Patent ID: 7087363

Claim:
A method of forming a top gate thin film transistor (TFT), comprising the steps of: providing a transparent substrate having at least one active area thereon, wherein the active area includes a channel area; forming a silicon layer on the substrate; using a first reticle, and forming a first photoresist layer on the silicon layer in the active area, wherein the first photoresist layer has a thick photoresist layer portion and a thin photoresist layer portion, and the thin photoresist layer portion corresponds to the channel area; using the first photoresist layer as a mask, removing part of the silicon layer to form a silicon island on the substrate in the active area, and removing the thin photoresist layer portion to expose the silicon island in the channel area; using the thick photoresist layer portion as a mask, implanting impurities into the silicon island in the channel area; removing the thick photoresist layer portion; forming a gate insulating layer on the silicon island and the substrate; using a second reticle, forming a metal layer on the gate insulating layer in the channel area; and using the metal layer as a mask, performing a high-dose ion implantation to form a source region and a drain region in part of the silicon island.