Crystallization kinetics and x-ray photoelectron spectroscopy of Ga2TeSb7 thin film

Ga2TeSb7 films were deposited on SiOx/Si(100) wafers by radio-frequency magnetron sputtering to assess its potential as a phase-change memory material. Electrical resistance of the film versus temperature (R-T) was measured at various heating rates. Crystallization kinetics was analyzed using the R-T curves. Crystallization temperature 253–260 °C and activation energy of crystallization 5.76 eV were deduced using Kissinger’s plot. The kinetic exponent (n) obtained from Ozawa’s plot decreases from 2.5 to 1.0 upon crystallization at 253 to 265 °C. The n value is less than 1.5 when crystallizing at ≥257 °C, denoting a growth-dominated mechanism. X-ray diffraction shows that the amorphous phase crystallizes into the R3m Sb-structure and surface roughness of the crystallized Ga2TeSb7 is 0.3 nm at all annealing temperatures. X-ray photoelectron spectra reveal little change in bonding status of the three elements before and after crystallization.