Method for depositing thin tungsten film with low resistivity and robust micro-adhesion characteristics

US8409987B2 · kind B2 · utility

Assignee

• Novellus Systems, Inc. · US

Inventors

• Anand Chandrashekar · Sunnyvale, US
• Mirko Glass · Freital, DE
• Raashina Humayun · Los Altos, US
• Michal Danek · Cupertino, US
• Kaihan Ashtiani · San Jose, US
• Feng Chen · San Jose, US
• Lana Hiului Chan · Santa Clara, US
• Anil U. Mane · Naperville, US

Key dates

• Filing date: Sep 23, 2011
• Grant date: Apr 2, 2013
• Expiry date: Sep 23, 2031

Classification

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

Abstract

Methods of forming low resistivity tungsten films with good uniformity and good adhesion to the underlying layer are provided. The methods involve forming a tungsten nucleation layer using a pulsed nucleation layer process at low temperature and then treating the deposited nucleation layer prior to depositing the bulk tungsten fill. The treatment operation lowers resistivity of the deposited tungsten film. In certain embodiments, the depositing the nucleation layer involves a boron-based chemistry in the absence of hydrogen. Also in certain embodiments, the treatment operations involve exposing the nucleation layer to alternating cycles of a reducing agent and a tungsten-containing precursor. The methods are useful for depositing films in high aspect ratio and/or narrow features. The films exhibit low resistivity at narrow line widths and excellent step coverage.