导模法生长6英寸氧化镓单晶的结晶界面变形度评估与控制研究

doi:10.16553/j.cnki.issn1000-985x.2025.0006

摘要/Abstract

摘要： 氧化镓单晶(β-Ga₂O₃)具有禁带宽度大、击穿场强高等优异性能,在高功率、深紫外等器件领域具有重要应用价值。导模法是生长大尺寸高品质氧化镓单晶的重要方法,然而导模炉内部加热与保温结构的周向对称性及模具与晶体的周向不对称性,容易导致晶体在宽度和厚度方向传热不均匀,从而引起结晶界面严重变形,影响晶体的稳定生长。本文综合考虑了导模炉内部包含氧化镓单晶各向异性热传导和热辐射吸收耦合作用在内的各种传热流动现象,开展了非轴对称结晶界面形状的动网格追踪,建立了导模法生长氧化镓单晶的三维全局传热数值模型,对比研究了2英寸与6英寸(1英寸=2.54 cm)氧化镓单晶生长过程的热量传递及结晶界面变形规律,评估了不同尺寸晶体生长的界面变形度,设计了减小6英寸晶体生长界面变形度的盖板结构。研究结果表明,6英寸氧化镓单晶生长在晶体宽度和厚度方向上表现出更加显著的传热不均匀,使大尺寸晶体生长时结晶界面变形度更大,晶体生长稳定性更差;盖板结构对晶体在宽度和厚度方向上的传热和界面变形度影响显著,厚盖板周向包裹晶体的结构能够为6英寸氧化镓单晶稳定生长创造适宜的条件。本文研究工作对于导模法稳定生长大尺寸高品质氧化镓单晶具有重要指导意义。

关键词: 导模法, 氧化镓单晶, 各向异性导热, 热辐射吸收, 结晶界面变形度, 热量传递

Abstract: β-Ga₂O₃ single crystals exhibit exceptional properties, such as a wide bandgap and high breakdown field strength, making them highly valuable for applications in high-power and deep ultraviolet devices. The edge-defined film-fed growth (EFG) method is a critical technique for producing large and high-quality β-Ga₂O₃ single crystals. However, the circumferential symmetry of the heating and insulation structure inside the EFG furnace, coupled with the circumferential asymmetry of the die and the crystal, leads to significant heat transfer non-uniformity in the width and thickness directions of the crystal, resulting in severe crystallization interface deformation that impairs the stable growth of the crystal. This study comprehensively considers various heat transfer phenomena, including the coupling effects of anisotropic thermal conductivity and thermal radiation absorption in β-Ga₂O₃ single crystals. A dynamic mesh tracking method is implemented to model non-axisymmetric crystallization interface shapes, and a three-dimensional global heat transfer numerical model is developed for the EFG growth of β-Ga₂O₃ single crystals. The heat transfer and crystallization interface deformation during the growth of 2-inch and 6-inch (1 inch=2.54 cm) β-Ga₂O₃ single crystals were compared and analyzed. Interface deformation for crystals of different sizes was evaluated, and a cover structure was designed to reduce deformation during the growth of 6-inch crystals. The results show that the growth of 6-inch β-Ga₂O₃ single crystals exhibits more significant heat transfer non-uniformity in the width and thickness directions of the crystal. This results in larger crystallization interface deformation and poorer crystal growth stability for larger crystals. The cover structure has a significant influence on both heat transfer in the width and thickness directions of the crystal and interface deformation. A thick cover that circumferentially wraps the crystal can create favorable conditions for the stable growth of 6-inch β-Ga₂O₃ single crystals. This research provides valuable guidance for ensuring the stable growth of large, high-quality β-Ga₂O₃ single crystals by the EFG method.

Key words: edge-defined film-fed growth (EFG) method, β-Ga₂O₃ single crystal, anisotropic thermal conductivity, thermal radiation absorption, crystallization interface deformation, heat transfer

中图分类号:

O782

王君岚, 李早阳, 杨垚, 祁冲冲, 刘立军. 导模法生长6英寸氧化镓单晶的结晶界面变形度评估与控制研究[J]. 人工晶体学报, 2025, 54(3): 396-406.

WANG Junlan, LI Zaoyang, YANG Yao, QI Chongchong, LIU Lijun. Evaluation and Control of Crystallization Interface Deformation in the Growth of 6-Inch β-Ga₂O₃ Crystals by EFG Method[J]. Journal of Synthetic Crystals, 2025, 54(3): 396-406.

参考文献

[1] SASAKI K. Prospects for β-Ga₂O₃: now and into the future[J]. Applied Physics Express, 2024, 17(9): 090101.
[2] PEARTON S J, YANG J C, CARY P H, et al. A review of Ga₂O₃ materials, processing, and devices[J]. Applied Physics Reviews, 2018, 5(1): 011301.
[3] TSAO J Y, CHOWDHURY S, HOLLIS M A, et al. Ultrawide-bandgap semiconductors: research opportunities and challenges[J]. Advanced Electronic Materials, 2018, 4(1): 1600501.
[4] STEPANOV S I, NIKOLAEV V I, BOUGROV V E, et al. Gallium oxide: properties and applications-a review[J]. Reviews on Advanced Materials Science, 2016, 44(1): 63-86.
[5] GALAZKA Z, IRMSCHER K, UECKER R, et al. On the bulk β-Ga₂O₃ single crystals grown by the Czochralski method[J]. Journal of Crystal Growth, 2014, 404: 184-191.
[6] 陈绍华, 穆文祥, 张晋, 等. Ni掺杂β-Ga₂O₃单晶的光、电特性研究[J]. 人工晶体学报, 2023, 52(8): 1373-1377.
CHEN S H, MU W X, ZHANG J, et al. Optical and electrical properties of Ni-doped β-Ga₂O₃ single crystal[J]. Journal of Synthetic Crystals, 2023, 52(8): 1373-1377 (in Chinese).
[7] 唐慧丽, 何诺天, 罗平, 等. 超宽禁带半导体β-Ga₂O₃单晶生长突破2英寸[J]. 人工晶体学报, 2017, 46(12): 2533-2534.
TANG H L, HE N T, LUO P, et al. Ultra-wide bandgap semiconductor β-Ga₂O₃ single crystal growth breaks through 2 inches[J]. Journal of Synthetic Crystals, 2017, 46(12): 2533-2534 (in Chinese).
[8] KURAMATA A, KOSHI K, WATANABE S, et al. Bulk crystal growth of Ga₂O₃[C]//Oxide-based Materials and Devices IX. January 27-February 1, 2018. San Francisco, USA. SPIE, 2018: 13.
[9] MU W X, JIA Z T, YIN Y R, et al. High quality crystal growth and anisotropic physical characterization of β-Ga₂O₃ single crystals grown by EFG method[J]. Journal of Alloys and Compounds, 2017, 714: 453-458.
[10] BU Y Z, SAI Q L, QI H J. Stability of interfacial thermal balance in thick β-Ga₂O₃ crystal growth by EFG[J]. Journal of Crystal Growth, 2023, 612: 127194.
[11] STELIAN C, BARTHALAY N, DUFFAR T. Numerical investigation of factors affecting the shape of the crystal-melt interface in edge-defined film-fed growth of sapphire crystals[J]. Journal of Crystal Growth, 2017, 470: 159-167.
[12] LE C C, LI Z Y, MU W X, et al. 3D numerical design of the thermal field before seeding in an edge-defined film-fed growth system for β-Ga₂O₃ ribbon crystals[J]. Journal of Crystal Growth, 2019, 506: 83-90.
[13] WANG J L, LI Z Y, QI C, et al. 3D numerical modeling and simulation of β-Ga₂O₃ crystal growth by edge-defined film-fed growth method[J]. Journal of Vacuum Science & Technology A, 2025, 43(1): 013202.
[14] GUO Z, VERMA A, WU X F, et al. Anisotropic thermal conductivity in single crystal β-gallium oxide[J]. Applied Physics Letters, 2015, 106(11): 111909.
[15] KLIMM D, AMGALAN B, GANSCHOW S, et al. The thermal conductivity tensor of β-Ga₂O₃ from 300 to 1275 K[J]. Crystal Research and Technology, 2023, 58(2): 2200204.
[16] ONSAGER L. Reciprocal relations in irreversible processes. I[J]. Physical Review, 1931, 37(4): 405-426.
[17] ONSAGER L. Reciprocal relations in irreversible processes. II[J]. Physical Review, 1931, 38(12): 2265-2279.
[18] CHENG L, WU Y L, ZHONG W B, et al. Photophysics of β-Ga₂O₃: phonon polaritons, exciton polaritons, free-carrier absorption, and band-edge absorption[J]. Journal of Applied Physics, 2022, 132(18): 185704.
[19] GALAZKA Z. Growth of bulk β-Ga₂O₃ single crystals by the Czochralski method[J]. Journal of Applied Physics, 2022, 131(3): 031103.
[20] 于行, 赵琪, 齐小方, 等. 热交换法掺钛蓝宝石晶体生长过程中内辐射传热对晶体热应力的影响[J]. 人工晶体学报, 2024, 53(7): 1212-1221.
YU H, ZHAO Q, QI X F, et al. Effect of internal radiation heat transfer on the thermal stress in growing Ti:sapphire crystal by heat exchanger method[J]. Journal of Synthetic Crystals, 2024, 53(7): 1212-1221 (in Chinese).
[21] BRAESCU L, EPURE S, DUFFAR T. Mathematical and numerical analysis of capillarity problems and processes[M]. //Crystal Growth Processes Based on Capillarity. John Wiley & Sons, Ltd, 2010: 465-524.
[22] 闵乃本. 晶体生长的物理基础[M]. 南京: 南京大学出版社, 2019.
MIN N B. Physical basis of crystal growth[M]. Nanjing: Nanjing University Press, 2019 (in Chinese).