Amorphization dynamics of Ge2Sb2T35 films under nano- and femtosecond laser pulse irradiation

Summary form only given. The aim of this work is to study the amorphization dynamics upon pulsed laser irradiation (ns and fs) with highest temporal resolution (ns and fs). The pump laser used was a femtosecond-seeded regeneratively amplified laser system operating at 800 nm central wavelength with a pulse duration that could be switched from 120 fs to 8 ns by blocking the seed laser. The reflectivity evolution was measured in real-time with ns resolution by focusing a cw probe laser at 532 nm onto the center of the region irradiated by the pump laser and measuring the reflection with a fast photodiode. The sputter-deposited was a 40 nm thick, crystalline Ge₂Sb₂Te₅ film on a Si wafer that was covered with a 10 nm thick SiO₂ layer.