FinFET structures and methods of forming the same

US11563120B2 · kind B2 · utility

Assignee

• TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. · TW

Inventors

• Yu-Sheng Wang · Taipei, TW
• Chi-Cheng Hung · Tainan, TW
• Chia-Ching Lee · Taipei, TW
• Chung-Chiang Wu · Taichung, TW
• Ching-Hwanq Su · Tainan, TW

Key dates

• Filing date: Oct 22, 2020
• Grant date: Jan 24, 2023
• Expiry date: Nov 12, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/691

Abstract

A method includes forming a first semiconductor fin protruding from a substrate and forming a gate stack over the first semiconductor fin. Forming the gate stack includes depositing a gate dielectric layer over the first semiconductor fin, depositing a first seed layer over the gate dielectric layer, depositing a second seed layer over the first seed layer, wherein the second seed layer has a different structure than the first seed layer, and depositing a conductive layer over the second seed layer, wherein the first seed layer, the second seed layer, and the conductive layer include the same conductive material. The method also includes forming source and drain regions adjacent the gate stack.