Impacts of spatial charge inhomogeneities on carrier transport fluctuations and premature breakdown were investigated in Schottky ampere-class Ga2O3 power diodes. Three prominent electron traps were detected in Ga2O3 epilayers by a combination of the depth-resolved capacitance spectroscopy profiling and gradual dry etching. The near-surface trap occurring at 1.06 eV below the conduction band minimum (EC), named E3, was found to be confined within a 180 nm surface region of the Ga2O3 epilayers. Two bulk traps at EC − 0.75 eV (E2*) and at EC − 0.82 eV (E2) were identified and interconnected with the VGa- and FeGa-type defects, respectively. In the framework of the impact ionization model, employing the experimental trap parameters, the TCAD simulated breakdown characteristics matched the experimental breakdown properties well, consistently with inverse proportionality to the total trap densities. In particular, the shallowest distributed E3 trap with the deepest level is responsible for higher leakage and premature breakdown. In contrast, Ga2O3 Schottky diodes without E3 trap exhibit enhanced breakdown voltages, and the leakage mechanism evolves from variable range hopping at medium reverse voltages, to the space-charge-limited conduction at high reverse biases. This work bridges the fundamental gap between spatial charge inhomogeneities and diode breakdown features, paving the way for more reliable defect engineering in high-performance Ga2O3 power devices.

中文翻译：

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安培级 Ga2O3 功率二极管缺陷态不均匀性的性能限制

研究了肖特基安培级 Ga2O3 功率二极管中空间电荷不均匀性对载流子传输波动和过早击穿的影响。通过深度分辨电容谱分析和逐步干法刻蚀的结合，在 Ga2O3 外延层中检测到了三个突出的电子陷阱。近表面陷阱发生在导带最小值 (EC) 以下 1.06 eV 处，称为 E3，被发现被限制在 Ga2O3 外延层的 180 nm 表面区域内。确定了 EC − 0.75 eV (E2*) 和 EC − 0.82 eV (E2) 处的两个体陷阱，并分别与 VGa 型和 FeGa 型缺陷互连。在碰撞电离模型的框架中，采用实验陷阱参数，TCAD 模拟的击穿特性与实验击穿特性很好地匹配，与总陷阱密度成反比。特别是，最浅分布且能级最深的 E3 陷阱会导致更高的泄漏和过早击穿。相比之下，没有 E3 陷阱的 Ga2O3 肖特基二极管表现出增强的击穿电压，并且泄漏机制从中等反向电压下的可变范围跳跃演变为高反向偏压下的空间电荷限制传导。这项工作弥合了空间电荷不均匀性和二极管击穿特征之间的根本差距，为高性能 Ga2O3 功率器件中更可靠的缺陷工程铺平了道路。