Semiconductor device and method for manufacturing the same

Abstract

There is provided a semiconductor device including: convex semiconductor layers formed on a semiconductor substrate via an insulating film; gate electrodes formed on a pair of facing sides of the semiconductor layers via a gate insulating film; a channel region formed of silicon between the gate electrodes in the semiconductor layers; a source extension region and a drain extension region formed of silicon germanium or silicon carbon on both sides of the channel region in the semiconductor layers; and a source region formed of silicon so as to adjoin to the opposite side of the channel region in the source extension region, and a drain region formed of silicon so as to adjoin to the opposite side of the channel region in the drain extension region in the semiconductor layers.

1 . A semiconductor device comprising: 
 convex semiconductor layers formed on a semiconductor substrate via an insulating film;    gate electrodes formed on a pair of facing sides of the semiconductor layers via a gate insulating film;    a channel region formed of silicon between the gate electrodes in the semiconductor layers;    a source extension region and a drain extension region formed of silicon germanium or silicon carbon on both sides of the channel region in the semiconductor layers; and    a source region formed of silicon so as to adjoin to the opposite side of the channel region in the source extension region, and a drain region formed of silicon so as to adjoin to the opposite side of the channel region in the drain extension region in the semiconductor layers.    
   
   
       2 . The semiconductor device according to  claim 1 , wherein the semiconductor layers are formed so that the surface of the source extension region and the drain extension region is located outside the surface of the channel region.  
   
   
       3 . The semiconductor device according to  claim 1 , wherein the source extension region and the drain extension region are formed of the silicon germanium or the silicon carbon evenly from the upper portion to the bottom portion of the semiconductor layers.  
   
   
       4 . The semiconductor device according to  claim 1 , wherein the semiconductor layers have a plurality of fins in each of which the channel region, the source extension region and the drain extension region is formed, and 
 the plurality of fins are formed so as to be connected by the silicon germanium or silicon carbon.    
   
   
       5 . The semiconductor device according to  claim 1 , wherein the semiconductor layers are formed on the semiconductor substrate so as to be connected to the semiconductor substrate and to penetrate the insulating film.  
   
   
       6 . The semiconductor device according to  claim 5 , wherein the silicon germanium or the silicon carbon is formed to a location lower than the upper surface of the insulating film.  
   
   
       7 . The semiconductor device according to  claim 1 , wherein the source region and the drain region are formed of the silicon germanium or the silicon carbon.  
   
   
       8 . A method for manufacturing a semiconductor device comprising: 
 depositing a mask material on a first semiconductor layer formed of silicon on a semiconductor substrate via a buried insulating film, and patterning the mask material and the first semiconductor layer, to form a first semiconductor layer having a convex shape;    forming gate insulating films on a pair of facing sides of the semiconductor layer;    depositing a gate electrode material on the buried insulating film, the gate insulating films, and the mask material, and pattering the gate electrode material, to form a gate electrode on the pair of facing sides and the upper surface of the first semiconductor layer via the gate insulating films and the mask material;    forming gate electrode sidewalls on the sides of the gate electrode, and removing the mask material formed on the first semiconductor layer and not coated by the gate electrode and the gate electrode sidewalls;    forming a source region and a drain region by the ion implantation of a predetermined impurity into the first semiconductor layer using the gate electrode and the gate electrode sidewalls as masks;    forming an insulating film on the buried insulating film, the first semiconductor layer, the gate electrode, and the gate electrode sidewalls;    forming a mask having a pattern wherein the upper surfaces of the gate electrode sidewalls are opened on the insulating film;    exposing a part of the first semiconductor layer by etching the insulating film and the gate electrode sidewalls using the mask;    removing the mask, and etching off the exposed first semiconductor layer;    forming a second semiconductor layer composed of silicon germanium or silicon carbide on the removed region; and    forming a source extension region and a drain extension region by the ion implantation of a predetermined impurity into the second semiconductor layer using the gate electrode and the insulating film as masks.    
   
   
       9 . The method for manufacturing a semiconductor device according to  claim 8 , wherein the second semiconductor layer is formed so that the surface of the second semiconductor layer is positioned outside the surface of the first semiconductor layer.  
   
   
       10 . The method for manufacturing a semiconductor device according to  claim 8 , wherein the second semiconductor layer is formed by the epitaxial growth of the silicon germanium or the silicon carbide using vapor-phase growth or solid-phase growth using the sidewall of the first semiconductor layer exposed on the sidewalls of the insulating film as seeds.  
   
   
       11 . The method for manufacturing a semiconductor device according to  claim 8 , wherein the first semiconductor layer is formed so as to have a plurality of fins.  
   
   
       12 . The method for manufacturing a semiconductor device according to  claim 11 , wherein the second semiconductor layer is formed so as to connect the plurality of fins.  
   
   
       13 . A method for manufacturing a semiconductor device comprising: 
 depositing a mask material on a first semiconductor layer formed of silicon on a semiconductor substrate via a buried insulating film, and patterning the mask material and the first semiconductor layer, to form a first semiconductor layer having a convex shape;    forming gate insulating films on a pair of facing sides of the first semiconductor layer;    depositing a gate electrode material on the buried insulating film, the gate insulating films, and the mask material, and pattering the gate electrode material, to form a gate electrode on the pair of facing sides and the upper surface of the first semiconductor layer via the gate insulating films and the mask material;    forming gate electrode sidewalls on the sides of the gate electrode, and removing the mask material formed on the first semiconductor layer and not coated by the gate electrode and the gate electrode sidewalls;    forming a source region and a drain region by the ion implantation of a predetermined impurity into the first semiconductor layer using the gate electrode and the gate electrode sidewalls as masks;    forming an insulating film on the buried insulating film, the first semiconductor layer, the gate electrode, and the gate electrode sidewalls;    planarizing the insulating film, and selectively removing the gate electrode sidewalls by wet etching to expose a part of the first semiconductor layer;    removing the mask, and etching off the exposed first semiconductor layer;    forming a second semiconductor layer composed of silicon germanium or silicon carbide on the removed region; and    forming a source extension region and a drain extension region by the ion implantation of a predetermined impurity into the second semiconductor layer using the gate electrode and the insulating film as masks.    
   
   
       14 . The method for manufacturing a semiconductor device according to  claim 13 , wherein the gate electrode sidewalls which has a higher etching rate than the etching rate of the insulating film is formed.  
   
   
       15 . The method for manufacturing a semiconductor device according to  claim 14 , wherein when a part of the first semiconductor layer is exposed, the gate electrode sidewalls are selectively removed by wet etching using hot phosphoric acid.  
   
   
       16 . The method for manufacturing a semiconductor device according to  claim 13 , wherein the second semiconductor layer is formed so that the surface of the second semiconductor layer is positioned outside the surface of the first semiconductor layer.  
   
   
       17 . The method for manufacturing a semiconductor device according to  claim 13 , wherein the second semiconductor layer is formed by the epitaxial growth of the silicon germanium or the silicon carbide using vapor-phase growth or solid-phase growth using the sidewall of the first semiconductor layer exposed on the sidewalls of the insulating film as seeds.  
   
   
       18 . The method for manufacturing a semiconductor device according to  claim 13 , wherein the first semiconductor layer is formed so as to have a plurality of fins.  
   
   
       19 . The method for manufacturing a semiconductor device according to  claim 18 , wherein the second semiconductor layer is formed so as to connect the plurality of fins.