Study on Texture Formation of Sb2Te Thin Films for Phase Change Memory Applications

We investigated the texture formation of Sb2Te thin films for phase change memory applications. The Sb2Te thin films with different thicknesses were deposited on Si (100) wafers by the magnetron sputtering method. As-deposited Sb2Te thin films were annealed at various temperatures and times. The texture characterization was performed by using X-ray diffraction (XRD) and electron backscatter diffraction (EBSD). Experimental results show that the annealed Sb2Te thin films exhibit the {11(2)0} and {10(1)0} prismatic texture. The formation of prismatic texture is induced by the lattice strain, surface energy, and coarse grains, in which the lattice strain is the essential origin of prismatic preference. Electronic transport properties of Sb2Te thin films were monitored by a physical property measurement system (PPMS). It was found that the formation of prismatic texture promotes the increase of carrier mobility. The stability of the film-substrate interface was also assessed by calculating mismatch. The prismatic-preferred Sb2Te thin films exhibit higher mismatch with a silicon wafer, reducing the interface stability.