Enhanced Operation Speed and Thermal Stability of a 150 nm-Thick SbTe Film by Y Doping for Optoelectronic Hybrid Phase-Change Memory

Abstract

Optoelectronic hybrid phase-change memory, as a kind of nonvolatile storage with ultrafast speed, has the potential to facilitate the integration of storage and computing and is regarded as a promising candidate for overcoming the “memory bottleneck”. However, the contradiction between thermal stability and operation speed in phase-change memory presents a challenge for the demands of in-memory computing. In this work, optoelectronic hybrid phase-change memory based on the Y-doped SbTe film is proposed to achieve ultrafast operation speed and high thermal stability. Results indicate that when the Y doping content is 27.4 at. %, the film exhibits good thermal stability with the crystallization temperature of 197 °C and a 10-year data retention of 121 °C. A low volume-change rate (0.5%) and resistance drift coefficient (0.006 at 85 °C for the film) are also obtained. Moreover, the operation speed reaches 26 ps for SET and 13 ps for RESET. Microstructural analysis reveals that the improved thermal stability is mainly due to the formation of Y–Te and Y–Sb bonds, enhancing the interaction between Y and Te atoms and the inhibition of grain growth. The ultrafast operation speed is primarily attributable to the structural similarity between amorphous and crystalline phases and the existence of the Sb–Sb vibrational mode. Consequently, the Y-doped SbTe film is promising for optoelectronic hybrid phase-change memory and has potential application in storage-computing integration.