Phase transition in SbxTe100-x amorphous films


Purpose. Thin films of Ge and Sb chalcogenides are suitable for creation of PCM devices that works on the basis of reversible “amorphous phase ↔ crystalline phase” transition. In this paper the results of the investigations temperature dependences electric resistance R and optical transmission θ of SbxTe100-x amorphous films are reported.
Methods. Nonisotermal crystallization of SbxTe100-x films was investigated by the method, which allows simultaneously measurements of optical transmission and electric resistance on the one samples. Investigations of R(T) and Q(T) dependences were carried out in the temperature range of 290-550 K. Heating rates were equal 0.75, 1.8 and 4.5 K/min.
Results and discussion. It was established that crystallization of films is accompanied by a sharp decrease of R and θ. The change of resistance rich of 3-4 orders higher of magnitude. Parameters of phase transition (the starting temperature from amorphous to crystalline state and temperature range of transition) depends on the chemical composition of the films and the heating rate. The results testifies about possibility to use the films of Sb-Te system for memory cells and temperature sensors production

Keywords: chalcogenide materials, amorphous films, phase transition, crystallization, memory cell