Method of depositing a thick titanium nitride film

US6548402B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Shulin Wang · Campbell, US
• Ming Xi · Palo Alto, US
• Frederick Wu · Cupertino, US
• Ramanujapuram A. Srinivas · San Jose, US
• Yehuda Demayo · San Jose, US
• Zvi Lando · Palo Alto, US
• Mei Chang · San Jose, US
• Russell C. Ellwanger · Hollister, US

Key dates

• Filing date: Jun 11, 1999
• Grant date: Apr 15, 2003
• Expiry date: Jun 11, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76877
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of forming a titanium nitride (TiN) layer using a reaction between ammonia (NH3) and titanium tetrachloride (TiCl4). In one embodiment, an NH3:TiCl4 ratio of about 8.5 is used to deposit a TiN layer at a temperature of about 500° C. at a pressure of about 20 torr. In another embodiment, a composite TiN layer is formed by alternately depositing TiN layers of different thicknesses, using process conditions having different NH3:TiCl4 ratios. In one preferred embodiment, a TiN layer of less than about 20 å is formed at an NH3:TiCl4 ratio of about 85, followed by a deposition of a thicker TiN layer at an NH3:TiCl4 ratio of about 8.5. By repeating the alternate film deposition using the two different process conditions, a composite TiN layer is formed. This composite TiN layer has an improved overall step coverage and reduced stress, compared to a standard TiN process, and is suitable for small geometry plug fill applications.