Thermal methods for cleaning post-CMP wafers

US7709400B2 · kind B2 · utility

Assignee

• Lam Research Corporation · US

Inventors

• Zhonghui Wang · Beijing, CN
• Tiruchirapalli Arunagiri · Fremont, US
• Fritz Redeker · Fremont, US
• Yezdi Dordi · Palo Alto, US
• John M. Boyd · Atascadero, US
• Mikhail Korolik · San Jose, US
• Arthur M. Howald · Pleasanton, US
• William Thie · Mountain View, US
• Praveen Nalla · Fremont, US

Key dates

• Filing date: May 8, 2007
• Grant date: May 4, 2010
• Expiry date: May 24, 2028

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/02074
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Methods for cleaning semiconductor wafers following chemical mechanical polishing are provided. An exemplary method exposes a wafer to a thermal treatment in an oxidizing environment followed by a thermal treatment in a reducing environment. The thermal treatment in the oxidizing environment both removes residues and oxidizes exposed copper surfaces to form a cupric oxide layer. The thermal treatment in the reducing environment then reduces the cupric oxide to elemental copper. This leaves the exposed copper clean and in condition for further processing, such as electroless plating.