COMPOSITE DUMMY GATE WITH CONFORMAL POLYSILICON LAYER FOR FINFET DEVICE

摘要

The present disclosure involves a FinFET. The FinFET includes a fin structure formed over a substrate. A gate dielectric layer is least partially wrapped around a segment of the fin structure. The gate dielectric layer contains a high-k gate dielectric material. The FinFET includes a polysilicon layer conformally formed on the gate dielectric layer. The FinFET includes a metal gate electrode layer formed over the polysilicon layer. The present disclosure provides a method of fabricating a FinFET. The method includes providing a fin structure containing a semiconductor material. The method includes forming a gate dielectric layer over the fin structure, the gate dielectric layer being at least partially wrapped around the fin structure. The method includes forming a polysilicon layer over the gate dielectric layer, wherein the polysilicon layer is formed in a conformal manner. The method includes forming a dummy gate layer over the polysilicon layer.