CVD reactor and method for cleaning a CVD reactor

A method for cleaning a process chamber (21) of a chemical vapor deposition (CVD) reactor, the CVD reactor comprising (i) a susceptor (2) for receiving one or more substrates (4) to be coated, (ii) the process chamber (21), (iii) a gas inlet element (1) for introducing a process gas into the process chamber (21), wherein the gas inlet element (1) contains at least one metal component (20) that has a metal surface that comes in contact with the process gas, (iv) at least one cooling channel (14, 17) for cooling the gas inlet element (1), (v) at least one process gas inlet opening (8, 10, 12) for introducing the process gas containing at least one reactive gas into the process chamber (21), wherein the at least one process gas inlet opening (8, 10, 12) is supplied by a process gas supply line (7, 9, 11), and (vi) a cleaning gas inlet opening (6) for introducing a cleaning gas into the process chamber (21), wherein the cleaning gas inlet opening (6) is supplied by a cleaning gas supply line (5), the method comprising:

• introducing, in a cleaning step, a cleaning gas into the process chamber (21) so as to convert deposits on a surface of the susceptor (2) into volatile components due to a chemical reaction of the deposits with the cleaning gas at a first temperature, wherein the deposits are formed during at least one deposition step due to an introduction of the at least one reactive gas into the process chamber (21);
• and
• transporting the volatile components out of the process chamber (21) by means of a first carrier gas,
• wherein a passivation layer is formed on the metal surface in a conditioning step that is carried out prior to the at least one deposition step,
• wherein the passivation layer prevents a detachment of metal constituents from the metal surface by the at least one reactive gas,
• wherein the metal surface is, during the cleaning step, cooled to a second temperature that is lower than the first temperature and at which the cleaning gas comes in contact with the passivation layer, but not react with the passivation layer in such a way that an effect of the passivation layer is impaired, and
• wherein the passivation layer is produced concomitant with a chemical reaction of a metallo-organic compound with metal atoms of the metal surface.