Thin film pyroelectric imaging array
AssigneeHoneywell Inc.
InventorPaul W. Kruse, Jr.
Life of this patent
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Abstract
A thin film pyroelectric imaging array fabricated as a Si wafer. A thin film of PbTiO.sub.3 is deposited on a thermally isolated bridge. The bridge suspends the PbTio.sub.3 sensor over a preferentially etched cavity in the Si wafer. Improved thermal isolation increases the responsivity of the sensor to incident radiation. The pyroelectric sensor formed can operate effectively at room temperature.
Claims11
A radiation sensor comprising:
- (a) a substrate having opposing flat surfaces wherein one surface has a cavity;
- (b) a microbridge suspended over the cavity comprised of a material selected from the group consisting of silicon oxide and silicon nitride, wherein the microbridge includes a plurality of support legs;
- (c) a first conductive thin film electrode deposited on one of the legs covering substantially half the surface of the microbridge;
- (d) a second conductive thin film electrode deposited on the opposing leg and substantially covering the remaining portion of the microbridge in such a manner as to allow a gap to exist between the first and second electrodes;
- (e) a thin film of pyroelectric material deposited on, and substantially covering, the surface of the first and second electrodes;
- and
- (f) a thin film conductor deposited on the surface of the pyroelectric material.
A radiation sensor having a plurality of radiation sensing pixels arranged in an array of pixels having an individual row and column address for each pixel and connected to be read out by said individual address, wherein the radiation sensing pixel comprises:
- (a) a substrate having opposing flat surfaces wherein one surface has a cavity;
- (b) a microbridge suspended over the cavity comprised of a material selected from the group consisting of silicon oxide and silicon nitride, wherein the microbridge includes a plurality of support legs;
- (c) a first conductive thin film electrode deposited on one of the legs covering substantially half the surface of the microbridge;
- (d) a second conductive thin film electrode deposited on the opposing leg and substantially covering the remaining portion of the microbridge in such a manner as to allow a gap to exist between the first and second electrodes;
- (e) a thin film of pyroelectric material deposited on, and substantially covering, the surface of the first and second electrodes;
- and
- (f) a thin film conductor deposited on the surface of the pyroelectric material.
A radiation sensor comprising:
- (a) a substrate having opposing flat surfaces wherein one surface has a cavity;
- (b) a microbridge suspended over the cavity comprised of a material selected from the group consisting of silicon oxide and silicon nitride, wherein the microbridge includes a plurality of support legs;
- (c) a first conductive thin film electrode deposited on one of the legs covering substantially half the surface of the microbridge;
- (d) a second conductive thin film electrode deposited on the opposing leg and substantially covering the remaining portion of the microbridge in such a manner as to allow a gap to exist between the first and second electrodes;
- (e) a thin film of pyroelectric material deposited on, and substantially covering, the surface of the first and second electrodes;
- and
- (f) a thin film conductor deposited on the surface of the pyroelectric material, and
- wherein the step of forming the cavity is accomplished by preferential etching.
Dependencies are inferred from the claim text.