PRAM (Phase change Random Access Memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change material has been researched in the field of optical data storage media. Among the phase change materials, Ge2Sb2Te5(GST) is very well known for its high optical contrast in the state of amorphous and crystalline. However, the characteristics required in solid state memory are quite different from optical ones. In this study, the structural properties of GST thin films with bottom electrode were investigated for PRAM. The 100-nm thick GST films were deposited on TiN/Si and TiAlN/Si substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films, we performed x-ray diffraction (XRD) and atomic force microscopy (AFM).