Semiconductor device and method of manufacturing the same

Abstract

A gate insulating film is formed on a main surface of a substrate in which an element isolation region is formed. A metal film is formed on the gate insulating film. A silicon film is formed on the metal film. A gate electrode of a MIS transistor composed of a stacked structure of the silicon film and metal film is formed on an element region and a high-resistance element composed of a stacked structure of the silicon film and metal film is formed on the element isolation region by patterning the silicon film and metal film. An acid-resistant insulating film is formed on the side of the gate electrode. The metal film of the high-resistance element is oxidized. A diffused layer of the MIS transistor is formed in the substrate.

1 . A method of forming a semiconductor device comprising:
 forming a gate insulating film on a main surface of a substrate in which an element isolation region is formed;   forming a metal film on the gate insulating film;   forming a silicon film on the metal film;   forming a gate electrode of a MIS transistor composed of a stacked structure of the silicon film and metal film on an element region and a high-resistance element composed of a stacked structure of the silicon film and metal film on the element isolation region by patterning the silicon film and metal film;   forming an acid-resistant insulating film on the side of the gate electrode;   oxidizing the metal film of the high-resistance element; and   forming a diffused layer of the MIS transistor in the substrate.   
     
     
         2 . The method according to  claim 1 , further comprising: after oxidizing the metal film, forming a protective film on the top and side of the high-resistance element; and forming a silicide layer on the gate electrode and diffused layer. 
     
     
         3 . The method according to  claim 1 , wherein the metal film is oxidized by plasma oxidation. 
     
     
         4 . The method according to  claim 1 , further comprising:
 after oxidizing the metal film, introducing impurities into the silicon film of the high-resistance element.   
     
     
         5 . The method according to  claim 1 , wherein the metal film is oxidized at a temperature of 400° C. for one hour. 
     
     
         6 . The method according to  claim 1 , wherein materials for the metal film are one of Ti, Zr, Hf, V, Nb and Ta or nitride or carbide of these. 
     
     
         7 . The method according to  claim 1 , wherein materials for the metal film are alloys of one of Ti, Zr, Hf, V, Nb and Ta and Al or Si or nitride or carbide of these alloys. 
     
     
         8 . The method according to  claim 1 , further comprising:
 forming a plurality of units of the high-resistance element connected in parallel in the element isolation regions when the gate electrode is formed on the element regions and the high-resistance elements is formed on the element isolation regions.   
     
     
         9 - 13 . (canceled)