Cryogenically-Pumped, Variable-Pressure, Chemical Vapor Deposition and Vapor Phase Epitaxy Reactor and Process
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
The VPE (vapor phase epitaxy) or CVD (chemical vapor deposition) reactor is sketched schematically in the figure. The main tube is made of quartz; the appendage, containing the source flask, pump-down port, etc., is made of quartz, or PYREX*, or stainless steel, etc. After positioning the substrate or substrates and connecting the source flask or flasks, the reactor is pumped-down below the desired pressure, and then backfilled to a desired pressure with an appropriate gas. A simple pumping system, such as using a sorption pump, would be adequate. The backfilling gas should not condense at T3, at the cold-trap end, which is normally cooled with liquid N2, H2 or He. In operation, the source flask valve can be opened for pumping down.