We report the pulse dependent threshold voltage ( ${V} _{t}$ ) variation of the Ovonic Threshold Switch (OTS) and its effect on the read window margin (RWM) in Cross-Point Memory (XPM). We found that OTS ${V} _{t}$ varies by the height and width of the write-current pulse. The varied ${V} _{t}$ is persistently maintained even after 2E4 cycling of the write pulse, which means that the phenomenon is not a temporary one, but a type of memory effect in OTS itself. Therefore, it would affect the overall ${V} _{t}$ window ( $\Delta {V}_{t}$ ) of XPM by changing the Set ${V} _{t}$ ( ${V} _{t\_{}{\text {Set}}}$ ) and Reset ${V} _{t}$ ( ${V} _{t\_{}{\text {Reset}}}$ ) when combined with either phase-change memory (PCM) or resistive memory (RM). High-resolution transmission electron microscopy (HRTEM) and fast Fourier transform (FFT) images have proved that this phenomenon is not caused by the phase change of the OTS. Instead, a sub-threshold analysis extracted from the Poole-Frenkel model suggests that the phenomenon is associated with the variation of the amorphous network either by changes in the atomic bonding configuration or trap density.

中文翻译：

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交叉点存储器中 Ovonic 阈值开关的脉冲相关阈值电压变化

我们报告了脉冲相关的阈值电压（ ${V} _{t}$ ) Ovonic 阈值开关 (OTS) 的变化及其对交叉点存储器 (XPM) 中读取窗口边距 (RWM) 的影响。我们发现 OTS ${V} _{t}$ 随写入电流脉冲的高度和宽度而变化。多样的 ${V} _{t}$ 即使在写入脉冲的 2E4 循环后仍持续保持，这意味着该现象不是暂时的，而是 OTS 本身的一种记忆效应。所以会影响整体 ${V} _{t}$ 窗户 （ $\Delta {V}_{t}$ ) 的 XPM 通过更改 Set ${V} _{t}$ ( ${V} _{t\_{}{\text {Set}}}$ ) 和重置 ${V} _{t}$ ( ${V} _{t\_{}{\text {Reset}}}$ ) 与相变存储器 (PCM) 或电阻存储器 (RM) 结合使用时。高分辨率透射电子显微镜 (HRTEM) 和快速傅立叶变换 (FFT) 图像证明，这种现象不是由 OTS 的相变引起的。相反，从 Poole-Frenkel 模型中提取的亚阈值分析表明，该现象与原子键配置或陷阱密度的变化导致的非晶网络的变化有关。