Observation of Fast Microscopic Phase Change Phenomena of Chalcogenide Thin Films

Fast microscopic phase change phenomena are observed in real time by measuring reflectivity and transmissivity of chalcogenide thin films. The method for calculating the complex index of refraction from reflectivity and transmissivity in microscopic area is also developed. By comparing the calculated reflectivity and transmissivity with the measured ones, the dynamic phase change phenomena of the film during and after the irradiation can be guessed. Phase change of TeOx film, Te-Ge-Sn-Au film and GeTe film is observed. For the TeOx film, a model for crystallizing process is proposed.