The p-GaN/AlGaN/GaN heterostructure, predominantly epitaxially grown on large-scale silicon wafers, has been widely used for producing consumer power switching devices and recently manifested favorable for developing GaN-based complementary devices and circuits. This work investigates the hole distribution and transport in this structure based on wide-temperature-range (20–600 K) Hall measurements and TCAD simulations. It is revealed that the p-channel thereof is composed of the bulk holes in the p-GaN and the two-dimensional hole gas (2DHG) at the p-GaN/AlGaN interface, and both substantially contribute to the lateral p-type conduction at room temperature. Their complementary temperature responses lead to conductivity enhancement at both high- and low-temperature regimes. The high-density (1.2 × 1013 cm−2) 2DHG is formed owing to the polarization-induced potential well and the ionization of the Mg acceptors that thermally diffused into the barrier during the epi-growth. Such ionized Mg acceptors would partially deplete the two-dimensional electron gas (2DEG) at the access region in the n-channel side where the p-GaN is removed and result in a trade-off between the carrier density of 2DHG and 2DEG.

中文翻译：

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p-GaN/AlGaN/GaN异质结构中空穴的分布和传输

p-GaN/AlGaN/GaN异质结构主要在大规模硅片上外延生长，已广泛用于生产消费类功率开关器件，并且最近表现出有利于开发基于GaN的互补器件和电路。这项工作基于宽温范围 (20–600 K) 霍尔测量和 TCAD 模拟，研究了该结构中的空穴分布和传输。结果表明，其p沟道由p-GaN中的体空穴和p-GaN/AlGaN界面处的二维空穴气（2DHG）组成，两者对横向p型传导有显着贡献。在室温下。它们互补的温度响应导致高温和低温条件下的电导率增强。高密度（1. 2 × 1013 cm−2) 2DHG 是由于极化引起的势阱和外延生长过程中热扩散到势垒中的 Mg 受体的电离而形成的。这种电离的镁受体将部分耗尽n沟道侧接入区的二维电子气(2DEG)，其中p-GaN被去除，并导致2DHG和2DEG的载流子密度之间的权衡。