Investigation on Phase Change Behaviors of Si-Sb-Te Alloy: The Effect of Tellurium Segregation

摘要

In this study, novel Si_2Sb_2Te_6 phase change material is investigated in detail for the phase change memory application using transmission electron microscopy and X-ray photoelectron spectroscopy. The phenomenon that Te diffuses to the film surface during phase switching and successively evaporates out has been confirmed. The phase change memory cells employing Si_2Sb_2Te_6 and Si_3Sb_2Te_3 materials are fabricated and programmed. For the Si_2Sb_2Te_6-based cell a data endurance of 5×10~5 cycles is achieved with a failure mode resembling reset stuck, which can be attributed to the migration of Tellurium during the operation cycles. It means that a thermally stable material system of Si_xSb_2Te_3 is preferred for the PCM applications.