Semiconductor device and manufacturing method thereof

Abstract

An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

1 . (canceled) 
     
     
         2 . A semiconductor device comprising:
 a first insulating film over a substrate, the first insulating film comprising silicon nitride;   a second insulating film over the first insulating film, the second insulating film comprising silicon oxide; and   an oxide semiconductor film over the second insulating film,
 wherein the oxide semiconductor film comprises indium and zinc. 
   
     
     
         3 . The semiconductor device according to  claim 2 ,
 wherein the oxide semiconductor film further comprises gallium.   
     
     
         4 . The semiconductor device according to  claim 2 ,
 wherein the first insulating film and the second insulating film each have a thickness of 50 nm to 100 nm.   
     
     
         5 . The semiconductor device according to  claim 2 ,
 wherein the oxide semiconductor film has a thickness of 200 nm or less.   
     
     
         6 . The semiconductor device according to  claim 2 ,
 wherein an amorphous state and a crystalline state exist in the oxide semiconductor film.   
     
     
         7 . The semiconductor device according to  claim 2 , further comprising a passivation film over the oxide semiconductor film,
 wherein the passivation film comprises silicon oxide.   
     
     
         8 . The semiconductor device according to  claim 7 ,
 wherein the passivation film is in direct contact with the oxide semiconductor film.   
     
     
         9 . The semiconductor device according to  claim 7 ,
 wherein the passivation film is in direct contact with the second insulating film.   
     
     
         10 . A semiconductor device comprising:
 a gate electrode over a substrate;   a first gate insulating film over the gate electrode, the first gate insulating film comprising silicon nitride;   a second gate insulating film over the first gate insulating film, the second gate insulating film comprising silicon oxide; and   an oxide semiconductor film over the second gate insulating film,
 wherein the oxide semiconductor film comprises indium and zinc. 
   
     
     
         11 . The semiconductor device according to  claim 10 ,
 wherein the oxide semiconductor film further comprises gallium.   
     
     
         12 . The semiconductor device according to  claim 10 ,
 wherein the first gate insulating film and the second gate insulating film each have a thickness of 50 nm to 100 nm.   
     
     
         13 . The semiconductor device according to  claim 10 ,
 wherein the oxide semiconductor film has a thickness of 200 nm or less.   
     
     
         14 . The semiconductor device according to  claim 10 ,
 wherein an amorphous state and a crystalline state exist in the oxide semiconductor film.   
     
     
         15 . A semiconductor device comprising:
 a gate electrode over a substrate;   a first gate insulating film over the gate electrode, the first gate insulating film comprising silicon nitride;   a second gate insulating film over the first gate insulating film, the second gate insulating film comprising silicon oxide;   an oxide semiconductor film over the second gate insulating film; and   a passivation film over the oxide semiconductor film,   wherein the passivation film comprises silicon oxide.   
     
     
         16 . The semiconductor device according to  claim 15 ,
 wherein the oxide semiconductor film comprises indium and zinc.   
     
     
         17 . The semiconductor device according to  claim 16 ,
 wherein the oxide semiconductor film further comprises gallium.   
     
     
         18 . The semiconductor device according to  claim 15 ,
 wherein the first gate insulating film and the second gate insulating film each have a thickness of 50 nm to 100 nm.   
     
     
         19 . The semiconductor device according to  claim 15 ,
 wherein the oxide semiconductor film has a thickness of 200 nm or less.   
     
     
         20 . The semiconductor device according to  claim 15 ,
 wherein an amorphous state and a crystalline state exist in the oxide semiconductor film.   
     
     
         21 . The semiconductor device according to  claim 15 ,
 wherein the passivation film is in direct contact with the oxide semiconductor film.   
     
     
         22 . The semiconductor device according to  claim 15 ,
 wherein the passivation film is in direct contact with the second gate insulating film.