Silicon pressure sensor
First Claim
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 perpendicular 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.
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Abstract
A monolithic silicon pressure sensor employing a four-terminal resistive element is formed in a thin monocrystalline silicon diaphragm. The resistive element is a diffused resistor having current contacts at the ends and two voltage contacts located midway between the current contacts and on opposite sides of a current axis defined between the two current contacts. The thin silicon diaphraghm has a square shape and is oriented in a (100) silicon surface with its sides parallel to a [110] crystal orientation. The resistor 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, a shear stress acting on the resistor generates a voltage which appears at the voltage contacts and which is proportional to the magnitude of the shear stress.
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Citations
17 Claims
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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 perpendicular 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- a silicon diaphragm of first conductivity type capable of flexing in response to changes in pressure;
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12. A silicon pressure sensor comprising:
- a monocrystalline 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 resistor. - View Dependent Claims (13, 14, 15, 16, 17)
- a monocrystalline 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;
Specification