Ultrahigh overall-performance phase-change memory by yttrium dragging

Abstract

Chalcogenide phase-change materials are well-acknowledged as data-storage media and are currently at the forefront as the basis of emerging neuromorphic devices, where analogue memory is used for both data storage and computation. However, neuromorphic devices are functionally more demanding, and the overall optimization of device performance is thus the top priority of phase-change materials development. Here, an ultrahigh overall-performance phase-change random access memory is described, including improved characteristics such as low resistance drift, high data retention, low power consumption, fast operation speed, and good cycling endurance, which has been achieved based on the phase-change materials, yttrium-doped Sb₂Te₃. Moreover, the resistance-drift mechanism of amorphous Sb₂Te₃ is firstly unraveled and attributed to temporal structural relaxation from a highly-stressed state towards an energetically more favorable equilibrium state, based on ab initio molecular-dynamics simulations. The yttrium dopant modifies the amorphous structure of Sb₂Te₃ and its atomic-drag effect improves the overall performance of the base material, paving the way toward the development of an advanced neuromorphic computing system.