Performance Improvement of Sb Phase Change Thin Film by Y Doping

Abstract

Yttrium-doped Sb phase change thin films were prepared by magnetron sputtering and the in-situ resistance temperature measurement system was used to study the process of phase change thin films. With the addition of yttrium atoms, the crystallization temperature of Sb thin film increases, indicating improvement of their thermal stability and data retention ability. Furthermore, yttrium-doped Sb thin films have higher crystalline and amorphous resistance, which is conducive to the phase transition by Joule heating under electric pulse current. The optical band gap energy increases after yttrium doping, which means lower conductivity and higher conduction activation energy. X-ray diffraction shows that the doping of yttrium atoms can inhibit the grain growth and refine the grain size. X-ray photoelectron spectroscopy was used to examine the chemical state of the element, indicating the formation of a new Y-Sb bond, which verifies the improvement of stability. According to atomic force microscopy images, the yttrium-doped Sb material exhibits a surface morphology with less roughness, implying better interfacial properties and reliability. In general, yttrium-doped Sb thin films have better development in the application of phase change memory.