Semiconductor device

Abstract

A semiconductor device is provided. The semiconductor device includes: a substrate; device isolation regions formed in the substrate; an impurity region formed in a region of the substrate between every two adjacent ones of the device isolation regions; a gate electrode formed on the substrate; first and second interlayer insulating films sequentially formed on the substrate; a metal interlayer insulating film formed on the second interlayer insulating film and comprising metal wiring layers; a first contact plug electrically connecting each of the metal wiring layers and the impurity region; and a second contact plug electrically connecting each of the metal wiring layers and the gate electrode, wherein the first contact plug is formed in the first and second interlayer insulating films, and the second contact plug is formed in the second interlayer insulating film.

What is claimed is: 
     
         1 . A semiconductor device comprising:
 a substrate;   device isolation regions formed in the substrate;   an impurity region formed in a region of the substrate between every two adjacent ones of the device isolation regions;   a gate electrode formed on the substrate;   metal wiring layers formed on the substrate;   a first contact plug electrically connecting each of the metal wiring layers and the impurity region and comprising first and second sub contact plugs which are sequentially formed on the impurity region; and   a second contact plug electrically connecting each of the metal wiring layers and the gate electrode,   wherein the first contact plug and the second contact plug are made of different conductive materials, and the second contact plug and the second sub contact plug are made of the same conductive material.   
     
     
         2 . The semiconductor of  claim 1 , wherein the conductive material that forms the second sub contact plug and the second contact plug has a lower resistance than the conductive material that forms the first sub contact plug. 
     
     
         3 . The semiconductor device of  claim 2 , wherein the conductive material that forms the first sub contact plug comprises tungsten. 
     
     
         4 . The semiconductor device of  claim 3 , wherein the conductive material that forms the second sub contact plug and the second contact plug comprises copper. 
     
     
         5 . The semiconductor device of  claim 4 , wherein the metal wiring layers comprise copper. 
     
     
         6 . The semiconductor device of  claim 1 , further comprising a silicide film formed on the impurity region. 
     
     
         7 . The semiconductor device of  claim 6 , wherein the gate electrode comprises a polysilicon film and a silicide film which is formed on the polysilicon film. 
     
     
         8 . The semiconductor device of  claim 1 , wherein the gate electrode is formed on each of the device isolation regions.