Process And Apparatus For Depositing Semiconductor Layers Using Two Process Gases, One Of Which is Preconditioned

Abstract

A method and device for depositing at least one layer, particularly a semiconductor layer, onto at least one substrate, which is situated inside a process chamber of a reactor while being supported by a substrate holder, is provided. The layer includes of at least two material components provided in a fixed stoichiometric ratio, which are each introduced into the reactor in the form of a first and a second reaction gas, and a portion of the decomposition products form the layer, whereby the supply of the first reaction gas, which has a low thermal activation energy, determines the growth rate of the layer, and the second reaction gas, which has a high thermal activation energy, is supplied in excess and is preconditioned, in particular, by an independent supply of energy.

1 . An apparatus for carrying out a process of depositing at least one layer on at least one substrate, said apparatus having a process chamber disposed in a reactor, which process chamber has a substrate holder for the at least one substrate, having a heating apparatus for heating the substrate holder to a process temperature, having a gas inlet member, which lies opposite the substrate holder, for introducing a first reaction gas into the process chamber, the gas inlet member having a multiplicity of openings for discharging the first reaction gas, which openings are disposed distributed over the surface of the gas inlet member lying opposite the substrate holder, and having an apparatus for preconditioning a second process gas which is to be introduced into the process chamber, characterized in that the preconditioning apparatus is disposed at an edge of the substrate holder in such a manner that the second reaction gas flows parallel to the substrate holder surface immediately above the substrate holder and transversely with respect to a direction in which the first process gas flows in. 
   
   
       2 . The apparatus according to  claim 1 , characterized in that the substrate holder is configured in the shape of a ring, and the preconditioning apparatus is located in the space inside the ring. 
   
   
       3 . The apparatus according to  claim 1 , characterized in that the substrate holder is in the shape of a trapezoid, and the preconditioning device is situated upstream of a narrow side of the trapezoid. 
   
   
       4 . The apparatus according to  claim 1 , characterized in that a cross-sectional area of the process chamber above the substrate holder is constant in the direction in which the gas flows out. 
   
   
       5 . The apparatus according to  claim 1 , characterized in that the gas inlet member is configured as a closed capped showerhead. 
   
   
       6 . The apparatus according to  claim 1 , characterized in that openings are adjacent to the openings in the gas inlet member both upstream and downstream of them in the main direction of gas flow, through which upstream and downstream openings carrier gas is introduced into the process chamber in a direction which is transverse to the main direction of gas flow, for the purpose of conditioning a diffusion/flow boundary layer. 
   
   
       7 . The apparatus according to  claim 1 , characterized in that the preconditioning apparatus includes a plasma generator. 
   
   
       8 . The apparatus according to  claim 1 , characterized in that the preconditioning apparatus has a heater. 
   
   
       9 . The apparatus according to  claim 1 , characterized in that a process chamber height is >75 mm and a rotational speed of the substrate holder, which is driven in rotation, is >100 rpm. 
   
   
       10 . The apparatus according to  claim 1 , characterized in that the injection of radicals takes place at an outer edge of a ring-shaped substrate holder. 
   
   
       11 . The apparatus according to  claim 1 , characterized in that metal alkyls are supplied through separate gas entry openings via a gas inlet system which includes two chambers. 
   
   
       12 . The apparatus according to  claim 11 , characterized by a preconditioning device, which is associated with the gas inlet member for the metal alkyls. 
   
   
       13 . The apparatus according to  claim 5 , characterized in that the showerhead has a process chamber height of between 10 mm and 75 mm.