The lateral carrier profile of amorphous indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) plays a significant role in determining the effective channel length (L_eff) and length scalability even when the physical gate length (L_g) is the same. Especially, devices with high carrier concentration that have a high mobility of 14.54 cm² V·s⁻¹ suffer from severe short channel effects at L_g = 1 µm due to the reduced L_eff. The current work proposes a systematic methodology for optimizing length scalability for a given L_g that involves engineering of the lateral carrier profile. Unique lateral carrier profiles are extracted using contour maps of ΔL and R_SD as a function of carrier profile parameters, and they are validated by comparing the measured L_eff, drain-to-source resistance, and current-voltage characteristics with the results of simulations using the extracted carrier profiles. Further, to overcome the trade-off between enhanced mobility and degraded V_T roll-off that occurs with increasing carrier concentration, an IGZO TFT with gate-insulator shoulders is fabricated to structurally form negative ΔL and physically increase L_eff, while also obtaining a high carrier concentration, ultimately achieving both optimal electrical performance, with mobility of 17.50 cm² V·s⁻¹, and complete control of the electrostatic integrity of the gate.

中文翻译：

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通过横向载流子分布工程和负 ΔL 扩展结构优化 InGaZnO 薄膜晶体管的长度可扩展性


即使物理栅极长度（ L _g ) 是相同的。特别是，具有高载流子浓度且迁移率高达 14.54 cm ² V·s ⁻¹ 的器件在 L _g = 1 µm 时会遭受严重的短沟道效应。由于 L _eff 减少。当前的工作提出了一种系统方法，用于优化给定 L _g 的长度可扩展性，其中涉及横向载体轮廓的工程。使用 ΔL 和 R _SD 等高线图作为载体轮廓参数的函数提取独特的横向载体轮廓，并通过比较测量的 L _eff 、漏极到源极来验证它们电阻和电流-电压特性以及使用提取的载流子分布的模拟结果。此外，为了克服随着载流子浓度的增加而出现的增强迁移率和降低的 V _T 滚降之间的权衡，制造了具有栅极绝缘体肩部的 IGZO TFT，以在结构上形成负 ΔL 并在物理上增加 L _eff ，同时还获得了高载流子浓度，最终实现了迁移率达到 17.50 cm ² V·s ⁻¹ 的最佳电性能，以及完全控制门的静电完整性。