This work experimentally investigates current conduction in 3-D NAND under up to 7 GPa of externally applied compressive mechanical stress. The impact of channel crystallinity and geometry is studied by comparing four types of Si channels: polycrystalline full channel, single-crystal full channel, polycrystalline macaroni channel, and single-crystal macaroni channel. In the studied channel types, the mechanical stress was found to cause reversible degradation of ${I} _{ \mathrm{\scriptscriptstyle ON}}$ (up to one order of magnitude) and ${I} _{ \mathrm{\scriptscriptstyle OFF}}$ (up to seven orders of magnitude). Using TCAD simulations, ${I} _{ \mathrm{\scriptscriptstyle ON}}$ and ${I} _{ \mathrm{\scriptscriptstyle OFF}}$ deterioration are attributed to carrier mobility and Si bandgap decreases under mechanical stress, respectively. The simulations also suggest that both effects depend on the channel morphology, which results in a different extent of stress impact on the four studied types of Si channels.

中文翻译：

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机械应力对 3-D Nand Flash 电流传导的影响

这项工作通过实验研究了在高达 7 GPa 的外部施加的压缩机械应力下 3-D NAND 中的电流传导。通过比较四种类型的 Si 通道：多晶全通道、单晶全通道、多晶通心粉通道和单晶通心粉通道，研究通道结晶度和几何形状的影响。在研究的通道类型中，发现机械应力会导致可逆退化 ${I} _{ \mathrm{\scriptscriptstyle ON}}$ （最多一个数量级）和 ${I} _{ \mathrm{\scriptscriptstyle OFF}}$ （最多七个数量级）。使用 TCAD 模拟， ${I} _{ \mathrm{\scriptscriptstyle ON}}$ 和 ${I} _{ \mathrm{\scriptscriptstyle OFF}}$ 劣化分别归因于载流子迁移率和机械应力下 Si 带隙的减小。模拟还表明，这两种影响都取决于通道形态，这导致对四种研究类型的 Si 通道产生不同程度的应力影响。