Thin film transistor, method of fabricating thin film transistor and pixel structure

Abstract

A method of fabricating a TFT includes providing a substrate where a gate, an insulating layer, and a channel layer are formed. A conductive layer is formed on the substrate to cover the channel layer and the insulating layer. A photoresist layer is formed on the conductive layer. A photo mask is placed above the photoresist layer and has a data line pattern, a source pattern, and a drain pattern. A first width (W 1 ) between the source pattern and the drain pattern and a second width (W 2 ) of the data line pattern satisfy the following: if W 1 −1(um), then W 2 +a(um), and 0.3<a<0.7. An exposing process is performed by using the photo mask, and a development process is performed to pattern the photoresist layer. The conductive layer is patterned by using the photoresist layer as an etching mask to form a source, a drain, and a data line.

What is claimed is: 
     
         1 . A method of fabricating a thin film transistor, comprising:
 providing a substrate, a gate, an insulating layer, and a channel layer being formed on the substrate;   forming a conductive layer on the substrate, the conductive layer covering the channel layer and the insulating layer;   forming a photoresist layer on the conductive layer;   placing a photo mask above the photoresist layer, the photo mask having a data line pattern, a source pattern, and a drain pattern, a first width (W 1 ) existing between the source pattern and the drain pattern, the data line pattern having a second width (W 2 ), wherein the first width (W 1 ) and the second width (W 2 ) satisfy the following:   if (W 1 ) is reduced by 1(um), then (W 2 ) is increased by a(um), and 0.3<a<0.7;   performing an exposing process with use of the photo mask and performing a development process to pattern the photoresist layer; and   patterning the conductive layer with use of the photoresist layer as an etching mask to form a source, a drain, and a data line.   
     
     
         2 . The method as claimed in  claim 1 , wherein a thickness of the photoresist layer corresponding to the data line pattern of the photo mask is greater than a thickness of the photoresist layer corresponding to the source pattern and the drain pattern of the photo mask. 
     
     
         3 . The method as claimed in  claim 2 , wherein the thickness of the photoresist layer corresponding to the data line pattern of the photo mask differs from the thickness of the photoresist layer corresponding to the source pattern and the drain pattern of the photo mask by about 4900 angstroms˜about 6200 angstroms. 
     
     
         4 . The method as claimed in  claim 1 , wherein energy of the exposing process is approximately 23 mj/cm 2 ˜26 mj/cm 2 .