Method of forming a CMOS thin film transistor device

摘要

A method of forming a CMOS thin film transistor device. A dry etching procedure is performed to remove part of a photoresist layer and part of a metal layer and thus forms a gate with a symmetrical cone shape and a remaining photoresist layer. The dielectric layer is thus exposed in the lightly doped area. Specially, the bottom width of the first gate is narrower than that of the first metal layer and the symmetrical cone shape is gradually thinner from bottom to top. Using the gate as a mask, an n^--ion implantation is performed to form a self-aligned and symmetrical LDD region in a semiconductor layer without additional photolithography steps.