Well implant through dummy gate oxide in gate-last process

摘要

The present disclosure relates to methods for fabricating a field-effect transistor. The method includes performing a pocket implantation to a semiconductor substrate; thereafter forming a polysilicon layer on the semiconductor substrate; and patterning the polysilicon layer to form a polysilicon gate. The field-effect transistor (FET) includes a well of a first type dopant, formed in a semiconductor substrate; a metal gate disposed on the semiconductor substrate and overlying the well; a channel formed in the semiconductor substrate and underlying the metal gate; source and drain regions of a second type dopant opposite from the first type, the source and drain regions being formed in the semiconductor substrate and on opposite sides of the channel; and a pocket doping profile of the first type dopant and being defined in the well to form a continuous and uniform doping region from the source region to the drain region.