Semiconductor device

Abstract

A transistor in which a short-channel effect is not substantially caused and which has switching characteristics even in the case where the channel length is short is provided. Further, a highly integrated semiconductor device including the transistor is provided. A short-channel effect which is caused in a transistor including silicon is not substantially caused in the transistor including an oxide semiconductor film. The channel length of the transistor including the oxide semiconductor film is greater than or equal to 5 nm and less than 60 nm, and the channel width thereof is greater than or equal to 5 nm and less than 200 nm. At this time, the channel width is made 0.5 to 10 times as large as the channel length.

1 . (canceled) 
     
     
         2 . A semiconductor device comprising:
 an oxide semiconductor film comprising:
 a first region; 
 a second region; and 
 a third region; 
   a gate electrode overlapping with the third region with a gate insulating film interposed inbetween;   an insulating film over the gate electrode;   a first wiring electrically connected to the first region via a first opening in the insulating film; and   a second wiring electrically connected to the second region via a second opening in the insulating film,   wherein the third region comprises a channel formation region,   wherein each of the first region and the third region does not overlap with the gate electrode,   wherein each of the first region and the second region comprises at least one element selected from helium, boron, nitrogen, neon, aluminum, phosphorus, arsenic, krypton, indium, tin, and antimony, and   wherein in a cross-sectional view along channel width direction the gate electrode overlaps with a top surface of the oxide semiconductor film and a side surface of the oxide semiconductor film.   
     
     
         3 . The semiconductor device according to  claim 2 , wherein each of the first region and the second region has lower resistance than the channel formation region. 
     
     
         4 . The semiconductor device according to  claim 2 , wherein the side surface of the oxide semiconductor film faces the gate electrode. 
     
     
         5 . A semiconductor device comprising:
 an oxide semiconductor film comprising:
 a first region; 
 a second region; and 
 a third region; 
   a gate electrode overlapping with the third region with a gate insulating film interposed inbetween;   an insulating film over the gate electrode;   a first wiring electrically connected to the first region via a first opening in the insulating film; and   a second wiring electrically connected to the second region via a second opening in the insulating film,   wherein the third region comprises a channel formation region,   wherein each of the first region and the third region does not overlap with the gate electrode,   wherein each of the first region and the second region comprises at least one element selected from helium, boron, nitrogen, neon, aluminum, phosphorus, arsenic, krypton, indium, tin, and antimony, and   wherein in a cross-sectional view along a direction in which the gate electrode extends the gate electrode overlaps with a top surface of the oxide semiconductor film and a side surface of the oxide semiconductor film.   
     
     
         6 . The semiconductor device according to  claim 5 , wherein each of the first region and the second region has lower resistance than the channel formation region. 
     
     
         7 . The semiconductor device according to  claim 5 , wherein the side surface of the oxide semiconductor film faces the gate electrode. 
     
     
         8 . A semiconductor device comprising:
 an oxide semiconductor film comprising:
 a first region; 
 a second region; and 
 a third region; 
   a gate electrode overlapping with the third region with a gate insulating film interposed inbetween;   an insulating film over the gate electrode;   a first wiring electrically connected to the first region via a first opening in the insulating film; and   a second wiring electrically connected to the second region via a second opening in the insulating film,   wherein the third region comprises a channel formation region,   wherein each of the first region and the third region does not overlap with the gate electrode,   wherein each of the first region and the second region has lower resistance than the channel formation region, and   wherein in a cross-sectional view along channel width direction the gate electrode overlaps with a top surface of the oxide semiconductor film and a side surface of the oxide semiconductor film.   
     
     
         9 . The semiconductor device according to  claim 8 , wherein the side surface of the oxide semiconductor film faces the gate electrode. 
     
     
         10 . A semiconductor device comprising:
 an oxide semiconductor film comprising:
 a first region; 
 a second region; and 
 a third region; 
   a gate electrode overlapping with the third region with a gate insulating film interposed inbetween;   an insulating film over the gate electrode;   a first wiring electrically connected to the first region via a first opening in the insulating film; and   a second wiring electrically connected to the second region via a second opening in the insulating film,   wherein the third region comprises a channel formation region,   wherein each of the first region and the third region does not overlap with the gate electrode,   wherein each of the first region and the second region has lower resistance than the channel formation region, and   wherein in a cross-sectional view along a direction in which the gate electrode extends the gate electrode overlaps with a top surface of the oxide semiconductor film and a side surface of the oxide semiconductor film.   
     
     
         11 . The semiconductor device according to  claim 10 , wherein the side surface of the oxide semiconductor film faces the gate electrode.