Method for depositing thin layers on a substrate in a height-adjustable process chamber

The invention relates to a method and a device for depositing thin layers on a substrate in a process chamber (4) arranged in a reactor housing (1, 2, 3), the bottom of said process chamber consisting of a temperable substrate holder (5) which can be rotatably driven about its vertical axis (6), and the cover of said chamber consisting of a gas inlet element (7). Said cover extends parallel to the bottom and forms, together with its gas outlets (8) arranged in a sieve-type manner, a gas exit surface (10) which extends over the entire substrate bearing surface (9) of the substrate holder (5), the process gas being introduced into the process chamber (4) through said gas exit surface. The invention is characterised in that the height of the process chamber which is defined by the distance (H) between the substrate bearing surface (9) and the gas exit surface (10) is varied before the beginning of the deposition process and/or during the deposition process.