Patent ID: 6576403
Filing Date: 2003-06-10
Classification: H01L

Abstract:
A method for forming a thin film transistor comprising:forming a gate insulating layer and a gate electrode on a polysilicon layer; forming a photoresist layer with a predetermined thickness on said gate electrode and on a portion of said polysilicon layer; and implanting first conductive type impurities into said polysilicon layer with said photoresist layer as a mask so that a first ion-implant region and a second ion-implant region are formed at the same time in one step, wherein said first ion-implant region is a region in said polysilicon layer that is positioned under said photoresist layer, and the doping concentration of said second ion-implant region is higher than that of said first ion-implant region, and wherein the first and second ion-implant regions are formed after the gate insulating layer and the gate electrode are formed.