Optical monitoring in a two-step chemical mechanical polishing process

US6506097B1 · kind B1 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Bret W. Adams · Sunnyvale, US
• Boguslaw A. Swedek · Cupertino, US
• Rajeev Bajaj · Fremont, US
• Savitha Nanjangud · San Jose, US
• Andreas Norbert Wiswesser · Mountain View, US
• Stan Tsai · Clifton Park, US
• David A. Chan · Sunnyvale, US
• Fred C. Redeker · Fremont, US
• Manoocher Birang · Los Gatos, US

Key dates

• Filing date: Jan 16, 2001
• Grant date: Jan 14, 2003
• Expiry date: Jun 6, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/30625
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

An optical monitoring system for a two-step polishing process which generates a reflectance trace for each of plurality of radial zones. The CMP apparatus may switch from a high-selectivity slurry to a low-selectivity slurry when any of the reflectance traces indicate initial clearance of the metal layer, and polishing may halt when all of the reflectance traces indicate that oxide layer has been completely exposed.