Transistor of semiconductor device, and method for manufacturing the same

Abstract

A semiconductor device and a method for forming the same are disclosed. The semiconductor device includes an epitaxial source/drain junction layer having an insulating film thereunder. The method comprises the step of forming a under-cut under an epitaxial source/drain junction layer so that an insulating film filling the under-cut can be formed.

1 . A transistor of a semiconductor device, comprising: 
 an epitaxial channel region disposed on an active region of a semiconductor substrate;    a stacked structure of an insulating film and an epitaxial source/drain junction layer disposed at both sides of the channel region; and    a stacked structure of a gate insulating film and a gate electrode disposed on the epitaxial channel region, wherein at least a portion of the gate insulating film overlap with the source/drain junction layer.    
   
   
       2 . The transistor of  claim 1 , wherein the insulating film is an oxide film or a nitride film.  
   
   
       3 . The transistor of  claim 1 , wherein the insulating film and the source/drain junction layer have a thickness ranging from 50 to 1000 Å, respectively.  
   
   
       4 . The transistor of  claim 1 , further comprising a device isolation film defining the active region, the thickness of the device isolation film being substantially the same as that of the stacked structure of the insulating film and the source/drain junction layer.  
   
   
       5 . The transistor of  claim 1 , wherein the source/drain junction layer and the channel region consist of epitaxial Si layers.  
   
   
       6 . The transistor of  claim 1 , wherein the thickness of the epitaxial channel region is substantially the same as that of the stacked structure of the insulating film and the source/drain junction layer.  
   
   
       7 - 26 . (canceled).