Influence of deposition parameters on the properties of sputtered Ge2Sb2Te5 films

The influence of deposition parameters such as the power applied to the target and the argon pressure during sputtering on the resulting properties of Ge2Sb2Te5 films has been investigated. Independent of deposition parameters all films deposited at room temperature were amorphous. Nevertheless X-ray reflectance showed a pronounced dependence of the rate upon the argon pressure in excellent agreement with the Keller-Simmons model. Furthermore, the film density also decreased with increasing argon pressure. This led to a corresponding change of the optical properties as revealed by spectroscopic ellipsometry. The crystallization temperature decreased with decreasing film density as revealed by measurements of the electrical resistivity.