Patent ID: 6566178
Filing Date: 2003-05-20
Classification: H01L,Y10S

Abstract:
A method of forming a thin film transistor, comprising:providing a substrate, sequentially forming a polysilicon layer, a gate oxide layer and a gate layer over the substrate; forming a photoresist layer over the gate layer, wherein the photoresist layer includes a base section and a top section with a width of the base section being greater than a width of the top section; removing a portion of the gate layer to expose the gate oxide layer while using the photoresist layer as a mask; conducting an ion implantation to form a first doped region in the polysilicon layer while using the photoresist layer as a mask; removing a portion of the photoresist layer such that photoresist material in the base section and outside the top section is completely removed, exposing the gate layer underneath and removing a pre-defined thickness of photoresist material from the top section, removing the exposed gate layer to form a gate electrode; and forming an undoped region on each side of the gate electrode.