Patent ID: 7033921
Filing Date: 2006-04-25
Classification: C30B

Abstract:
1. Method for depositing a plurality of crystalline semiconductor layers on at least one crystalline semiconductor substrate, in which gaseous starting substances are introduced into a process chamber of a reactor through a gas inlet member, which starting substances, if appropriate after a chemical vapor phase and/or surface reaction, accumulate on the surface of a semiconductor substrate, which is disposed on a substrate holder in the process chamber, so as to form the semiconductor layer, the semiconductor layer and the semiconductor substrate forming a crystal, from either (a) one or more elements from main group V, (b) elements from main groups III and V, or (c) elements from main groups II and VI, wherein, in a first process step for deposition of a first semiconductor layer, a first process gas consisting of one or more first starting substances is introduced into the process chamber, the decomposition products of which process gas form the crystal of a first semiconductor layer, and wherein, for the purpose of doping the first semiconductor layer, small quantities of a second starting substance can be introduced into the process chamber, characterized in that, in a second process step before or after the first process step, a second process gas, which contains the second starting substance and if appropriate further gases, is introduced into the same process chamber in order to deposit a second semiconductor layer, the decomposition products of this second process gas forming a second semiconductor layer, having a crystal which differs from the crystal of the first semiconductor layer, it being possible for small quantities of a first starting substance to be introduced into the process chamber for the purpose of doping the second semiconductor layer.