Process for Depositing Thin Layers on a Substrate in a Process Chamber of Adjustable Height

Abstract

An apparatus for depositing thin layers on a substrate in a process chamber arranged in a reactor housing, the bottom of the process chamber consisting of a temperable substrate holder which can be rotatably driven about its vertical axis, and the cover of the chamber consisting of a gas inlet element. The cover extends parallel to the bottom and forms, together with its gas outlets arranged in a sieve-type manner, a gas exit surface which extends over the entire substrate bearing surface of the substrate holder, the process gas being introduced into the process chamber through the gas exit surface. The height of the process chamber is variable before the beginning of the deposition process and/or during the deposition process, which height is defined by the distance between the substrate bearing surface and the gas exit surface.

1 . Apparatus for depositing thin layers on a substrate, comprising:
 a process chamber which is disposed in a reactor housing which can be closed in a gastight manner, and the base of which is formed by a temperature-controllable substrate holder that can be driven in rotation about its vertical axis and the cover of which is formed by a gas inlet member, the cover extending parallel to the base and, by means of its gas outlet openings which are disposed in the manner of a sieve, forming a gas outlet surface which extends over an entire substrate support surface of a substrate holder;   wherein the process chamber height, which is defined by the spacing between the substrate support surface and the gas outlet surface, is adjustable by spacers that are associated with the reactor housing for adjusting the process chamber height in order to displace the substrate holder with respect to the base of the reactor housing;   wherein the spacers are formed by a spindle drive;   wherein the height of a heating element disposed beneath the substrate holder and carrier plate to which the heating element is fixedly connected, is adjustable together with the substrate holder;   wherein a plurality of threaded spindles are synchronous rotatable by means of a motor; and   wherein spindle bearings are disposed beneath the carrier plate.   
   
   
       2 . Apparatus according to  claim 1 , characterized in that the process chamber is surrounded annularly by a gas outlet ring, having a multiplicity of openings, which are approximately at the level of the substrate holder support surface, wherein said outlet ring rests on the carrier plate and is vertically displaced together with the carrier plate. 
   
   
       3 . Apparatus according to  claim 2 , characterized in that spindle nuts are disposed in the spindle bearings located beneath the carrier plate. 
   
   
       4 . Apparatus according to  claim 3 , characterized in that the heating element is formed by a radiofrequency coil, which, inside the substrate holder, generates heat by induction of eddy currents. 
   
   
       5 . Apparatus according to  claim 4 , characterized in that the carrier plate is disposed between said heating element and said substrate holder.