Etched Al0.32Ga0.68N/GaN HEMTs with high output current and breakdown voltage (> 600 V)
Etched Al0.32Ga0.68N/GaN HEMTs with high output current and breakdown voltage (> 600 V)
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具有高输出电流和击穿电压 (> 600 V) 的蚀刻 Al0.32Ga0.68N/GaN HEMT
DOI：
10.1049/mnl.2017.0651
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发表时间：
2018
影响因子：
1.3
通讯作者：
Duan BX
中科院分区：
文献类型：
--
作者：
Duan Baoxing;Xie Shenlong;Guo Haijun;Yang Yintang;Duan BX
通过在靠近漏极侧的栅极边缘处刻蚀AlGaN层，提出了具有高阻GaN缓冲层的具有刻蚀AlGaN外延层的新型AlGaN/GaN高电子迁移率晶体管（刻蚀AlGaN/GaN高电子迁移率晶体管，HEMT）。探讨了AlGaN层的厚度与2D电子气（2DEG）浓度的关系。降低蚀刻阻挡层下的2DEG密度以优化2DEG的表面电场和迁移率。电场被刻蚀的AlGaN层重塑，具有远离栅极边缘的额外电场峰值。额外电场峰的存在有效地降低了栅极附近的电场峰值，从而提高了击穿电压。由于低的2DEG浓度，2DEG的迁移率增加，这提高了输出电流（IDS）。由于优化的表面电场，实验BV从常规结构的152 V提高到蚀刻AlGaN/GaN HEMT的620 V。最大输出电流（Imax）从381 mA/mm提高到478 mA/mm。BV和Ron，sp之间的权衡得到了改善，突破了硅的限制。结果表明，栅边缘刻蚀技术可以显著提高AlGaN/GaN HEMT器件的BV和I DS。
By etching the AlGaN layer close to the gate edge of the drain side, the novel AlGaN/GaN high-electron-mobility transistor with the etched AlGaN epitaxial layer (etched AlGaN/GaN high-electron-mobility transistors, HEMTs) is proposed in this work with the high-resistance GaN buffer layer. The relationship between the 2D electron gas (2DEG) concentration and the thickness of the AlGaN layer has been explored. The 2DEG density under the etched barrier is reduced to optimise the surface electric field and mobility of 2DEG. The electric field is reshaped by the etched AlGaN layer, featuring an extra electric field peak far away from the gate edge. The electric field peak near the gate is decreased effectively because of the extra electric field peak, which therefore improves the breakdown voltage (BV). The mobility of 2DEG is increased because of the low 2DEG concentration, which improves the output current (I DS). The experimental BV is improved from 152 V for the conventional structure to 620 V for etched AlGaN/GaN HEMTs because of the optimised surface electric field. The maximum output current (I max) is increased from 381 to 478 mA/mm. The trade-off between the BV and R on,sphas been improved to break the silicon limit. It is concluded that the gate-edge etching technique can significantly increase both BV and I DS for AlGaN/GaN HEMTs.