Patent ID: 8152927

Claim:
A device for depositing crystalline layers on one or more crystalline substrates in a process chamber by means of reaction gases that are introduced into the process chamber and undergo pyrolytic reactions therein, comprising: a carrier plate which can be heated from one side; at least one substrate holder resting above the carrier plate and holding at least one crystalline substrate; at least one compensation plate disposed upstream of the at least one substrate holder such that reaction gases reach the at least one crystalline substrate only after passing over the compensation plate, wherein the compensation plate is distinct from and at least partially surrounds the substrate holder and rests above the carrier plate so as to form a horizontal gap; and at least one first spacer, being a separate part that is removable from the device and being exchangeable with at least one second spacer having a different height, disposed between the carrier plate and the at least one compensation plate for defining the gap height; wherein the gap height of the horizontal gap upstream of the substrate holder in the direction of flow is variable by exchanging the at least one first spacer for the at least one second spacer to influence the local surface temperature of the compensation plate.