Intake system for an MOCVD reactor

The invention relates to a device for depositing in particular crystalline layers on one or more particular crystalline substrates in a process chamber (1) having a ceiling (2) and one of these vertically opposed heated base (3) for receiving the substrates (4), with a gas inlet member (5) having vertically superposed gas inlet zones (6, 7) is formed to separate introducing at least a first and a second gaseous starting material, which starting materials together with a carrier gas, the process chamber (1) pass through in the horizontal direction, whereby the gas stream in an immediately at the gas inlet member (5) adjacent the inlet zone (EZ) homogenized, and the starting materials are at least partially vorzerlegt whose decomposition products in an adjacent located at the inlet zone (EZ) growth zone (GZ) with continuous depletion of the gas flow on the substrates (4) deposited , It is essential, an additional gas inlet zone (8) of the gas inlet member (5) for one of the two starting materials for the reduction of the horizontal extent of the inlet zone (EZ).