Numerical Analysis of Breakdown Voltage Enhancement in AlGaN/GaN HEMTs With a High-k Passivation Layer
Numerical Analysis of Breakdown Voltage Enhancement in AlGaN/GaN HEMTs With a High-k Passivation Layer
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DOI：
10.1109/ted.2014.2298194
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发表时间：
2014-03-01
影响因子：
3.1
通讯作者：
Horio, Kazushige
中科院分区：
文献类型：
--
作者：
Hanawa, Hideyuki;Onodera, Hiraku;Horio, Kazushige
通过考虑缓冲层中的深层供体和深层受体，对高电子迁移率晶体管（hemt）的击穿特性进行了二维分析。研究了关断击穿电压与钝化层相对介电常数和钝化层厚度的关系。结果表明，随着er的增加，断开状态击穿电压也随之增加。这是因为栅极漏极边缘的电场随着电流的增加而减弱。这是因为在绝缘体中，施加的电压一般会均匀下降，因此，当绝缘体附着在半导体上时，如果绝缘体的er更高，则沿半导体的电压降在栅极的漏极边缘变得更平滑。由于栅极漏极边的电场随着d的增加而减弱，因此断极击穿电压随d的增加而增加。结果表明，具有高k和厚钝化层的AlGaN/GaN hemt具有高击穿电压。
2-D analysis of breakdown characteristics in AlGaN/GaN high electron mobility transistors (HEMTs) is performed by considering a deep donor and a deep acceptor in a buffer layer. The dependence of the OFF-state breakdown voltage on the relative permittivity of the passivation layer er and the thickness of the passivation layer d are studied. It is shown that as er increases, the OFF-state breakdown voltage increases. This is because the electric field at the drain edge of the gate is weakened as er increases. This occurs because in the insulator the applied voltage tends to drop uniformly in general, and hence when the insulator is attached to the semiconductor, the voltage drop along the semiconductor becomes smoother at the drain edge of the gate if the er of the insulator is higher. It is also shown that the OFF-state breakdown voltage increases as d increases because the electric field at the drain edge of the gate is weakened as d increases. It is concluded that AlGaN/GaN HEMTs with a high-k and thick passivation layer should have high breakdown voltages.