Thermopower Modulation Analyses of High-Mobility Transparent Amorphous Oxide Semiconductor Thin-Film Transistors
Thermopower Modulation Analyses of High-Mobility Transparent Amorphous Oxide Semiconductor Thin-Film Transistors
复制标题
高迁移率透明非晶氧化物半导体薄膜晶体管的热功率调制分析
DOI：
10.1021/acsaelm.2c01210
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发表时间：
2022
影响因子：
4.7
通讯作者：
Ohta Hiromichi
中科院分区：
文献类型：
--
作者：
Yang Hui;Zhang Yuqiao;Matsuo Yasutaka;Magari Yusaku;Ohta Hiromichi
基于透明非晶氧化物半导体InSnZnOx（ITZO）的薄膜晶体管（TFT）表现出高场效应迁移率（μFE）。虽然ITZO-TFT作为下一代平板显示器的背板越来越受到关注，但由于缺乏以热功率（S）作为衡量标准的系统定量分析，高μ FE的来源仍然不清楚。在这里，我们表明，高μ FE源于极轻的载流子有效质量（m*）和长的载流子弛豫时间（τ）。对几种不同载流子浓度的ITZO薄膜的S测量表明，ITZO薄膜的m ~* 为0.11m ~ 0，是商用氧化物半导体非晶InGaZnO_4的m ~*（0.16m ~ 0）的约70%。然后，我们制作了底栅顶接触ITZO-TFT显示出优异的晶体管特性（μFE ≤ 58 cm 2 V-1 s-1），使用非晶AlOx作为栅极绝缘体，并证明了有效厚度随栅极电压的增加。这表明，体主要贡献于漏极电流，这导致τ长达10.3.6 fs，是非晶InGaZnO 4-TFT（10.9 fs）的四倍。目前的结果对于进一步提高ITZO-TFT的迁移率是有用的。
Transparent amorphous oxide semiconductor InSnZnOx(ITZO)-based thin-film transistors (TFTs) exhibit a high field-effect mobility (μFE). Although ITZO-TFTs have attracted increasing attention as a next-generation backplane of flat panel displays, the origin of the high μFEremains unclear due to the lack of systematic quantitative analyses using thermopower (S) as the measure. Here, we show that the high μFEoriginates from an extremely light carrier effective mass (m*) and a long carrier relaxation time (τ). TheSmeasurements of several ITZO films with different carrier concentrations clarified thatm* of ITZO films is ∼0.11m0, which is ∼70% of that of a commercial oxide semiconductor, amorphous InGaZnO4(∼0.16m0). We then fabricated bottom-gate-top-contact ITZO-TFTs displaying excellent transistor characteristics (μFE∼ 58 cm2V–1s–1) using amorphous AlOxas the gate insulator and demonstrated that the effective thickness increases with the gate voltage. This suggests that the bulk predominantly contributes to the drain current, which results in τ as long as ∼3.6 fs, which is quadruple that of amorphous InGaZnO4-TFTs (∼0.9 fs). The present results are useful to further improve the mobility of ITZO-TFTs.