Phase change memory based on Ta–Sb–Te alloy –Towards a universal memory

Abstract

To date, high Reset energy and the contradiction between crystallization speed and amorphous thermal stability are still bottlenecks for phase change memory (PCM) to achieve universal memory. Here, we demonstrate PCM based on Ta0.3Sb2Te3 alloy, showing 3 ns Set speed, 165 °C ten-years data retention and 95% reduced power consumption compared to Ge2Sb2Te5-based device. The Ta exists in the grain boundary and partially enters Sb2Te3 grains, resulting in defects and extremely small grain size, which is responsible for the superior all-round performance. The excellent thermal property rooted in the strong Ta–Te bonds strengthens the robustness of atomic matrices. The ultra-low Reset energy is attributed to the low melting temperature, low thermal conductivity and easier melting of the cubic phase. The ultrafast crystallization originates from fine grains and defects inducing rapid atomic structure change under external electric field. These findings provide a feasible solution for implementing a universal memory.