Display device

Abstract

A display device includes a pixel portion in which a pixel electrode layer is arranged in a matrix, and an inverted staggered thin film transistor having a combination of at least two kinds of oxide semiconductor layers with different amounts of oxygen is provided corresponding to the pixel electrode layer. In the periphery of the pixel portion in this display device, a pad portion is provided to be electrically connected to a common electrode layer formed on a counter substrate through a conductive layer made of the same material as the pixel electrode layer. One objection of our invention to prevent a defect due to separation of a thin film in various kinds of display devices is realized, by providing a structure suitable for a pad portion provided in a display panel.

1 . (canceled) 
     
     
         2 . A semiconductor device comprising:
 a pixel portion; and   a connection portion outside the pixel portion,   wherein the connection portion comprises:
 a first conductive layer separated from a gate wiring of the pixel portion, wherein the first conductive layer and the gate wiring comprise aluminum; 
 a second conductive layer separated from a source wiring of the pixel portion, the second conductive layer and the source wiring comprise aluminum; and 
 a transparent conductive film over the second conductive layer, 
   wherein the second conductive layer is electrically connected to the first conductive layer and the transparent conductive film,   wherein the second conductive layer is located over the first conductive layer with a first insulating layer interposed therebetween,   wherein the transparent conductive film is located over the first conductive layer with the first insulating layer and a second insulating layer interposed therebetween,   wherein the first insulating layer comprises a first opening and the second insulating layer comprises a second opening,   wherein the transparent conductive film overlaps with the first opening and the second opening,   wherein the second opening does not overlap with the first opening,   wherein the second conductive layer overlaps with the first conductive layer,   wherein the second conductive layer comprises a first region having a first width and a second region having a second width smaller than the first width, the second region extending from the first region,   wherein in a first direction, the second region of the second conductive layer extends beyond a side edge of the first conductive layer and a side edge of the transparent conductive film,   wherein in the first direction, the transparent conductive film extends beyond both side edges of the first conductive layer,   wherein in a second direction intersecting with the first direction, the first width of the first region of the second conductive layer is smaller than a width of the first conductive layer and smaller than a width of the transparent conductive film, and   wherein the semiconductor device has a function of driving in FFS mode.   
     
     
         3 . The semiconductor device according to  claim 2 , wherein the connection portion is located in a position which does not overlap a sealant. 
     
     
         4 . A semiconductor device comprising:
 a pixel portion; and   a connection portion outside the pixel portion,   wherein the connection portion comprises:
 a first conductive layer separated from a gate wiring of the pixel portion, wherein the first conductive layer and the gate wiring comprise aluminum; 
 a second conductive layer separated from a source wiring of the pixel portion, the second conductive layer and the source wiring comprise aluminum; and 
 a transparent conductive film over the second conductive layer, 
   wherein the second conductive layer is electrically connected to the first conductive layer and the transparent conductive film,   wherein the second conductive layer is located over the first conductive layer with a first insulating layer interposed therebetween,   wherein the transparent conductive film is located over the first conductive layer with the first insulating layer and a second insulating layer interposed therebetween,   wherein the first insulating layer comprises a first opening and the second insulating layer comprises a second opening and a third opening,   wherein the transparent conductive film overlaps with the first opening and the second opening,   wherein the second opening does not overlap with the first opening,   wherein the third opening does not overlap with the first opening,   wherein the second conductive layer overlaps with the first conductive layer,   wherein the second conductive layer comprises a first region having a first width and a second region having a second width smaller than the first width, the second region extending from the first region,   wherein in a first direction, the second region of the second conductive layer extends beyond a side edge of the first conductive layer and a side edge of the transparent conductive film,   wherein in the first direction, the transparent conductive film extends beyond both side edges of the first conductive layer,   wherein in a second direction intersecting with the first direction, the first width of the first region of the second conductive layer is smaller than a width of the first conductive layer and smaller than a width of the transparent conductive film, and   wherein the semiconductor device has a function of driving in FFS mode.   
     
     
         5 . The semiconductor device according to  claim 4 , wherein the connection portion is located in a position which does not overlap a sealant.