To resolve the parasitic problems and to fully leverage the superiority of GaN-based high electron mobility transistors, monolithic integration of different function blocks is a promising solution. The enhancement mode (E-mode) GaN-based p-channel heterostructure field-effect transistor (p-HFET) is one of the key components. Herein, the threshold voltage (V_TH) is modeled, and the influence of the Mg out-diffusion effect on V_TH is investigated. The impact of the diffusion coefficient of Mg, the Mg concentration in the p-GaN layer, the thicknesses of the AlGaN layer (t_b), p-GaN channel layer (t_ch), and an oxide layer (t_ox) on V_TH are all taken into consideration for systematic exploration. The analysis illustrates that lower Mg concentration, smaller diffusion coefficient, and thinner p-GaN channel and AlGaN layers facilitate the realization of E-mode p-HFETs. Furthermore, it can be observed that lower Mg concentration in the p-GaN layer diminishes the V_TH sensitivity to the thickness of the p-GaN channel layer. Hence, a heterostructure with two p-GaN layers of different concentrations is suggested to reduce the complexity of the etching technique while improving the ohmic contacts. As a result, the model can effectively guide the design of GaN-based E-mode p-HFETs.

中文翻译：

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Mg外扩散效应对GaN基p沟道异质结构场效应晶体管阈值电压的影响

为了解决寄生问题并充分利用基于GaN的高电子迁移率晶体管的优势，不同功能块的单片集成是一种有前途的解决方案。增强型（E 型）GaN 基 p 沟道异质结构场效应晶体管（p-HFET）是关键元件之一。在此，对阈值电压 ( VTH )_进行建模，并研究Mg 向外扩散效应对VTH_的影响。Mg 的扩散系数、p-GaN 层中的 Mg 浓度、AlGaN 层的厚度 ( t _b )、p-GaN 沟道层 ( t _ch ) 和氧化层 ( t _ox ) 对V的影响_TH都被考虑在内进行系统探索。分析表明，较低的 Mg 浓度、较小的扩散系数以及较薄的 p-GaN 沟道和 AlGaN 层有助于实现 E 模式 p-HFET。此外，可以观察到 p-GaN 层中较低的 Mg 浓度会降低_VTH对p-GaN 沟道层厚度的敏感性。因此，建议采用具有两个不同浓度的 p-GaN 层的异质结构，以降低蚀刻技术的复杂性，同时改善欧姆接触。因此，该模型可以有效地指导基于 GaN 的 E 型 p-HFET 的设计。