Phase change behavior of Ge1Cu2Te3 thin films

The electrical resistances on the crystallization process of co-sputtered Ge-Cu-Te films were investigated by a two-point probe method. It was found that the amorphous Ge1Cu2Te3 film crystallized into a single Ge1Cu2Te3 phase, which lead to a large resistance drop. The crystallization temperature of the Ge1Cu2Te3 amorphous film was higher than the conventional Ge2Sb2Te5 amorphous film. The activation energy for the crystallization of the Ge1Cu2Te3 amorphous film was higher than that of the Ge2Sb2Te5 amorphous film. The Ge1Cu2Te3 compound with a low melting point can be expected to be suitable as a phase change material for PCRAM.