助熔剂过量辅助液相外延GaN晶体的生长过程研究

doi:10.16553/j.cnki.issn1000-985x.2025.0229

摘要/Abstract

摘要： 本文采用Na助熔剂液相外延法，系统研究了生长时间对GaN晶体的表面形貌、产率与质量的影响，并结合生长过程中坩埚内物料的变化和N离子浓度的计算，研究了助熔剂过量辅助液相外延GaN晶体的生长过程。结果表明，随着生长时间的延长，晶体表面形貌由初期的较小尺寸山脊状逐渐转变为棱台状，最终发育为大尺寸山脊状。晶体外延厚度随生长时间的延长而增加，生长时间为100 h时生长厚度内为1 500 μm；同时，晶体产率显著提升，与生长时间基本呈线性关系。生长时间为100 h时，GaN单晶产率、多晶产率和总产率分别约为65.5%、18.5%和84.0%。在生长初期，（0002）面X射线摇摆曲线（XRC）半峰全宽低于270″，并随生长时间延长逐渐变大。对生长过程中熔体内剩余物料的计算结果表明，剩余金属Ga的质量随生长时间线性减少，而剩余金属Na的质量在生长初期略有上升，后期趋于稳定。数值计算结果显示，随着生长时间的延长，熔体内N离子浓度呈增大的趋势。本研究可为调控GaN晶体形貌、提升产率及优化生长工艺提供了重要的实验与理论依据。

关键词: GaN; 钠助熔剂法; 液相外延; 助熔剂过量; 生长过程

Abstract: This study systematically investigated the effects of surface morphology， yield and quality of GaN crystals grown for different durations by adopting the Na flux liquid phase epitaxy method. Combined with the change of material in the crucible and calculation of N ion concentration during the growth process， the growth process of GaN crystal by flux-excess-assisted liquid phase epitaxy was elucidated. The results indicate that with the extension of growth time， the surface morphology of the crystals gradually evolves from the initial small-sized ridge-like to the pyramids shape， and eventually develops into large-sized ridge-like morphologies. The epitaxial thickness of the crystals increases with the extension of growth time， and the growth thickness is approximately 1 500 μm when the growth time is 100 h. Meanwhile， the crystal yield is significantly improved， exhibiting an approximately linear correlation with the growth time. When the growth time is 100 h， the single crystals yield， polycrystals yield and total yield of GaN are about 65.5%， 18.5% and 84.0%， respectively. In the initial growth stage， the full width at half maximum （FWHM） of the X-ray rocking curve （XRC） for the （0002） plane is less than 270″， and it gradually increases with the extension of growth time. The calculation results of the residual materials in the melt during growth process show that the mass of residual metallic Ga decreases linearly with growth time， whereas the mass of residual metallic Na increases slightly in the initial growth stage and then stabilizes in the later stage. Numerical calculation results reveal that the N ion concentration in the melt shows an increasing trend with the extension of growth time. This work provides important experimental and theoretical basis for regulating the morphology， improving the yield and optimizing the growth process of GaN crystals.

Key words: GaN; Na flux method; liquid phase epitaxy; flux-excess; growth process

中图分类号:

O782

杨琛, 黄戈萌, 潘荣林, 马明, 夏颂, 范世, 李振荣. 助熔剂过量辅助液相外延GaN晶体的生长过程研究[J]. 人工晶体学报, 2026, 55(3): 423-430.

YANG Chen, HUANG Gemeng, PAN Ronglin, MA Ming, XIA Song, FAN Shiji, LI Zhenrong. Growth Process of GaN Crystals by Flux-Excess-Assisted Liquid Phase Epitaxy[J]. Journal of Synthetic Crystals, 2026, 55(3): 423-430.

图/表 10

图1 不同生长时间的GaN晶体表面的XRD图谱

Fig.1 XRD patterns of GaN crystal surfaces grown for different durations

图2 不同生长时间的GaN晶体表面SEM照片

Fig.2 SEM images of GaN crystal surfaces grown for different durations

图3 不同生长时间的GaN晶体的断面形貌

Fig.3 Cross-sectional morphologies of GaN crystals grown for different durations

图4 不同生长时间的GaN晶体的产率

Fig.4 Yield of GaN crystals grown for different durations

图5 不同生长时间的GaN晶体表面的XRC FWHM变化曲线

Fig.5 Variation curve of XRC FWHM on GaN crystal surfaces grown for different durations

图6 熔体中助熔剂Na的质量随生长时间的变化曲线

Fig.6 Variation curve of flux Na mass in melt with growth time

图7 熔体中Ga摩尔分数随生长时间的变化曲线

Fig.7 Variation curve of Ga molar fraction in melt with growth time

图8 GaN晶体生长结束时熔体中的N离子浓度分布

Fig.8 N ion concentration distribution in melt at end of GaN crystal growth

图9 生长界面处的N离子浓度分布

Fig.9 N ion concentration distribution at growth interface

表1 不同生长时间的生长界面处CN的最大值（CN，max）和最小值（CN，min）

Tabel 1 Maximum value （CN，max） and minimum value （CN，min） of CN at growth interfaces grown for different durations

Parameter	6 h	12 h	25 h	50 h	75 h	100 h
C_N，min/（10²⁰ atoms∙cm^-3）	1.114 072	1.117 922	1.121 926	1.132 350	1.147 992	1.162 402
C_N_，_max/（10²⁰ atoms∙cm^-3）	1.120 388	1.124 275	1.128 259	1.138 709	1.154 464	1.168 979
ΔC_N/（10²⁰ atoms∙cm^-3）	0.006 316	0.006 353	0.006 330	0.006 359	0.006 472	0.006 577

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