Very low thermal budget channel implant process for semiconductors

US6180468A · kind A · utility

Assignee

• Advanced Micro Devices, Inc. · US

Inventors

• Bin Yu · Cupertino, US
• Emi Ishida · Sunnyvale, US
• Scott Luning · San Francisco, US
• Timothy Thurgate · Sunnyvale, US

Key dates

• Filing date: Oct 23, 1998
• Grant date: Jan 30, 2001
• Expiry date: Oct 23, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/0227

Abstract

An ultra-low thermal budget process is provided for channel implant by using a reverse process sequence where a conventional MOS transistor is formed without the channel implant. The originally deposited polysilicon gate is removed, a nitride film deposition and etch is used to form a nitride spacer with a predetermined configuration, and a self-aligned channel implant is performed. After the channel implantation, anneal and super-retrograded doping, the nitride spacer and the gate oxide are removed for subsequent regrowth of a second gate oxide and a polysilicon deposition to form a second polysilicon gate.