Abstract: An optoelectronic device such as an LED or laser which produces spontaneous emission by recombination of carriers (electrons and holes) trapped in Quantum Confinement Regions formed by transverse thickness variations in Quantum Well layers of group III nitrides.

Abstract: An optoelectronic device such as an LED or laser which produces spontaneous emission by recombination of carriers (electrons and holes) trapped in Quantum Confinement Regions formed by transverse thickness variations in Quantum Well layers of group III nitrides.

Abstract: An electronic device has an alloy layer containing magnesium oxide and at least one of zinc oxide and cadmium oxide and having a cubic structure on a substrate. The alloy layer may be directly on the substrate or, alternatively, one or more buffer layers may be between the alloy layer and the substrate. The alloy layer may be domain-matched epitaxially grown directly on the substrate, or may be lattice-matched epitaxially grown directly on the buffer layer. The cubic layer may also be used to form single and multiple quantum wells. Accordingly, electronic devices having wider bandgap, increased binding energy of excitons, and/or reduced density of growth and/or misfit dislocations in the active layers as compared with conventional III-nitride electronic devices may be provided.

Abstract: The present invention describes a process for the isolation of polyhydroxybutyrate of the formula 1 1

Abstract: An electronic device has an alloy layer containing magnesium oxide and at least one of zinc oxide and cadmium oxide and having a cubic structure on a substrate. The alloy layer may be directly on the substrate or, alternatively, one or more buffer layers may be between the alloy layer and the substrate. The alloy layer may be domain-matched epitaxially grown directly on the substrate, or may be lattice-matched epitaxially grown directly on the buffer layer. The cubic layer may also be used to form single and multiple quantum wells. Accordingly, electronic devices having wider bandgap, increased binding energy of excitons, and/or reduced density of growth and/or misfit dislocations in the active layers as compared with conventional III-nitride electronic devices may be provided.

Abstract: An electronic device has an alloy layer containing magnesium oxide and at least one of zinc oxide and cadmium oxide and having a cubic structure on a substrate. The alloy layer may be directly on the substrate or, alternatively, one or more buffer layers may be between the alloy layer and the substrate. The alloy layer may be domain-matched epitaxially grown directly on the substrate, or may be lattice-matched epitaxially grown directly on the buffer layer. The cubic layer may also be used to form single and multiple quantum wells. Accordingly, electronic devices having wider bandgap, increased binding energy of excitons, and/or reduced density of growth and/or misfit dislocations in the active layers as compared with conventional III-nitride electronic devices may be provided.

Abstract: An improved method of zone-melting recrystallizing of a silicon film on an insulator in which the film is implanted and annealed to achieve a reduction of the density of defects within the film.

Abstract: Epitaxial growth of films on single crystal substrates having a lattice mismatch of at least 10% through domain matching is achieved by maintaining na.sub.1 within 5% of ma.sub.2, wherein a.sub.1 is the lattice constant of the substrate, a.sub.2 is the lattice constant of the epitaxial layer and n and m are integers. The epitaxial layer can be TiN and the substrate can be Si or GaAs. For instance, epitaxial TiN films having low resistivity can be provided on (100) silicon and (100) GaAs substrates using a pulsed laser deposition method. The TiN films were characterized using X-ray diffraction (XRD), Rutherford back scattering (RBS), four-point-probe ac resistivity, high resolution transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques. Epitaxial relationship was found to be <100> TiN aligned with <100> Si. TiN films showed 10-20% channeling yield. In the plane, four unit cells of TiN match with three unit cells of silicon with less than 4.0% misfit.

Abstract: Disclosed is a method for the development of diamond thin films on a non-diamond substrate. The method comprises implanting carbon ions in a lattice-plane matched or lattice matched substrate. The implanted region of the substrate is then annealed to produce a diamond thin film on the non-diamond substrate. Also disclosed are the diamond thin films on non-diamond lattice-plane matched substrates produced by this method. Preferred substrates are lattice and plane matched to diamond such as copper, a preferred implanting method is ion implantation, and a preferred annealing method is pulsed laser annealing.

Abstract: A method of forming gallium arsenide on silicon heterostructure including the use of strained layer superlattices in combination with rapid thermal annealing to achieve a reduced threading dislocation density in the epilayers. Strain energy within the superlattices causes threading dislocations to bend, preventing propagation through the superlattices to the epilayer. Rapid thermal annealing causes extensive realignment and annihilation of dislocations of opposite Burgers vectors and a further reduction of threading dislocations in the epilayer.

Abstract: The phase of the YBa.sub.2 Cu.sub.3 O.sub.9-.delta. having a perovskite unit cell structure of approximately the following dimensions a=3.8A, b=3.9A, and c=13.55A has been discovered and identified.

Abstract: A method for reducing defects after zone melting and recrystallization of semiconductor films formed on an insulator over a semiconductor substrate by selectively removing portion of a first layer over the semiconductor film, amorphizing the exposed film portion and laterally regrowing the amorphized region.

Abstract: An improved method of zone-melting and recrystallizing of polysilicon film on an insulator over silicon is described.

Abstract: A method for reducing the defect and dislocation density in III-V material layers deposited on dissimilar substrates is disclosed. The method involves ion implantation of dopant materials to create amorphous regions within the layers followed by an annealing step during which the amorphous regions are recrystallized to form substantially monocrystalline regions. The wafers produced by the process are particularly well suited for optoelectronic devices.

Abstract: Apparatus for mounting a semiconductor device chip and making electrical connections thereto is disclosed. A semiconductor device chip has its backside connected to the surface of a substrate, and its upper surface includes a plurality of electrical pads across the entire surface thereof. A translator chip having a plurality of first electrical contacts disposed generally across the interior portion thereof are in electrical contact with the semiconductor device chip electrical pads, and a plurality of second electrical contacts disposed generally around the perimeter of the translator chip are electrically connected with the electrical terminals in the substrate to which the chip is attached. Heat may be removed from the semiconductor device chip through its backside via cooling channels in the substrate.

Abstract: This invention is a new process for producing refractory crystalline oxides having improved or unusual properties. The process comprises the steps of forming a doped-metal crystal of the oxide; exposing the doped crystal in a bomb to a reducing atmosphere at superatmospheric pressure and a temperature effecting precipitation of the dopant metal in the crystal lattice of the oxide but insufficient to effect net diffusion of the metal out of the lattice; and then cooling the crystal. Preferably, the cooling step is effected by quenching. The process forms colloidal precipitates of the metal in the oxide lattice. The process may be used, for example, to produce thermally stable black MgO crystalline bodies containing magnetic colloidal precipitates consisting of about 99% Ni. The Ni-containing bodies are solar-selective absorbers, having a room-temperature absorptivity of about 0.96 over virtually all of the solar-energy spectrum and exhibiting an absorption edge in the region of 2 .mu.m.

Abstract: This invention is a new method for the formation of high-quality ohmic contacts on wide-band-gap semiconducting oxides. As exemplified by the formation of an ohmic contact on n-type BaTiO.sub.3 containing a p-n junction, the invention entails depositing a film of a metallic electroding material on the BaTiO.sub.3 surface and irradiating the film with a Q-switched laser pulse effecting complete melting of the film and localized melting of the surface layer of oxide immediately underlying the film. The resulting solidified metallic contact is ohmic, has unusually low contact resistance, and is thermally stable, even at elevated temperatures. The contact does not require cleaning before attachment of any suitable electrical lead.This method is safe, rapid, reproducible, and relatively inexpensive.

Abstract: This invention is a method for improving the electrical properties of silicon semiconductor material. The method comprises irradiating a selected surface layer of the semiconductor material with high-power laser pulses characterized by a special combination of wavelength, energy level, and duration. The combination effects melting of the layer without degrading electrical properties, such as minority-carrier diffusion length. The method is applicable to improving the electrical properties of n- and p-type silicon which is to be doped to form an electrical junction therein. Another important application of the method is the virtually complete removal of doping-induced defects from ion-implanted or diffusion-doped silicon substrates.

Abstract: This invention is an improved method for preparing p-n junction devices, such as diodes and solar cells. High-quality junctions are prepared by effecting laser-diffusion of a selected dopant into silicon by means of laser pulses having a wavelength of from about 0.3 to 1.1 .mu.m, an energy area density of from about 1.0 to 2.0 J/cm.sup.2, and a duration of from about 20 to 60 nanoseconds. Initially, the dopant is deposited on the silicon as a superficial layer, preferably one having a thickness in the range of from about 50 to 100 A. Depending on the application, the values for the above-mentioned pulse parameters are selected to produce melting of the silicon to depths in the range from about 1000 A to 1 .mu.m. The invention has been used to produce solar cells having a one-sun conversion efficiency of 10.6%, these cells having no antireflective coating or back-surface fields.