Abstract: A method for imparting a pattern to a flowable resist material on a substrate entails providing a resist layer so thin that during a stamp wedging process, the resist never completely fills the space between the substrate and the bottom surface of a stamp between wedge protrusions, leaving gap everywhere therebetween. A gap remains between the resist and the extended surface of the stamp. If the resist layer as deposited is somewhat thicker than the targeted amount, it will simply result in a smaller gap between resist and tool. The presence of a continuous gap assures that no pressure builds under the stamp. Thus, the force on the protrusions i determined only by the pressure above the stamp and is well controlled, resulting in well-controlled hole sizes. The gap prevents resist from being pumped entirely out of any one region, and thus prevents any regions from being uncovered of resist. The stamp can be pulsed in its contact with the substrate, repeatedly deforming the indenting protrusions.

Abstract: A workpiece is transported using a porous belt, which belt delivers a workpiece to a chuck, upon which the workpiece is held by vacuum. The belt can be porous PTFE. A flexible stamp is preheated, before it is applied to a workpiece, by drawing the stamp toward a heated plate, for instance by vacuum.

Abstract: The present inventions relate to the formation of a thin polymer film on a substrate. Apparatus is described for transforming a solid polymer resist into an aerosol of small particles, electrostatically charging and depositing the particles onto a substrate, and flowing the particles into a continuous layer. Apparatus is further described for transforming solid resist into an aerosol of small particles by heating the resist to form a low viscosity liquid such as is compatible with nebulization and applying the techniques of jet or impact nebulization and aerosol particle sizing to form the aerosol. A method is further described of using ionized gas to confer charge onto the aerosol particles and using a progression of charging devices establish an electric field directing the flow of charged particles to the substrate. The progression of charging devices and associated apparatus results in high collection efficiency for the aerosol particles.

Abstract: A pressure differential can be applied across a mold sheet and a semiconductor (e.g. silicon) wafer (e.g. for solar cell) is formed thereon. Relaxation of the pressure differential can allow release of the wafer. The mold sheet may be cooler than the melt. Heat is extracted through the thickness of the forming wafer. The temperature of the solidifying body is substantially uniform across its width, resulting in low stresses and dislocation density and higher crystallographic quality. The mold sheet can allow flow of gas through it. The melt can be introduced to the sheet by: full area contact with the top of a melt; traversing a partial area contact of melt with the mold sheet, whether horizontal or vertical, or in between; and by dipping the mold into a melt. The grain size can be controlled by many means.

Abstract: Semiconductor photovoltaic cells have surfaces that are textured for processing and photovoltaic reasons. The absorbing regions may have parallel grooves that reduce loss of solar energy that would otherwise be lost by reflection. One form of texturing has parallel grooves and ridges. The cell also includes regions of metallization for collecting the generated electrical carriers and conducting them away, which may be channels. The topography is considered during production, using a process that takes advantage of the topography to govern what locations upon will receive a specific processing, and which locations will not receive such a processing. Liquids are treated directly into zones of the cell. They migrate throughout a zone and act upon the locations contacted. They do not migrate to other zones, due to impediments to fluid flow that are features of the surface texture, such as edges, walls and ridges.

Abstract: Semiconductor bodies, such as for solid state electronics and photovoltaic cells, have surfaces that are textured for processing, charge carrying and photovoltaic reasons. Absorbing regions may have grooves that reduce loss of solar energy by reflection. Semiconductor bodies also include metallizations for conducting electrical carriers, which may be channels. Production processes take advantage of the topography to govern which locations will receive a specific processing, and which locations will not. Liquids are treated directly into zones. They migrate throughout a zone and act upon the locations contacted. They do not migrate to other zones, due to impediments to flow, such as edges, walls and ridges. Liquid may also be deposited and migrate within a zone, to block or mask a subsequent activity, such as etching.

Abstract: An original wafer, typically silicon, has the form of a desired end PV wafer. The original may be made by rapid solidification or CVD. It has small grains. It is encapsulated in a clean thin film, which contains and protects the silicon when recrystallized to create a larger grain structure. The capsule can be made by heating a wafer in the presence of oxygen, or steam, resulting in silicon dioxide on the outer surface, typically 1-2 microns. At least one support element supports the wafer at the time the capsule is provided and blocks only minimal surface area from contact with the film forming atmosphere. There may be a plurality of support elements, or a surface may provide such support. The capsule contains the molten material during recrystallization, and protects against impurities. Recrystallization may be in air. After recrystallization, the capsule is removed.

Abstract: An interposer sheet can be used for making semiconductor bodies, such as of silicon, such as for solar cell use. It is free-standing, very thin, flexible, porous and able to withstand the chemical and thermal environment of molten semiconductor without degradation. It is typically of a ceramic material, such as silica, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbide, silicon carbonitride, silicon oxycarbonitride and others. It is provided between a forming surface of a mold sheet, and the molten material from which a semiconductor body will be formed. It may be secured to the forming surface or deposited upon the melt. The interposer sheet suppresses grain nucleation, and limits heat flow from the melt. It promotes separation of the semiconductor body from the forming surface. It can be fabricated before its use. Because free-standing and not adhered to the forming surface, problems of mismatch of CTE are minimized.

Abstract: A pressure differential is applied across a mold sheet and a semiconductor (e.g. silicon) wafer (e.g. for solar cell) is formed thereon. Relaxation of the pressure differential allows release of the wafer. The mold sheet may be cooler than the melt. Heat is extracted almost exclusively through the thickness of the forming wafer. The liquid and solid interface is substantially parallel to the mold sheet. The temperature of the solidifying body is substantially uniform across its width, resulting in low stresses and dislocation density and higher crystallographic quality. The mold sheet must allow flow of gas through it. The melt can be introduced to the sheet by: full area contact with the top of a melt; traversing a partial area contact of melt with the mold sheet, whether horizontal or vertical, or in between; and by dipping the mold into a melt. The grain size can be controlled by many means.

Abstract: A porous lift off layer facilitates removal of films from surfaces, such as semiconductors. A layer, with porosities typically larger than the film thickness is provided where no film is desired. The film is applied over the porous layer and also where it is desired. The porous material and the film are then removed from areas where film is not intended. The porous layer can be provided as a slurry, dried to open porosities, or fugitive particles within a field, which disassociate upon the application of heat or solvent. The film can be removed by etchant that enters through porosities that have arisen due to the film not bridging the spaces between solid portions. Etchant attacks both film surfaces. Particles may have diameters of four to ten times the film thickness. Particles may be silica, alumina and ceramics. Porous layers can be used in depressions or on flat surfaces.

Abstract: Patterned substrates for photovoltaic and other uses are made by pressing a flexible stamp upon a thin layer of resist material, which covers a substrate, such as a wafer. The resist changes phase or becomes flowable, flowing away from locations of impression, revealing the substrate, which is subjected to some shaping process, typically etching. Portions exposed by the stamp being are removed, and portions that protected by the resist, remain. A typical substrate is silicon, and a typical resist is a wax. Workpiece textures include extended grooves, discrete, spaced apart pits, and combinations and intermediates thereof. Platen or rotary patterning apparatus may be used. Rough and irregular workpiece substrates may be accommodated by extended stamp elements. Resist may be applied first to the workpiece, the stamp, or substantially simultaneously, in discrete locations, or over the entire surface of either. The resist dewets the substrate completely where desired.

Abstract: An original wafer, typically silicon, has the form of a desired end PV wafer. The original may be made by rapid solidification or CVD. It has small grains. It is encapsulated in a clean thin film, which contains and protects the silicon when recrystallized to create a larger grain structure. The capsule can be made by heating a wafer in the presence of oxygen, or steam, resulting in silicon dioxide on the outer surface, typically 1-2 microns. Further heating creates a molten zone in space, through which the wafer travels, resulting in recrystallization with a larger grain size. The capsule contains the molten material during recrystallization, and protects against impurities. Recrystallization may be in air. Thermal transfer through backing plates minimizes stresses and defects. After recrystallization, the capsule is removed.

Abstract: Semiconductor photovoltaic cells have surfaces that are textured for processing and photovoltaic reasons. The absorbing regions may have grooves that reduce loss of solar energy that would otherwise be lost by reflection. One form of texturing has grooves and ridges. The cell also includes metallizations for collecting generated electrical carriers and conducting them away, which may be channels. The topography is considered during production, using a process that takes advantage of the topography to govern what locations will receive a specific processing, and which locations will not. Liquids are treated directly into zones. They migrate throughout a zone and act upon the locations contacted. They do not migrate to other zones, due to impediments to flow, such as edges, walls and ridges. Liquid may also be deposited and migrate within a zone, to block or mask a subsequent activity, such as etching.

Abstract: Semiconductor photovoltaic cells have surfaces that are textured for processing and photovoltaic reasons. The absorbing regions may have grooves that reduce loss of solar energy that would otherwise be lost by reflection. One form of texturing has grooves and ridges. The cell also includes metallizations for collecting generated electrical carriers and conducting them away, which may be channels. The topography is considered during production, using a process that takes advantage of the topography to govern what locations will receive a specific processing, and which locations will not. Liquids are treated directly into zones. They migrate throughout a zone and act upon the locations contacted. They do not migrate to other zones, due to impediments to flow, such as edges, walls and ridges. Liquid may also be deposited and migrate within a zone, to block or mask a subsequent activity, such as etching.

Abstract: A pressure differential is applied across a mold sheet and a semiconductor (e.g. silicon) wafer (e.g. for solar cell) is formed thereon. Relaxation of the pressure differential allows release of the wafer. The mold sheet may be cooler than the melt. Heat is extracted almost exclusively through the thickness of the forming wafer. The liquid and solid interface is substantially parallel to the mold sheet. The temperature of the solidifying body is substantially uniform across its width, resulting in low stresses and dislocation density and higher crystallographic quality. The mold sheet must allow flow of gas through it. The melt can be introduced to the sheet by: full area contact with the top of a melt; traversing a partial area contact of melt with the mold sheet, whether horizontal or vertical, or in between; and by dipping the mold into a melt. The grain size can be controlled by many means.

Abstract: Semiconductor photovoltaic cells have surfaces that are textured for processing and photovoltaic reasons. The absorbing regions may have parallel grooves that reduce loss of solar energy that would otherwise be lost by reflection. One form of texturing has parallel grooves and ridges. The cell also includes regions of metallization for collecting the generated electrical carriers and conducting them away, which may be channels. The topography is considered during production, using a process that takes advantage of the topography to govern what locations upon will receive a specific processing, and which locations will not receive such a processing. Liquids are treated directly into zones of the cell. They migrate throughout a zone and act upon the locations contacted. They do not migrate to other zones, due to impediments to fluid flow that are features of the surface texture, such as edges, walls and ridges.

Abstract: A porous lift off layer facilitates removal of films from surfaces, such as semiconductors. A film is applied over a patterned porous layer, the layer comprising openings typically larger than the film thickness. The porous material and the film are then removed from areas where film is not intended. The porous layer can be provided as a slurry, dried to open porosities, or fugitive particles within a field, which disassociate upon the application of heat or solvent.

Abstract: A pressure differential is applied across a mold sheet and a semiconductor (e.g. silicon) wafer (e.g. for solar cell) is formed thereon. Relaxation of the pressure differential allows release of the wafer. The mold sheet may be cooler than the melt. Heat is extracted almost exclusively through the thickness of the forming wafer. The liquid and solid interface is substantially parallel to the mold sheet. The temperature of the solidifying body is substantially uniform across its width, resulting in low stresses and dislocation density and higher crystallographic quality. The mold sheet must allow flow of gas through it. The melt can be introduced to the sheet by: full area contact with the top of a melt; traversing a partial area contact of melt with the mold sheet, whether horizontal or vertical, or in between; and by dipping the mold into a melt. The grain size can be controlled by many means.

Abstract: Materials that contain liquid are deposited into grooves upon a surface of a work piece, such as a silicon wafer to form a solar cell. Liquid can be dispensed into work piece paths, such as grooves under pressure through a dispensing tube. The tube mechanically tracks in the groove. The tube may be small and rest at the groove bottom, with the sidewalls providing restraint. Or it may be larger and ride on the top edges of the groove. A tracking feature, such as a protrusion, Non-circular cross-sections, molded-on protrusions and lobes also enhance tracking. The tube may be forced against the groove by spring or magnetic loading. Alignment guides, such as lead-in features may guide the tube into the groove. Restoring features along the path may restore a wayward tube. Many tubes may be used. Many work pieces can be treated in a line or on a drum.

Abstract: A pressure differential is applied across a mold sheet and a semiconductor (e.g. silicon) wafer is formed thereon. Relaxation of the pressure differential allows release of the wafer. The mold sheet may be cooler than the melt. Heat is extracted almost exclusively through the thickness of the forming wafer. The liquid and solid interface is substantially parallel to the mold sheet. The temperature of the solidifying body is substantially uniform across its width, resulting in low stresses and dislocation density and higher crystallographic quality. The mold sheet must allow flow of gas through it. The melt can be introduced to the sheet by: full area contact with the top of a melt; traversing a partial area contact of melt with the mold sheet, whether horizontal or vertical, or in between; and by dipping the mold into a melt. The grain size can be controlled by many means.