Semiconductor device and method of manufacturing semiconductor device

Abstract

A semiconductor device includes a semiconductor substrate; a first gate insulation film formed on the semiconductor substrate; a second gate insulation film formed on the semiconductor substrate; a first gate electrode formed on the first gate insulation film and fully silicided; and a second gate electrode formed on the second gate insulation film and fully silicided, a gate length or a gate width of the second gate electrode being larger than that of the first gate electrode, and a thickness of the second gate electrode being smaller than that of the first gate electrode.

1 . A semiconductor device comprising: 
 a semiconductor substrate;    a first gate insulation film formed on the semiconductor substrate;    a second gate insulation film formed on the semiconductor substrate;    a first gate electrode formed on the first gate insulation film and fully silicided; and    a second gate electrode formed on the second gate insulation film and fully silicided, a gate length or a gate width of the second gate electrode being larger than that of the first gate electrode, and a thickness of the second gate electrode being smaller than that of the first gate electrode.    
   
   
       2 . The semiconductor device according to  claim 1 , wherein 
 the bottom surface of the second gate electrode is disposed at a higher level from the surface of the semiconductor substrate than the bottom surface of the first gate electrode.    
   
   
       3 . The semiconductor device according to  claim 2 , wherein 
 the upper surface of the second gate electrode is disposed at a same level as the upper surface of the first gate electrode.    
   
   
       4 . The semiconductor device according to  claim 1 , wherein 
 the thickness from the bottom surface to the upper surface of the second gate electrode is less than a half of the thickness from the bottom surface to the upper surface of the first gate electrode.    
   
   
       5 . The semiconductor device according to  claim 1 , wherein 
 the gate length or the gate width of the first gate electrode is less than 50 nm,    the gate length or the gate width of the second gate electrode is more than 50 nm.    
   
   
       6 . The semiconductor device according to  claim 2  further comprising: 
 a metal layer functioning as a source layer or a drain layer.    
   
   
       7 . The semiconductor device according to  claim 6  further comprising: 
 a high-concentration layer provided around the metal layer and having an impurity concentration higher than the impurity concentration of a well diffusion layer formed on the semiconductor substrate or the impurity concentration of the semiconductor substrate.    
   
   
       8 . A semiconductor device comprising: 
 a semiconductor substrate;    a first gate insulation film formed on the semiconductor substrate;    a second gate insulation film formed on the semiconductor substrate;    a first gate electrode formed on the first gate insulation film and fully silicided; and    a second gate electrode including a plurality of sub-gate electrodes formed on the second gate insulation film, the second gate electrode having a gate length or a gate width larger than that of the first gate electrode, wherein    the plurality of sub-gate electrodes are fully silicided.    
   
   
       9 . The semiconductor device according to  claim 8 , wherein 
 the thickness from the bottom surface to the upper surface of the first gate electrode is same as the thickness from the bottom surface to the upper surface of the sub-gate electrodes.    
   
   
       10 . The semiconductor device according to  claim 8 , wherein 
 the gate length or the gate width of the first gate electrode is same as the gate length or the gate width of the sub-gate electrode.    
   
   
       11 . The semiconductor device according to  claim 8 , wherein 
 the second gate electrode includes a silicide layer provided on the second gate insulation film between the adjacent sub-gate electrodes.    
   
   
       12 . A semiconductor device comprising: 
 a semiconductor substrate;    a first gate insulation film formed on the semiconductor substrate;    a second gate insulation film formed on the semiconductor substrate;    a first gate electrode formed on the first gate insulation film and fully silicided; and    a second gate electrode including particles and provided on the second gate insulation film and fully silicided, the area of the semiconductor substrate occupied by the second gate electrode being larger than that of the first gate electrode.    
   
   
       13 . The semiconductor device according to  claim 12 , wherein 
 the particles are made of insulation materials or cavities.    
   
   
       14 . The semiconductor device according to  claim 12 , wherein 
 the volume of the silicide in the second gate electrode is equal to the volume of the silicide in the first gate electrode.    
   
   
       15 . The semiconductor device according to  claim 12 , wherein 
 the first gate electrode is made of Ni 2 Si,    the second gate electrode is made of NiSi.    
   
   
       16 . The semiconductor device according to  claim 12 , wherein 
 the first gate electrode has a two-layer structure constituted by an Ni 2 Si layer and an Ni(SiGe) layer,    the second gate electrode is made of NiSi.    
   
   
       17 . A method of manufacturing a semiconductor device comprising: 
 preparing a semiconductor substrate having a first surface region and a second surface region;    epitaxially growing a semiconductor region on the second surface region;    forming a first gate insulation film on the first surface region and forming a second gate insulation film on the semiconductor region;    forming a first gate electrode on the first gate insulation film, and forming a second gate electrode on the second gate insulation film, the second gate electrode having a height equal to that of the first gate electrode and having a width larger than that of the first gate electrode;    depositing a metal film on the first gate electrode and on the second gate electrode; and    fully siliciding the first gate electrode and the second gate electrode.    
   
   
       18 . A method of manufacturing a semiconductor device comprising: 
 preparing a semiconductor substrate having a first surface region and a second surface region;    etching the semiconductor substrate of the first surface region;    forming a first gate electrode on the first gate insulation film, and forming a second gate electrode on the second gate insulation film;    forming a first gate electrode on the first gate insulation film, and forming a second gate electrode on the second gate insulation film, the second gate electrode having a height equal to that of the first gate electrode and having a width larger than that of the first gate electrode;    covering source and drain diffusion layers or silicide electrodes with an interlayer insulation film, the source and drain diffusion layers or the suicide electrodes being formed on both sides of the first gate electrode and both sides of the second gate electrode;    polishing the interlayer insulation film to expose the upper surface of the first gate electrode and the upper surface of the second gate electrode;    depositing a metal film on the first gate electrode and on the second gate electrode; and    fully siliciding the first gate electrode and the second gate electrode.    
   
   
       19 . A method of manufacturing a semiconductor device comprising: 
 preparing a semiconductor substrate having a first surface region and a second surface region;    forming a first gate insulation film on the first surface region and forming a second gate insulation film on the second surface region;    depositing a gate electrode material on the first and second gate insulation films;    etching the gate electrode material on the first gate insulation film to form a first gate electrode and etching the gate electrode material on the second gate insulation film to form a second gate electrode which includes a plurality of sub-gate electrodes arranged on the second gate insulation film and which occupies an area larger than an area occupied by the first gate electrode on the semiconductor substrate;    depositing a metal film on the first gate electrode and the second gate electrode; and    fully siliciding the first gate electrode and the second gate electrode.    
   
   
       20 . A method of manufacturing a semiconductor device comprising: 
 preparing a semiconductor substrate having a first surface region and a second surface region;    forming a first gate insulation film on the first surface region and forming a second gate insulation film on the second surface region;    depositing a gate electrode material on the first and second gate insulation films;    implanting oxygen into the gate electrode material on the second gate insulation film;    annealing the gate electrode material to form particles in the gate electrode material on the second gate insulation film;    forming a first gate electrode on the first gate insulation film, and forming a second gate electrode on the second gate insulation film, the second gate electrode having a width larger than that of the first gate electrode;    depositing a metal film on the first gate electrode and the second gate electrode; and    fully siliciding the first gate electrode and the second gate electrode.