Reducing the stochasticity of crystal nucleation to enable subnanosecond memory writing

TLDR

Phase‑change RAM devices are limited by the speed of crystallization. The authors combined theory with selection criteria to isolate a scandium‑doped antimony telluride (SST) that crystallizes in subnanoseconds. The SST‑based RAM achieved a 700‑picosecond write time, an order of magnitude faster than prior phase‑change memories and competitive with conventional DRAM, SRAM, and flash. Rao et al., Science, this issue p.

Abstract

Fast phase change with no preconditions Random access memory (RAM) devices that rely on phase changes are primarily limited by the speed of crystallization. Rao et al. combined theory with a simple set of selection criteria to isolate a scandium-doped antimony telluride (SST) with a subnanosecond crystallization speed (see the Perspective by Akola and Jones). They synthesized SST and constructed a RAM device with a 700-picosecond writing speed. This is an order of magnitude faster than previous phase-change memory devices and competitive with consumer dynamic access, static random access, and flash memory. Science , this issue p. 1423 ; see also p. 1386