Thin Film Transistor with Increased Doping Regions

Abstract

A transistor that may be used in electronic displays to selectively activate one or more pixels. The transistor includes a metal layer, a silicon layer deposited on at least a portion of the metal layer, the silicon layer includes an extension portion that extends a distance past the metal layer, and at least three lightly doped regions positioned in the silicon layer. The at least three lightly doped regions have a lower concentration of doping atoms than other portions of the silicon layer forming the transistor.

What is claimed is:  
     
         1 . A transistor comprising:
 a metal layer;   a silicon layer deposited on at least a portion of the metal layer, the silicon layer including an extension portion that extends a distance past the metal layer; and   at least three lightly doped regions positioned in the silicon layer.   
     
     
         2 . The transistor of  claim 1 , wherein the silicon layer is a poly-silicon material. 
     
     
         3 . The transistor of  claim 1 , wherein the at least three doped regions of the at least one doped region have different lengths. 
     
     
         4 . The transistor of  claim 3 , wherein lengths gradually increase from a first end of the silicon layer towards the metal layer. 
     
     
         5 . The transistor of  claim 1 , wherein spacing portions of the silicon layer are positioned between the at least three lightly doped regions, wherein the spacing portions have an increased density of impurity atoms as compared to the at least three lightly doped regions. 
     
     
         6 . The transistor of  claim 5 , wherein the spacing portions each have a length that is substantially the same as a length of the at least three lightly doped regions. 
     
     
         7 . The transistor of  claim 1 , wherein the at least three lightly doped regions are positioned on the extension portion of the silicon layer. 
     
     
         8 . An electronic display comprising:
 at least one pixel; and   a transistor communicatively coupled to the at least one pixel and configured to selectively activate the pixel, the transistor comprises:
 a metal layer; 
 a silicon layer deposited on at least a portion of the metal layer, the silicon layer including an extension portion that extends a distance past the metal layer; and 
 at least three lightly doped regions positioned in the silicon layer. 
   
     
     
         9 . The electronic display of  claim 6 , wherein the at least three lightly doped regions are separated by portions of the silicon layer having a higher concentration of doping atoms than the at least three lightly doped regions. 
     
     
         10 . The electronic display of  claim 7 , wherein the at least three lightly doped regions have varying lengths.