Texas Instruments Corporation

Raytheon Company

Raytheon Ti Systems, Inc.

Raytheon Ti System, Inc.

Donald F Weirauch

Thomas C Penn

Dipankar Chandra

William G Manns

Thomas S Spinelli

John H Tregilgas

Luigi Colombo

Malcolm John Bevan

Sebastian R Borrello

Herbert F Schaake

Sidney G Parker

Carlos A Castro

Jerry L Norris

Walter L Kriss

Kent R Carson

John A Dodge

Gary D Schmidt

This is an integral IR detector system with at least two epitaxial HgCdTe sensors on integrated silicon or GaAs circuitry and also a method of fabricating such system. The system can comprise: a) integrated silicon or GaAs circuitry 110; b) an epitaxial lattice-match layer (e.g. ZnSe 114) on a top surface of the circuit; c) an epitaxial insulating layer (e.g. CdTe 102) on the lattice-match layer; and d) at least two epitaxial HgCdTe sensors 101,121 on the insulating layer, with the HgCdTe sensors being electrically connected to the circuitry. Preferably, the circuitry is silicon. Preferably, an IR transparent, spacer layer (e.g. CdTe 120 or CdZnTe) is on the HgCdTe sensors and an HgCdTe filter 122 is on the spacer layer. Preferably, at least one of the HgCdTe sensors and the HgCdTe filter is laterally continuously graded.

Integrated infrared detection system

Methods are described for the depositing of a plurality of films, preferably mercury cadmium telluride (HgCdTe), whose compositions vary in a controlled manner to provide unique infrared spectral absorption and detection properties. HgCdTe films 64 and 70 are deposited on opposite sides of electrically insulating, IR transmissive film 42. Initially these HgCdTe films may be of uniform composition laterally from 62 to 66 and 68 to 72. However the interdiffusion and segregation coefficients of Hg and Cd are different and vary differently with respect to temperature. By placing film 70 in contact with heater 9, a controlled lateral gradient in composition of the film may be effected because 44 is hotter than 45 and will produce higher Cd concentration at 68 than 72. Similarly 62 will be higher in Cd than 66, however, the gradient will be much less because 64 is cooler than 70. Through the use of a heater 60, the lateral compositional gradient of 64 may be varied with respect to film 70. The close tracking of the IR properties of 70 and 64 can provide useful and novel integrated IR devices such as multiple band spectrometers.

Method of fabricating a laterally continuously graded mercury cadmium

This is a sensor for, and a method of, determining if a particular type of flame is present, using at least two uncooled HgCdTe detector films on a common IR transmissive substrate. Specific examples of the types of radiation which can be identified include gasoline flames, natural gas flames, and organic combustion flames (identified, e.g., by comparing the amount of combined carbon dioxide and carbon monoxide to the amount of water vapor). The ratio of carbon dioxide to carbon monoxide can also be determined. The sensor can include a first HgCdTe filter (88) on a common IR transmissive substrate (42), a first uncooled HgCdTe detector film (86) over the first filter (88), and a second uncooled HgCdTe detector film (92) on a CdTe insulator which is either on the first uncooled HgCdTe detector film, or on a second HgCdTe filter (94) provided on the common IR transmissive substrate.

Uncooled infrared sensors for the detection and identification of

This is a mercury cadmium telluride flame detector which can be operated at room temperature, and a method for making such a detector. It utilizes at least two different compositions of mercury cadmium telluride on a common substrate; and has at least two contact areas on at least one of said mercury cadmium telluride compositions. In one embodiment, the substrate 104 is transparent and an upper mercury cadmium telluride layer 88 is over an insulating layer 89, which insulating layer is over a lower mercury cadmium telluride layer 90 and the lower mercury cadmium telluride is on said substrate, and contact areas 86 are provided on said upper mercury cadmium telluride layer 88, whereby the lower layer 90 filters radiation prior to the radiation reaching the upper layer 88. Preferably the insulating layer is cadmium telluride, the contact areas 86 are mercury telluride, and said upper layer, said insulating layer and said lower layer are epitaxial layers. In another embodiment, the substrate is transparent and different compositions of mercury cadmium telluride are fabricated on a deposition template by liquid phase epitaxial growth where the composition varies with time during said growth of the film and a top portion of said film is lapped at an angle to provide a first lapped surface and a bottom portion of said film and said deposition template are lapped away to provide a second lapped surface substantially parallel to said first lapped surface, and said lapped film is adhered to the substrate and said lapped film is etched to provide said different compositions of mercury cadmium telluride spaced from one another.

Mercury cadmium telluride devices for detecting and controlling open

A multiple film integrated infrared (IR) detector assembly 85 consists of detector films 86, 88, 90 having different IR spectral sensitivities which are deposited on a breadboard IR transmissive but electrically insulating substrate 42. Substrate 42 is deposited on an IR filter layer comprising an HgCdTe film 70. By various techniques described, filter film 70 has a varying composition from edge 68 to 72. This compositional gradient of film 70 results in varying IR spectral absorption as shown by IR transmission graphs 10, 12, 14. Film 70 acts as a graded IR filter in concert with the response of the detector films 86, 88, 90. By the proper choice of the compositional gradients in these films, and as a result the IR spectral response, an integrated IR spectrometer may be fabricated whereby each detector 86, 87, 90 detects only specific narrow bands of IR wavelengths.

Mercury cadmium telluride infrared filters and detectors and methods of

A method is provided for producing an n-type or p-type epitaxial layer using a doped substrate material. The method includes growing a substrate (12), preferably from a material to which an epitaxial layer can be lattice-matched. The substrate (12) is doped with a predetermined concentration of dopant (14). Preferably, the dopant (14) possesses the ability to rapidly diffuse through a material. An epitaxial layer (16) is grown upon the doped substrate (12). The epitaxial layer (16) and the doped substrate are annealed, thereby causing the dopant (14) to diffuse from the substrate (14) into the epitaxial layer (16).

Method for doping epitaxial layers using doped substrate material

This is an uncooled HgCdTe IR sensor, and method of fabricating an uncooled HgCdTe IR sensor. The method comprises; growing an HgCdTe film on an IR transparent substrate, and shaping the substrate into a lens configuration. The HgCdTe IR sensor can comprise an epitaxial, HgCdTe film on an IR transparent substrate, with the substrate shaped in a lens configuration, creating an intregal, controlled (e.g. wide angle) field of view sensor. Reflections at the interface between the HgCdTe and the lens are substantially reduced, and problems of attaching HgCdTe to the lens are also substantially reduced. Preferably, the HgCdTe film is grown by liquid phase epitaxy, the substrate is CdZnTe or CdTe, and/or the substrate is shaped into a hemisphere or a cylindrical section. In one embodiment, an IR transparent overlayer is grown on an HgCdTe film 10 and the substrate is shaped into a hemisphere lens 16 and the IR transparent overlayer is shaped into an hemispherical lens 18. The HgCdTe film may also have a top surface with a non-uniform compositional gradient, to provide an HgCdTe IR sensor which can detect a wide range of optical wavelengths.

Uncooled mercury cadmium telluride infrared devices with integral

A method and apparatus are provided for holding and positioning objects for a single diamond point turning operation. The objects which may include liquid phase epitaxy films are mounted on multiple platforms (10, 46). The platforms (10, 46) are securely connected to a base (20). The platforms (10, 46) are positioned, independently from one another, for elevation and orientation relative to the base (20) while the platforms (10, 46) are securely connected to the base (20).

Method for positioning and processing LPE films

Methods of annealing Hg.sub.1-x Cd.sub.x Te slices (56) in a mercury reflux chamber (32, 34) with a mercury reservoir (52) at the bottom and condensation regions at the top (62) is disclosed. The chamber is heated by a furnace (44) that creates an annealing region encompassing both the reservoir and a holder (46) for the Hg.sub.1-x Cd.sub.x Te slices (56). In preferred embodiment methods reservoir (52) is heated to 270.degree. C. for two hours to sixty days. An annealing immediately after LPE growth by use of either mercury vapor from the melt or a separate reservoir is also disclosed.

Reflux annealing device and method

The disclosure relates to a method of purifying cadmium and tellurium and forming pure, stoichiometric cadmium telluride therefrom as well as the apparatus for making such cadmium telluride. The cadmium and tellurium are purified by heating each separately to volatilization and passing water in a reducing gas through the volatilized cadmium and tellurium to react with impurities and form gases or precipitates. The cadmium and tellurium are volatilized at different predetermined temperatures such that the amount of each volatilized will be the same so that reaction later takes place with stoichiometric amounts of the elements to form the cadmium telluride. The cadmium telluride is then condensed at low enough temperature so that the remaining gases pass out of the system.

Method of forming stoichiometric II-VI compounds of high purity

An electronic circuit interconnection system provides high density mounting of ceramic chip-carrier integrated circuit devices or other beam-lead, dual-in-line (DIP), tape-automated-bonded (TAB), flip-chip, or direct-mounted i.c. devices with wire-bonded interconnects or the like on an economical, dimensionally-stable, interconnection substrate which has high heat dissipating properties. The substrate has glass components which are fused onto etched metal patterns and which are proportioned relative to the metal patterns so that the heat-expansion properties of the substrate correspond to those of the i.c. devices to maintain bond integrity between the i.c. leads and circuit paths on the substrate and so that the substrate has sufficient heat-dissipating properties to permit the high density i.c. mounting. The substrates incorporate circuit paths, device mounting pads, edge terminals, pin mounting holes and other typical substrate features in the etched patterns in multimetal laminated metal plates of selected thickness which are coated on one or both sides with glass frit fused to the plates. Where substrates with more than one layer are desired, glass-coated plates are stacked with pin mounting holes and the like aligned and the glass coatings are fused together. Metal vias extend through the glass coatings where desired to interconnect metal layers of the substrate.

Electronic circuit interconnection system

An electronic circuit interconnection system provides high density mounting on ceramic chip-carrier integrated circuit devices or other beam-lead, dual-in-line (DIP), tape-automated-bonded (TAB), flip-chip, or direct-mounted i.c. devices with wire-bonded interconnects or the like on an economical, dimensionally-stable, interconnection substrate which has high heat dissipating properties. The substrate has glass components which are fused onto etched metal patterns and which are proportioned relative to the metal patterns so that the heat-expansion properties of the substrate correspond to those of the i.c. devices to maintain bond integrity between the i.c. leads and circuit paths on the substrate and so that the substrate has sufficient heat-dissipating properties to permit the high density i.c. mounting. The substrates incorporate circuit paths, device mounting pads, edge terminals, pin mounting holes and other typical substrate features in the etched patterns in multimetal laminated metal plates of selected thickness which are coated on one or both sides with glass frit fused to the plates. Where substrates with more than one layer are desired, glass-coated plates are stacked with pin mounting holes and the like aligned and the glass coatings are fused together. Metal vias extend through the glass coatings where desired to interconnect metal layers of the substrate.

The problem of CdTe sticking to quartz boats is avoided by preventing any presence of cadmium oxides in the as-compounded CdTe. This is accomplished by distilling the cadmium under a high vacuum immediately prior to the CdTe compounding step.

Oxide-free CdTe synthesis

An electronic circuit interconnection system permitting high density mounting of ceramic chip-carrier integrated circuit devices or other beam-lead, dual-in-line (DIP), tape-automated-bonded (TAB), flip-chip, or direct-mounted i.c. devices with wire-bonded interconnects or the like has economical, dimensionally-stable, interconnection substrate which has high heat dissipating properties. The substrate has glass components which are fused onto etched metal patterns and which are proportioned relative to the metal patterns so that the heat-expansion properties of the substrate correspond to those of the i.c. devices to maintain bond integrity between the i.c. leads and circuit paths on the substrate and so that the substrate has sufficient heat-dissipating properties to permit the high density i.c. mounting. The substrates incorporate circuit paths, device mounting pads, edge terminals, pin mounting holes and other typical substrate features in the etched patterns in multimetal laminated metal plates of selected thickness which are coated on one or both sides with glass frit fused to the plates. Where substrates with more than one layer are desired, glass-coated plates are stacked with pin mounting holes and the like aligned and the glass coatings are fused together. Metal vias extend through the glass coatings where desired to interconnect metal layers of the substrate.

Growing community of inventors

Dallas, TX, United States of America

Donald F Weirauch