Understanding the effect of dry etching on nanoscale phase-change memory

Abstract

PCM (phase-change memory) is an important class of data storage, operating based on the Joule heating-induced reversible switching of chalcogenide alloys. Nanoscale PCM often requires advanced microfabrication techniques such as dry (plasma) etching, but the possible impacts of process damages or imperfections on the device performance still remain relatively unexplored. This is critical because some chemical etching species are known to cause over-etching with rough edge onto the sidewall of a phase-change material. It is also possible that the phase-change material experiences a composition change due to etching-induced re-deposition of by-products or thermal stress. In this study, a finite-element simulation is performed to understand the effect of dry etching on the RESET characteristics of a nanoscale PCM device to provide a guideline on the PCM manufacturing and cell design.