Ning Jing, Yang Zhichun, Wu Haidi, Dong Xinmeng, Zhang Yaning, Chen Yufei, Zhang Xinbo, Wang Dong, Hao Yue, Zhang Jincheng
The State Key Laboratory of Wide-Bandgap Semiconductor Devices and Integrated Technology, Xi'an, China.
Shaanxi Joint Key Laboratory of Graphene, Xidian University, Xi'an, China.
Nat Commun. 2025 Aug 31;16(1):8144. doi: 10.1038/s41467-025-63666-x.
The self-heating effect in wide bandgap semiconductor devices makes epitaxial GaO on diamond substrates crucial for thermal management. However, the lack of wafer-scale single-crystal diamond and severe lattice mismatch limit its industrial application. This study presents van der Waals β-GaO (VdW-β-GaO) grown on high-thermal-conductivity polycrystalline diamond. VdW forces modify the coupling state between the single-crystal thin film and polycrystalline substrate. Tunable growth of ( ) VdW-β-GaO is achieved by leveraging the mismatch between graphene and the oxygen surface densities of varying crystal orientations and their oxygen-partial-pressure dependence. The 350 nm thick, high-crystallinity films exhibit a smallest rocking curve FWHM value of 0.18° and a root mean square roughness of 6.71 nm. Graphene alleviated interfacial thermal expansion stress; β-GaO/diamond interface exhibits an ultralow thermal boundary resistance of 2.82 m·K/GW. Photodetectors exhibit a photo-to-dark current ratio of 10 and a responsivity of 210 A/W, confirming the strategy's practicality and technological significance.
宽带隙半导体器件中的自热效应使得在金刚石衬底上生长外延GaO对于热管理至关重要。然而，缺乏晶圆级单晶金刚石以及严重的晶格失配限制了其工业应用。本研究展示了在高导热率多晶金刚石上生长的范德华β-GaO（VdW-β-GaO）。范德华力改变了单晶薄膜与多晶衬底之间的耦合状态。通过利用石墨烯与不同晶体取向的氧表面密度之间的失配及其对氧分压的依赖性，实现了（ ）VdW-β-GaO的可调谐生长。350 nm厚的高结晶度薄膜展现出最小半高宽为0.18°的摇摆曲线值以及6.71 nm的均方根粗糙度。石墨烯减轻了界面热膨胀应力；β-GaO/金刚石界面表现出2.82 m·K/GW的超低热边界电阻。光电探测器展现出10的光暗电流比和210 A/W的响应度，证实了该策略的实用性和技术意义。
