Semiconductor structure having a metal gate with side wall spacers

摘要

A method of forming a semiconductor structure having a metal gate. Firstly, a semiconductor substrate is provided. Subsequently, at least a gate structure is formed on the semiconductor substrate. Afterwards, a spacer structure is formed to surround the gate structure. Then, an interlayer dielectric is formed. Afterwards, a planarization process is performed for the interlayer dielectric. Then, a portion of the sacrificial layer is removed to form an initial etching depth, such that an opening is formed to expose a portion of the spacer structure. The portion of the spacer structure exposed to the opening is removed so as to broaden the opening. Afterwards, remove the sacrificial layer completely via the opening. Finally, a gate conductive layer is formed to fill the opening.

主权项

1. A method of forming a semiconductor structure having a metal gate, the method comprising the following steps:
providing a semiconductor substrate; forming at least a gate structure on the semiconductor substrate, the gate structure comprising a gate dielectric layer and a gate sacrificial layer; forming a spacer structure on a peripheral side wall of the gate structure; forming an interlayer dielectric layer covering the gate structure and the spacer structure; planarizing the interlayer dielectric layer to expose the gate sacrificial layer; removing a portion of the gate sacrificial layer to an initial etching depth to form an opening and expose a portion of the spacer structure, wherein the initial etching depth is at least larger than half of a height of the gate sacrificial layer in the step of removing the portion of the sacrificial layer to the initial etching step; after removing the portion of the gate sacrificial layer, removing a portion of the spacer structure exposed to the opening to broaden the opening; removing the gate sacrificial layer completely; and forming a gate conductive layer to fill the opening.