A common AlGaN/GaN current-aperture vertical effect transistor (CAVET) with a SiO 2 current blocking layer on the GaN substrate is compared to two similar structures with the stepped and linearly graded AlGaN barrier layer, respectively. The approach resulted in high threshold voltages (V th ) of −2.6 V and −3.6 V, compared to V th = −4.4 V for the common device. And the breakdown voltage of two modified CAVETs was increased from 541 V to 711 V and 613 V, respectively. This reveals the great potential of polarization doping for fabricating enhancement-mode and high-voltage power transistors. A mechanism accounting for the improvement in the device performance by modulating the heterojunction electron gas (HEG) is presented. Meanwhile the stepped graded AlGaN is discovered to be better than the linearly graded AlGaN in modulating the HEG. Furthermore, a trench structure is involved in the AlGaN/GaN CAVET with the stepped graded AlGaN in order to obtai...

中文翻译：

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AlGaN / GaN CAVET中的极化掺杂调制异质结电子气

将在GaN衬底上具有SiO 2电流阻挡层的常见AlGaN / GaN电流孔垂直效应晶体管（CAVET）与具有阶梯式和线性渐变AlGaN势垒层的两个相似结构进行了比较。与普通器件的V th = -4.4 V相比，该方法产生了-2.6 V和-3.6 V的高阈值电压（V th）。并且两个修改的CAVET的击穿电压分别从541 V增加到711 V和613V。这揭示了极化掺杂在制造增强型和高压功率晶体管中的巨大潜力。提出了一种通过调制异质结电子气（HEG）改善器件性能的机制。同时，在调制HEG方面，发现阶梯式渐变AlGaN优于线性渐变式AlGaN。