Fabrication method of semiconductor device and semiconductor device

Abstract

Gases for film formation are introduced from a plurality of holes provided at a gas nozzle into a processing chamber of a batch-type CVD film-forming apparatus to cause a turbulence of the gases within the processing chamber. In the state where the chamber is kept at a pressure within an atmospheric and quasi-atmospheric pressure region, a silicon-germanium film is epitaxially grown on a semiconductor wafer placed within the processing chamber. Subsequently, a strained silicon film is epitaxially grown on the silicon-germanium film. Thereafter, a semiconductor element is formed in the semiconductor wafer on which the silicon-germanium film and the strained silicon film have been formed, respectively.

1 - 11 . (canceled)  
   
   
       12 . A semiconductor device, comprising: 
 a semiconductor substrate;    a silicon-germanium film epitaxially grown over said semiconductor substrate; and    a silicon film epitaxially grown over said silicon-germanium film,    wherein a distribution of concentration of germanium along a thickness of said silicon-germanium film has a peak in an intermediate region along the thickness of said silicon-germanium film.    
   
   
       13 . The semiconductor device according to  claim 12 , further comprising a silicon film formed between said semiconductor substrate and said silicon-germanium film.  
   
   
       14 . The semiconductor device according to  claim 12 , wherein the distribution of concentration of germanium along the thickness of said silicon-germanium film increases from the vicinity of an interface at the side of said semiconductor substrate toward an inward direction of said silicon-germanium film, once decreases toward the interface at the silicon film side after having once had said peak in said intermediate region, and is kept substantially constant to an extent of the interface at the silicon film side.  
   
   
       15 . The semiconductor device according to  claim 12 , wherein a concentration of germanium in said silicon-germanium film in the vicinity of the interface between said silicon-germanium film and said silicon film is within a range of from 5 to 40 atomic %.  
   
   
       16 . The semiconductor device according to  claim 12 , wherein a difference between said peak of the concentration of germanium in said silicon-germanium film and a concentration of germanium in said silicon-germanium film in the vicinity of the interface between said silicon-germanium film and said silicon film is within a range of from 1 to 40 atomic %.  
   
   
       17 . The semiconductor device according to  claim 12 , wherein a difference between said peak of the concentration of germanium in said silicon-germanium film and a concentration of germanium in said silicon-germanium film in the vicinity of the interface between said silicon-germanium film and said silicon film is within a range of from 3 to 20 atomic %.  
   
   
       18 . The semiconductor device according to  claim 12 , wherein a difference between said peak of the concentration of germanium in said silicon-germanium film and a concentration of germanium in said silicon-germanium film in the vicinity of the interface between said silicon-germanium film and said silicon film is within a range of from 5 to 10 atomic %.  
   
   
       19 . The semiconductor device according to  claim 12 , wherein a ratio of said peak of the concentration of germanium in said silicon-germanium film to the concentration of germanium in said silicon-germanium film in the vicinity of the interface between said silicon-germanium film and said silicon film is within a range of from 1.02 to 9.0.  
   
   
       20 . The semiconductor device according to  claim 12 , wherein a ratio of said peak of the concentration of germanium in said silicon-germanium film to the concentration of germanium in said silicon-germanium film in the vicinity of the interface between said silicon-germanium film and said silicon film is within a range of from 1.1 to 3.0.  
   
   
       21 . The semiconductor device according to  claim 12 , wherein a ratio of said peak of the concentration of germanium in said silicon-germanium film to the concentration of germanium in said silicon-germanium film in the vicinity of the interface between said silicon-germanium film and said silicon film is within a range of from 1.2 to 1.7.  
   
   
       22 - 39 . (canceled)