Semiconductor device including multiple field effect transistors, with first fets having oxide spacers and the second fets having oxide nitride oxidation protection

Abstract

A semiconductor device and a manufacturing method thereof permitting the quality of gate insulating films to be prevented from deteriorating and thereby permitting electrical characteristics of the device to be prevented from deteriorating are provided. In a semiconductor device including a plurality of field effect transistors, an oxidation protection film 21 is formed on a side of one gate electrode 19.

1 - 2 . (Cancelled).  
   
   
       3 . A semiconductor device including a plurality of field effect transistors including a first field effect transistor and a second field effect transistor, 
 said first field effect transistor including,    a pair of first source/drain regions formed on a main surface of a semiconductor substrate, spaced apart from each other and having a first channel region therebetween,    a first gate insulating film formed on said first channel region and having a first thickness, and    a first gate electrode formed on said first gate insulating film,    said second field effect transistor including,    a pair of second source/drain regions formed on the main surface of said semiconductor substrate, spaced apart from each other and having a second channel region therebetween, a second gate insulating film formed on said second channel region and having a second thickness larger than said first thickness, and    a second gate electrode formed on said second gate insulating film,    an anti-oxidation conductive film being formed on at least one of said first and second gate insulating films.    
   
   
       4 . The semiconductor device as recited in  claim 3 , further comprising a semiconductor film having a conductive impurity and formed at a position between said anti-oxidation conductive film and at least one of said first and second gate insulating films.  
   
   
       5 . A semiconductor device including a plurality of field effect transistors including a first field effect transistor and a second field effect transistor, 
 said first field effect transistor including,    a pair of first source/drain regions formed on a main surface of a semiconductor substrate, spaced apart from each other and having a channel region therebetween,    a first gate insulating film formed on said first channel region and having a first thickness, and    a first gate electrode formed on said first gate insulating film,    said second field effect transistor including,    a pair of second source/drain regions formed on the main surface of said semiconductor substrate, spaced apart from each other and having a second channel region therebetween,    a second gate insulating film formed on said second channel region and having a second thickness larger than said first thickness, and    a second gate electrode formed on said second gate insulating film,    a protection conductive film being formed on and in contact with at least one of said first and second gate insulating films.    
   
   
       6 . The semiconductor device as recited in  claim 5 , further comprising an anti-oxidation insulation film for preventing said protection conductive film from being oxidized being formed on said protection conductive film.  
   
   
       7 . The semiconductor device as recited in  claim 5 , wherein 
 one of said first and second gate electrodes have said protection conductive film as a first conductive film,    an insulating film formed on said first conductive film, and a second conductive film formed on said insulating film.    
   
   
       8 . The semiconductor device as recited in  claim 5 , wherein 
 said protection conductive film includes first and second protection conductive films,    said first protection conductive film is formed on and in contact with said first gate insulating film, and    said second protection conductive film is formed on and in contact with said second gate insulating film,    said first protection conductive film and second protection conductive film are substantially identical in thickness.    
   
   
       9 . The semiconductor device as recited in  claim 5 , wherein 
 said protection conductive film is formed by depositing a film having an amorphous structure.    
   
   
       10 . The semiconductor device as recited in  claim 5 , further comprising an anti-oxidation film formed on and in contact with said protection conductive film.  
   
   
       11 - 17 . (Cancelled)