Abstract: Ferroelectric materials useful in monolithic uncooled infrared imaging use Ca and Sn substitutions in PbTiO3 and also have alternatives with dopants such as Dy, Ho, Bi, Ce, and Fe. The ferroelectrics may also be used in non-volatile integrated circuit memories.

Abstract: An infrared detector (10) includes a substrate (16) having thereon an array of detector elements (21, 139). Each detector element has a membrane (41, 81, 91, 111, 141), which includes an amorphous silicon layer (51, 142) in contact with at least two electrodes (53, 56-57, 92, 112-113, 143-145) that are made of a titanium/aluminum alloy which absorbs infrared radiation. In order to obtain a desired temperature coefficient of resistance (TCR), the amorphous silicon layer may optionally be doped. The effective resistance between the electrodes is set to a desired value by appropriate configuration of the electrodes and the amorphous silicon layer. The membrane includes two outer layers (61-62, 146-147) made of an insulating material. Openings (149) may optionally be provided through the membrane.

Abstract: A preferred embodiment of this invention comprises a conductive lightly donor doped perovskite layer (e.g. lightly La doped BST 34), and a high-dielectric-constant material layer (e.g. undoped BST 36) overlaying the conductive lightly donor doped perovskite layer. The conductive lightly donor doped perovskite layer provides a substantially chemically and structurally stable electrical connection to the high-dielectric-constant material layer. A lightly donor doped perovskite generally has much less resistance than undoped, acceptor doped, or heavily donor doped HDC materials. The amount of donor doping to make the material conductive (or resistive) is normally dependent on the process conditions (e.g. temperature, atmosphere, grain size, film thickness and composition). This resistivity may be further decreased if the perovskite is exposed to reducing conditions.

Abstract: The invention described is a method of forming an improved dielectric material by adding lead to an original perovskite material having an original critical grain size to form a lead enhanced perovskite material, then forming a layer of the lead enhanced perovskite material having an average grain size less than the original critical grain size whereby the dielectric constant of the layer is substantially greater than the dielectric constant of the original perovskite material with an average grain size similar to the average grain size of the layer. The critical grain size, as used herein, means the largest grain size such that the dielectric constant starts to rapidly decrease with decreasing grain sizes. Preferably, the lead enhanced perovskite material is further doped with one or more acceptor dopants whereby the resistivity is substantially increased and/or the loss tangent is substantially decreased.

Abstract: A pyroelectric detector system, the pyroelectric detector element therefor and the method of making the detector element which comprises an integrated circuit (1) and a pyroelectric detector element (7) coupled to the integrated circuit and thermally isolated from the integrated circuit. The element includes a lead-containing pyroelectric layer having a pair of opposing surfaces and having a thickness to provide a resonant cavity for radiations in a predetermined frequency range. A bottom electrode (5) opaque to radiations in the predetermined frequency range is secured to one of the pair of opposing surfaces and a top electrode (9, 11) is secured to the other of the pair of opposing surfaces which is semi-transparent to radiations in the predetermined frequency range. The top electrode is taken from the group consisting of platinum and nichrome. The lead-containing pyroelectric layer is preferably lead titanate.

Abstract: A preferred embodiment of this invention comprises a conductive lightly donor doped perovskite layer (e.g. lightly La doped BST 34), and a high-dielectric-constant material layer (e.g. undoped BST 36) overlaying the conductive lightly donor doped perovskite layer. The conductive lightly donor doped perovskite layer provides a substantially chemically and structurally stable electrical connection to the high-dielectric-constant material layer. A lightly donor doped perovskite generally has much less resistance than undoped, acceptor doped, or heavily donor doped HDC materials. The amount of donor doping to make the material conductive (or resistive) is normally dependent on the process conditions (e.g. temperature, atmosphere, grain size, film thickness and composition). This resistivity may be further decreased if the perovskite is exposed to reducing conditions.

Abstract: Ceramic powder (50) may be disposed within a flexible mold (30 and 130) to form a dense ceramic wafer (60) by hydrostatic pressing. The ceramic powder (50) may include various types of pyroelectric material or bolometric material. One or more substrates (20 and 24) may be disposed within the flexible mold (30 and 130) to form the desired dense ceramic wafer (60). The flexible mold (30 and 130) may be placed in one or more vacuum sealed bags (38) prior to hydrostatic pressing. Also, a vibration table (70) may be used to minimize any void spaces in the ceramic powder (50) prior to hydrostatic pressing.

Abstract: A method of polishing ferroelectric materials and specifically perovskite materials and still more specifically barium strontium titanate (1) wherein the surface (5) to be polished is initially partially smoothened or planarized by mechanical abrading with final smoothening or planarization provided by a chemical polishing with a polishing wheel using an acidic solution containing essentially the acid, hydrogen peroxide and water. Preferred acids are perchloric acid, acetic acid, nitric acid and combinations thereof.

Abstract: An optical coating for an uncooled focal plane array detector where the optical coating comprises a porous film. The porous film preferably comprises a xerogel.

Abstract: A preferred embodiment of this invention comprises a conductive lightly donor doped perovskite layer (e.g. lightly La doped BST 34), and a high-dielectric-constant material layer (e.g. undoped BST 36) overlaying the conductive lightly donor doped perovskite layer. The conductive lightly donor doped perovskite layer provides a substantially chemically and structurally stable electrical connection to the high-dielectric-constant material layer. A lightly donor doped perovskite generally has much less resistance than undoped, acceptor doped, or heavily donor doped HDC materials. The amount of donor doping to make the material conductive (or resistive) is normally dependent on the process conditions (e.g. temperature, atmosphere, grain size, film thickness and composition). This resistivity may be further decreased if the perovskite is exposed to reducing conditions.

Abstract: A method and structure for etching a thin film perovskite layer (e.g., barium strontium titanate 836) overlying a second material without substantially etching the second material. The method comprises forming a substantially-silicon-free dielectric etchstop layer (e.g., aluminum nitride 858) on a second dielectric layer comprising silicon (e.g., silicon dioxide 818), depositing the perovskite layer over the etchstop layer, forming a mask layer (e.g., photoresist 842) over the perovsklte layer, patterning and removing portions of the mask layer to form a desired pattern, and etching portions of the perovskite layer not covered by the mask layer, whereby the etching stops on the etchstop layer. The structure comprises a substantially-silicon-free dielectric etchstop layer overlying a second dielectric layer comprising silicon, and a perovskite layer having a desired pattern and comprising an etched side overlying a substantially unetched portion of the etchstop layer.

Abstract: Thermal sensor (36) may include a thermally sensitive element (50), a first thin film electrode (52) and a second thin film electrode (54). The thermally sensitive element (50) may include a plurality of preferentially-ordered crystals. The first thin film electrode (52) may include a plurality of digits (53) in communication with the thermally sensitive element (50). The digits (53) of the first thin film electrode (52) may be in spaced relation with one another. The second thin film electrode (54) may include a plurality of digits (55) in communication with the thermally sensitive element (50) opposite the first thin film electrode (52). The digits (55) of the second thin film electrode (54) may be in spaced relation with one another and in spaced interposed relation with the digits (53) of the first thin film electrode (52).

Abstract: A thermal sensor (36, 84, 114) comprising a thermal assembly (44, 88, 118) and a signal flowpath (46, 90, 120). The thermal assembly (44, 88, 118) may comprise a thermally sensitive element (50) and a pair of electrodes (52, 54). The thermally sensitive element (50) may generate a signal representative of an amount of thermal radiation incident to the thermally sensitive element (50). The electrodes (52, 54) may collect the signal generated by the thermally sensitive element (50). The signal flowpath (46, 90, 120) may transmit the signal collected by the electrodes (52, 54) to the substrate (34, 82, 112). The signal flowpath (46, 90, 120) may comprise a pair of arms (56, 58, 92, 122) each extending from an electrode (52, 54) and be connected to the substrate (34, 82, 112). The arms (56, 58, 92, 122) may support the thermal assembly (44, 88, 118) in spaced relation with the substrate (34, 82, 112). The arms (56, 58, 92, 122) may be formed of a thermally insulating material.

Abstract: Method of stress-aligning a thermally sensitive element may comprise the step of forming a thin film layer of thermally sensitive material (80). The thin film layer of thermally sensitive material (80) may be crystallized. A stress alignment layer (82) may be formed in communication with the thin film layer of thermally sensitive material (80). The thin film layer of thermally sensitive material (80) may be heated above a transition temperature of the thermally sensitive material. The stress alignment layer (82) may be expanded relative to the thin film layer of thermally sensitive material (80). The thin film layer of thermally sensitive material (80) may be cooled below the transition temperature of the thermally sensitive material.

Abstract: Thermal sensor (36) mounted to a substrate (34). The thermal sensor (36) may include a thermally sensitive element (50), a first thin film electrode (52) and a second thin film electrode (54). The thermally sensitive element (50) may comprise a plurality of preferentially-ordered crystals. The first thin film electrode (52) may be disposed adjacent to the thermally sensitive element (50). The second thin film electrode (54) may be disposed adjacent to the thermally sensitive element (50) opposite the first thin film electrode (52).

Abstract: Method of preferentially-ordering a thermally sensitive element (50) may comprise the step of forming a first thin film layer of electrically conductive material (75). A thin film layer of thermally sensitive material (80) may be formed on a surface of the first layer of electrically conductive material (75). A second thin film layer of electrically conductive material (85) of lanthanum strontium cobalt oxide (LSCO) may be formed on a surface of the layer of thermally sensitive material (80) opposite the first thin film layer (75). A nucleation layer (87) may be formed in communication with the surface of the layer of thermally sensitive material (80) opposite the first thin film layer (75). The layer of thermally sensitive material (80) may be crystallized beginning at the surface of the thermally sensitive layer (80) in communication with nucleation layer (87). The nucleation layer (87) may be removed.

Abstract: Thermal sensor (36) mounted to a substrate (34). The thermal sensor may include a first thin film electrode (52), a nucleation element (55), a thermally sensitive element (50) and a second thin film electrode (54). The first thin film electrode (52) may be disposed adjacent to the nucleation element(52). The thermally sensitive element (50) may be in electrical communication with the first thin film electrode (52). The thermally sensitive element (50) may comprise a plurality of preferentially-ordered crystals. The second thin film electrode (54) may be in electrical communication with the thermally sensitive element (50) opposite the nucleation element (55).

Abstract: A thermal detector having an optical coating comprising a porous film 64. The porous film preferably comprises a xerogel or aerogel and is greater than 80% porous. An optional optical impedance matching layer 66 may be deposited over the porous film 64. Advantages include decreased thickness of the thermal sensor, improved acuity of the image produced by the system, lower manufacturing temperatures, and the ability to use electrodes that are opaque to infrared energy.

Abstract: The invention forms improved ferroelectric (or pyroelectric) material by doping an intrinsic perovskite material having an intrinsic ferroelectric (or pyroelectric) critical grain size with one or more donor dopants, then forming a layer of the donor doped perovskite material having an average grain size less than the intrinsic ferroelectric (or pyroelectric) critical gran size whereby the remanent polarization (or pyroelectric figure of merit) of the layer is substantially greater than the remanent polarization (or pyroelectric figure of merit) of the intrinsic perovskite material with an average grain size similar to the average grain size of the layer. The critical ferroelectric (or pyroelectric) grain size, as used herein, means the largest grain size such that the remanent polarization (or pyroelectric figure of merit) starts to rapidly decrease with decreasing grain sizes.

Abstract: A pyroelectric detector system and the pyroelectric detector element therefor having an integrated circuit (1) and a pyroelectric detector element (7) coupled to the integrated circuit and thermally isolated from the integrated circuit. The element includes a lead-containing pyroelectric layer having a pair of opposing surfaces and having a thickness to provide a resonant cavity for radiations in a predetermined frequency range. A bottom electrode (5) opaque to radiations in the predetermined frequency range is secured to one of the pair of opposing surfaces and a top electrode (9, 11) is secured to the other of the pair of opposing surfaces which is semi-transparent to radiations in the predetermined frequency range.The top electrode is taken from the group consisting of platinum and nichrome. The lead-containing pyroelectric layer is preferably lead titanate.