On the link between electroluminescence, gate current leakage, and surface defects in AlGaN/GaN high electron mobility transistors upon off-state stress
On the link between electroluminescence, gate current leakage, and surface defects in AlGaN/GaN high electron mobility transistors upon off-state stress
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DOI：
10.1063/1.4737904
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发表时间：
2012-07
影响因子：
4
通讯作者：
M. M. Bajo-M.;C. Hodges;M. Uren;Martin Kuball
中科院分区：
文献类型：
--
作者：
M. M. Bajo-M.;C. Hodges;M. Uren;Martin Kuball
通过电致发光（EL）分析、栅漏电流（IG）监测和半导体表面原子力显微镜（AFM）成像，研究了AlGaN/GaN高电子迁移率晶体管在关态应力作用下的退化.结果表明，IG在应力作用下的退化是由于每个EL点下面的单个缺陷的综合作用，每个缺陷对总IG的贡献为几μA。在去除接触和钝化后，发现半导体表面上的EL点和凹坑之间存在直接的一一对应关系。反向偏压，导电针尖AFM成像表明，这些表面凹坑确实充当泄漏路径。因此，EL热点，表面坑，和栅极电流泄漏之间的直接关系被证明。还讨论了表面凹坑的形态及其可能的来源。
The degradation of AlGaN/GaN high electron mobility transistors after off-state stress is studied by means of electroluminescence (EL) analysis, gate leakage current (Ig) monitoring, and atomic force microscopy (AFM) mapping of the semiconductor surface. It is found that the degradation of Ig upon stress is due to the combined effect of the individual defects underlying each of the EL spots, which contribute a few μA each to the total Ig. After removal of contacts and passivation, a direct one-to-one correspondence between EL spots and pits on the semiconductor surface is found. Reverse bias, conducting-tip AFM imaging showed that these surface pits do indeed act as leakage paths. Thus, the direct relationship between EL hot spots, surface pits, and gate current leakage is demonstrated. Discussion on the morphology of the surface pits and their possible origin is also provided.