Patent ID: 6734034
Filing Date: 2004-05-11
Classification: H01L,Y10S

Abstract:
A method of forming a thin film transistor and its associated driver, comprising:providing a substrate, wherein the substrate is divided into a first type thin film transistor region, a second type thin film transistor region and a pixel thin film transistor region; forming a patterned polysilicon layer over the substrate; sequentially forming a gate oxide layer and a gate layer over the patterned polysilicon layer and the substrate; forming a patterned first photoresist layer over the first type thin film transistor region, the second type thin film transistor region and the pixel thin film transistor region; removing a portion of the gate layer to form a first type thin film transistor gate while using the first photoresist layer as a mask; conducting a first ion implantation to form a first doped region in the polysilicon layer on each side of the first type thin film transistor gate; removing the first photoresist layer; forming a patterned second photoresist layer over the second type thin film transistor region, the pixel thin film transistor region and the first type thin film transistor region, wherein the second photoresist layer over the pixel thin film transistor region includes a top section and a base 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 second photoresist layer as a mask; conducting a second ion implantation to form a second doped region in the polysilicon layer using the second photoresist layer as a mask; removing a portion of the second photoresist layer such that photoresist material in the base section 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; and removing the exposed gate layer to form a pixel thin film transistor gate electrode.