AlN single crystal grown by physical vapor transport (PVT) using homogeneous seed is considered as the most promising approach to obtain high-quality AlN boule.In this work,the morphology of AlN single crystals grown ...AlN single crystal grown by physical vapor transport (PVT) using homogeneous seed is considered as the most promising approach to obtain high-quality AlN boule.In this work,the morphology of AlN single crystals grown under different modes (3D islands and single spiral center) were investigated.It is proved that,within an optimized thermal distribution chamber system,the surface temperature of AlN seed plays an important role in crystal growth,revealing a direct relationship between growth mode and growth condition.Notably,a high-quality AlN crystal,with (002) and (102) reflection peaks of 65and 36 arcsec at full width at half maximum (FWHM),was obtained grown under a single spiral center mode.And on which,a high-quality Al_x Ga_(1–x) N epitaxial layer with high Al content (x=0.54) was also obtained.The FWHMs of (002) and (102) reflection of Al_x Ga_(1–x) N were 202 and 496 arcsec,respectively,which shows superiority over their counterpart grown on SiC or a sapphire substrate.展开更多
通过热力学理论对物理气相传输(PVT)法AlN晶体生长过饱和度进行分析,分别从软件模拟和晶体生长实验对衬底表面的温度分布进行调控,进而控制衬底表面AlN晶体生长的驱动力。理论上,采用Comsol模拟软件对坩埚结构的温度分布进行模拟仿真,...通过热力学理论对物理气相传输(PVT)法AlN晶体生长过饱和度进行分析,分别从软件模拟和晶体生长实验对衬底表面的温度分布进行调控,进而控制衬底表面AlN晶体生长的驱动力。理论上,采用Comsol模拟软件对坩埚结构的温度分布进行模拟仿真,模拟结果表明:复合型衬底可以显著改变衬底表面的温度分布,达到改变衬底表面AlN气氛的过饱和度的目的;实验上,采用PVT法AlN晶体的生长实验验证了软件模拟结果。采用复合型衬底生长AlN晶体时,通过对衬底表面的温度分布调控可有效控制晶体生长驱动力,进而实现形核位置和形核数量的控制。经过6~8 h AlN晶体生长后,可获得尺寸约为12 mm、厚度约为3 mm的AlN单晶。喇曼光谱和XRD双晶摇摆曲线测试结果表明晶体质量良好。展开更多
本文采用物理气相传输法对不同衬底温度和温差下制备的氮化铝(AlN)晶体形貌进行研究,研究结果表明AlN晶体生长受到AlN晶面表面能、Al基元平均动能和AlN晶体表面极性的共同影响。当温差为60℃时,AlN晶体(0001)面生长速率小于(10-10)面,Al...本文采用物理气相传输法对不同衬底温度和温差下制备的氮化铝(AlN)晶体形貌进行研究,研究结果表明AlN晶体生长受到AlN晶面表面能、Al基元平均动能和AlN晶体表面极性的共同影响。当温差为60℃时,AlN晶体(0001)面生长速率小于(10-10)面,AlN以带状形式生长。将该工艺应用于AlN同质生长中,研究结果表明:温差为60℃时AlN晶体(0001)面呈现畴生长模式,该晶体质量最差;温差为35℃时AlN晶体(0001)面呈现台阶流生长模式,该晶体质量最优;温差为20℃时AlN晶体(0001)面呈现台阶簇生长模式,该晶体容易开裂。通过工艺优化最终获得了直径为40 mm AlN单晶衬底,完全满足器件制备需求。展开更多
基金supported by the National Key Research and Development Plan of China (2017YFB0404103)the National Natural Science Foundation of China (No.51702297)。
文摘AlN single crystal grown by physical vapor transport (PVT) using homogeneous seed is considered as the most promising approach to obtain high-quality AlN boule.In this work,the morphology of AlN single crystals grown under different modes (3D islands and single spiral center) were investigated.It is proved that,within an optimized thermal distribution chamber system,the surface temperature of AlN seed plays an important role in crystal growth,revealing a direct relationship between growth mode and growth condition.Notably,a high-quality AlN crystal,with (002) and (102) reflection peaks of 65and 36 arcsec at full width at half maximum (FWHM),was obtained grown under a single spiral center mode.And on which,a high-quality Al_x Ga_(1–x) N epitaxial layer with high Al content (x=0.54) was also obtained.The FWHMs of (002) and (102) reflection of Al_x Ga_(1–x) N were 202 and 496 arcsec,respectively,which shows superiority over their counterpart grown on SiC or a sapphire substrate.
基金Shenzhen Science and Technology Program(JCYJ20210324141607019)Natural Science Foundation of Shandong Province(ZR2022QF044)National Natural Science Foundation of China(52202265)。
文摘通过热力学理论对物理气相传输(PVT)法AlN晶体生长过饱和度进行分析,分别从软件模拟和晶体生长实验对衬底表面的温度分布进行调控,进而控制衬底表面AlN晶体生长的驱动力。理论上,采用Comsol模拟软件对坩埚结构的温度分布进行模拟仿真,模拟结果表明:复合型衬底可以显著改变衬底表面的温度分布,达到改变衬底表面AlN气氛的过饱和度的目的;实验上,采用PVT法AlN晶体的生长实验验证了软件模拟结果。采用复合型衬底生长AlN晶体时,通过对衬底表面的温度分布调控可有效控制晶体生长驱动力,进而实现形核位置和形核数量的控制。经过6~8 h AlN晶体生长后,可获得尺寸约为12 mm、厚度约为3 mm的AlN单晶。喇曼光谱和XRD双晶摇摆曲线测试结果表明晶体质量良好。
文摘本文采用物理气相传输法对不同衬底温度和温差下制备的氮化铝(AlN)晶体形貌进行研究,研究结果表明AlN晶体生长受到AlN晶面表面能、Al基元平均动能和AlN晶体表面极性的共同影响。当温差为60℃时,AlN晶体(0001)面生长速率小于(10-10)面,AlN以带状形式生长。将该工艺应用于AlN同质生长中,研究结果表明:温差为60℃时AlN晶体(0001)面呈现畴生长模式,该晶体质量最差;温差为35℃时AlN晶体(0001)面呈现台阶流生长模式,该晶体质量最优;温差为20℃时AlN晶体(0001)面呈现台阶簇生长模式,该晶体容易开裂。通过工艺优化最终获得了直径为40 mm AlN单晶衬底,完全满足器件制备需求。
