Abstract: A method is described which makes it possible to use VLSI-quality crystalline semiconductor substrates for the fabrication of the active devices of Active Matrix Flat Panels (AMFPD). The VLSI substrates are provided by arranging a layer of light transparent material in those areas of a semiconductor wafer in which no active device has to be provided, eliminating the semiconductor wafer whereby a transparent wafer is obtained with crystalline semiconductor regions therein and then shaping the transparent wafer into a sized module unit. Several module units can be bonded to a glass substrate and a conductive material is then deposited to make electrical interconnections between the module units. The bonding operation can be performed either at room temperature using a light-transparent glue or at higher temperature using a wafer bonding technique known in the art of Silicon-On-Insulator technology.

Abstract: A method of synthesizing a large area, single crystalline, semiconductor wafer in which the semiconductor is grown on a substrate having a lower melting temperature and higher specific gravity than the overlying semiconductor. The substrate is disposed within an open container or holder having a drain plug. First, a very thin layer of semiconductor is grown on the substrate. Then, the temperature is raised to melt the substrate and anneal the very thin layer of semiconductor. Next, growth of the semiconductor film now floating on the molten substrate is resumed until the desired thickness is obtained. Then, the molten substrate is drained from the holder, the temperature lowered to room temperature, and the nascent large area semiconductor wafer removed from the holder.

Abstract: To manufacture epitaxial wafers with a smaller amount of semiconductor crystals at a lower cost by means of an efficient epitaxial growth process. An epitaxial wafer is made by forming, by means of epitaxial growth, GaAlAs layers with identical structures on both sides of a GaAs substrate wafer with the crystal plane orientation of {100}. The epitaxial wafer is then divided in the GaAs substrate wafer portion into two pieces to obtain two epitaxial wafers. To perform the epitaxial growth process, a plurality of GaAs substrate wafers are held at their edges and then the GaAs substrate wafers are placed in a Ga solution at prescribed spatial intervals. To divide the epitaxial wafer in the GaAs substrate portion into two pieces, the substrate wafer portion is cut parallel to the main surface. Or, the GaAs substrate wafer can also be removed by means of etching while the epitaxial wafer is rotated at a high speed in the etching solution.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: Single-crystal diamond consisting of isotopically pure carbon-12 or carbon-13 has been found to have a thermal conductivity higher than that of any substance previously known, typically at least 40% higher than that of naturally occurring IIA diamond. It may be prepared by a method comprising an initial step of low pressure chemical vapor deposition employing an isotopically pure hydrocarbon in combination with hydrogen, followed by comminution of the diamond thus obtained and conversion thereof to single-crystal diamond under high pressure conditions.