This work presents the optimization of a NiO/ β\beta -Ga2O3 heterojunction diode (HJD) by adjusting the structural parameters of the NiO layer. A rapid thermal annealing (RTA) process was utilized to modulate the hole concentration of the sputtered NiO. The influence of the NiO layer geometry and its hole concentration on the HJDs’ electrical properties has been thoroughly investigated and discussed based on both the experimental study and the technology computer-aided design (TCAD) simulation. It was found that the forward current of the HJDs was mainly determined by the size of the anode electrode regardless of the NiO layer dimension, indicating the poor current spreading within the NiO film. Enlarging the NiO layer dimension with a fixed anode or adjusting the hole concentration to an optimal value could benefit the device breakdown voltage ( VB{V}_{B} ) by reducing the electric field crowding effect. An optimum value of ∼2×1017{\sim }2\,\, {}\times {} 10^{17} cm−3 was determined for the HJDs with a drift layer doping concentration of 1.8×10161.8\,\, {}\times {}10^{16} cm−3. To achieve a good balance between VB{V}_{B} and the specific ON-resistance ( RON,sp{R}_{{\mathrm {ON,sp}}} ), a double-layer structure ( p+\text{p}^{+} NiO/ p−\text{p}^{-} NiO) was adopted and optimized, yielding a greatly enhanced performance in the NiO/ β\beta -Ga2O3 HJDs. The results provided a useful insight into the p−\text{p}^{-} NiO-related β\beta -Ga2O3 power device design.

中文翻译：

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高功率应用 NiO/β-Ga2O3 异质结二极管的优化


这项工作提出了通过调整 NiO 层的结构参数来优化 NiO/ β\beta -Ga2O3 异质结二极管（HJD）。利用快速热退火 (RTA) 工艺来调节溅射 NiO 的空穴浓度。基于实验研究和技术计算机辅助设计（TCAD）模拟，对 NiO 层几何形状及其空穴浓度对 HJD 电性能的影响进行了深入研究和讨论。研究发现，HJD 的正向电流主要由阳极电极的尺寸决定，与 NiO 层的尺寸无关，这表明 NiO 膜内的电流扩散较差。使用固定阳极扩大 NiO 层尺寸或将空穴浓度调整到最佳值可以通过减少电场拥挤效应来提高器件击穿电压（ VB{V}_{B} ）。对于漂移层掺杂浓度为 1.8×10161.8\,\, 的 HJD，确定了最佳值 ∼2×1017{\sim }2\,\, {}\times {} 10^{17} cm−3 {}\times {}10^{16} cm−3。为了在 VB{V}_{B} 和特定导通电阻 ( RON,sp{R}_{{\mathrm {ON,sp}}} ) 之间实现良好的平衡，双层结构 ( p+\text {p}^{+} NiO/ p−\text{p}^{-} NiO)被采用和优化，大大增强了NiO/ β\beta -Ga2O3 HJD的性能。结果为 p−\text{p}^{-} NiO 相关 β\beta -Ga2O3 功率器件设计提供了有用的见解。