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.

主权项

1. A semiconductor device, comprising:
a semiconductor layer disposed over a substrate, the semiconductor layer having a first fin-like structure and a second fin-like structure; a gate dielectric layer wrapped around at least a portion of both the first fin-like structure and the second fin-like structure on the semiconductor layer; a gate layer disposed over and in contact with the gate dielectric layer over the first fin-like structure in a substantially conformal manner, wherein the gate layer has a substantially constant thickness, wherein the gate layer does not extend over the second fin-like structure; and a metal gate layer disposed over the gate layer and the second fin-like structure, the metal gate layer being in direct contact with the gate dielectric layer over the second fin-like structure an interlayer dielectric layer feature disposed adjacent the metal gate layer, the interlayer dielectric layer formed over the first fin-like structure and the second fin-like structure, wherein the interlayer dielectric feature comprises:
an elongated portion, the elongated portion being positioned between and running parallel to the first fin-like structure and the second fin-like structure; anda set of perpendicularly extending portions that extend perpendicular from the elongated portion, the perpendicularly extending portions extending over the first fin-like structure and the second fin-like structure.