Effect of thickness on crystallization behavior in GeSb9 phase change films

Phase change behavior in GeSb9 thin films with different thickness were investigated by utilizing in situ resistance measurements. It is found that the crystallization temperatures and resistances increase with decreasing of film thickness. The analysis of X-ray diffraction indicated that the grain size decreases and the crystallization is suppressed by decreasing film thickness. The surface roughness of thin films was measured by atomic forced microscopy. The obtained values of Avrami indexes indicate that the nucleation rate decreases with decreasing the film thickness. The phase change memory devices based on GeSb9 thin films were fabricated and the lower RESET power consumption was observed for thinner film.