Patent ID: 7170146

Claim:
A method for manufacturing a thin film transistor (TFT) comprising the steps of: providing a substrate; forming a non-single crystal semiconductor film over said substrate; forming an insulating layer over said non-single crystal semiconductor film, said insulating layer comprising a relatively thicker portion and a relatively thinner portion; and performing a doping procedure with dopants penetrating through said insulating layer, thereby simultaneously forming, in said non-single crystal semiconductor film, at least one lightly doped region under said relatively thicker portion of said insulating layer and at least one heavily doped region under said relatively thinner portion of said insulating layer; wherein said step of forming said insulating layer further comprises the steps of: forming a plurality of gate structures over said insulating layer; forming a mask between said gate structures; forming a said mask over said relatively thicker portion of said insulating layer; partially etching said insulating layer to result in said relatively thinner portion of said insulating layer; and removing said mask.