Phase-Change Characteristics and Thermal Stability of GeTe/Sb_2Te_3 Nanocomposite Multilayer Films

摘要

GeTe/Sb_2Te_3 nanocomposite multilayer films were deposited by RF magnetron sputtering on SiO_2/Si(100) substrates. The temperature dependence of the sheet resistance of multilayer films with various thickness ratios of GeTe to Sb_2Te_3 was investigated and compared with that of Ge_2Sb_2Te_5. In situ resistance measurements were employed to follow the phase-change process. The crystallization temperature and activation energy for the crystallization of multilayer films increased with the thickness ratio of GeTe to Sb_2Te_3 within the materials. The multilayer films possessed the merits of high thermal stability and high crystallization speed. The failure time for GeTe/Sb_2Te_3 nanocomposite multilayer films was longer than that for Ge_2Sb_2Te_5 at 110℃. We conclude that GeTe/Sb_2Te_3 nanocomposite multilayer films are good candidates for phase-change random-access memory (PCRAM) applications.