Accurate Measurements of Temperatures in the DUV Post-Exposure Bake Process.

A system for monitoring the dynamic temperature profile during the deep UV (DUV) post-exposure bake (PEB) is described. Platinum resistance temperature detectors (RTDs) are embedded into silicon wafers. Hardware and software convert the resistances to temperatures. The RTD calibration is National Institute of Standards and Technology (NIST) traceable. The wafers are tested on both a thermally uniform and stable hot plate and a production PEB hot plate. The temperature profiles for the PEB are fitted to a heat transfer model allowing heating and cooling time constants to be determined. High accuracy and precision are demonstrated. Reliability through 2000 thermal cycles is shown. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]