A Fast and High Endurance Phase Change Memory Based on In-Doped Sb₂Te₃

The relatively slow set speed and poor cycle endurance of typical phase change memories constrain their ambitious goal of replacing all memories in complex hierarchical memory systems. Here, we demonstrate phase change memory devices based on In–Sb 2 Te 3 (InST) with a size of 250 nm, showing the SET speed down to 1 ns and the excellent cycle endurance up to 3.6 × 10 8 times under 5 ns pulse operation. Doped In atoms occupy cation vacancy lattice positions in Sb 2 Te 3, where they establish robust bonds with Te atoms and restore the lattice’s integrity. Rapid crystallization is made possible by the great ability of the In rings to grasp the surrounding Te atoms and the high stability of the In–Te connection. In amorphous InST, lower concentrations of lone pair electrons and voids point to a more compact structure that contributes to good cycle durability by lowering the density difference between the crystalline and amorphous states. These findings provide a feasible candidate for completely replacing the DRAM.