Abstract: A process of making strain-free, heavily carbon-doped p-type epitaxial layers for use in high performance devices and at least one such device so made. The process essentially includes the epitaxial deposition of a strain-free, carbon-doped p-type layer in a GaAs HBT device to form the base layer thereof in a manner that includes the balancing of the strain of the crystal lattice structure caused by the carbon doping by co-doping the base layer with an isovalent and isoelectric dopant. The co-doping also improves device performance. It also effects alloy hardening, which inhibits further defect formation, improves mobility and carrier lifetime of the base layer and, by narrowing the energy gap, it improves ohmic contact formation.

Abstract: A stream of gaseous source compounds and their ranges of relative ratios useful in the deposition of thin film ferroelectric materials by CVD are disclosed. The stream of gaseous source compounds are used in combination with a CVD reactor flushed with an inert gas and maintained at a predetermined internal pressure and, a substrate disposed within the CVD reactor and maintained at a predetermined temperature. The steam of gaseous source compounds include a Zr source compound, a Ti source compound, a Pb source compound, an oxidizing agent compound, and an inert gas, as well as their ranges of relative ratios to deposit lead-zirconate-titanate, related ferroelectrics, specifically including lead-lanthanum-zirconium-titanate.

Abstract: Improved methods for the treatment of spherical surfaces designed to improve their physical and chemical properties are disclosed. The methods include the provision of a fixture by which a plurality of spherical workpieces are presented to a treatment source in a way that their entire respective spherical surfaces are uniformly treated and to a uniform predetermined depth. The fixture is mounted for motion about two axes normal to each other. The methods include randomization of the motion about one of the two axes of motion by interrupting one of the two motions for a predetermined period of time. The treatment sources include: pulsed electron beam and light sources, plasma sources, reaction chambers for CVD or MOCVD, sputtering, sputter enhanced ion implantation sources and physical vapor deposition in conjunction with an ion beam source.

Abstract: An improved method and an apparatus for the ion implantation of spherical surfaces are disclosed. The method includes the provision of a revised fixture by which a plurality of spherical workpieces are presented to a large area ion beam in a way that their entire respective spherical surfaces are uniformly ion implanted to improve their surface characteristics. The fixture includes a disc mounted for motion about two axes normal to each other, a plurality of holes formed in a the disc loosely to accommodate therein a plurality of spherical workpieces, each of the plurality of holes formed with a spherical bottom and having a cleaning orifice, cooling means disposed on one side of the disc, a thermocouple operatively mounted in association with the disc, and a cover plate mounted on a second side of the disc and provided with a plurality of apertures concentric with the plurality of holes formed in the disc.

Abstract: An improved photovoltaic cell and a process of making it are disclosed. Essentially, the process merges the technology of ESB with the phenomenon of total internal reflection to provide a photovoltaic cell of improved conversion efficiency and comprising a solar cell formed of a semiconductor material and provided with a front contact, a cover plate formed of a glass having a thermal expansion coefficient matching that of the semiconductor material, with the back surface of the cover plate provided with a plurality of V-grooves overlying the front contact and being electrostatically bonded to the solar cell. The V-grooves serve both as clearance slots for the front contact and its converging facets as reflecting surfaces to direct incident light onto the cell's surfaces in between the front contact grid lines.

Abstract: An improved process of making a ferroelectric electronic component, such as a non-volatile RAM or an electro-optic switching array, is disclosed. The process essentially includes the separate formation of two subassemblies and then connecting them by placing one on top of the other. Electrical contacts are made by "bumping" or other "flip chip" techniques.

Abstract: An improved method and an apparatus for the ion implantation of spherical surfaces are disclosed. The method includes the provision of a revised fixture by which a plurality of spherical workpieces are presented to a large area ion beam in a way that their entire respective spherical surfaces are uniformly ion implanted to improve their surface characteristics. The fixture includes a disc mounted for motion about two axes normal to each other, a plurality of holes formed in a the disc loosely to accommodate therein a plurality of spherical workpieces, each of the plurality of holes formed with a spherical bottom and having a cleaning orifice, cooling means disposed on one side of the disc, a thermocouple operatively mounted in association with the disc, and a cover plate mounted on a second side of the disc and provided with a plurality of apertures concentric with the plurality of holes formed in the disc.

Abstract: A method and an apparatus for the ion implantation of spherical surfaces are disclosed. The method essentially includes the provision of a fixture by which a plurality of spherical workpieces are presented to a large area ion beam in a way that their entire respective spherical surfaces are uniformly ion implanted to improve their surface characteristics. The fixture basically includes a solid disc mounted for motion about two axes normal to each other, a plurality of cages formed in a first surface of the disc loosely to accommodate therein a plurality of spherical workpieces, cooling means disposed on a second surface of the disc, and a cover plate and/or mask mounted on the first surface of the disc and provided with a plurality of apertures concentric with the plurality of cages formed in the disc.

Abstract: A sputter enhanced ion implantation process is disclosed that uses to advantage the ion beam sputtering phenomenon to deposit layers of coatings on surfaces of interest simultaneously with ion implanting that surface, and that without the use of a separate evaporation system. The process can be applied to almost any workpiece of varied geometries. The process can be used for the deposition of hard coatings as well as ion implanting soft solid lubricants into various substrates. The process is particularly suitable for improving the physical and chemical properties of workpieces exposed to excessive wear, erosion, corrosion and fatigue and workpieces benefitting from a reduced coefficient of friction, such as ball bearings, gears, toolings, orthopaedic surgical implants and the like.

Abstract: An improved patterning process, useful for the metallization of highly efficient photovoltaic cells, the formation of X-ray lithography masks in the sub half-micron range, and in the fabrication of VLSI and MMIC devices, is disclosed. The improved patterning process includes the steps of providing a substrate with a photoactive layer, patterning the photoactive layer with an inclined profile, depositing on both the substrate and the patterned photoactive layer a layer of disjointed metal such that the thickness of the metal layer exceeds that of the patterned photoactive layer and that the metal layer deposited on the substrate is formed with walls normal to the surface of the substrate. Preferably, the deposition of the disjointed metal layer is effected by evaporative metallization in a direction normal to the surface of the substrate. The deposited metal layer on the substrate is characterized by a high aspect ratio, with a rectangular cross section.

Abstract: A metal alloy with a treated surface and the process of effecting the treated surface are disclosed whereby its ion release under static, stress and crevice corrosion and corrosive wear conditions is reduced. The metal alloy preferably is an ASTM F-75 Co-Cr-Mo alloy. The preferred process includes providing a workpiece formed of such a metal alloy with a coating of biologically compatible elements, such as a noble metal and then exposing the thus coated surface thereof to bombardment by an ion beam, whereby a plurality of noble metal atoms, together with a plurality of ions from the beam, are driven into the surface of the workpiece a certain distance. Another preferred process includes the direct ion implantation of a workpiece with biocompatible elements, such as nitrogen, tantalum and inert gas ions. Preferably, such a workpiece finds application as an orthopaedic implant.

Abstract: An ion implantation process for plastics is disclosed which materially enhances their surface hardness and their resistance to chemical attack. The plastics include the polycarbonates, the acrylics and their combinations, and ultra high molecular weight polyethylenes. The plastics are ion implanted by energetic ions such as aluminum, magnesium, silicon, titanium, yttrium, fluorine and chlorine ions. Such ion implanted plastics, in their transparent form, find uses such as aircraft, spacecraft, auto transparencies, lenses for safety and eyeglasses and contact lenses, face and gas masks and the like. In their non-transparent form, the ion implanted plastics are useful as ball bearings, safety helmets, floor coverings, appliance and auto moldings and the like.

Abstract: An improved radially designed gas manifold is disclosed for the precise mixing and admission of a plurality of gases into a processing chamber, and being characterized by rapid switching from one gas to another or from one set of gas mixture to another set of gas mixture, and yet occupying a minimum of dead space. The radial gas manifold includes a body provided with an axial mixing channel and a plurality of gas conduits formed in the body in parallel spaced relation to the mixing channel and connected thereto. A pair of annular ducts also are formed in the body adjacent its respective ends, with one of the pair connected to both the mixing channel and to each of the gas conduits, and the other of the pair connected to each of the gas conduits and being vented. A pair of valves are mounted in tandem for each of the gas conduits and means are provided to alternately open and close one of the pair of valves.

Abstract: A process for preventing surface discoloration in orthopedic implants made of titanium and its alloys is disclosed. Such surface discoloration is apt to occur when the orthopedic implants are ion implanted to improve their wear characteristics. The process essentially includes exposing all fixtures and shields, made of pure titanium, located in an implant chamber, to an ion beam, creating a vacuum within the chamber not exceeding about 5.times.10.sup.-5 torr, introducing an orthopedic implant within the chamber to be directly exposed to the beam, and reducing the ion beam current power density so as not to exceed about 1.0 watt/cm.sup.2. Exposing the fixtures and shields to the ion beam first serves to remove surface contamination therefrom, followed by forming a surface layer thereon. This surface layer effectively lowers the sputtering coefficient of the fixtures and shields, and thus reduces the amount of material sputtered from areas exposed to the ion beam to unexposed areas.

Abstract: A passivated deep p/n junction obtained by ion implantation is disclosed. The passivated deep p/n junction is formed in a wafer, preferably a silicon wafer, thus providing an emitter region that is both lightly doped and extending to a depth of about one micrometer. The emitter region in turn is provided with a surface layer so as to reduce surface recombination. Preferably, the surface layer is a silicon oxide layer of about 0.01 micrometer thickness. The p/n junction is obtained by ion implantation whereby the dopant is introduced at room temperature and then distributed thermally. The surface layer preferably is formed near the end of the thermal distribution by admitting a small amount of dry oxygen to a gas stream, and passing the gas stream along the surface of the wafer.

Abstract: A solar cell of novel construction is disclosed featuring the formation of a p-n junction at its rear surface. This allows for a reduction in series resistance and optimization of the p-n junction. The solar cell has a metallic front contact and is lightly doped to reduce contact resistance at the interface between the front contact and the front surface of the cell. The solar cell preferably is formed of either n-type or p-type silicon, with the p-n junction preferably formed therein by ion implantation. Preferably, the solar cell is about 50 micrometers thick and, possesses a conversion efficiency of at least 15% over an input intensity range of from about one to about 1,000 suns. The solar cell is particularly useful for concentrator solar cells intended for operation at high intensity (in excess of 500 suns).

Abstract: A solar cell of improved conversion efficiency and a process of making it are disclosed. The solar cell is designed to trap incident light within the cell by multiple internal reflections and thus increases the absorption of light in the cell. The solar cell is formed with a plurality of spaced parallel grooves on both the front and the back surfaces. The direction of the grooves on the front surface is at an angle with respect to the direction of the grooves on the back surface.

Abstract: A solar cell of improved conversion efficiency and a process of making it are disclosed. The solar cell is designed to trap incident light within the cell by multiple internal reflections and thus increases the absorption of light in the cell. The solar cell is formed with a plurality of spaced parallel grooves on both the front and the back surfaces. The direction of the grooves on the front surface is at an angle with respect to the direction of the grooves on the back surface.

Abstract: An improved process, optimizing quality and growth rate with independent control of residual stress, is disclosed for the growing of membranes for use as X-ray lithography mask blanks. The process comprises providing a mounting fixture and a low-cost substrate material thereon, cooling the substrate to about the boiling point of hydrogen by passing a liquid coolant in contact with the fixture, depositing by a low-temperature plasma-enhanced method a thin membrane onto the cooled substrate, removing the substrate and the thereon deposited membrane from the fixture, and allowing the substrate thermally to expand by gradually assuming ambient room temperature, whereby the membrane will acquire optimum tensile stress. Preferably, the low-cost substrate is low grade industrial silicon and the membrane is formed of boron nitride, silicon carbide, silicon nitride, amorphous silicon, diamondlike carbon, aluminum oxide, beryllium and silicon oxide.

Abstract: An improved reaction chamber for CVD is disclosed that combines the advantageous features of the known horizontal and vertical designs while minimizing their respective short comings. The improved reaction chamber essentially comprises a vertical, double-walled reaction tube having a tapered top provided with a concentric gas inlet, a cooled base plate supporting the reaction tube and provided with a gas outlet, and a tapered susceptor operatively supported within the reaction tube, in close proximity to its tapered top and defining an angle therebetween. This angle varies from zero to about nineteen degrees and preferably is between ten to seventeen degrees. Preferably, the susceptor is rotatably and replaceably supported by a hollow rod, axially accommodating therein a thermocouple for monitoring the temperature within the reaction tube. The tapered top of the reaction tube can be shaped like a cone or like a pyramid with planar side surfaces.