Overlay metrology by pupil phase analysis

US8582114B2 · kind B2 · utility

Assignee

• KLA-TENCOR CORPORATION · US

Inventors

• Amnon Manassen · Haifa, IL
• Daniel Kandel · Aseret, IL
• Moshe Baruch · Kiryat Shmona, IL
• Vladimir Levinski · Milpitas, US
• Noam Sapiens · Cupertino, US
• Joel Seligson · Kiryat Shmona, IL
• Andy Hill · Sunnyvale, US
• Ohad Bachar · Timrat, IL
• Daria Negri · Nesher, IL
• Ofer Zaharan · Jerusalem, IL

Key dates

• Filing date: Aug 15, 2011
• Grant date: Nov 12, 2013
• Expiry date: Jan 13, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70633
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The present invention may include measuring a first phase distribution across a pupil plane of a portion of illumination reflected from a first overlay target of a semiconductor wafer, wherein the first overlay target is fabricated to have a first intentional overlay, measuring a second phase distribution across the pupil plane of a portion of illumination reflected from a second overlay target, wherein the second overlay target is fabricated to have a second intentional overlay in a direction opposite to and having the same magnitude as the first intentional overlay, determining a first phase tilt associated with a sum of the first and second phase distributions, determining a second phase tilt associated with a difference between the first and second phase distributions, calibrating a set of phase tilt data, and determining a test overlay value associated with the first and second overlay target.