Semiconductor device and manufacturing process therefor

Abstract

There is provided a semiconductor device comprising a dielectric film made of a high dielectric constant material, in which a leak current is reduced in the film and which exhibits improved device reliability. Specifically, a dielectric film 142 is a metal-compound film having a composition represented by the formula MO x C y N z wherein x, y and z meet the conditions: 0<x, 0.1≦y≦1.25, 0.01≦z and x+y+z=2; and M comprises at least Hf or Zr.

What is claimed is:  
     
         1 . A semiconductor device comprising a semiconductor substrate and a metal-compound film thereon, wherein the metal-compound film has a composition represented by the formula: 
       MO x C y N z   
       wherein x, y and z meet the conditions: 0<x, 0.1≦y≦1.25,0. 0 1≦z and x+y+z=2; and M comprises at least Hf or Zr.  
     
     
         2 . The semiconductor device as claimed in  claim 1 , wherein the formula further meets the conditions: 0.7≦x≦1.85 and 0.05≦z≦0 .2.  
     
     
         3 . The semiconductor device as claimed in  claim 1 , wherein the metal-compound film is formed by chemical vapor deposition.  
     
     
         4 . The semiconductor device as claimed in  claim 1 , wherein the metal-compound film is formed by atomic layer deposition.  
     
     
         5 . A semiconductor device comprising a semiconductor substrate, a pair of electrodes thereon and a capacitor comprising a dielectric film between the electrodes, wherein the dielectric film comprises a metal-compound film having a composition represented by the formula: 
       MO x C y   N   z   
       wherein x, y and z meet the conditions: 0<x, 0.1≦y≦1.25, 0.01≦z and x+y+z=2; and M comprises at least Hf or Zr.  
     
     
         6 . The semiconductor device as claimed in  claim 5 , wherein said pair of electrodes comprise one or more of metal-compound selected from the group consisting of TiN, Ti, TaN, Ta, W, WN, Pt, Ir and Ru.  
     
     
         7 . The semiconductor device as claimed in  claim 5 , wherein said pair of electrodes comprise TiN.  
     
     
         8 . The semiconductor device as claimed in  claim 5 , wherein the thickness of said pair of electrodes is 5 to 40 nm.  
     
     
         9 . The semiconductor device as claimed in  claim 5 , further comprising a gate electrode formed on the semiconductor substrate; a transistor comprising: 
 a source and a drain regions formed in the semiconductor substrate whose surfaces are silicided; and    a connecting plug for connecting the source and the drain regions in the transistor with the capacitor.    
     
     
         10 . A semiconductor device comprising a semiconductor substrate; a gate insulating film formed on the main surface of the semiconductor substrate; a gate electrode on the gate insulating film; and a source and a drain regions formed on the semiconductor substrate which together sandwich the gate electrode, 
 wherein the gate insulating film comprises a metal-compound film having a composition represented by the formula:   MO x C y N z     wherein x, y and z meet the conditions: 0<x, 0.1≦y≦1.25, 0.01≦z and x+y+z=2; and M comprises at least Hf or Zr.    
     
     
         11 . A process for manufacturing a semiconductor device, comprising the step of forming a metal-compound film having a composition represented by the formula: 
       MO x C y N z   
       wherein x, y and z meet the conditions: 0<x, 0.1≦y≦1.25, 0.01≦z and x+y+z=2; and M comprises at least Hf or Zr, on a semiconductor substrate by atomic layer deposition.  
     
     
         12 . The process for manufacturing a semiconductor device as claimed in  claim 11 , wherein the formula meets the conditions: 0.7≦x≦1.85 and 0.05≦z≦0.2.  
     
     
         13 . The process for manufacturing a semiconductor device as claimed in  claim 11 , wherein when forming the metal-compound film by atomic layer deposition, M(NRR′) 4  wherein M comprises at least Hf or Zr; and R and R′ independently represent hydrocarbon, is used as a component of a deposition gas.  
     
     
         14 . The process for manufacturing a semiconductor device as claimed in  claim 11 , wherein when forming the metal-compound film by atomic layer deposition, one or more of gases selected from the group consisting of NO, N 2 O, NO 2 , H 2 O, O 2  and O 3  are used as an oxidizer gas.  
     
     
         15 . The process for manufacturing a semiconductor device as claimed in  claim 11 , comprising the step of annealing the metal-compound film under nitrogen or a nitrogen-containing atmosphere after forming the metal-compound film, to introduce nitrogen into the metal-compound film.  
     
     
         16 . The process for manufacturing a semiconductor device as claimed in  claim 15 , wherein the step of introducing nitrogen into the metal-compound film is conducted using a remote plasma.  
     
     
         17 . A process for manufacturing a semiconductor device comprising forming a first electrode, a dielectric film and a second electrode on a semiconductor substrate, 
 wherein the step of forming the dielectric film comprises forming a metal-compound film having a composition represented by the formula:   MO x C y N z     wherein x, y and z meet the conditions: 0<x, 0.1≦y≦1.25, 0.01≦z and x+y+z=2; and M comprises at least Hf or Zr, on a semiconductor substrate by atomic layer deposition.    
     
     
         18 . The process for manufacturing a semiconductor device as claimed in  claim 17 , further comprising the steps of: 
 forming a gate electrode on the semiconductor substrate;    introducing a dopant into the main surface of the semiconductor substrate to form a source and a drain regions such that the gate electrode is sandwiched between the regions;    siliciding the surfaces of the source and the drain regions; and    forming an interlayer insulating film over the gate electrode, the source region and the drain region, then selectively removing the interlayer insulating film to form a contact hole reaching the source and the drain regions, and then filling the contact hole with a metal film to form a connecting plug,    wherein the first electrode is formed such that the connecting plug is connected with the first electrode;    the dielectric film is formed at 200° C. to 400° C. both inclusive and the first and the second electrodes are formed at 500° C. or lower.    
     
     
         19 . The process for manufacturing a semiconductor device as claimed in  claim 17 , wherein the step of forming the first electrode comprises forming the first electrode by ALD, CVD or sputtering at 500° C. or lower, and the step of forming the second electrode comprises forming the second electrode by ALD, CVD or sputtering at 500° C. or lower.  
     
     
         20 . A process for manufacturing a semiconductor device comprising the steps of: 
 forming a gate insulating film on a semiconductor substrate;    forming a gate electrode film on the gate insulating film;    shaping the gate insulating film and the gate electrode film into a given shape to form a gate electrode; and    introducing a dopant into the main surface of the semiconductor substrate to form a source and a drain regions such that the gate electrode is sandwiched between the regions,    wherein the step of forming the gate insulating film comprises forming a metal-compound film having a composition represented by the formula:   MO x C y N z     wherein x, y and z meet the conditions: 0<x, 0.1≦y≦1. 25, 0.01≦z and x+y+z=2; and M comprises at least Hf or Zr, on a semiconductor substrate by atomic layer deposition.