METAL GATE STRUCTURE AND MANUFACTURING METHOD THEREOF

摘要

The present disclosure provides a semiconductor structure includes a semiconductor layer having a surface, and an interlayer dielectric (ILD) defining a metal gate over the surface of the semiconductor layer. The metal gate includes a high-k dielectric layer, a capping layer, and a work function metal layer. A thickness of the capping layer sidewall distal to a corner of the capping layer, is substantially thinner than a thickness which is around center of the capping layer bottom. The present disclosure provides a method for manufacturing a semiconductor structure. The method includes forming a metal gate recess, forming a high-k dielectric layer, forming a first capping layer, forming a second capping layer on the first capping layer, removing or thinning down the first capping layer sidewall, and removing the second capping layer.

主权项

1. A semiconductor structure, comprising:
a semiconductor substrate having a surface; an interlayer dielectric (ILD) defining a recess over the surface of the semiconductor substrate; a spacer lining a sidewall of the recess; a high-k dielectric layer lining a bottom of the recess and a sidewall of the spacer; a capping layer on the high-k dielectric layer, wherein a bottom portion of the capping layer and a bottom portion of the high-k dielectric layer forms an interface proximal to the bottom of the recess; and a work function metal layer on the capping layer;wherein a thickness around a center of the bottom portion of the capping layer is T1, a thickness of the sidewall portion of the capping layer, measured at a point at a distance from the interface which is greater than 4 times T1, is thicker than or equal to about 0 and thinner than about 0.5T1.