Operation speed is a key challenge in phase-change random-access memory (PCRAM) technology, especially for achieving sub-nanosecond high-speed cache-memory. Commercialized PCRAM products are limited by the tens of nanoseconds writing speed, originating from the stochastic crystal nucleation during the crystallization of amorphous Ge2Sb2Te5. Here we demonstrate an alloying strategy to speed up the crystallization kinetics. The new compound we designed allows a writing speed of only 700 picoseconds without pre-programming in a large conventional PCRAM device. This ultrafast crystallization stems from the reduced stochasticity of nucleation. Controlling nucleation through alloy design paves the way for the development of cache-type PCRAM technology to boost the working efficiency of computing systems.
Feng Rao, Wei Zhang, Evan Ma et al. Science (2017) DOI: 1126/science.aao3212