High-Threshold-Stability GeSe-Based Selector-Only Memory Enabled by Gallium Doping

作者：Yaru Zhang, Jinyu Wen, C. Yi, Lun Wang, Zixuan Liu, Ziqi Chen, Hao Tong, Xiangshui Miao · 发表于：IEEE Electron Device Letters · 年份：2025 · DOI：10.1109/led.2025.3598975 · 被引用次数：8 · 研究领域：Phase-change materials and chalcogenides、Photonic and Optical Devices、Advanced Memory and Neural Computing

Selector-only memory (SOM), which utilizes threshold voltage (${\mathrm {V}}_{\mathbf {\textit {th}}}$) shift in ovonic threshold switching (OTS) devices for data storage, has emerged as a promising storage-class memory (SCM) candidate due to its low latency, high density, and cost-effectiveness. However,${\mathrm {V}}_{\mathbf {\textit {th}}}$instability, including variability and drift, remains a major reliability challenge. Here, we propose a gallium (Ga) doping strategy to enhance${\mathrm {V}}_{\mathbf {\textit {th}}}$stability. Guided by double energy well OTS model, we employed ab-initio molecular dynamics (AIMD) calculations to analyze the effects of various dopants on the coordination numbers (CNs) and bonding characteristics that govern${\mathrm {V}}_{\mathbf {\textit {th}}}$stability in SOM materials, identifying Ga as the optimal dopant. Compared to undoped GeSe-based SOM ($\gamma =35.1$mV/dec, endurance$= {10}^{{6}}$cycles), Ga-doped SOM exhibits significantly enhanced performance: reduced drift (16.5 mV/dec), improved endurance ($\gt {10}^{{9}}$cycles), suppressed variability ($\sigma ~0\lt 0.2$V,$\sigma 1\lt 0.068$V,$\sigma $is defined as the standard deviation between${\mathrm {V}}_{\mathbf {\textit {th}}}$), and enhanced thermal stability (>400°C). Notably, excessive doping degrades performance, aligning with theoretical predictions and validating our screening approach. This work provides both mechanistic insights and practical guidance for developing highly...