Study on mechanism of current collapse and knee voltage drift for AlGaN/GaN HEMTs
Study on mechanism of current collapse and knee voltage drift for AlGaN/GaN HEMTs
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DOI：
10.7498/aps.59.5730
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发表时间：
2010-08
期刊：
影响因子：
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通讯作者：
Wang Lin;Hu Weida;Chen Xiaoshuang;Lu Wei
中科院分区：
文献类型：
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作者：
Wang Lin;Hu Weida;Chen Xiaoshuang;Lu Wei
本文综述了势垒层陷阱、缓冲层陷阱和表面电荷对电流崩塌和势垒电压变化的影响，指出表面电荷浓度和势垒层陷阱浓度的变化对沟道中二维电子能密度的影响不大。当表面电荷浓度发生变化时，势垒层的弯曲电压漂移和电流崩塌强度与量子势垒势能的变化密切相关。缓冲层比势垒层具有更强的局域效应，当体陷阱浓度发生变化时，弯曲电压漂移主要由二维电子能密度的变化引起。但与表面电荷情况相比变化较小。量子井势能变化是导致膝部电压变化的重要原因，电流崩塌的强度由势能的大小和二维电子气的密度决定。
In this article, we comprehensively showed the impact of barrier layer traps, buffer layer traps and surface charge on current collapse and knee voltage change, pointed out that the change in the concentration of surface charge and barrier layer traps have little influence on the 2DEG density in the channel.When the concentration of surface charge changes, the knee voltage drift and strength of current collapse are in close connection with the change of potential energy in quantum well.Buffer layer has stronger local effect than barrier layer, when the concentration of bulk traps change in these layers, knee voltage drift is mainly caused by the change of 2DEG density, but has less change compared with the situation of surface charge.Potential energy changes in the quantum well is an important reason for the change of knee voltage, the strength of current collapse is determined by the size of potential energy and 2DEG density.