Silicon nitride dry trim without top pulldown

US8431461B1 · kind B1 · utility

Assignee

• Lam Research Corporation · US

Inventors

• Qinghua Zhong · Nanhu, CN
• Yoshie Kimura · Castro Valley, US
• Tae Won Kim · Dublin, US
• Qian Fu · Pleasanton, US
• Gladys So-Wan Lo · Fremont, US
• Ganesh Upadhyaya · Pleasanton, US
• Yoko Yamaguchi · Union City, US

Key dates

• Filing date: Dec 16, 2011
• Grant date: Apr 30, 2013
• Expiry date: Dec 16, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/015

Abstract

A method for forming devices with silicon gates over a substrate is provided. Silicon nitride spacers are formed on sides of the silicon gates. An ion implant is provided using the silicon nitride spacers as masks to form ion implant regions. A nonconformal layer is selectively deposited over the spacers and gates that selectively deposits a thicker layer on tops of the gates and spacers and between spacers than on sidewalls of the silicon nitride spacers. Sidewalls of the nonconformal layer are etched away on sidewalls of the silicon nitride spacers. The silicon nitride spacers are trimmed.