Abstract: An apparatus for depositing a thin film of amorphous or polycrystalline silicon on substrates by a low-pressure chemical vapor deposition process includes a high-speed pump device connected to one end of a vapor deposition chamber and operative to maintain in the vapor deposition chamber a pressure at or below 20 milliTorr, an inlet adjacent the other end of the chamber for introducing gas into the chamber such that the gas flows from the gas inlet toward the pump device, and a substrate support within the vapor deposition chamber for orientating the major faces of the substrates substantially perpendicularly to the gas flow direction, wherein the combined conductance of the vapor deposition chamber, substrate support, and substrates is at least ten times the conductance of the pump device.

Abstract: In order to deposit films of materials, such as polysilicon or silicon dioxide, on major surfaces of substrates by a low-pressure chemical vapor deposition (LPCVD) process, gas, such as a silane gas, is admitted to a chamber at one end and is pumped through the chamber by a pump. The substrates are mounted such that the general direction of gas flow is perpendicular to the substrate major surface, and are heated to cause reaction of the gas to form the required film. In order to achieve uniformity of the deposited films over a number of substrates, the pressure in the deposition chamber is maintained below 10m Torr.

Abstract: A deposition process includes the steps of heating a substrate, and passing silane gas over the substrate such that the heated substrate causes decomposition of the silane gas thereby to cause deposition of polysilicon film on the substrate. The temperature of the substrate and the pressure of the silane gas are controlled so as to increase the grain size of the deposited films.

Abstract: In a process for manufacturing a thin film transistor, a first polysilicon layer is formed on a substrate and a silicon dioxide layer is formed on a region of the first polysilicon layer leaving exposed regions of that layer. A second polysilicon layer is formed on the silicon dioxide layer and aligned therewith. Regions of a selectively-grown electrically-conductive film are deposited on the second polysilicon layer and on the exposed regions of the first polysilicon layer, the film being such that it wil not grow on the edges of the silicon dioxide layer, but will grow on the exposed polysilicon to form gate, source and drain electrodes. The edges of the silicon dioxide layer therefore remain uncoated. The film may be formed of tungsten or may be formed, for example, by selective silicon epitaxy, phosphorus doped.