Crystallization kinetics of Ga–Sb–Te films for phase change memory

Abstract Ga–Sb–Te ternary thin films were prepared by co-sputtering using targets GaSb and Sb 8 Te 2 . Crystallization processes of these films were studied by measuring the temperature-dependent electrical resistance during non-isothermal heating. The activation energy ( E a ), rate factor ( K o ), and kinetics exponent ( n ) were deduced from Kissinger and Ozawa's plots, respectively. The crystallization temperatures ( T x = 108∼319°C) increase with increasing GaSb contents. The activation energy (1.82∼7.52 eV) increases with increasing Ga content until 31.6 at.% then it decreases. The crystallization mechanisms of compositions A∼D (Ga 17∼32 Sb 71∼62 Te 12∼6 ), as evidenced from n values, are nuclei formation and subsequent crystal growth; the nucleation rate decreases with grain growth. While composition E (Ga 38.2 Sb 57.7 Te 4.1 ) reveals an n value lower than 1.5, it implies the one-dimensional crystal growth from the nuclei. The crystallization time of each composition was evaluated using JMA equation using all derived kinetics parameters. Composition C (Ga 26.4 Sb 65.2 Te 8.4 ), showing the shortest crystallization time, is suggested for phase change RAM applications.