Publications
Prof. Zonghoon Lee’s Atomic-Scale Electron Microscopy Lab
Publications
Link to Google Scholar
Publications in Nature | Science | their sister journals
Nature 2024 / Nature Communications, 14:4747, 2023 / Nature Communications, 13:4916, 2022 / Nature Communications, 13:2759, 2022 / Nature, 596, 519-524, 2021 / Nature, 582, 511-514, 2020 / Nature Nanotechnology, 15, 289-295, 2020 / Nature Nanotechnology, 15, 59-66, 2020 / Science Advances, 6 (10), eaay4958, 2020 / Nature Electronics, 3, 207-215, 2020 / Nature Communications, 11 (1437), 2020 / Nature Energy, 3, 773-782, 2018 / Nature Communications, 8:1549, 2017 / Nature Communications, 6:8294, 2015 / Nature Communications, 6:7817, 2015 / Nature Communications, 5:3383, 2014
Abstract
Resistance drift in phase change memory (PCM) reduces the accuracy of analog computing applications such as neural network inference. Recently, PCMs based on superlattice (SL) phase change layers have shown low resistance drift, however the origin of this low drift remains unexplored. Here, we uncover that resistance drift in SL-PCM based on alternating layers of Sb2Te3 and Ge2Sb2Te5 (GST) is controlled by the number of SL interfaces as well as the degree of SL intermixing. Temperature-dependent measurements reveal smaller and more stable activation energy upon annealing (thus suppressed structural relaxation) in our SL-PCM vs. control GST devices, accounting for the low resistance drift. By controlling SL interfaces, we achieve low resistance drift coefficient v<0.01 in these SL-PCMs, maintained after extensive cycling and at various read voltages and intervals - showing robustness required for analog computing with PCM.