异质外延Ga2O3薄膜及其肖特基二极管性能研究
Study on Heteroepitaxial Ga2O3 Films and Their Schottky Diode Performance
摘要
β‑ Ga₂O₃作为宽禁带半导体，在功率电子领域应用潜力巨大，但异质外延的晶体质量调控是其器件化的关键瓶颈。本文采用碳热还原法，在4H‑ SiC及分别带有 10 nm、100 nm Al₂O₃缓冲层的4H‑ SiC 衬底上外延制备 β‑ Ga₂O₃薄膜，系统研究衬底结构对其晶体质量、生长模式及器件性能的影响。结果表明，引入Al₂O₃缓冲层可明显改善 β‑ Ga₂O₃晶体质量，其中 10 nm 缓冲层已达临界调控厚度，其 (-201) 晶面 XRD 摇摆曲线半高宽为 0.977 ，呈层状台阶流生长，表面平整度高、厚度波动小于 6%，生长速率达 2.71 μm/h。100 nm Al₂O₃则因热膨胀失配出现层间滑移，薄膜呈岛状生长，晶体质量无进一步提升。基于 10 nm Al₂O₃缓冲层的 β‑ Ga₂O₃肖特基二极管性能优异，正向开启电压3.46 V，反向击穿电压 186 V，击穿前反向漏电流极低。本研究阐明了 Al₂O₃缓冲层的关键作用，证实 10 nm 为最优厚度，兼顾成本与性能，为氧化镓功率器件的低成本、规模化制备提供了工艺与理论支撑。
Abstract
iAs a wide-bandgap semiconductor, β‑ Ga₂O₃ has great potential in the field of power electronics, but controlling the crystal quality of heteroepitaxial films is the key bottleneck for its device applications. In this work, β‑ Ga₂O₃ thin films were epitaxially grown on 4H‑ SiC substrates and 4H‑ SiC substrates with 10 nm and 100 nm Al₂O₃ buffer layers using the carbothermal reduction method. The influence of substrate structure on the crystal quality, growth mode, and device performance was systematically studied. The results show that the introduction of an Al₂O₃ buffer layer can significantly improve the crystal quality of β‑ Ga₂O₃. A 10 nm buffer layer has already reached the critical thickness for regulation, with a (-201) plane XRD rocking curve full width at half maximum of 0.977 , exhibiting a terraced layer-by-layer growth, high surface flatness, thickness fluctuation of less than 6%, and a growth rate of 2.71 μm/h. For a 100 nm Al₂O₃ layer, interlayer slip occurs due to thermal expansion mismatch, resulting in island-like growth of the film, and no further improvement in crystal quality is observed.β‑ Ga₂O₃ Schottky diodes based on the 10 nm Al₂O₃ buffer layer show excellent performance, with a forward turn-on voltage of 3.46 V, a reverse breakdown voltage of 186 V, and extremely low reverse leakage current before breakdown. This study clarifies the key role of the Al₂O₃ buffer layer, confirms that 10 nm is the optimal thickness balancing cost and performance, and provides process and theoretical support for the low-cost, large-scale fabrication of gallium oxide power devices..关键词
氧化镓/异质外延/碳热还原法Key words
Gallium oxide/heteroepitaxy/carbothermal reduction method引用本文复制引用
黄明玮,张赫之.异质外延Ga2O3薄膜及其肖特基二极管性能研究[EB/OL].(2026-03-26)[2026-03-27].http://www.paper.edu.cn/releasepaper/content/202603-261.学科分类
半导体技术
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