Semiconductor device and method for fabricating the same

Abstract

A gate electrode is formed over a semiconductor region with a gate insulating film interposed therebetween. An extended high-concentration dopant diffused layer of a first conductivity type is formed in part of the semiconductor region beside the gate electrode through diffusion of a first dopant. A pocket dopant diffused layer of a second conductivity type is formed under the extended high-concentration dopant diffused layer through diffusion of heavy ions. The pocket dopant diffused layer includes a segregated part that has been formed through segregation of the heavy ions.

1 . A semiconductor device comprising: 
 a gate electrode formed over a semiconductor region with a gate insulating film interposed therebetween;    an extended high-concentration dopant diffused layer of a first conductivity type that has been formed in part of the semiconductor region beside the gate electrode through diffusion of a first dopant; and    a pocket dopant diffused layer of a second conductivity type that has been formed under the extended high-concentration dopant diffused layer through diffusion of heavy ions,    wherein the pocket dopant diffused layer includes a segregated part that has been formed through segregation of the heavy ions.    
   
   
       2 . A semiconductor device according to  claim 1 , wherein the segregated part of the pocket dopant diffused layer overlaps with a profile of the extended high-concentration dopant diffused layer.  
   
   
       3 . A semiconductor device according to  claim 1 , further comprising: 
 a sidewall formed on side faces of the gate electrode; and    a high-concentration dopant diffused layer of the first conductivity type, which has been formed in part of the semiconductor region beside the sidewall to come into contact with an outer periphery of the extended high-concentration dopant diffused layer, has a junction deeper than that of the extended high-concentration dopant diffused layer and has been formed through diffusion of a second dopant.    
   
   
       4 . A semiconductor device according to  claim 1 , further comprising a dopant diffused layer, which has been formed in part of the semiconductor region under the gate electrode through diffusion of a third dopant and will be a channel region.  
   
   
       5 . A semiconductor device according to  claim 1 , wherein the heavy ions are indium ions.