Abstract: A method for producing crystals of silicon carbide in a furnace. The furnace has a crucible with a cavity in which the cavity has first and second spaced-apart regions. The crucible cavity of the furnace is capable of being heated, preferably by induction or resistance heating, with insulation placed around the crucible and crucible cavity. A source material of silicon carbide is provided at the first region of the crucible cavity, and a monocrystalline seed is placed at the second region of the crucible cavity. A first growth stage is then conducted in which the first region and the second region of the crucible cavity are heated to at least the sublimation temperature of silicon carbide under substantially isothermal conditions. Then, a second growth stage is conducted in which a temperature gradient is provided between the first and the second region of the crucible cavity, such that the seed in the second crucible region is kept at a temperature lower than a temperature of the first crucible region.

Abstract: A method of fabrication of low dislocation single crystal indium-doped gallium arsenide, and improved crystal structure. The method is an improved liquid encapsulant Czochralski process with an indium doping level of 5.times.10.sup.19 to 3.times.10.sup.20 indium atoms per cubic centimeter incorporated into the large diameter, long single crystal. The initial melt of elemental indium, gallium, and arsenic contain about 1 atom percent of indium, and inclusion of the indium permits high yield growth of crystals with desired near stoichiometric or slightly arsenic rich composition which exhibit the desired electrical characteristics.

Abstract: A focal plane array including a first integrated circuit for infrared radiation (IR) detection and a second integrated circuit for signal processing is assembled in a flip-chip structural configuration. Each integrated circuit includes an array of metallic contacts on a surface thereof for interconnection in the flip-chip arrangement. The contact array of the IR detector includes a substantially greater number of contacts than the contact array of the signal processor. Consequently, it is not a prerequisite to precisely align the two integrated circuits in a one-to-one contact relationship for the flip-chip bonding operation therebetween. Thus, each metallic contact of the signal processor may be roughly aligned and bonded to a corresponding group of metallic contacts of the IR detector array without altering significantly the operation of the overall focal plane array as long as at least one metallic contact of the IR detector array is included in each corresponding contact group.

Abstract: A method and apparatus for removing heavy metal impurities such as gold, silver, nickel and copper from a crystalline substrate is described incorporating a damaged crystalline layer which may be formed by excessive doping to trap or getter heavy metal impurities to enhance the majority carrier lifetime of the detector material.The invention overcomes the problem of degraded responsivity in radiant energy crystalline detectors after high temperature processing, in excess of 900.degree. C., which permits surface contaminants such as gold, silver, nickel and copper to diffuse through the detector material raising the net donor density.

Abstract: A focal plane array including a first integrated circuit for infrared radiation (IR) detection and a second integrated circuit for signal processing is assembled in a flip-chip structural configuration. Each integrated circuit includes an array of metallic contacts on a surface thereof for interconnection in the flip-chip arrangement. The contact array of the IR detector includes a substantially greater number of contacts than the contact array of the signal processor. Consequently, it is not a prerequisite to precisely align the two integrated circuits in a one-to-one contact relationship for the flip-chip bonding operation therebetween. Thus, each metallic contact of the signal processor may be roughly aligned and bonded to a corresponding group of metallic contacts of the IR detector array without altering significantly the operation of the overall focal plane array as long as at least one metallic contact of the IR detector array is included in each corresponding contact group.

Abstract: A method and apparatus for removing heavy metal impurities such as gold, silver, nickel and copper from a crystalline substrate is described incorporating a damaged crystalline layer which may be formed by excessive doping to trap or getter heavy metal impurities to enhance the majority carrier lifetime of the detector material.The invention overcomes the problem of degraded responsivity in radiant energy crystalline detectors after high temperature processing, in excess of 900.degree. C., which permits surface contaminants such as gold, silver, nickel and copper to diffuse through the detector material raising the net donor density.

Abstract: A display apparatus for displaying a plurality of physical parameters has a plurality of electrically-operable display regions which are to be operated in accordance with respective physical parameters. The display regions each comprise a plurality of display sections disposed in spaced array, an electrode which is common to all display sections in that display region, and a plurality of individual electrodes associated with individual and respective ones of the display sections in that display region. The electrodes of the said plurality of individual electrodes associated with one display region are coupled to respective ones of the said plurality of individual electrodes associated with another display region to form respective groups of electrodes.

Abstract: Display apparatus for displaying the magnitude of a physical parameter includes a plurality of display regions each of which contains a plurality of electrically-operable display sections. The display apparatus also includes an electric circuit means responsive to an electric signal representative of the said magnitude which is arranged to operate the display sections in a cyclic manner in accordance with that magnitude. To this end, the electric circuit means is arranged, during a first period of each cycle, to effect operation of any display regions in which all sections therein require to be operated and, during a second period of each cycle, to effect appropriate operation of any other display region in which only at least one of the display sections thereof require to be operated.

Abstract: An improved radiant energy sensor incorporating a number of elongated detectors, reflecting means for reflecting incident light into the elongated detectors, and circuitry on a crystalline substrate, is described wherein the reflecting means directs radiant energy into the elongated detectors.