Analysis of buffer-impurity and field-plate effects on breakdown characteristics in small-sized AlGaN/GaN high electron mobility transistors
Analysis of buffer-impurity and field-plate effects on breakdown characteristics in small-sized AlGaN/GaN high electron mobility transistors
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DOI：
10.1088/0268-1242/27/8/085016
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发表时间：
2012-08
影响因子：
1.9
通讯作者：
H. Onodera;K. Horio
中科院分区：
文献类型：
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作者：
H. Onodera;K. Horio
通过考虑缓冲层中的深给体和深受体，对具有较短栅极长度和短栅极-漏极距离的场极板AlGaN/GaN高电子迁移率晶体管的击穿特性进行了二维分析。结果表明，当缓冲层中受体密度较大时，击穿电压由载流子的冲击电离决定，击穿电压随场板长度的增加而减小。这是因为电场极板边缘和漏极之间的距离变得非常短，而那里的电场变得非常大。另一方面，当缓冲层中的受体密度较低时，缓冲漏电流变得非常大，这可以决定击穿电压，击穿电压变得非常低。在这种情况下，击穿电压随着场极板长度的增加而增加。
The two-dimensional analysis of breakdown characteristics in field-plate AlGaN/GaN high electron mobility transistors with a relatively short gate length and short gate-to-drain distances is performed by considering a deep donor and a deep acceptor in a buffer layer. It is shown that when the acceptor density in the buffer layer is high, the breakdown voltage is determined by the impact ionization of carriers, and it can decrease with increasing the field-plate length. This is because the distance between the field-plate edge and the drain becomes very short and the electric field there becomes very high. On the other hand, when the acceptor density in the buffer layer is relatively low, the buffer leakage current becomes very large and this can determine the breakdown voltage, which becomes very low. In this case, the breakdown voltage increases with increasing the field-plate length.