Impact of interface traps on switching behavior of normally-OFF AlGaN/GaN MOS-HEMTs
Impact of interface traps on switching behavior of normally-OFF AlGaN/GaN MOS-HEMTs
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界面陷阱对常断 AlGaN/GaN MOS-HEMT 开关行为的影响
DOI：
10.1002/pssc.201510189
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发表时间：
2016-02
期刊：
影响因子：
--
通讯作者：
Zhang B
中科院分区：
文献类型：
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作者：
Shi YY;Zhou Q;Jin Y;Chen BW;Chen WJ;Huang W;Zhang B
本文报道了对硅衬底上正常关断的Al_2O_3/GaN金属氧化物半导体高电子迁移率晶体管(MOS-HEMTs)的两级导通特性的实验观察。通过模拟和测量验证了不同能级的氧化物/GaN界面陷阱对器件开关行为的影响。在GaN缓冲层导带底部(EIT=EC-0.4 eV)下方0.4 eV处的界面陷阱密度DIT=6.5×1012 cm-2是导致观察到的两级开启特性的原因。界面陷阱的动态电子填充引起的弱费米级钉扎(WFLP)可能阻碍电子在Al_2O_3/GaN MOS沟道中的积累，从而在开启过程中表现出过早的开启。(2015Wiley-VCH Verlag GmbH&Co.KGaA，Weinheim)
In this paper, we report an experimental observation of the two-stage turn-on characteristic in normally-OFF Al2O3/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) on Si substrate. The impact of oxide/GaN interface traps with different energy levels on the switching behavior of the device was extensively examined by simulation and verified by measurements. The interface traps at 0.4 eV below the bottom of the conduction band (Eit = EC-0.4 eV) of GaN buffer with a density of Dit= 6.5×1012 cm-2 was identified responsible for the observed two-stage turn-on characteristic. The weak Fermi-level pinning (WFLP) induced by the dynamic electron filling of interface traps may hamper the electron from accumulating in the Al2O3/GaN MOS-channel and then manifests a premature turn-on during the switching-on process. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)