Patent ID: 7033902

Claim:
A method for making a thin film transistor with lightly doped regions, comprising: providing a substrate with a semiconductor material layer; forming an insulation layer over the semiconductor material layer; forming a conductive layer over the insulation layer; forming a photoresist layer over the conductive layer; applying a first exposure energy to the photoresist layer to form a first exposed region; applying a second exposure energy to the photoresist layer to form a second exposed region, wherein the first exposure energy is different from the second exposure energy; performing a development process on the photoresist layer to form a full-through pattern and a non-through pattern; etching a first portion of the conductive layer exposed through the full-through pattern and the gate insulation layer underneath the first portion of the conductive layer, and thereby exposing a source and a drain region in the semiconductor material layer to be formed; doping the source region and the drain region of the semiconductor material layer at high dopant concentration to form a source and a drain; removing the non-through pattern to expose a second portion of the conductive layer; etching the exposed second portion of the conductive layer to expose a lightly doped region; and lightly doping in the lightly doped region of the conductive layer.