Semiconductor device and fabricating method thereof

Abstract

An interlayer film covering a semiconductor device formed on the semiconductor substrate has a film having ability of gettering the metal impurities invading from an upper portion of the interlayer film, and with this ability, the metal impurities are prevented from reaching the semiconductor substrate.

What is claimed:  
     
         1 . A fabricating method of a semiconductor device comprising the steps of: 
 forming, on a semiconductor substrate, a diffusion-preventing film for preventing metal impurities invading from an upper portion of said semiconductor substrate from reaching said semiconductor substrate,    forming an insulating film on said diffusion-preventing film,    forming a wire groove in said insulating film,    forming a metal film in said wire groove and on said insulating film, and    removing said metal film deposited on said insulating film by a CMP such that said metal film is remained in said wire groove to form a metal wire.    
     
     
         2 . A fabricating method of a semiconductor device according to  claim 1 , wherein said CMP is carried out using slurry including ferric nitrate.  
     
     
         3 . A fabricating method of a semiconductor device according to  claim 1 , wherein said metal film is Cu.  
     
     
         4 . A fabricating method of a semiconductor device according to  claim 1 , wherein said diffusion-preventing film is either one of a polysilicon film and a SIPOS film.  
     
     
         5 . A fabricating method of a semiconductor device according to  claim 4 , wherein said diffusion-preventing film includes B or P.  
     
     
         6 . A fabricating method of a semiconductor device according to  claim 1 , further comprising the steps of: 
 forming first and second insulating film under and on said diffusion-preventing film, respectively,    forming a contact hole in said second insulating film, said diffusion-preventing film and said first insulating film such that said contact hole reaches said semiconductor substrate, and    forming a third insulating film on an inner wall of said contact hole.