Abstract Effect of an ultrathin ZnO interface layer (IL) on the band alignment and carrier transportation in atomic-layer-deposited ZrO2 high-k gate dielectrics on p-In0.2Ga0.8As substrates has been investigated. Based on x-ray photoelectron spectroscopy (XPS), the valence-band offset and conduction-band offset of ZrO2/ZnO bilayer with In0.2Ga0.8As are found to be 2.36 and 1.86 eV, respectively. Meanwhile, introducing ZnO IL has made the conduction-band offset increased by 0.26 eV as compared with monolayer ZrO2, thus remarkably suppressing the gate leakage current. It has been revealed by the current density-voltage characteristics measured from 27 °C to 102 °C that Schottky emission is dominant at low positive bias, while Ohm's law dominates the conduction mechanism at high positive bias for ZnO passivated p-In0.2Ga0.8As. However, for ZrO2/In0.2Ga0.8As, the leakage current follows Schottky emission at low positive bias and space-charge-limited conduction at high bias, which is in good agreement with the energy-band parameters extracted by XPS. The ZnO passivation dependent energy-band diagrams of the ZrO2/p-In0.2Ga0.8As heterostructures presented in this paper could be very valuable and beneficial for making ZrO2/ZnO/InGaAs great potential gate stacks in future III-V-based high-performance and low-power devices.

中文翻译：

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通过原子层沉积ZnO钝化层调节ZrO2/In0.2Ga0.8As栅叠层的能带排列和电流传导机制

摘要 研究了超薄 ZnO 界面层 (IL) 对 p-In0.2Ga0.8As 衬底上原子层沉积 ZrO2 高 k 栅极电介质的能带对准和载流子传输的影响。基于 X 射线光电子能谱 (XPS)，发现具有 In0.2Ga0.8As 的 ZrO2/ZnO 双层的价带偏移和导带偏移分别为 2.36 和 1.86 eV。同时，引入ZnO IL使导带偏移比单层ZrO2增加0.26 eV，从而显着抑制了栅极漏电流。从 27°C 到 102°C 测量的电流密度 - 电压特性表明，肖特基发射在低正偏压下占主导地位，而欧姆定律在高正偏压下主导 ZnO 钝化 p-In0.2Ga0 的传导机制。 8As。然而，对于 ZrO2/In0.2Ga0.8As，漏电流在低正偏压下遵循肖特基发射，在高偏压下遵循空间电荷限制传导，这与 XPS 提取的能带参数非常吻合。本文中提出的 ZrO2/p-In0.2Ga0.8As 异质结构的 ZnO 钝化相关能带图对于在未来的 III-V 族高-性能和低功耗设备。