Enhancement-Mode m-plane AlGaN/GaN Heterojunction Field-Effect Transistors with +3 V of Threshold Voltage Using Al2O3 Deposited by Atomic Layer Deposition
Enhancement-Mode m-plane AlGaN/GaN Heterojunction Field-Effect Transistors with +3 V of Threshold Voltage Using Al2O3 Deposited by Atomic Layer Deposition
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DOI：
10.1143/apex.4.096501
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发表时间：
2009-01
影响因子：
2.3
通讯作者：
T. Fujiwara;R. Yeluri;D. Denninghoff;Jing Lu;S. Keller;J. Speck;S. Denbaars;U. Mishra
中科院分区：
文献类型：
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作者：
T. Fujiwara;R. Yeluri;D. Denninghoff;Jing Lu;S. Keller;J. Speck;S. Denbaars;U. Mishra
采用原子层沉积（ALD）技术制备了增强型m平面AlGaN/GaN异质结场效应晶体管。获得了+ 3v的阈值电压和4×106的开/关比，表现出优异的亚阈值区域特性。这些结果是使用非极性m平面GaN， Al2O3作为栅极电介质和凹槽栅极结构获得的。该器件在+7 V的栅源电压（Vgs）下最大漏源电流为138 mA/mm，在Vgs=+5 V时最大跨导为45 mS/mm。采用光电辅助电容电压法测量了Al2O3与m平面GaN的界面态密度（Dit）， Dit为（1-2）×1012 cm-2 eV-1。这些结果表明ALD沉积在m平面GaN上的Al2O3具有用于功率开关器件的潜力。
Enhancement-mode m-plane AlGaN/GaN heterojunction field-effect transistors were fabricated with an Al2O3 gate dielectric deposited by atomic layer deposition (ALD). A threshold voltage of +3 V and an on/off ratio of 4×106 were obtained, demonstrating excellent subthreshold region characteristics. These results were achieved using non-polar m-plane GaN, Al2O3 as a gate dielectric, and a recessed-gate structure. The devices exhibited 138 mA/mm of maximum drain–source current at a gate–source voltage (Vgs) of +7 V and 45 mS/mm of maximum transconductance at Vgs=+5 V. The interface state density (Dit) of Al2O3 and m-plane GaN was measured using the photo assisted capacitance–voltage method, showing a Dit of (1–2)×1012 cm-2 eV-1. These results indicate the potential of Al2O3 deposited by ALD on m-plane GaN for power switching devices.