Current Collapse Reduction in AlGaN/GaN HEMTs by High-Pressure Water Vapor Annealing
Current Collapse Reduction in AlGaN/GaN HEMTs by High-Pressure Water Vapor Annealing
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DOI：
10.1109/ted.2015.2440442
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发表时间：
2015-08-01
影响因子：
3.1
通讯作者：
Kuzuhara, Masaaki
中科院分区：
文献类型：
--
作者：
Asubar, Joel T.;Kobayashi, Yohei;Kuzuhara, Masaaki
我们已经证明了第一次显着减少AlGaN/GaN高电子迁移率晶体管（HEMT）的高压水蒸气退火（HPWVA）的电流崩塌。经受HPWVA的器件表现出相当低的动态导通电阻（R-ON），这表明这些器件的性能得到了高度改善。对归一化动态罗恩实验结果的分析表明，HPWVA消除了更深的陷阱，从而大大降低了电流崩溃。X射线光电子能谱（XPS）的研究表明，在氧的核心水平O 1 s峰显着增加。此外，角分辨XPS表明表面氧化层的形成。这些结果表明，在HPWVA处理的样品中的电流崩塌的有效减少可能是由于由HPWV到AlGaN表面中产生的活性氧物种的掺入。这些氧原子最终填补了近表面的氮空位，并促进形成Ga 2 O3自然氧化物和可能的Ga 2 O低价氧化物，这是已知的是一个优秀的III-V族表面钝化剂。HPWVA是一种相对简单、低损伤和低温的工艺，因此，它被认为是实现具有改进性能的AlGaN/GaN HEMT的高度可行和有前途的替代方案。
We have demonstrated for the first time a remarkable reduction of current collapse in AlGaN/GaN high-electron-mobility transistors (HEMTs) by high-pressure water vapor annealing (HPWVA). The device subjected to HPWVA exhibited considerably low dynamic ON-resistance (R-ON), suggesting highly improved performance of these devices. Analyses of the results on normalized dynamic RON experiments have shown the elimination of deeper traps by HPWVA, leading to the substantially reduced current collapse. X-ray photoelectron spectroscopy (XPS) studies revealed a significant increase in the oxygen core-level O 1s peak. Moreover, angle-resolved XPS suggested the formation of surface oxide layer. These results indicate that the effective reduction of current collapse in the HPWVA-processed samples is likely due to the incorporation of active oxygen species generated by the HPWV into the AlGaN surface. These oxygen atoms eventually fill up near-surface nitrogen vacancies and promote the formation of Ga2O3 native oxide and possibly Ga2O suboxide, which is known to be an excellent III-V surface passivant. HPWVA is a relatively simple, low-damage, and low-temperature process, and hence, it is found to be a highly feasible and promising alternative for realizing AlGaN/GaN HEMTs with improved performance.