Display device

Abstract

A protective circuit includes a non-linear element which includes a gate electrode, a gate insulating layer covering the gate electrode, a first oxide semiconductor layer overlapping with the gate electrode over the gate insulating layer, a channel protective layer overlapping with a channel formation region of the first oxide semiconductor layer, and a pair of a first wiring layer and a second wiring layer whose end portions overlap with the gate electrode over the channel protective layer and in which a conductive layer and a second oxide semiconductor layer are stacked. Over the gate insulating layer, oxide semiconductor layers with different properties are bonded to each other, whereby stable operation can be performed as compared with Schottky junction. Thus, the junction leakage can be reduced and the characteristics of the non-linear element can be improved.

1 . (canceled) 
     
     
         2 . A semiconductor device comprising:
 a first scan line;   a second scan line;   a first transistor; and   a second transistor,   wherein one of a source and a drain of the first transistor and a gate of the first transistor are electrically connected to the first scan line,   wherein the other of the source and the drain of the first transistor is electrically connected to the second scan line,   wherein one of a source and a drain of the second transistor and a gate of the second transistor are electrically connected to the second scan line, and   wherein the other of the source and the drain of the second transistor is electrically connected to the first scan line.   
     
     
         3 . The semiconductor device according to  claim 2 ,
 wherein a channel formation region of the first transistor comprises an oxide semiconductor, and   wherein a channel formation region of the second transistor comprises an oxide semiconductor.   
     
     
         4 . A semiconductor device comprising:
 a first scan line;   a second scan line;   a first transistor;   a second transistor; and   a pixel electrode,   wherein one of a source and a drain of the first transistor and a gate of the first transistor are electrically connected to the first scan line,   wherein the other of the source and the drain of the first transistor is electrically connected to the second scan line,   wherein one of a source and a drain of the second transistor and a gate of the second transistor are electrically connected to the second scan line,   wherein the other of the source and the drain of the second transistor is electrically connected to the first scan line, and   wherein the pixel electrode overlaps with the first scan line.   
     
     
         5 . The semiconductor device according to  claim 4 ,
 wherein a channel formation region of the first transistor comprises an oxide semiconductor, and   wherein a channel formation region of the second transistor comprises an oxide semiconductor.   
     
     
         6 . A semiconductor device comprising:
 a pixel portion comprising:
 a first pixel electrically connected to a first scan line; and 
 a second pixel electrically connected to a second scan line; 
   a first protective circuit outside the pixel portion, the first protective circuit comprising a first transistor; and   a second protective circuit outside the pixel portion, the second protective circuit comprising a second transistor,   wherein one of a source and a drain of the first transistor and a gate of the first transistor are electrically connected to the first scan line,   wherein the other of the source and the drain of the first transistor is electrically connected to the second scan line,   wherein one of a source and a drain of the second transistor and a gate of the second transistor are electrically connected to the second scan line,   wherein the other of the source and the drain of the second transistor is electrically connected to the first scan line,   wherein a channel width of the first transistor is larger than a channel length of the first transistor,   wherein a channel width of the second transistor is larger than a channel length of the second transistor, and   wherein the first pixel comprises:
 a transistor; 
 an insulating film over the transistor; and 
 a pixel electrode over the insulating film, the pixel electrode electrically connected to the transistor. 
   
     
     
         7 . The semiconductor device according to  claim 6 ,
 wherein a channel formation region of the first transistor comprises an oxide semiconductor, and   wherein a channel formation region of the second transistor comprises an oxide semiconductor.   
     
     
         8 . The semiconductor device according to  claim 6 , wherein the pixel electrode overlaps with the first scan line.