Buffer Design to Minimize Current Collapse in GaN/AlGaN HFETs
Buffer Design to Minimize Current Collapse in GaN/AlGaN HFETs
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DOI：
10.1109/ted.2012.2216535
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发表时间：
2012-12-01
影响因子：
3.1
通讯作者：
Kuball, Martin
中科院分区：
文献类型：
--
作者：
Uren, Michael J.;Moereke, Janina;Kuball, Martin
在漂移扩散模拟中研究了GaN/AlGaN异质结场效应晶体管中电流崩塌（CC）的体陷阱诱导分量，区分了位于带隙顶部和底部的受主陷阱，Fe和C用作具体示例。结果表明，Fe掺杂的结果在一个固有的，但相对较小的贡献，在脉冲条件下的色散。该模拟与双脉冲实验具有合理的定量一致性。使用深层次的本征生长缺陷的模拟产生了类似的结果。相比之下，碳可以诱导依赖于掺杂密度的强CC。这种差异归因于陷阱水平，无论是本征或非本征掺杂剂，导致电阻性n型缓冲区或p型浮置缓冲区与偏置依赖的耗尽区。这一见解为确保RF或功率应用的半绝缘缓冲区掺杂所需的补偿方案提供了关键设计概念。
The bulk trap-induced component of current collapse (CC) in GaN/AlGaN heterojunction field-effect transistors is studied in drift diffusion simulations, distinguishing between acceptor traps situated in the top and the bottom half of the bandgap, with Fe and C used as specific examples. It is shown that Fe doping results in an inherent but relatively minor contribution to dispersion under pulse conditions. This simulation is in reasonable quantitative agreement with double pulse experiments. Simulations using deep-level intrinsic growth defects produced a similar result. By contrast, carbon can induce a strong CC which is dependent on doping density. The difference is attributed to whether the trap levels, whether intrinsic or extrinsic dopants, result in a resistive n-type buffer or a p-type floating buffer with bias-dependent depletion regions. This insight provides a key design concept for compensation schemes needed to ensure semi-insulating buffer doping for either RF or power applications.