Abstract: Apparatus for shielding substrates from plasma developed adjacent the ends of r.f. powered cathodes, the apparatus adapted for use in a glow discharge deposition system in which successive amorphous semiconductor layers are deposited onto a substrate. The deposition system includes at least one deposition chamber into which process gases are introduced and disassociated in the presence of electrodynamic fields created between a cathode and a substrate. The shielding apparatus of the present invention comprises a pair of relatively narrow, elongated plates adapted to be spacedly disposed in the deposition chamber so as to lie in a plane substantially parallel to the plane of the substrate. By disposing one of the plates adjacent each of the ends of the cathode, only homogeneous semiconductor films formed by uniform electrodynamic fields produced adjacent the central portion of the cathode are deposited onto the substrate.

Abstract: An electroplated substrate, characterized by a substantially reduced number of surface defects, for the fabrication of thin film electronic devices. The substrate is prepared in an electroforming process by electroplating onto and removing a metallic layer from the surface of a specifically prepared, substantially defect-free mandril. The substrate may be provided with a preselected surface finish by either (1) texturing the mandril or (2) controlling the parameters of the electroplating process to control the morphology of the deposit. The substrate is especially adapted for the fabrication of thin film photoresponsive devices which incorporate specular or diffuse back reflectors, since the texture may be controlled to provide for the appropriate type of reflectivity. Large area, thin film semiconductor devices incorporating the electroplated substrate are readily scribed to form electrically isolated small area segments for the fabrication of modules, arrays and the like.

Abstract: A method for introducing sweep gas through a baffle system adapted for use with glow discharge deposition apparatus in which successive amorphous semiconductor layers are deposited on a substrate. The deposition apparatus includes at least a pair of adjacent dedicated deposition chambers into each of which different process gases are introduced, the chambers being operatively connected by a gas gate. Inert gases are swept through the gas gate to minimize back diffusion of process gases from the chambers. The baffle system is adapted to prevent said sweep gases from entering into turbulent flow when traveling through the gas gate passageway. Further, a sufficient volume per unit time of sweep gas is introduced to insure that some sweep gas flows into the cathode region of the first chamber, thereby substantially preventing process gases and plasma from escaping from the cathode region and forming silane powder.

Abstract: An improved semiconductor device, adapted to provide electrical current in response to light energy incident thereon, includes a first electrode, an active semiconductor body atop the first electrode, a second electrode atop the semiconductor body, and at least one defect region which is capable of providing a low resistance shunt path for the flow of electrical current between the electrodes of the device. The improvement comprises a continuous transparent barrier layer (1) operatively disposed between the semiconductor body and one of the electrodes of the device and (2) adapted to decrease the flow of electrical current through the at least one defect region of the semiconductor device. The barrier layer is formed from a magnesium fluoride based material. Methods of (1) fabricating improved semiconductor devices and (2) preventing operational mode failures due to latent detents are also disclosed.

Abstract: An electroplated substrate, characterized by a substantially reduced number of surface defects, for the fabrication of thin film electronic devices. The substrate is prepared in an electroforming process by electroplating onto and removing a metallic layer from the surface of a specifically prepared, substantially defect-free mandril. The substrate may be provided with a preselected surface finish by either (1) texturing the mandril or (2) controlling the parameters of the electroplating process to control the morphology of the deposit. The substrate is especially adapted for the fabrication of thin film photoresponsive devices which incorporate specular or diffuse back reflectors, since the texture may be controlled to provide for the appropriate type of reflectivity. Large area, thin film semiconductor devices incorporating the electroplated substrate are readily scribed to form electrically isolated small area segments for the fabrication of modules, arrays and the like.

Abstract: A system for introducing, confining and evacuating process gases adjacent the cathode region of glow discharge deposition apparatus, said apparatus adapted to deposit at least one layer of semiconductor material onto a substrate. The deposition apparatus includes at least one dedicated deposition chamber into which process gases are introduced for glow discharge disassociation into species. The system of the present invention includes a baffling manifold adjacent the cathode, said manifold adapted to (1) substantially prevent adjacent slowly and rapidly moving streams of process gases from forming flow patterns as the semiconductor material is deposited onto the substrate, and (2) thoroughly mix the process gases for only introducing homogeneous, uniform process gas mixtures into the plasma region, thereby preventing adjacent nonhomogeneous, nonuniform mixtures from forming flow patterns as the semiconductor material is deposited onto the substrate.

Abstract: An upstream cathode system for use with glow discharge deposition apparatus, said apparatus adapted for the production of large area photovoltaic devices. In such apparatus, process gases are commonly introduced into a deposition chamber from a gas manifold disposed on the upstream side of a substrate. As the process gases are drawn across the surface of the substrate, they are continuously disassociated and recombined under the influence of an electromagnetic field developed by a deposition cathode or microwave generator. By providing a precathode system, upstream of the deposition cathode or microwave generator, (1) impurities in the process gases, (2) contaminants from the walls of the deposition chamber and (3) initially disassociated and recombined process gas compositions may be deposited onto and collected from a collection plate disposed upstream of the substrate.

Abstract: An improved method of and apparatus for depositing thin films, such as indium tin oxide, onto substrates, which deposition comprises one step in the fabrication of electronic, semiconductor and photovoltaic devices. The method includes the novel steps of combining the use of (1) an electron beam to vaporize a source of solid material, and (2) electromagnetic energy to provide an ionizable plasma from reactant gases. By passing the vaporized solid material through the plasma, it is activated prior to the deposition thereof onto the substrate. In this manner, the solid material and the reactant gases are excited to facilitate their interaction prior to the deposition of the newly formed compound onto the substrate.

Abstract: A non-destructive method of electro-coating a preselected pattern of electrically insulating or conducting material onto a semiconductor device which includes a photoresponsive junction. The method includes the step of illuminating the semiconductor device prior to initiating the flowing of electro-coating current therethrough. The method has particular utility in providing electroplated grid patterns and connections on large area photovoltaic cells. Also disclosed is the use of current generated by a photovoltaic cell to effect the electro-coating thereof.

Abstract: Large area photovoltaic devices are defined by applying a pattern of electrically-insulating material directly atop the exposed surface of the semiconductor material. Methods of producing these photovoltaic devices in a continuous or batch process are also disclosed herein. Each large area device may include a matrix of electrically-isolated segments, each segment including a common substrate, a semiconductor body atop the substrate, and a transparent, electrically-conductive coating atop the semiconductor layer. Each large area photovoltaic device may include additionally or independently thereof, an electrically-inactive region also defined by the insulating material. The instant method of producing the photovoltaic devices eliminates the scribing steps required by prior art processes, while the product includes a boundary which separates the adjacent, electrically-isolated segments.

Abstract: An upstream or predeposition cathode system for use with glow discharge deposition apparatus, said apparatus adapted for the continuous production of large area photovoltaic devices. In such apparatus, process gases are commonly introduced into a deposition chamber from a gas manifold disposed upstream of a substrate. As the process gases are drawn across the surface of the substrate, they are disassociated and recombined under the influence of an electromagnetic field developed by a deposition cathode or microwave generator. By providing a precathode system upstream of the deposition cathode or microwave generator, (1) impurities in the process gases, (2) contaminants from the walls of the deposition chamber and (3) initially disassociated and recombined process gas compositions may be deposited onto and collected from a collection plate disposed upstream of the substrate.

Abstract: A system for introducing, confining and evacuating process gases adjacent the cathode region of glow discharge deposition apparatus, said apparatus adapted to deposit at least one layer of semiconductor material onto a substrate. The deposition apparatus includes at least one dedicated deposition chamber into which process gases are introduced for glow discharge disassociation into species. The system of the present invention includes a baffling manifold adjacent the cathode, said manifold adapted to substantially reduce areas of localized rarification and compression of process gases flowing through the plasma region for substantially preventing adjacent stagnant and rapidly moving areas of process gases from forming nonuniform flow patterns as the semiconductor layer is deposited on the surface of the substrate. The system is also adapted to expose the entire transverse width of the substrate for the deposition of semiconductor material thereunto.

Abstract: A magnetic gas gate adapted to operatively connect two adjacent dedicated chambers, in the first chamber of which a first layer is deposited upon a magnetic web of substrate material and in the second chamber of which a second layer is deposited onto the first layer. The first chamber has introduced thereinto gas constituents used to form the first layer while the second chamber (1) has introduced thereinto gas constituents used to form the second layer which constituents include at least one gas not introduced into the first chamber; and (2) is operatively associated with a mechanism for unidirectionally drawing the gases from the first chamber side of the gas gate toward the second chamber side of the gas gate. It is important that the second chamber gas constituents be substantially prevented from backflowing or diffusing through the gas gate to contaminate the gas constituents in the first chamber.

Abstract: A reduced capacitance electrode assembly for use in an alternating current plasma system provides reduced input capacitance to an associated tuning network. The assembly includes an electrode adapted to receive alternating current power for maintaining a plasma region and a plurality of electrically conductive plates. The plates are closely spaced apart by less than a predetermined distance on one side of the electrode for precluding the formation of a plasma region on the one side of the electrode and for providing a plurality of series capacitances to present a substantially reduced capacitance to the alternating current power.The reduced capacitance electrode assembly is particularly useful in a system for making photovoltaic devices wherein a plurality of amorphous semiconductor materials is deposited onto a continuous conductive substrate moving through a corresponding plurality of deposition chambers.

Abstract: Electrical interconnections for a large area photovoltaic cells, electrical interconnections for adjacent large area photovoltaic cells and the methods of producing those connections are disclosed herein. The cells are, preferably, of the type which include a plurality of electrically isolated, small area segments sharing a common substrate, a semiconductor body atop the substrate and a transparent, conductive coating atop the semiconductor body. The electrical interconnections include: an electrically-conductive strip interconnecting the small area segments of each large area to provide a first electrode of that cell; and access to the substrate from the layered surface of each large area cell to provide the second electrode of that cell. The electrodes may be electrically-interconnected in series or parallel.

Abstract: An improved glow discharge deposition apparatus for depositing amorphous layers upon at least one substrate, the apparatus including a housing capable of withstanding vacuum pressures, a substrate upon which the amorphous layers are deposited, an r.f. powered cathode adapted to cooperate with the substrate for producing a plasma region in the housing, layer-producing materials adapted to be introduced into the plasma region, and heating elements for warming the substrate to a deposition-effecting temperature. The improvement is provided by an electrically insulated base adapted to support the cathode in a non-horizontal, preferably a vertical, plane and a prop adapted to support the substrate in a plane adjacent and parallel to the non-horizontal plane in which the cathode is supported.

Abstract: A method of electrically isolating portions of a large surface area semiconductor body for various purposes such as the production of improved photovoltaic and semiconductor devices is disclosed herein. In the preferred embodiment, the photovoltaic devices are of the type which include a common, electrically conductive substrate layer, a semiconductor body deposited upon the substrate layer, and a transparent electrically conductive coating layer is deposited atop the amorphous body.

Abstract: Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment.