Chlorine-based hardmask removal

US9478434B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Xikun Wang · Sunnyvale, US
• Mandar B. Pandit · Wilsonville, US
• Zhenjiang Cui · San Jose, US
• Mikhail Korolik · San Jose, US
• Anchuan Wang · San Jose, US
• Nitin K. Ingle · San Jose, US
• Jie Liu · Beijing, CN

Key dates

• Filing date: Nov 17, 2014
• Grant date: Oct 25, 2016
• Expiry date: Nov 17, 2034

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31144
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of removing titanium nitride hardmask is described. The hardmask resides above a low-k dielectric layer prior to removal and the low-k dielectric layer retains a relatively low net dielectric constant after the removal process. The low-k dielectric layer may be part of a dual damascene structure having copper at the bottom of the vias. A non-porous carbon layer is deposited prior to the titanium nitride hardmask removal to protect the low-k dielectric layer and the copper. The titanium nitride hardmask is removed with a gas-phase etch using plasma effluents formed in a remote plasma from a chlorine-containing precursor. Plasma effluents within the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium nitride.