Active matrix substrate, display device, and image sensing device

Abstract

There is provided an active matrix substrate which enables to shorten a fabrication process of a pixel electrode, improve exposure precision by self alignment, and prevent leakage failures between pixel electrodes. The active matrix substrate has TFTs disposed in the shape of a matrix. On a light permeable substrate, there are formed gate signal lines and capacity lines. On a gate insulating film on the lines, there are formed in sequence a semiconductor layer, a source electrode and a drain electrode separated right and left by a channel protection layer. Thus, the TFTs are fabricated. Then, the entire substrate is covered with an interlayer insulating film. On top of the interlayer insulating film, there are formed pixel electrodes, which are connected to the TFTs through contact holes piercing through the interlayer insulating film. The pixel electrodes are formed by applying on the interlayer insulating film a photosensitive transparent resin such as negative acrylic polymerized resin containing ITO, ATO or ZnO as transparent conductive particles, performing exposure from the back side of the substrate, and conducting development.

What is claimed is:  
     
         1 . An active matrix substrate comprising: 
 switching elements disposed in a shape of a matrix;    gate signal lines controlling the switching elements;    source signal lines connected to the switching elements and formed orthogonal to the gate signal lines;    an interlayer insulating film formed on the switching elements, the gate signal lines, and the source signal lines; and    pixel electrodes formed on the interlayer insulating film and connected to the switching elements through contact holes piercing through the interlayer insulating film, wherein    the pixel electrodes are made from a photosensitive conductive material.    
     
     
         2 . The active matrix substrate as defined in    claim 1   , wherein the photosensitive conductive material is transparent.  
     
     
         3 . The active matrix substrate as defined in    claim 1   , wherein the photosensitive conductive material has negative type photosensitivity.  
     
     
         4 . The active matrix substrate as defined in    claim 1   , wherein the photosensitive conductive material is made from photosensitive resin and conductive particles dispersed in the photosensitive resin.  
     
     
         5 . The active matrix substrate as defined in    claim 4   , wherein the conductive particles are either indium tin oxide, antimony tin oxide, or zinc oxide.  
     
     
         6 . The active matrix substrate as defined in    claim 1   , wherein the photosensitive conductive material contains color agents.  
     
     
         7 . A flat panel display device having the active matrix substrate as defined in    claim 1   .  
     
     
         8 . A flat panel image sensing device having the active matrix substrate as defined in    claim 1   .