Metal gate structures and methods of fabricating the same in field-effect transistors

US11476351B2 · kind B2 · utility

Assignee

• TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. · TW

Inventors

• Ru-Shang Hsiao · Dashulong, TW
• Ching-Hwanq Su · Tainan, TW
• Pin Chia Su · Danei, TW
• Ying Hsin Lu · Tainan, TW
• I-Shan Huang · Tainan, TW

Key dates

• Filing date: Jul 30, 2020
• Grant date: Oct 18, 2022
• Expiry date: Sep 2, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/038

Abstract

A method includes forming a dummy gate stack over a fin protruding from a semiconductor substrate, forming gate spacers on sidewalls of the dummy gate stack, forming source/features over portions of the fin, forming a gate trench between the gate spacers, which includes trimming top portions of the gate spacers to form a funnel-like opening in the gate trench, and forming a metal gate structure in the gate trench. A semiconductor structure includes a fin protruding from a substrate, a metal gate structure disposed over the fin, gate spacers disposed on sidewalls of the metal gate structure, where a top surface of each gate spacer is angled toward the semiconductor fin, a dielectric layer disposed over the top surface of each gate spacer, and a conductive feature disposed between the gate spacers to contact the metal gate structure, where sidewalls of the conductive feature contact the dielectric layer.