Patent ID: 7244667

Claim:
A method for the production of thin epitaxial semiconductor layers, characterized in that: a) there are provided a plurality of semiconductor substrates of a diameter of at least 150 mm and having surfaces to be coated, for simultaneous treatment in a low pressure batch reactor ( 5 ), b) the surfaces to be coated of the semiconductor substrates are cleaned by a wet chemical process or in the gaseous phase or both, c) the cleaned semiconductor substrates are heated together in the low pressure batch reactor ( 5 ) to a first temperature (prebake temperature) and the surfaces to be coated are subjected together to a hydrogen prebake operation at a first reactor pressure, d) the semiconductor substrates are transferred together from the low pressure batch reactor ( 5 ) into a low pressure hot or warm wall batch reactor ( 6 ) in an inert atmosphere or in a vacuum or both after the hydrogen prebake operation, e) the semiconductor substrates are heated in the low pressure hot or warm wall batch reactor ( 6 ) to a second temperature (deposition temperature) lower than the first temperature (prebake temperature), and after attainment of a condition of thermodynamic equilibrium the semiconductor layers are deposited on the surfaces to be coated in a chemical gaseous deposition (CVD) process at a second reactor pressure equal to or lower than the first reactor pressure, and f) the CVD process is effected under such conditions that deposition is controlled by surface reactions on the substrate and thus gas transport in the low pressure hot or warm wall batch reactor ( 6 ) is of subordinate significance, g) wherein the deposition of a semiconductor layer is controlled in such a way that deposition of a thin epitaxial semiconductor layer ends when the thin epitaxial semiconductor layer has reached a predetermined thickness of between 10 nm and 1000 nm.