Characterization of electronic states at insulator/(Al)GaN interfaces for improved insulated gate and surface passivation structures of GaN-based transistors
Characterization of electronic states at insulator/(Al)GaN interfaces for improved insulated gate and surface passivation structures of GaN-based transistors
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DOI：
10.7567/jjap.53.100213
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发表时间：
2014-09
影响因子：
1.5
通讯作者：
Zenji Yatabe;Y. Hori;Wangong Ma;J. Asubar;M. Akazawa;Taketomo Sato;T. Hashizume
中科院分区：
文献类型：
--
作者：
Zenji Yatabe;Y. Hori;Wangong Ma;J. Asubar;M. Akazawa;Taketomo Sato;T. Hashizume
本文对绝缘体/(Al)GaN界面的电子态进行了系统的表征，尤其侧重于绝缘体/AlGaN/GaN结构。首先，我们回顾了有关GaN金属 - 绝缘体 - 半导体（MIS）结构的重要研究结果。由于其较大的带隙和较高的化学稳定性，SiO₂是一种对MIS晶体管应用有吸引力的材料。原位SiNₓ对提高高电子迁移率晶体管（HEMTs）的工作稳定性是有效的。同时，Al₂O₃/GaN结构具有高的带隙偏移和低的界面态密度，这对于绝缘栅应用也是理想的。我们提出了一种用于描述HEMT MIS结构的电容 - 电压（C - V）特性的计算方法，以评估绝缘体/AlGaN界面的电子态特性。为了评估绝缘体/AlGaN界面的近中带隙态，已经开发了一种使用光子能量小于GaN带隙的光辅助C - V技术。通过将计算与光辅助C - V技术相结合，我们估算了Al₂O₃/AlGaN界面的界面态密度分布。
This paper presents a systematic characterization of electronic states at insulators/(Al)GaN interfaces, particularly focusing on insulator/AlGaN/GaN structures. First, we review important results reported for GaN metal–insulator–semiconductor (MIS) structures. SiO2 is an attractive material for MIS transistor applications due to its large bandgap and high chemical stability. In-situ SiNx is effective for improving the operation stability of high electron mobility transistors (HEMTs). Meanwhile, Al2O3/GaN structures have high band offsets and low interface state densities, which are also desirable for insulated gate applications. We have proposed a calculation method for describing capacitance–voltage (C–V) characteristics of HEMT MIS structures for evaluating electronic state properties at the insulator/AlGaN interfaces. To evaluate near-midgap states at insulator/AlGaN interfaces, a photo-assisted C–V technique using photon energies less than the bandgap of GaN has been developed. Using the calculation in conjunction with the photo-assisted C–V technique, we estimate interface state density distributions at the Al2O3/AlGaN interfaces.