Raman Study on the Crystallization Characteristics of Amorphous Ge2Sb2Te5 Film

Phase-change materials are the basis for next generation memory devices, but the fundamental mechanism of the phase transitions has not been elucidated clearly. In this paper, the microstructure treated by isothermal and the laser radiance was compared by Raman spectroscopy. It was found that the peak similar to 105 cm(-1) originated from GeTe4 tetrahedral structure and the intensity of this peak became weak with the enhancement of laser pulse energy and extension of annealing time. Moreover, we also ascribed the Raman peaks in specific positions to the GeTe4-nGen (n=0, 1, 2, 3) tetrahedral structures.