Abstract: A polycrystalline silicon substrate for a solar cell formed by growing a high purity polycrystalline silicon layer on a surface of a base obtained by slicing a polycrystalline silicon ingot obtained by melting metallurgical grade silicon and performing one-direction solidification, wherein one-direction solidification is performed on a melt prepared by adding B to molten metallurgical grade silicon at an amount of 2×1018 cm?3 to 5×1019 cm?3 based on the concentration in the melt to produce the polycrystalline silicon ingot. With this structure, it is possible to easily obtain a polycrystalline silicon substrate having resistivity and the type of conductivity suitable for manufacture of a solar cell.

Abstract: A solar cell is produced by dipping a multicrystalline silicon substrate 28 in a solution 24 containing silicon, growing a silicon layer on the substrate 28 while decreasing with time the temperature drop rate of the solution during the dipping of the substrate in the solution, and forming a pn junction in the silicon layer. Thereby, there is provided a silicon layer production method that can form a thick layer while restraining the degree of roughness, whereby a low-cost, multicrystalline-silicon solar cell production method is provided that realizes both a large current and a high FF.

Abstract: A process for producing a single crystal silicon wafer, comprising the steps of forming a porous layer on a single crystal silicon substrate comprising a silicon whose concentration of mass number 28 silicon isotope is less than 92.5% on an average; dissolving a starting silicon whose concentration of mass number 28 silicone isotope whose mass number is more than 98% on an average in a melt for liquid-phase epitaxy until said starting silicon becomes to be a supersaturated state in said melt under reductive atmosphere maintained at high temperature: immersing said single crystal silicon substrate in said melt to grow a single crystal silicon layer on the surface of said porous layer of said single crystal silicon substrate; and peeling said single crystal silicon layer from a portion of said porous layer.

Abstract: An SiGe layer is grown on a silicon substrate. The SiGe layer or the silicon substrate and SiGe layer are porosified by anodizing the SiGe layer to form a strain induction porous layer or a porous silicon layer and strain induction porous layer. An SiGe layer and strained silicon layer are formed on the resultant structure. The SiGe layer in the stacking growth step only needs to be on the uppermost surface of the porous layer. For this reason, an SiGe layer with a low defect density and high concentration can be formed. Since the SiGe layer on the strain induction porous layer can achieve a low defect density without lattice mismatching. Hence, a high-quality semiconductor substrate having a high strained silicon layer can be obtained.

Abstract: A liquid-phase growth process for continuously growing a crystal film on a plurality of substrates with respect to their one side surfaces, characterized in that said plurality of substrates are kept afloat on the surface of a flowing solution for liquid-phase epitaxy which comprises a crystallizing material dissolved in a solvent in a supersaturated state and which is flowing in a solution flow passage, and while said plurality of substrates being moved by virtue of said flowing solution in said solution flow passage, a crystal film is grown on the surfaces of said plurality of substrates which are in contact with said flowing solution. A liquid-phase growth apparatus suitable for practicing said liquid-phase growth process.

Abstract: In a liquid phase growth process comprising immersing a substrate in a melt held in a crucible, a crystal material having been dissolved in the melt, and growing a crystal on the substrate, at least a group of substrates to be immersed in the melt held in the crucible are fitted to the supporting rack at a position set aside from the center of rotation of the crucible or supporting rack, and the crystal is grown on the surface of the substrate thus disposed. This can provide a liquid phase growth process which can attain a high growth rate, can enjoy uniform distribution of growth rate in each substrate and between the substrates even when substrates are set in a large number in one batch, and can readily keep the melt from reaction and contamination even when the system has a large size, and provide a liquid phase growth system suited for carrying out the process.

Abstract: A liquid-phase growth apparatus for growing a crystal on a substrate includes a crucible containing a solution that contains a raw material for forming the crystal, and a substrate holder for vertically holding the substrate. The substrate holder includes connectors, a receiving component, and a push component. The receiving component and the push component are opposite to each other and are connected by the connectors. The push component holds an upper portion of the substrate while the receiving component holds a lower portion of the substrate. The substrate holder containing the vertically held substrate is dipped into the solution. The receiving component ascends with buoyancy in the solution contained in the crucible, so that the substrate is now held securely and prevented from cracking due to thermal expansion.

Abstract: A liquid-phase growth apparatus for growing a crystal on a substrate includes a crucible containing a solution that contains a taw material for forming the crystal, and a substrate holder for vertically holding the substrate. The substrate holder includes connectors, a receiving component, and a push component. The receiving component and the push component are opposite to each other and are connected by the connectors. The push component holds an upper portion of the substrate while the receiving component holds a lower portion of the substrate. The substrate holder containing the vertically held substrate is dipped into the solution. The receiving component ascends with buoyancy in the solution contained in the crucible, so that the substrate is now held securely and prevented from cracking due to thermal expansion.

Abstract: A method of manufacturing a semiconductor substrate includes a growing step of growing a second single crystalline semiconductor on a first single crystalline semiconductor, a blocking layer forming step of forming a blocking layer on the second single crystalline semiconductor, and a relaxing step of generating crystal defects at a portion deeper than the blocking layer to relax a stress acting on the second single crystalline semiconductor. The blocking layer includes, e.g., a porous layer, and prevents the crystal defects at the portion deeper than the blocking layer from propagating to the surface of the second single crystalline semiconductor.

Abstract: A wafer cassette comprises a holding member having a depression corresponding to the shape of the substrate, and a cover having an opening smaller than the surface size of the substrate. The substrate is to be held in the depression by means of the holding member and the cover, and the substrate is to be covered at its one-side surface, side and all peripheral region of the other-side surface, with the holding member at its depression and with the cover at the edge of its opening. Also disclosed are a liquid-phase growth system and a liquid-phase growth process which make use of the wafer cassette.

Abstract: A liquid-phase growth method for immersing a polycrystalline substrate in a melt in a crucible wherein crystal ingredients are dissolved, thereby growing poly crystals upon the substrate, comprises a first step for growing poly crystals to a predetermined thickness, and a second step for melting back a part of the poly crystals grown in the first step in the melt, wherein the relative position between the substrate and melt is changed between the first step and second step, bringing melt with different temperature into contact with the polycrystalline surface. The obtained poly crystals have properties rivaling those of poly crystals used in conventional solar cells but with little risk of trouble such as line breakage of grid electrodes in application to solar cells, and can be obtained in great quantities at low costs.

Abstract: An apparatus for producing semiconductor thin films in which the semiconductor thin films are allowed to grow on a plurality of substrates by dipping the plurality of substrates into a solution filled in a crucible, the solution containing a semiconductor as a solute, while moving the same in the solution. An angle between a direction of a normal line on a central portion of a growing surface of each substrate and the direction of the movement of the substrates is set to be in 87 degrees or less and the movement of the substrates generates a flow of the solution.

Abstract: There is provided a process of producing a multicrystalline silicon substrate having excellent characteristics as a solar cell substrate. A multicrystalline silicon ingot made by directional solidification 10 is cut such that a normal line of a principal surface 14 of a multicrystalline silicon substrate 13 is substantially perpendicular to a longitudinal direction of crystal grains 11 of the multicrystalline silicon ingot made by directional solidification 10.

Abstract: There is provided a photovoltaic device in which at least one pin-junction is formed in a thin film semiconductor deposited on a substrate, the substrate including: a base including polycrystalline silicon; and a polycrystalline silicon layer formed on the base by liquid phase growth, in which at least a part of a surface of the polycrystalline silicon layer has unevenness composed of facet surfaces. The photovoltaic device prevents a reduction in photoelectric conversion efficiency due to the absence of preferable unevenness, an increase in cost due to the use of an expensive material, and a reduction in throughput in the photovoltaic device, and has a preferable characteristic and high productivity.

Abstract: The method of arranging an electrode according to the present invention includes: arranging an electrode material (103) for forming a eutectic with silicon on a silicon base (101) having unevenness; heating the silicon base (101) at a temperature equal to or higher than a eutectic temperature of the silicon and the electrode material (103); and cooling the silicon base (101) to flatten the unevenness on a surface of the silicon base just under the arranged electrode material (103). The present invention can provide a method of arranging an electrode on an uneven surface, which is a simple method and enables mass-production, and more particularly a method of arranging an electrode on a surface of a solar cell which can realize high efficiency of the solar cell.

Abstract: Provided is a continuous production method for crystalline silicon, including: retaining melted silicon in a crucible; solidifying a portion close to a surface of raw material silicon by providing a negative temperature gradient upward from the crucible; holding the solidified crystalline silicon by a pulling means; and pulling the solidified crystalline silicon at a predetermined rate, while shaping a sectional shape of the solidified crystalline silicon by bringing the solidified crystalline silicon in contact with an opened heater when the solidified crystalline silicon passes through an opening portion of the opened heater having an opening of a predetermined shape and maintained at a temperature higher than a melting point of the raw material silicon. The method allows continuous production of a crystalline silicon ingot having uniform crystallinity or impurity concentration and high quality at low cost even when low purity raw material silicon such as metallurgical grade silicon is used.

Abstract: A liquid-phase growth process comprising immersing a base substrate in a solution containing reactant species to be grown dissolved therein which is accommodated in a crucible and growing a crystal film on said substrate, characterized in that a capping member is kept afloat on the surface of said solution before said substrate is immersed in said solution and said capping member is subsided in said solution upon immersing said substrate in said solution. A liquid-phase growth apparatus suitable for practicing said liquid-phase growth process.

Abstract: Metal-grade silicon is melted and solidified in a mold to form a plate-shaped silicon layer and a crystalline silicon layer is made thereon, thereby providing a cheap solar cell without a need for a slicing step.

Abstract: A liquid phase growth method is provided which comprises dipping a seed substrate in a solution in a vessel having a crystal raw material melted therein and growing a crystal on the substrate, wherein a fin is provided on a bottom of the vessel, for regulating a flow of the solution from a central portion outside in a radial direction in the vessel; a flow-regulating plate is provided in the vicinity of an inner sidewall of the vessel, for regulating a flow of the solution from the bottom upwardly; and the vessel is rotated while regulating a flow of the solution by an action of the fin and the flow-regulating plate to bring the solution into contact with the seed substrate. Thus, there is provided a liquid phase growth method and apparatus capable of providing a high growth rate and showing little difference in the growth rate among the substrates or within the same substrate even when a number of substrates are charged in one batch.

Abstract: In a process for producing a semiconductor member, and a solar cell, making use of a thin-film crystal semiconductor layer, the process includes the steps of: (1) anodizing the surface of a first substrate to form a porous layer at least on one side of the substrate, (2) forming a semiconductor layer at least on the surface of the porous layer, (3) removing the semiconductor layer at its peripheral region, (4) bonding a second substrate to the surface of the semiconductor layer, (5) separating the semiconductor layer from the first substrate at the part of the porous layer, and (6) treating the surface of the first substrate after separation and repeating the above steps (1) to (5).