Abstract: The present invention describes a method of producing an MOS, bipolar and Bimos pedestal transistor wherein the source, drain, and gate metals are in place prior to the source/drain diffusion in a MOS transistor; and the emitter and base metals are in place before junction formation on the bipolar transistors. This is accomplished in MOS devices by a first blanket implantation of impurities into a first polysilicon layer during processing and a second blanket implantation into a second polysilicon layer subsequent to deposition of the metal layers. This is accomplished in bipolar devices by the above, or by blanket implantations subsequent to the deposition of the metal layers.

Abstract: A method is disclosed for improving the crystallinity of semiconductor ribbon material while increasing the material throughput and decreasing energy requirements. The crystallinity of a ribbon of semiconductor material can be improved by forming a localized molten zone in the material and sweeping this molten zone along the length of the material. As the molten zone refreezes, the material is locally recrystallized with enhanced grain size. In accordance with the invention, two ribbons are positioned back-to-back with a slight spacing between the ribbons. Energy sources are focused on the outer surfaces of the two ribbons to create a molten zone in each of the ribbons. Because of the close proximity between the ribbons, much of the energy reradiated from each molten zone is absorbed by the adjacent ribbon. The molten zones are then swept along both of the ribbons to simultaneously cause crystal improvement in both ribbons.

Abstract: An improved process is disclosed for the deposition in a reactor vessel of silicon on the interior walls of the reactor vessel and for the subsequent separation of the silicon from those walls. The reactor vessel has a generally rectangular cross section and is formed of a refractory material from which the deposited silicon separates by thermal expansion shear separation during cool down of the vessel and the deposited silicon. To improve the output of the deposition system, a plurality of partitions are provided in the reactor vessel and integral with the reactor walls. These partitions act as additional deposition surfaces, increasing the number of silicon sheets deposited as well as increasing the efficiency of the chemical reaction.

Abstract: Apparatus and method are provided for thermally treating a semiconductor substrate. According to the method, the substrate is isothermally heated to an elevated temperature near the thermal treatment temperature and then is further heated to a higher temperature at which the thermal treatment occurs. Following the thermal treatment the substrate is isothermally cooled to a sufficiently low temperature to avoid thermally induced defects.

Abstract: A step-wise process is disclosed for the efficient deposition of silicon. The process begins by reacting trichlorosilane and hydrogen on a heated substrate to deposit silicon. Silicon deposition efficiency of this reaction is determined by measuring the silicon to chlorine ratio in the deposition reaction effluent. The silicon-bearing effluent from the deposition reaction includes trichlorosilane, dichlorosilane, and silicon tetrachloride. The silicon-bearing effluent is collected in a first accumulator. The deposition reaction is continued using the collected quantity of silicon-bearing effluent together with an additional quantity of trichlorosilane as an input to the continuing reaction. The additional quantity of trichlorosilane is determined to make up the amount of silicon deposited in the previous step.

Abstract: A practical photovoltaic module is disclosed which is protected from reverse bias damage and which displays minimal power loss resulting from temporary inoperativeness of one or more individual photovoltaic cells included in the module. The module includes a plurality of series connected photovoltaic cells. Protection from inoperativeness of one or more of these cells is provided with only minimal power loss by providing a reversely poled diode across each of the series connected cells.

Abstract: An improved lubricated tissue consists of a sheet of absorbent paper and an array of regions of the absorbent paper impregnated with a lubricating material. The impregnated regions each have a size that is small in comparison to the size of the tissue. The array is arranged in a substantially uniform manner throughout said sheet. Thus, the regions of the array are at least substantially surrounded by absorbent paper free of lubricating materials.

Abstract: An interconnection system for interconnecting a plurality of photovoltaic devices. The photovoltaic devices each have a first and a second side and the interconnect system is located on the second side of the photovoltaic devices. A sheet of dielectric material and a sheet of electrically conductive material are bonded together and positioned so that the dielectric material is next to the photovoltaic devices. A plurality of patterns are formed in the sheet of electrically conductive material. The patterns each have angled tabs punched therein so that the angled tabs are punched through both the electrically conductive material and the dielectric material. When a photovoltaic device is positioned within a group of angled tabs, the angled tabs can be brought into contact with electrical contacts on the first side of the photovoltaic device. The group of angled tabs are electrically common to a part of the pattern which has an extended portion which extends beneath an adjacent photovoltaic device.

Abstract: A surface etchant for silicon comprising an anisotropic etchant containing silicon is disclosed. The etchant provides a textured surface of randomly spaced and sized pyramids on a silicon surface. It is particularly useful in reducing the reflectivity of solar cell surfaces.

Abstract: This disclosure relates to a semiconductor solar energy device which is of the PN-type and utilizes a dielectric anti-reflective coating on the side of the device that faces the sunlight. The fabrication techniques used in making this semiconductor device include the use of a rough or textured pyramid shaped silicon surface beneath the anti-reflective coating to increase solar cell efficiency. Also, ion implantation is used to form the PN junction in the device. The ion implanted region located on the side of the device that is subjected to the sunlight is configured in order to permit metal ohmic contact to be made thereto without shorting through the doped region during sintering of the metal contacts to the semiconductor substrate. The dielectric anti-reflective coating, in one embodiment, is a composite of silicon dioxide and silicon nitride layers.

Abstract: An interconnection system for interconnecting a plurality of photovoltaic devices. The photovoltaic devices each have a first and a second side and the interconnect system is located on the second side of the photovoltaic devices. A sheet of dielectric material and a sheet of electrically conductive material are bonded together and positioned so that the dielectric material is next to the photovoltaic devices. A plurality of patterns are formed in the sheet of electrically conductive material. The patterns each have angled tabs punched therein so that the angled tabs are punched through both the electrically conductive material and the dielectric material. When a photovoltaic device is positioned within a group of angled tabs, the angled tabs can be brought into contact with electrical contacts on the first side of the photovoltaic device. The group of angled tabs are electrically common to a part of the pattern which has an extended portion which extends beneath an adjacent photovoltaic device.

Abstract: A method of producing a ribbon of polycrystalline silicon, which includes contacting a moving surface carrying a layer of particulate semiconductor silicon, with a gaseous silicon source, is disclosed. The gaseous silicon source permeates the layer of particulate silicon and, with heat applied, deposits silicon that knits the silicon particles together to a continuous, coherent polycrystalline ribbon. The ribbon is then separated from the moving surface for further processing, for example, conversion to monocrystalline silicon.