AI 中文总结
本研究通过锁相电场穿透技术直接映射铟基氧化物半导体TFT的态密度，揭示了尺寸依赖的带尾局域化机制，证实无序主导的输运特性，为低维氧化物半导体电子学的无序调控提供了方法。
AI 中文摘要
随着非晶氧化物半导体晶体管向低维沟道缩小，无序诱导的局域化预计将变得愈发重要，但该输运机制对应的电子态仍难以通过实验解析。本研究采用基于锁相的电场穿透技术，直接映射铟基氧化物半导体薄膜晶体管（TFT）的有效态密度（DOS）。提取的量子电容、载流子密度和化学势表明，在无序主导的输运机制中，带尾态并非仅为被动陷阱，而是具备屏蔽活性与部分输运活性。与几何相关的DOS映射显示，有效DOS随沟道长度呈指数衰减，证明存在尺寸依赖的带尾局域化，为局域化诱导的阈值电压 roll-off 机制提供了微观起源。温度依赖测量表明，无序主导的DOS在低温下被显著抑制，而扩展扩散态几乎不变，证实了局域化起源。通过调控薄膜厚度、O2退火工艺及In/Ga/Zn组分，本研究进一步实现了无序与有效DOS局域化的系统性抑制。本研究确立了直接DOS映射作为局域化物理的器件级探针，为低维氧化物半导体电子学的无序调控提供了途径。
英文摘要
Disorder-induced localization is expected to become increasingly important as amorphous oxide semiconductor transistors are scaled toward low-dimensional channels, yet the electronic states responsible for this transport regime remain difficult to resolve experimentally. Here, we use a lock-in-based electric-field penetration technique to directly map the effective density of states (DOS) in In-based oxide semiconductor thin-film transistors (TFTs). The extracted quantum capacitance, carrier density, and chemical potential reveal a disorder-dominated transport regime in which band-tail states are not merely passive traps, but become screening-active and partially transport-active. Geometry-dependent DOS mapping shows an exponential suppression of the effective DOS with channel length, demonstrating size-dependent band-tail localization and providing a microscopic origin for a distinct localization-induced threshold-voltage roll-off mechanism. Temperature-dependent measurements show that the disorder-dominated DOS is strongly suppressed at low temperatures, while extended diffusive states remain nearly unchanged, confirming the localization origin. By tuning film thickness, O2 annealing, and In/Ga/Zn composition, we further demonstrate systematic suppression of disorder and effective-DOS localization. This work establishes direct DOS mapping as a device-level probe of localization physics and provides a pathway for engineering disorder in low-dimensional oxide semiconductor electronics.
Comments30 pages
