Threshold Voltage Instability in Al2O3/GaN/AlGaN/GaN Metal-Insulator-Semiconductor High-Electron Mobility Transistors
Threshold Voltage Instability in Al2O3/GaN/AlGaN/GaN Metal-Insulator-Semiconductor High-Electron Mobility Transistors
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DOI：
10.1143/jjap.50.110202
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发表时间：
2011-11-01
影响因子：
1.5
通讯作者：
Chen, Kevin J.
中科院分区：
文献类型：
--
作者：
Huang, Sen;Yang, Shu;Chen, Kevin J.
通过直流电压（I-V）、高频电容电压（C-V） （HFCV）和准静态C-V （QSCV）表征，系统地研究了以15nm原子层沉积（ALD） Al2O3为栅极介质的氮化镓基金属-绝缘体-半导体高电子迁移率晶体管（MIS-HEMTs）的阈值电压（V-th）不稳定性。Al2O3/GaN/AlGaN/GaN MIS二极管和GaN/AlGaN/GaN肖特基二极管在双模（上下扫频）HFCV特性中仅表现出微小的阈值电压滞后（δ V-th） （< 10 mV），因为扫频期间的最大正向偏置（V- f,V-max）设置为0 V，而MIS二极管在V- f，V-max增加到+5 V时出现明显的δ V-th（高达0.9 V）。因此，通过增加传递特性测量中的最大V-GS （V-GS,V-max）来研究相应的miss - hemt中V-th的稳定性。一旦VGS超过+1 V，就会发生显著的正V-th移位，而在Schottky-gate AlGaN/GaN hemt中仍然没有这种V-th不稳定性。Al2O3/GaN/AlGaN/GaN mishemts中v -th不稳定性的原因是Al2O3/GaN/AlGaN/GaN界面上的类受体深态。由于这些界面态的填充和发射过程缓慢，低频QSCV技术成功地捕获了它们。(C) 2011 .日本应用物理学会
The threshold voltage (V-th) instability in GaN-based metal-insulator-semiconductor high-electron mobility transistors (MIS-HEMTs) with 15-nm atomic-layer-deposited (ALD) Al2O3 as gate dielectrics is systematically investigated by dc current-voltage (I-V), high-frequency capacitance-voltage (C-V) (HFCV), and quasi-static C-V (QSCV) characterizations. Both Al2O3/GaN/AlGaN/GaN MIS diode and GaN/AlGaN/GaN Schottky diode only exhibit tiny threshold-voltage hysteresis (Delta V-th) (< 10 mV) in double-mode (up and down sweep) HFCV characteristics as the maximum forward bias (V-F,V-max) during the sweep is set to 0 V, while an apparent Delta V-th (as large as 0.9 V) emerges as V-F,V-max is increased to +5 V for the MIS diode. The stability of V-th in the corresponding MIS-HEMTs is thus studied by increasing the maximum V-GS (V-GS,V-max) in the measurement of transfer characteristics. Significant positive V-th shift occurred once the VGS, max exceeds +1 V, while such V-th-instability is still absent in Schottky-gate AlGaN/GaN HEMTs. It is suggested that the acceptor-like deep states at Al2O3/GaN interface account for the V-th-instability in Al2O3/GaN/AlGaN/GaN MIS-HEMTs. As the filling and emission processes of these interface states are slow, they are successfully captured by low-frequency QSCV techniques. (C) 2011 The Japan Society of Applied Physics