Infineon Technologies Sc300 Gmbh & Co., Kg

Torsten Seidel

Thorsten Schedel

A method for exposing a semiconductor wafer compensates for the effects of process inhomogeneities, e.g. in semiconductor etching or deposition processes, by individually adjusting sets of exposure parameters of an exposure tool for any exposure field. The exposure parameters are preferably the dose and the focus, which are varied across the semiconductor wafer.

Method for exposing a semiconductor wafer

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.

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Dresden, Germany

Torsten Seidel