-03-27 1975-10-07 Nat Semiconductor Corp Method of fabrication of silicon pressure transducer sensor units
DE2714644A1 (en) * 1977-04-01 1978-10-05 Siemens Ag Semiconductor integrated circuit pressure transducer - uses piezoelectric or Hall effect element on deformable beam supported at one end

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3994009A (en) * 1973-02-12 1976-11-23 Honeywell Inc. Stress sensor diaphragms over recessed substrates
US3968466A (en) * 1973-10-09 1976-07-06 Kabushiki Kaisha Toyota Chuo Kenkyusho Pressure transducer
US3918019A (en) * 1974-03-11 1975-11-04 Univ Leland Stanford Junior Miniature absolute pressure transducer assembly and method
US4204185A (en) * 1977-10-13 1980-05-20 Kulite Semiconductor Products, Inc. Integral transducer assemblies employing thin homogeneous diaphragms
US4275406A (en) * 1978-09-22 1981-06-23 Robert Bosch Gmbh Monolithic semiconductor pressure sensor, and method of its manufacture

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0146709A2 (en) * 1983-12-16 1985-07-03 Hitachi, Ltd. Pressure sensor
EP0146709A3 (en) * 1983-12-16 1988-09-07 Hitachi, Ltd. Pressure sensor
EP0195232A2 (en) * 1985-03-20 1986-09-24 Hitachi, Ltd. Piezoresistive strain sensing device
EP0195232A3 (en) * 1985-03-20 1989-10-25 Hitachi, Ltd. Piezoresistive strain sensing device
US6474162B1 (en) 1995-08-08 2002-11-05 Eads Deutschland Gmbh Micromechanical rate of rotation sensor (DRS)
EP1785711A2 (en) * 2005-11-10 2007-05-16 Honeywell Inc. Pressure and Temperature Sensing Element
EP1785711A3 (en) * 2005-11-10 2008-05-14 Honeywell Inc. Pressure and Temperature Sensing Element

Also Published As

Publication number Publication date
BR8108314A (en) 1982-03-09
IT1142466B (en) 1986-10-08
EP0050136A1 (en) 1982-04-28
US4317126A (en) 1982-02-23
KR830005684A (en) 1983-09-09
JPS57500491A (en) 1982-03-18
KR840002283B1 (en) 1984-12-14
IT8148201A0 (en) 1981-04-03
EP0050136A4 (en) 1984-07-03

Similar Documents

Publication Publication Date Title
US4317126A (en) Silicon pressure sensor
US10775248B2 (en) MEMS strain gauge sensor and manufacturing method
US5178016A (en) Silicon pressure sensor chip with a shear element on a sculptured diaphragm
US4462018A (en) Semiconductor strain gauge with integral compensation resistors
US5614754A (en) Hall device
US3270554A (en) Diffused layer transducers
KR100741520B1 (en) Semiconductor pressure sensor having diaphragm
US6642594B2 (en) Single chip multiple range pressure transducer device
US4275406A (en) Monolithic semiconductor pressure sensor, and method of its manufacture
US4503709A (en) Pressure sensor
Gieles et al. Miniature pressure transducers with a silicon diaphragm
US5412993A (en) Pressure detection gage for semiconductor pressure sensor
US3916365A (en) Integrated single crystal pressure transducer
US4726232A (en) Temperature coefficient compensated pressure transducer
US3213681A (en) Shear gauge pressure-measuring device
US5163329A (en) Semiconductor pressure sensor
US4442717A (en) Compensation and normalization apparatus for shear piezoresistive gage sensors
JPH0554709B2 (en)
JP3116384B2 (en) Semiconductor strain sensor and manufacturing method thereof
JPH0554708B2 (en)
JP2715738B2 (en) Semiconductor stress detector
Chang et al. Study of the fabrication of a silicon pressure sensor
JPH01236659A (en) Semiconductor pressure sensor
JPH0510830B2 (en)
JPH034568A (en) Semiconductor pressure sensor

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 1981901066

Country of ref document: EP

AK Designated states

Designated state(s): BR JP

AL Designated countries for regional patents

Designated state(s): DE FR GB NL SE

WWP Wipo information: published in national office

Ref document number: 1981901066

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1981901066

Country of ref document: EP