Apparatus and methods for detecting overlay errors using scatterometry

US7242477B2 · kind B2 · utility

Assignee

• KLA-Tencor Technologies Corp. · US

Inventors

• Walter D. Mieher · Los Gatos, US
• Ady Levy · Sunnyvale, US
• Boris Golovanesky · Haifa, IL
• Michael Friedmann · Nesher, IL
• Ian Smith · Los Gatos, US
• Michael Adel · Zichron Ya'akov, IL
• Mark Ghinovker · Migdal HaEmek, IL
• Christopher F. Bevis · Los Gatos, US
• Noam Knoll · Jerusalem, IL
• Moshe Baruch · Kiryat Shmona, IL

Key dates

• Filing date: Feb 23, 2004
• Grant date: Jul 10, 2007
• Expiry date: Aug 4, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/213
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Disclosed is a method for determining an overlay error between at least two layers in a multiple layer sample. A sample having a plurality of periodic targets that each have a first structure in a first layer and a second structure in a second layer is provided. There are predefined offsets between the first and second structures. Using a scatterometry overlay metrology, scatterometry overlay data is obtained from a first set of the periodic targets based on one or more measured optical signals from the first target set on the sample. Using an imaging overlay metrology, imaging overlay data is obtained from a second set of the periodic targets based on one or more image(s) from the second target set on the sample.