Method for adjusting a temperature in a resist process

US6806008B2 · kind B2 · utility

Assignee

• Infineon Technologies SC 300 GmbH & Co. KG · DE

Inventors

• Thorsten Schedel · Dresden, DE
• Torsten Seidel · Dresden, DE

Key dates

• Filing date: Jul 3, 2002
• Grant date: Oct 19, 2004
• Expiry date: Nov 2, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/40
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A test reticle having a pad and antenna structures with varying critical dimensions is provided to measure sidewall angles developing in the resist sidewalls of clear lines. These sidewall angles originate from resist flow due to the occurrence of excessively high temperatures in a resist process on a lithographic track after the exposure of a semiconductor wafer. A scanning electron microscope is used to perform the measurement. A sequence of temperatures is applied in each postbake step to process a wafer, and the sidewall angle is determined afterwards from e.g. a critical dimension measurement with a known resist thickness. An error signal is issued, if a threshold value of a sidewall angle is exceeded. The temperature of the resist process, e.g. the postbake, is then adjusted to a temperature below the temperature causing the warning signal.