CVD METHOD AND CVD REACTOR

The invention relates to a device and a method for depositing semiconductor layers, in particular made of a plurality of components on one or more substrates (21) contacting a susceptor (2), wherein process gases can be introduced into the process chamber (1) through flow channels (15, 16; 18) of a gas inlet organ (8), together with a carrier gas, said carrier gas permeating the process chamber (1) substantially parallel to the susceptor and exits through a gas outlet organ (7), wherein the products of decomposition build up the process gases as a coating at least in regions on the substrate surface and on the surface of the gas outlet organ (7) disposed downstream of the susceptor (2) at a distance (D) from the downstream edge (21) thereof. In order to deposit contamination-free layers in sequential process steps without intermediate replacement or intermediate cleaning of the gas outlet organ, according to the invention the distance (D) is great enough to prevent products of decomposition outgassing from the coating of the gas outlet organ (7) at the second process temperature from reaching the substrate (21) by counterflow diffusion.