Buffer-Induced Current Collapse in GaN HEMTs on Highly Resistive Si Substrates
Buffer-Induced Current Collapse in GaN HEMTs on Highly Resistive Si Substrates
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DOI：
10.1109/led.2018.2864562
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发表时间：
2018-10-01
影响因子：
4.9
通讯作者：
Kuball, Martin
中科院分区：
文献类型：
--
作者：
Chandrasekar, Hareesh;Uren, Michael J.;Kuball, Martin
我们证明了GaN-on-Si射频hemt中的高电阻Si衬底不作为绝缘体，而是作为静态操作的导电接地面，并且可以引起显著的反向感应电流崩溃。缓冲器的衬底斜坡特性与器件模拟结果一致，表明电流崩溃是由氮化镓层内的电荷再分配引起的。然后提出了改变外延中的电荷存储和泄漏以抵消这种影响的潜在解决方案。
We demonstrate that the highly resistive Si substrate in GaN-on-Si RF HEMTs does not act as an insulator, but instead behaves as a conductive ground plane for static operation and can cause significant back-gate-induced current collapse. Substrate ramp characterization of the buffer shows good agreement with device simulations and indicates that the current collapse is caused by charge-redistribution within the GaN layer. Potential solutions, which alter charge storage and leakage in the epitaxy to counter this effect, are then presented.