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

In this study, novel Si 2 Sb 2 Te 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 2 Sb 2 Te 6 and Si 3 Sb 2 Te 3 materials are fabricated and programmed. For the Si 2 Sb 2 Te 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 x Sb 2 Te 3 is preferred for the PCM applications.