Chinese Optics Letters, Vol. 2, Issue 9, 09555 (2004)
Laser induced crystallization of as-deposited amorphous Ge2Sb2Te5 films
Guangjun Zhang1,*, Donghong Gu1, Fuxi Gan1, Zhenrong Sun2, and Jianyu Guo2
- 1Laboratory for High Density Optical Storage, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
- 2East China Normal University, Shanghai 200062
Crystallization is induced by pulsed laser irradiation of as-deposited amorphous Ge2Sb2Te5 films. Changes of the irradiated areas have been analyzed with the reflectivity contrast. As laser fluences increasing, the reflectivity contrast increases from 0%-2% to 14%-16%, which indicates the structure of as-deposited films transforms from amorphous to crystalline phases. The process of crystallization driven by the movement and rearrangement of atoms is described. And also the influence of the pulse duration on the threshold of crystallization is discussed, the results show that a lower threshold of crystallization can be produced for as-deposited films irradiated by the laser with short pulse duration. However, by the laser with long pulse duration, crystallization can only be formed with a higher threshold. The crystallization of films by irradiation of laser pulses is studied by Raman spectra.