IN-SITU DETERMINATION OF PHOTORESIST GLASS-TRANSITION TEMPERATURE BY WAFER CURVATURE MEASUREMENT TECHNIQUES

The glass transition temperature (Tg) is an important feature of the g lassy polymer matrix that forms the structure of lithographic films. T g is usually determined through thermal analysis, generally using Diff erential Scanning Calorimetry (DSC). However, this kind of equipment, encountered in a laboratory environment, is not easily available on an industrial site. This paper demonstrates that the Tg of photoresists can also be determined using wafer curvature measurement (WCM) techniq ues. This non destructive technique can easily be performed in a clean -room environment. This new possibility for determining the Tg of resi st films in an industrial environment should facilitate the understand ing and control of lithographic processes.