Semiconductor device and method of fabricating the same

Abstract

A semiconductor device 1 according to one embodiment of the invention includes: a semiconductor substrate 10 ; a convex region 12 provided on the semiconductor substrate 10 ; a gate insulating film 100 provided on the convex region 12 ; a channel region 101 located in the convex region 12 under the gate insulating film 100 ; source/drain regions 115 provided on both sides of the convex region 12 and having extensions 115 a on both sides of the channel region 101 ; and a halo layer 110 provided between the convex region 12 and the source/drain region 115 so as to contact with the convex region 12.

What is claimed is: 
     
         1 . A method of fabricating a semiconductor device, comprising:
 forming a gate electrode on a semiconductor substrate via a gate insulating film;   forming gate sidewalls on a side face of the gate electrode;   etching the semiconductor substrate using the gate electrode having the gate sidewalls formed thereon as a mask;   epitaxially growing a halo layer on the semiconductor substrate, the semiconductor substrate having been etched in the process of etching the semiconductor substrate; and   epitaxially growing a source/drain region on the halo layer.   
     
     
         2 . The method of fabricating a semiconductor device according to  claim 1 , further comprising:
 forming a cap layer on the gate electrode,   wherein, in the process of etching the semiconductor substrate, the cap layer is formed and the semiconductor substrate is etched using the gate electrode having the gate sidewalls formed thereon as a mask.   
     
     
         3 . The method of fabricating a semiconductor device according to  claim 1 , wherein the semiconductor substrate is etched by a dry etching process. 
     
     
         4 . The method of fabricating a semiconductor device according to  claim 1 , wherein the semiconductor substrate is etched to a depth such that a distance from an interface between the surface of the semiconductor substrate and the gate insulating film to the surface of the etched semiconductor substrate is at least greater than a thickness of an extension provided in a semiconductor device to be fabricated. 
     
     
         5 . The method of fabricating a semiconductor device according to  claim 1 , further comprising:
 forming a spacer on the surfaces of the gate sidewalls and the semiconductor substrate after the process of etching the semiconductor substrate; and   etching the semiconductor substrate using the spacer as a mask.   
     
     
         6 . The method of fabricating a semiconductor device according to  claim 5 , wherein, in the process of etching the semiconductor substrate using the spacer as a mask, the semiconductor substrate is etched to a depth such that a distance from an interface between the surface of the semiconductor substrate and the gate insulating film to the surface of the etched semiconductor substrate is greater than a thickness of the source/drain region. 
     
     
         7 . The method of fabricating a semiconductor device according to  claim 1 , wherein the halo layer is epitaxially grown while adding an impurity. 
     
     
         8 . The method of fabricating a semiconductor device according to  claim 1 , wherein the source/drain region is epitaxially grown while adding an impurity. 
     
     
         9 . The method of fabricating a semiconductor device according to  claim 1 , further comprising:
 after forming the halo layer, exposing a portion of the semiconductor substrate by etching the halo layer, the semiconductor substrate having been etched in the process of etching the semiconductor substrate,   wherein the process of epitaxially growing the source/drain region is performed after the exposure process.   
     
     
         10 . The method of fabricating a semiconductor device according to  claim 5 , further comprising:
 an ion implantation process for implanting an epitaxial growth suppressing substance into the surface of the semiconductor substrate after the spacer formation process.