GaN基光电器件材料生长方法研究
摘要
III族氮化物半导体材料以其优异的特性正在发挥着越来越广泛的作用。以GaN基蓝光、绿光及深紫外LED为核心技术的半导体照明技术正在引领着一场新的产业革命。经过近十几年的发展,GaN基蓝光LED已成功实现商业化,在景观灯、背光源、照明灯领域都得到广泛应用。GaN基微波功率器件也逐渐进入商业应用。
随着III族氮化物器件研究和应用的深入,GaN基光电子器件和微波功率器件都对材料性能提出了更高的要求。对于LED器件,为了提升增强量子效率、降低非发光复合、减少缺陷对光子的吸收,需要有高结晶质量、低缺陷密度材料的外延技术、高性能的p型掺杂技术和高效率、高均匀性的多量子阱结构制备技术的支持。对于微波功率器件,为提升器件击穿电压、提高功率密度并降低器件寄生效应,同样对高结晶质量、低缺陷密度的材料有迫切的需求。
在上述需求背景下,本文对Ⅲ族氮化物半导体器件应用相关的关键问题进行了研究,研究内容主要包括基于蓝宝石衬底高质量GaN、AlN及其合金的生长工艺、高性能p型掺杂工艺、InGaN/GaN多量子阱结构制备及实现上述技术的MOCVD设备。本文总结了作者对上述研究工作和认识,主要贡献和成果如下:
1、MOCVD系统研制
参与研制了自主知识产权的MOCVD系统,提出了恒流配气系统的方法及配套工艺,在应用过程中对其配气系统进行了改进。
2、GaN类材料的外延技术研究
对GaN类材料的外延技术和工艺进行了系统的研究,本文提出,在具有大晶格失配的GaN、AIN和AlGaN材料的外延生长中,脉冲式表面增强反应对金属原子表面迁移特性的改善,基于应力调制的超晶格结构和自成核层生长就开始设计的应力匹配和调制技术,是获得高结晶质量、低缺陷密度外延材料的关键因素。本文以应力匹配为基本手段对GaN类材料的外延结构和工艺进行了优化。
对GaN材料外延生长过程的各个阶段进行了微观形貌的分析,得到了各个生长阶段影响材料整体结晶质量的关键因素。给出了超薄AlN成核层的优化工艺和缓冲层退火的方法,该方法可在显著提高GaN外延材料的结晶质量。
对AN外延材料实际生长过程中的困难进行了分析,提出了一种新的脉冲式表面增强反应的方法,并对其关键工艺因素进行了优化,获得了XRD(002)面摇摆曲线半高宽38arcsec,(102)面摇摆曲线半高宽198arcsec的高结晶质量A1N外延材料,为目前已报道的最好结果。
通过对不同Al组分AlGaN材料表面形貌的分析,确定了AlGaN材料高质量外延工艺中应力匹配的关键因素。提出了基于应力调制的超晶格插入层方法,通过对超晶格插入层结构和组分的优化,获得了不同组分的AlGaN外延材料的优化结构和工艺,制备出了不同Al组分的高结晶质量、低缺陷密度的AlGaN外延材料。
3、GaN类材料的p型掺杂技术研究
对于p型GaN材料的制备,通过系统的实验和分析,对制备p型材料的生长温度、Ga/Mg摩尔比和退火工艺进行了优化。并采用了大气退火工艺,获得了电阻率小于1Ω-·cm的p-GaN外延材料。
对于p-AlGaN材料的制备,在获得的低缺陷密度AlGaN材料的基础上,采用均匀掺杂方法,获得了电阻率为4.37Ω-·cm的p-Al0.25Ga0.75N材料。
以脉冲式表面增强反应MOCVD法为基础,提出了用于Mg δ掺杂的脉冲式生长方法,并对脉冲式δ掺杂制备p-AlGaN材料的工艺进行了研究,获得了电阻率为1.92Q·cm的p-Al0.25Ga0.75N材料。
4、GaN基多量子阱结构生长研究
为解决In组分的有效掺入和工艺稳定性的问题,给出了具有势阱限制层和量子阱退火工艺的多量子阱结构和工艺,获得了具有生长温度钝化特点的量子阱结构和制备工艺,实现了在高In掺入效率、高波长稳定性的制备工艺。并在一定程度上实现了梯形量子阱结构,可对消除电子和空穴波函数的实空间分离具有一定的作用,有效提高器件的发光效率。该工艺对商用LED器件的性能稳定性和成品率提高有极大的价值。
为解决因MOCVD系统配气系统波动和工艺温度波动引起的量子阱黄带发光过强和片上波长均匀性低的问题,文本在自产的MOCVD系统上设计并实现了恒流配气的MO源供应模块和配套工艺,实现了高片上波长均匀性的生长模式,为高成品率的LED外延片制备奠定了基础。
为解决极化效应引起的载流子实空间分离造成的发光复合效率低的问题,本文设计并实现了势垒掺In的InGaN/GaN多量子阱结构,通过对势垒生长阶段TMIn流量参数的优化,获得了优化工艺。器件测试结果表明,势垒掺In的优化工艺,可将器件的发光效率提升15.61%,具有良好的效果。
自2000年开始进行GaN基材料和器件的研究以来,形成的高亮度蓝光LED器件制造技术已经在2007年实现了产业化转移,以本文技术为基础建设了年产LED外延片10万片,管芯25亿只的LED外延片和管芯制造企业。
Due to the advantageous properties, III-Nitride semiconductor materials and itsapplications are becoming more and more important. Semiconductor lightingengineering, based on blue, green and ultraviolet LEDs, is leading a new industrialrevolution. GaN based blue LEDs have been commercialized successfully, which arewidely used in fields of landscape lamp, backlight and lighting lamp. Meanwhile, GaNbased microwave power devices are being gradually commercialized.
With the progress in research and application on III-Nitride devices, GaN basedoptoelectronic devices and microwave power devices have great demand on materialproperties. For LEDs, to increase quantum efficiency, decrease non-radiativerecombination,and reduce trap-induced photon absorption, epitaxial technique with highcrystal quality and low defect density, high performance p-type doping technique andhigh efficiency and uniformity multiple quantum-well structure manufacturingtechnique are required. For microwave power devices, to increase breakdown voltage,improve power density and reduce parasitic effects, the same demands are needed.
Based on the above background, several key issues related to the application ofIII-nitride semiconductor devices have been studied in this thesis, which include highquality GaN, AlN and alloy growth methods on sapphire substrate, high performancep-type doping, InGaN/GaN multiple quantum-well structure prepatation, and MOCVDsystems for realizing above processing. The major contributions and achievements areshown in the following:
1. MOCVD system development
It includes two parts: participating in the development of independent intellectualproperty rights MOCVD system, and improving gas-supply system during application.
2. Research on epitaxial technique based on GaN-class materials
Via research on epitaxial technique and processing for GaN-class materials, it isconcluded that in the growth of epitaxial for big mismatch materials(GaN, AlN, AlGaN,etc), surface ehanced reaction pulse methodGsuper lattice structure to stress-modulationand stress match-and-modulation starting from nucleation layer growth are the keyfactors to obtain high crystal quality and low defect density epitaxial materials. In thisthesis, the epitaxial structure and processing of GaN-class materials are optimized basedon stress matching.
Micro-morphology at different stage during GaN materials epitaxial growth havebeen analyzed, and the main factors that affect material crystal quality are obtained.Optimized processing for super thin AlN nucleation layer and annealing technique forbuffer layer have been proposed. It can significantly improve the crystal quality ofepitaxial material.
By analyzing the difficulties during AlN epitaxial material growth, pulsedsurface-enhancement reaction technique is proposed and crucial processing factors are optimized. High-quality AlN epitaxial material with XRDM002RRC FWHM38arcsecM102RRC FWHM198arcsec are obtained. The characteristic parameters are ininternational top-class level.
By analyzing the morphology of AlGaN with different Al content, crucial factorsfor stress matching during high-quality epitaxial processing have been determined.Super lattice insert layer, based on stress modulation, have been proposed. Viaoptimization of insert layer structure and content, high quality and low defect densityAlGaN epitaxial material with different Al content have been obtained.
3. Study on p-type doping technique for GaN-class materials
The growth temperature, Ga/Mg mole ratio and annealing processing for p-typeGaN fabrication are optimized. By utilizing air-annealing, p-GaN epitaxial withresistance less than1Ω·cm are obtained.
By using uniform doping technique, p-Al0.25Ga0.75N with resistance of4.37Ω·cm isrealized. Based on surface enhancement reaction MOCVD, plused δ-doping p-AlGaNprocessing has been investigated, and p-Al0.25Ga0.75N with resistance of1.92Ω·cm hasbe obtained.
4. Investigation on the growth of GaN-based multiple quantum-well structure
To solve the effective doping of In and processing stability, multi quantum-wellstructure and processing with well cladding layer and anneal process have beenproposed. The fabrication processing characterized by high In doping efficiency andhigh wavelength stability has been realized. Trapezoid quantum-well structure, whichcan improve luminous efficiency has been preliminary achieved. This processing is ofgreat value to the stability and yield of commercial LEDs.
In order to solve problem of YL and low wavelength uniformity due to thefluctuation of MOCVD gas-supply and process temperature, a new type of gas-supplysystem for MO source module has been designed. Related processing with highwavelength uniformility have been realized, which builds up a good basis for high yieldLED epitaxial wafer.
To overcome polarization-induced low lighting recombination efficiency,InGaN/GaN multi-quantum well structure with In doped barrier and low temperatureGaN cladding layer has been designed and realized, and the related processing has beenoptimized. Combine with quantum well annealing process, it is demonstrated that theluminous efficiency has a significant increase of15.61%.
High brightness blue LEDs, which are based on the above research, have beentransferred to industry in2007. Nowadays, the company has great capability of100’000epitaxial wafers and2.5billion LED chips per year.
随着III族氮化物器件研究和应用的深入,GaN基光电子器件和微波功率器件都对材料性能提出了更高的要求。对于LED器件,为了提升增强量子效率、降低非发光复合、减少缺陷对光子的吸收,需要有高结晶质量、低缺陷密度材料的外延技术、高性能的p型掺杂技术和高效率、高均匀性的多量子阱结构制备技术的支持。对于微波功率器件,为提升器件击穿电压、提高功率密度并降低器件寄生效应,同样对高结晶质量、低缺陷密度的材料有迫切的需求。
在上述需求背景下,本文对Ⅲ族氮化物半导体器件应用相关的关键问题进行了研究,研究内容主要包括基于蓝宝石衬底高质量GaN、AlN及其合金的生长工艺、高性能p型掺杂工艺、InGaN/GaN多量子阱结构制备及实现上述技术的MOCVD设备。本文总结了作者对上述研究工作和认识,主要贡献和成果如下:
1、MOCVD系统研制
参与研制了自主知识产权的MOCVD系统,提出了恒流配气系统的方法及配套工艺,在应用过程中对其配气系统进行了改进。
2、GaN类材料的外延技术研究
对GaN类材料的外延技术和工艺进行了系统的研究,本文提出,在具有大晶格失配的GaN、AIN和AlGaN材料的外延生长中,脉冲式表面增强反应对金属原子表面迁移特性的改善,基于应力调制的超晶格结构和自成核层生长就开始设计的应力匹配和调制技术,是获得高结晶质量、低缺陷密度外延材料的关键因素。本文以应力匹配为基本手段对GaN类材料的外延结构和工艺进行了优化。
对GaN材料外延生长过程的各个阶段进行了微观形貌的分析,得到了各个生长阶段影响材料整体结晶质量的关键因素。给出了超薄AlN成核层的优化工艺和缓冲层退火的方法,该方法可在显著提高GaN外延材料的结晶质量。
对AN外延材料实际生长过程中的困难进行了分析,提出了一种新的脉冲式表面增强反应的方法,并对其关键工艺因素进行了优化,获得了XRD(002)面摇摆曲线半高宽38arcsec,(102)面摇摆曲线半高宽198arcsec的高结晶质量A1N外延材料,为目前已报道的最好结果。
通过对不同Al组分AlGaN材料表面形貌的分析,确定了AlGaN材料高质量外延工艺中应力匹配的关键因素。提出了基于应力调制的超晶格插入层方法,通过对超晶格插入层结构和组分的优化,获得了不同组分的AlGaN外延材料的优化结构和工艺,制备出了不同Al组分的高结晶质量、低缺陷密度的AlGaN外延材料。
3、GaN类材料的p型掺杂技术研究
对于p型GaN材料的制备,通过系统的实验和分析,对制备p型材料的生长温度、Ga/Mg摩尔比和退火工艺进行了优化。并采用了大气退火工艺,获得了电阻率小于1Ω-·cm的p-GaN外延材料。
对于p-AlGaN材料的制备,在获得的低缺陷密度AlGaN材料的基础上,采用均匀掺杂方法,获得了电阻率为4.37Ω-·cm的p-Al0.25Ga0.75N材料。
以脉冲式表面增强反应MOCVD法为基础,提出了用于Mg δ掺杂的脉冲式生长方法,并对脉冲式δ掺杂制备p-AlGaN材料的工艺进行了研究,获得了电阻率为1.92Q·cm的p-Al0.25Ga0.75N材料。
4、GaN基多量子阱结构生长研究
为解决In组分的有效掺入和工艺稳定性的问题,给出了具有势阱限制层和量子阱退火工艺的多量子阱结构和工艺,获得了具有生长温度钝化特点的量子阱结构和制备工艺,实现了在高In掺入效率、高波长稳定性的制备工艺。并在一定程度上实现了梯形量子阱结构,可对消除电子和空穴波函数的实空间分离具有一定的作用,有效提高器件的发光效率。该工艺对商用LED器件的性能稳定性和成品率提高有极大的价值。
为解决因MOCVD系统配气系统波动和工艺温度波动引起的量子阱黄带发光过强和片上波长均匀性低的问题,文本在自产的MOCVD系统上设计并实现了恒流配气的MO源供应模块和配套工艺,实现了高片上波长均匀性的生长模式,为高成品率的LED外延片制备奠定了基础。
为解决极化效应引起的载流子实空间分离造成的发光复合效率低的问题,本文设计并实现了势垒掺In的InGaN/GaN多量子阱结构,通过对势垒生长阶段TMIn流量参数的优化,获得了优化工艺。器件测试结果表明,势垒掺In的优化工艺,可将器件的发光效率提升15.61%,具有良好的效果。
自2000年开始进行GaN基材料和器件的研究以来,形成的高亮度蓝光LED器件制造技术已经在2007年实现了产业化转移,以本文技术为基础建设了年产LED外延片10万片,管芯25亿只的LED外延片和管芯制造企业。
Due to the advantageous properties, III-Nitride semiconductor materials and itsapplications are becoming more and more important. Semiconductor lightingengineering, based on blue, green and ultraviolet LEDs, is leading a new industrialrevolution. GaN based blue LEDs have been commercialized successfully, which arewidely used in fields of landscape lamp, backlight and lighting lamp. Meanwhile, GaNbased microwave power devices are being gradually commercialized.
With the progress in research and application on III-Nitride devices, GaN basedoptoelectronic devices and microwave power devices have great demand on materialproperties. For LEDs, to increase quantum efficiency, decrease non-radiativerecombination,and reduce trap-induced photon absorption, epitaxial technique with highcrystal quality and low defect density, high performance p-type doping technique andhigh efficiency and uniformity multiple quantum-well structure manufacturingtechnique are required. For microwave power devices, to increase breakdown voltage,improve power density and reduce parasitic effects, the same demands are needed.
Based on the above background, several key issues related to the application ofIII-nitride semiconductor devices have been studied in this thesis, which include highquality GaN, AlN and alloy growth methods on sapphire substrate, high performancep-type doping, InGaN/GaN multiple quantum-well structure prepatation, and MOCVDsystems for realizing above processing. The major contributions and achievements areshown in the following:
1. MOCVD system development
It includes two parts: participating in the development of independent intellectualproperty rights MOCVD system, and improving gas-supply system during application.
2. Research on epitaxial technique based on GaN-class materials
Via research on epitaxial technique and processing for GaN-class materials, it isconcluded that in the growth of epitaxial for big mismatch materials(GaN, AlN, AlGaN,etc), surface ehanced reaction pulse methodGsuper lattice structure to stress-modulationand stress match-and-modulation starting from nucleation layer growth are the keyfactors to obtain high crystal quality and low defect density epitaxial materials. In thisthesis, the epitaxial structure and processing of GaN-class materials are optimized basedon stress matching.
Micro-morphology at different stage during GaN materials epitaxial growth havebeen analyzed, and the main factors that affect material crystal quality are obtained.Optimized processing for super thin AlN nucleation layer and annealing technique forbuffer layer have been proposed. It can significantly improve the crystal quality ofepitaxial material.
By analyzing the difficulties during AlN epitaxial material growth, pulsedsurface-enhancement reaction technique is proposed and crucial processing factors are optimized. High-quality AlN epitaxial material with XRDM002RRC FWHM38arcsecM102RRC FWHM198arcsec are obtained. The characteristic parameters are ininternational top-class level.
By analyzing the morphology of AlGaN with different Al content, crucial factorsfor stress matching during high-quality epitaxial processing have been determined.Super lattice insert layer, based on stress modulation, have been proposed. Viaoptimization of insert layer structure and content, high quality and low defect densityAlGaN epitaxial material with different Al content have been obtained.
3. Study on p-type doping technique for GaN-class materials
The growth temperature, Ga/Mg mole ratio and annealing processing for p-typeGaN fabrication are optimized. By utilizing air-annealing, p-GaN epitaxial withresistance less than1Ω·cm are obtained.
By using uniform doping technique, p-Al0.25Ga0.75N with resistance of4.37Ω·cm isrealized. Based on surface enhancement reaction MOCVD, plused δ-doping p-AlGaNprocessing has been investigated, and p-Al0.25Ga0.75N with resistance of1.92Ω·cm hasbe obtained.
4. Investigation on the growth of GaN-based multiple quantum-well structure
To solve the effective doping of In and processing stability, multi quantum-wellstructure and processing with well cladding layer and anneal process have beenproposed. The fabrication processing characterized by high In doping efficiency andhigh wavelength stability has been realized. Trapezoid quantum-well structure, whichcan improve luminous efficiency has been preliminary achieved. This processing is ofgreat value to the stability and yield of commercial LEDs.
In order to solve problem of YL and low wavelength uniformity due to thefluctuation of MOCVD gas-supply and process temperature, a new type of gas-supplysystem for MO source module has been designed. Related processing with highwavelength uniformility have been realized, which builds up a good basis for high yieldLED epitaxial wafer.
To overcome polarization-induced low lighting recombination efficiency,InGaN/GaN multi-quantum well structure with In doped barrier and low temperatureGaN cladding layer has been designed and realized, and the related processing has beenoptimized. Combine with quantum well annealing process, it is demonstrated that theluminous efficiency has a significant increase of15.61%.
High brightness blue LEDs, which are based on the above research, have beentransferred to industry in2007. Nowadays, the company has great capability of100’000epitaxial wafers and2.5billion LED chips per year.
引文
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[1.19]段猛,郝跃.GaN基蓝色LED的研究进展.西安电子科技大学学报.2003,30(01)：60
[1.20]于占涛.半导体照明网.2009-6-15
[1.21]J.Han, et.al. AlGaN/GaN quantum well ultraviolet light emitting diodes. Appl. Phys. Lett.1998,73:1688
[1.22]Chitnis, M.Asif. Khan, et.al. High DC power325nm emission deep UV LEDs over sapphire. Electronics Letters.2002,38(25):1709
[1.23]W.H.Sun, M.Asif. Khan,et.al. Continuous Wave Milliwatt Power AlGaN Light Emitting Diodes at280nm. JpnJ. Appl. Phys.2004,43:L1419
[1.24]C.Touzia, F. Omne, T.Boufadena, et.al., Realisation of 'SolarBlind' AlGaN Photodetectors: Measured and calculated spectral response, Microelectronics Journal,2006, Vol.37,336-339
[1.25]V. Adivarahan, M.Asif. Khan,et.al.250nm AlGaN light-emitting diodes. Appl.Phys.Lett.2004,85(12):2175
[1.26]Hideki Hirayama, et.al.226-273nm AlGaN deep-ultraviolet light-emitting diodes fabricated on multilayer AlN buffers on sapphire. Phys.Sta.Sol.(c).2008,5(9):2969
[2.1]T. Chu, K. Ito, R. Smeltzer, et al. Crystal growth and characterization of gallium nitride, Journal of The Electrochemical Society,1974,121,159
[2.2]S. Nakamura, Tasuhiro Harada, and Masayuki Seno, Novel metalorganic chemical vapor deposition system for GaN growth, Appl. Phys. Lett.,1991,58(18):2021-2023
[2.3]A. Watanabe, T. Takeuchi, K. Hirosawa, H. Amano, K. Hiramatsu, and I. Akasaki, Growth of single crystalline GaN on a Si substrate using AlN as an intermediate layer, J. Crystal Growth,1993,128(1),391
[2.4]H.X. Wang, T. Wang,S. Mahanty F. Komatsu, T. Inaoka, K. Nishino, S. Sakai, Growth of GaN layer by metal-organic chemical vapor deposition system with a novel three-flow reactor, Journal of Crystal Growth,2000,218(2)148
[3.1]S. Yoshida, S. Misawa, and S. Gonda, mprovements on the electrical and luminescent properties of reactive molecular beam epitaxially grown GaN films by using AIN-coated sapphire substrates, Appl. Phys. Lett.,1983,42(5),427-429
[3.2]H. Amano et al. Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer. Applied Physics Letters,1986,48:353
[3.3]Nakamura.S, Mukai, High-quality InGaN films grown on GaN films. Jpn. J. Appl. Phys.1992,31:L1457
[3.4]T. Lei, T.D. Moustakas, R.J. Graham, Y. He and S. J. Berkowitz, J. Appl. Phys.1992,71:4933
[3.5]Nakamura S, Senoh M, Iwasa N, et.al. High-Brightness InGaN Blue, Green and Yellow Light-Emitting Diodes with Quantum Well Structures [J]. Japanese Journal of Applied Physics, Part2: Letters,1995,34(7A), L797-L799
[3.6]Keller S, Kapolnek D, Bernd P K, et.al. Effect of the Trimethylgallium Flow during Nucleation Layer Growth on the properties of GaN grown on Sapphire[J]. Japanese Journal of Applied Physics, Part2:Letters,1996,35,L285-288
[3.7]Ki Soo,Chang Seok Oh,Kang Jea Lee,Gye Mo Yang,. Effects of growth rate of a GaN buffer layer on the properties of GaN on a sapphire substrate[J]. Journal of Applied Physics.1999.85(12),8441-8444
[3.8]赵智彪,齐鸣,朱福英等,缓冲层对氮化镓二维生长的影响[J]。功能材料与器件学报。2002年6月,第8卷,第136页
[3.9]Kyeong J J, Choi, J H, Jin K H, et.al. Buffer-layer-free growth of high-quality epitaxial GaN films on4H-SiC substrate by metal-organic chemical vapor deposition[J], Journal of Crystal Growth,2005,276(3-4),407-414
[3.10]Davidsson S K, Falth J F, Liu X Y, et.al."Effect of AlN nucleation layer on the structural properties of bulk GaN grown on sapphire by molecular-beam epitaxy", Journal of Applied Physics,2005,98(1),016109
[3.11]Hayashi.N., Kamiyama.S, Takeuchi.T, et.al."Electrical conductivity of low-temperature-deposited Alo.1Gao.9N interlayer", Japanese Journal of Applied Physics, Part1,2000, Vol.39, No.12A,6493-6495
[3.12]J. Han, K. E. Waldrip, S. R. Lee, et.al,"Control and elimination of cracking of AlGaN using low-temperature AlGaN interlayers",2001, Vol.78, No.l, Appl.Phys.Lett.7883
[3.13]A. D. Bykhovski, B. L. Gelmont and M. S. Shur."Elastic strain relaxation and piezoeffect inGaN-AlN, GaN-AlGaN and GaN-InGaN superlattices”,1997J. Appl. Phys.81(9),6332
[3.14] J. P. Zhang, H. M. Wang, M. E. Gaevski, et.al,“Crack-free thick AlGaN grown on sapphireusing AlN/AlGaN superlattices for strain management,2002, Appl. Phys, Lett.,80(19),3542-3544
[3.15] Chen, C.Q, Zhang, J.P, Gaevski, M.E, et.al,“AlGaN layers grown on GaN using strain-reliefinterlayers”,2002, Appl. Phys, Lett.80(26),4961-4963
[3.16] M. A. Khan, J. N. Kuznia, R. A. Skogman, et.al.,“Low pressure metalorganic chemical vapordeposition of AlN over sapphire substrates”,1992, Appl. Phys. Lett.61(21),2539-2541
[3.17] Zhang, J.P.(1); Kuokstis, E.(1); Fareed, Q.(1), et.al,“Title:Pulsed atomic layer epitaxy ofquaternary AlInGaN layers for ultraviolet light emitters”,2001, Physica Status Solidi A,188(1),95-99
[3.18] M. A. Khan, J. N. Kuznia, D. T. Olson, T. George and W. T. Pike.“GaN/AlN digital alloyshort-period superlattices by switched atomic layer”,1993, Appl. Phys. Lett.63(25),3470-3472
[3.19] H.Hirayama,et.al.222-282nm AlGaN and InAlGaN-based deep-UV LEDs fabricated onhigh-quality AlN on sapphire.2009, Phys.Status Solidi A,1-7
[3.20] B Ryan G et.al. Growth characteristics of AlN on sapphire substrates by modifiedmigration-enhanced epitaxy.2009.J.Cryst.Growth.31(10):2834
[3.21] E.Kenichi,et.al. High-temperature growth of thick AlN layers on sapphire (0001) substratesby solid source halide vapor-phase epitaxy.2008, J.Cryst.Growth.310(17):4016
[4.1] H.Amano, M.Kito, K.Hiramatsu, et al,“P-type conduction in Mg-doped GaN treated withlow-energy electron beam irradiation (LEEBI)”,Jpn.J.Appl.Phys,1989,28,L2112
[4.2] S. Nakamura, N. Iwasa, M. Senoh, et al.“Hole compensation mechanism of p-type GaN films”,Jpn. J. Appi. Phys.,1992, vol.31,1258-1266
[4.3] Nakamura S. Crystal growth method for gallium nitride-based compound semiconductor. USpatent:5290393,1994
[4.4] Z.Y.Fan, J.Y.Lin and H.X.Jiang,“Achieving conductive high Al-content AlGaN alloys for deepUV photonics”, Quantum Sensing and Nanophotonic Device,2007,Vol.647964791I-6~64791I-7
[4.5] C. H. Seager, S. M. Myers, A. F. Wright, et al.“Drift, diffusion, and trapping of hydrogen inp-type GaN”. Journal of Applied Physics,2002,92:7246
[4.6] C. Bayram, J.L. Pau, R. McClintock, et al.“Delta-doping optimization for high quality p-typeGaN”.2008, Journal of applied physics,104:083515-4
[4.7]E. F. Schubert, J. E. Cunningham and W. T. Tsang,"Electron-mobility enhancement and electron-concentration enhancement in δ-doped n-GaAs at T=300K", Soild State Communications, August1987,Volume63,591-594.
[4.8]Klaus Ploog,"Delta-(°-) doping in MBE-grown GaAs:Concept and device application",1987, Journal of Crystal Growth, Volume81,304-313
[4.9]K. H. Kim, J. Li, S. X. Jin, et al,"Ⅲ-nitride ultraviolet light-emitting diodes with delta doping", Appl.Phys.Lett2003,83,566-568
[4.10]Arpan,Chakraborty Craig G.Moe, Yuan Wu, et al,"Electrical and structural characterization of Mg-doped p-type A10.69Ga0.31Nfilms on SiC substrate", Journal of Applied Physics,2007,101,053717-1-053717-5
[4.11]冯倩,王峰祥,郝跃,“Mg掺杂对AlGaN薄膜特性的影响”,物理学报,2004年10月,第53卷,第10期,3588-3589.
[4.12]Jorg Neugebauer, Tosja K. Zywietz,et al."Adatom Kinetics On and Below the Surface:The Existence of a New Diffusion Channel",Phys. Rev. Lett.2003, Volume90,056101。
[4.13]M.L.Nakarmi, K. Ⅱ.Kim, J.Li,et al."Enhanced p-type conduction in GaN and AlGaN by Mg-δ doping", Appl.Phys.Lett.,2003,Vol.82,3041-3043
[4.14]J.Bai. T.Wang, P.J.Parbrook,et al."A study of dislocations in AIN and GaN films grown on sapphire substrates",2005, Journal of Crystal Growth,282,292-293
[5.1]Tavernier P R, Etzkorn E V, Wang Y, et al."Two-step growth of high-quality GaN by hydride vapor phase epitaxy", Applied Physics Letters,2000,77(12).1804-1806
[5.2]高瑛,缪国庆,吕少哲等,“用MOCVD技术在A1203衬底上外延GaN的光致发光研究”,光子学报,1997,26(11),982-986
[5.3]范隆,郝跃,冯倩等,SiC/AIN上外延GaN薄膜的黄带发光与晶体缺陷的关系”,光子学报,2003,32(8),977-980
[5.4]Cho Y H, Lee S K,. Kwack H S, et al."Carrier loss and luminescence degradation in green-light-emitting InGaN quantum wells with micron-scale indium clusters", Applied Physics Letters,2003,83(13),2578-2580
[5.5]Eastman L F, Tilak V, Smart J, et al."Undoped AlGaN/GaN HEMTs for Microwave Power Amplification", IEEE Transactions on Electron Devices.2001,48(3).479-484
[5.6]Mishra U K, Parikh P, Wu Y,"AlGaN/GaN HEMTs-An Overview of Device Operation and Applications". Proceedings of the IEEE,2002,90(6),1022-1031
[5.7]李炳乾,基于金属线路板的新型大功率LED及其光电特性研究,光子学报,2005,34(3),372-374
[5.8]Su Y K, Chang S J, Ko C H, et al."InGaN/GaN Light Emitting Diodes With a p-Down Structure". IEEE Transactions on Electron Devices,2002.49(8).1361-1366
[5.9]Shigefusa F C, Shikanai A, Deguchi T, et al."Comparison of Optical Properties of GaN/AlGaN and InGaN/GaN Single Quantum Wells", Japanese Journal of Applied Physics, Part1,2000.39(5),2417-2424
[5.10]Kim H, Ju S P, Hwang H,"Effects of Current Spreading on the Performance of GaN-Based Light-Emitting Diodes", IEEE Transactions on Electron Devices,2001,48(6),1065-1069
[5.11]Tanoue F, Sakakivara S, Ohora M, et.al."Growth of InGaN prepared by a hot wall beam epitaxy system with NH3", Journal of Crystal Growth,1998,189(2),47-51
[5.12]M.Shiojiri, C.C.Chou, J.T.Hsu, J.R.Yang, H.Saijo."Structure and formation mecha-nism of V defects in Multiple InGaN/GaN quantum well layers", J.Appl.Phys.2006,99:073505-0735007
[5.13]邢艳辉,韩军,刘建平等,“垒掺In提高InGaN/GaN多量子阱发光特性”,物理学报,Vo1.56,No.12.7295-7298
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[1.3] W.C.Johnson, J.E.Parsons, et al. Epitaxial growth and structural characterization of single GaN,J Phys Chem.1932,36:2561
[1.4] T. Chu, K. Ito, R. Smeltzer, et al. Crystal growth and characterization of gallium nitride[J].Journal of The Electrochemical Society,1974. vol.121, p.159
[1.5] H. P. Maruska and J. J. Tietjen, The preparation and properties of vapour-deposited single-crystal-line GaN. Appl. Phys. Lett.,1969,15(10),327
[1.6] S. Yoshida, S. Misawa, and S. Gonda, mprovements on the electrical and luminescentproperties of reactive molecular beam epitaxially grown GaN films by using AlN-coated sapphiresubstrates, Appl. Phys. Lett.,1983,42(5),427-429
[1.7] H. Amano et al. Metalorganic vapor phase epitaxial growth of a high quality GaN film using anAlN buffer layer. Applied Physics Letters,1986,48:353
[1.8] Nakamura.S, Mukai, High-quality InGaN films grown on GaN films. Jpn. J. Appl. Phys.1992,31: L1457
[1.9] T. Lei, T.D. Moustakas, R.J. Graham, Y. He and S. J. Berkowitz, J. Appl. Phys.1992,71:4933
[1.10] H.Amano, I Akasaki. Novel aspects of the growth of nitrides by MOVPE. J. Phys: Condens.Matter.2001,13:6935
[1.11] H.Amano, I Akasaki, et.al. Metalorganic vapor phase epitaxial growth of a high quality GaNfilm suing an AlN buffer layer. Appl. Phys. Lett.,1986,48:353
[1.12] Nakamura S. Crystal growth method for gallium nitride-based compound semiconductor. USpatent:5290393,1994
[1.13] S. Nakamura, N. Iwasa, M. Senoh, et al.“Hole compensation mechanism of p-type GaNfilms”, Jpn. J. Appi. Phys.,1992, vol.31,1258-1266
[1.14] S. Nakamura, Tasuhiro Harada, and Masayuki Seno, Novel metalorganic chemical vapordeposition system for GaN growth, Appl. Phys. Lett.,1991,58(18):2021-2023
[1.15] S. Nakamura, T. Mukai, M. Senoh, High-power GaN p-n junction blue-light-emitting diodes,Japanese Journal of Applied Physics30, L1998(1991)
[1.16]郝跃,周小伟,王阳元等.绿色微纳电子学.科学出版社,2010
[1.17]Nakamura S J, Mukai T. Candela-class High-brightness InGaN/AlGaN Double-heterostrcture Blue-Light-Emitting Diodes. Appl Phys Lett,1994,64(13):1687-1689
[1.18]Nakamura S J, Mukai T. High-brightness InGaN/AlGaN Double-heterostrcture Blue-Green-Light-Emitting Diodes. J Appl Phys,1994,76(12):8189-8191
[1.19]段猛,郝跃.GaN基蓝色LED的研究进展.西安电子科技大学学报.2003,30(01)：60
[1.20]于占涛.半导体照明网.2009-6-15
[1.21]J.Han, et.al. AlGaN/GaN quantum well ultraviolet light emitting diodes. Appl. Phys. Lett.1998,73:1688
[1.22]Chitnis, M.Asif. Khan, et.al. High DC power325nm emission deep UV LEDs over sapphire. Electronics Letters.2002,38(25):1709
[1.23]W.H.Sun, M.Asif. Khan,et.al. Continuous Wave Milliwatt Power AlGaN Light Emitting Diodes at280nm. JpnJ. Appl. Phys.2004,43:L1419
[1.24]C.Touzia, F. Omne, T.Boufadena, et.al., Realisation of 'SolarBlind' AlGaN Photodetectors: Measured and calculated spectral response, Microelectronics Journal,2006, Vol.37,336-339
[1.25]V. Adivarahan, M.Asif. Khan,et.al.250nm AlGaN light-emitting diodes. Appl.Phys.Lett.2004,85(12):2175
[1.26]Hideki Hirayama, et.al.226-273nm AlGaN deep-ultraviolet light-emitting diodes fabricated on multilayer AlN buffers on sapphire. Phys.Sta.Sol.(c).2008,5(9):2969
[2.1]T. Chu, K. Ito, R. Smeltzer, et al. Crystal growth and characterization of gallium nitride, Journal of The Electrochemical Society,1974,121,159
[2.2]S. Nakamura, Tasuhiro Harada, and Masayuki Seno, Novel metalorganic chemical vapor deposition system for GaN growth, Appl. Phys. Lett.,1991,58(18):2021-2023
[2.3]A. Watanabe, T. Takeuchi, K. Hirosawa, H. Amano, K. Hiramatsu, and I. Akasaki, Growth of single crystalline GaN on a Si substrate using AlN as an intermediate layer, J. Crystal Growth,1993,128(1),391
[2.4]H.X. Wang, T. Wang,S. Mahanty F. Komatsu, T. Inaoka, K. Nishino, S. Sakai, Growth of GaN layer by metal-organic chemical vapor deposition system with a novel three-flow reactor, Journal of Crystal Growth,2000,218(2)148
[3.1]S. Yoshida, S. Misawa, and S. Gonda, mprovements on the electrical and luminescent properties of reactive molecular beam epitaxially grown GaN films by using AIN-coated sapphire substrates, Appl. Phys. Lett.,1983,42(5),427-429
[3.2]H. Amano et al. Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer. Applied Physics Letters,1986,48:353
[3.3]Nakamura.S, Mukai, High-quality InGaN films grown on GaN films. Jpn. J. Appl. Phys.1992,31:L1457
[3.4]T. Lei, T.D. Moustakas, R.J. Graham, Y. He and S. J. Berkowitz, J. Appl. Phys.1992,71:4933
[3.5]Nakamura S, Senoh M, Iwasa N, et.al. High-Brightness InGaN Blue, Green and Yellow Light-Emitting Diodes with Quantum Well Structures [J]. Japanese Journal of Applied Physics, Part2: Letters,1995,34(7A), L797-L799
[3.6]Keller S, Kapolnek D, Bernd P K, et.al. Effect of the Trimethylgallium Flow during Nucleation Layer Growth on the properties of GaN grown on Sapphire[J]. Japanese Journal of Applied Physics, Part2:Letters,1996,35,L285-288
[3.7]Ki Soo,Chang Seok Oh,Kang Jea Lee,Gye Mo Yang,. Effects of growth rate of a GaN buffer layer on the properties of GaN on a sapphire substrate[J]. Journal of Applied Physics.1999.85(12),8441-8444
[3.8]赵智彪,齐鸣,朱福英等,缓冲层对氮化镓二维生长的影响[J]。功能材料与器件学报。2002年6月,第8卷,第136页
[3.9]Kyeong J J, Choi, J H, Jin K H, et.al. Buffer-layer-free growth of high-quality epitaxial GaN films on4H-SiC substrate by metal-organic chemical vapor deposition[J], Journal of Crystal Growth,2005,276(3-4),407-414
[3.10]Davidsson S K, Falth J F, Liu X Y, et.al."Effect of AlN nucleation layer on the structural properties of bulk GaN grown on sapphire by molecular-beam epitaxy", Journal of Applied Physics,2005,98(1),016109
[3.11]Hayashi.N., Kamiyama.S, Takeuchi.T, et.al."Electrical conductivity of low-temperature-deposited Alo.1Gao.9N interlayer", Japanese Journal of Applied Physics, Part1,2000, Vol.39, No.12A,6493-6495
[3.12]J. Han, K. E. Waldrip, S. R. Lee, et.al,"Control and elimination of cracking of AlGaN using low-temperature AlGaN interlayers",2001, Vol.78, No.l, Appl.Phys.Lett.7883
[3.13]A. D. Bykhovski, B. L. Gelmont and M. S. Shur."Elastic strain relaxation and piezoeffect inGaN-AlN, GaN-AlGaN and GaN-InGaN superlattices”,1997J. Appl. Phys.81(9),6332
[3.14] J. P. Zhang, H. M. Wang, M. E. Gaevski, et.al,“Crack-free thick AlGaN grown on sapphireusing AlN/AlGaN superlattices for strain management,2002, Appl. Phys, Lett.,80(19),3542-3544
[3.15] Chen, C.Q, Zhang, J.P, Gaevski, M.E, et.al,“AlGaN layers grown on GaN using strain-reliefinterlayers”,2002, Appl. Phys, Lett.80(26),4961-4963
[3.16] M. A. Khan, J. N. Kuznia, R. A. Skogman, et.al.,“Low pressure metalorganic chemical vapordeposition of AlN over sapphire substrates”,1992, Appl. Phys. Lett.61(21),2539-2541
[3.17] Zhang, J.P.(1); Kuokstis, E.(1); Fareed, Q.(1), et.al,“Title:Pulsed atomic layer epitaxy ofquaternary AlInGaN layers for ultraviolet light emitters”,2001, Physica Status Solidi A,188(1),95-99
[3.18] M. A. Khan, J. N. Kuznia, D. T. Olson, T. George and W. T. Pike.“GaN/AlN digital alloyshort-period superlattices by switched atomic layer”,1993, Appl. Phys. Lett.63(25),3470-3472
[3.19] H.Hirayama,et.al.222-282nm AlGaN and InAlGaN-based deep-UV LEDs fabricated onhigh-quality AlN on sapphire.2009, Phys.Status Solidi A,1-7
[3.20] B Ryan G et.al. Growth characteristics of AlN on sapphire substrates by modifiedmigration-enhanced epitaxy.2009.J.Cryst.Growth.31(10):2834
[3.21] E.Kenichi,et.al. High-temperature growth of thick AlN layers on sapphire (0001) substratesby solid source halide vapor-phase epitaxy.2008, J.Cryst.Growth.310(17):4016
[4.1] H.Amano, M.Kito, K.Hiramatsu, et al,“P-type conduction in Mg-doped GaN treated withlow-energy electron beam irradiation (LEEBI)”,Jpn.J.Appl.Phys,1989,28,L2112
[4.2] S. Nakamura, N. Iwasa, M. Senoh, et al.“Hole compensation mechanism of p-type GaN films”,Jpn. J. Appi. Phys.,1992, vol.31,1258-1266
[4.3] Nakamura S. Crystal growth method for gallium nitride-based compound semiconductor. USpatent:5290393,1994
[4.4] Z.Y.Fan, J.Y.Lin and H.X.Jiang,“Achieving conductive high Al-content AlGaN alloys for deepUV photonics”, Quantum Sensing and Nanophotonic Device,2007,Vol.647964791I-6~64791I-7
[4.5] C. H. Seager, S. M. Myers, A. F. Wright, et al.“Drift, diffusion, and trapping of hydrogen inp-type GaN”. Journal of Applied Physics,2002,92:7246
[4.6] C. Bayram, J.L. Pau, R. McClintock, et al.“Delta-doping optimization for high quality p-typeGaN”.2008, Journal of applied physics,104:083515-4
[4.7]E. F. Schubert, J. E. Cunningham and W. T. Tsang,"Electron-mobility enhancement and electron-concentration enhancement in δ-doped n-GaAs at T=300K", Soild State Communications, August1987,Volume63,591-594.
[4.8]Klaus Ploog,"Delta-(°-) doping in MBE-grown GaAs:Concept and device application",1987, Journal of Crystal Growth, Volume81,304-313
[4.9]K. H. Kim, J. Li, S. X. Jin, et al,"Ⅲ-nitride ultraviolet light-emitting diodes with delta doping", Appl.Phys.Lett2003,83,566-568
[4.10]Arpan,Chakraborty Craig G.Moe, Yuan Wu, et al,"Electrical and structural characterization of Mg-doped p-type A10.69Ga0.31Nfilms on SiC substrate", Journal of Applied Physics,2007,101,053717-1-053717-5
[4.11]冯倩,王峰祥,郝跃,“Mg掺杂对AlGaN薄膜特性的影响”,物理学报,2004年10月,第53卷,第10期,3588-3589.
[4.12]Jorg Neugebauer, Tosja K. Zywietz,et al."Adatom Kinetics On and Below the Surface:The Existence of a New Diffusion Channel",Phys. Rev. Lett.2003, Volume90,056101。
[4.13]M.L.Nakarmi, K. Ⅱ.Kim, J.Li,et al."Enhanced p-type conduction in GaN and AlGaN by Mg-δ doping", Appl.Phys.Lett.,2003,Vol.82,3041-3043
[4.14]J.Bai. T.Wang, P.J.Parbrook,et al."A study of dislocations in AIN and GaN films grown on sapphire substrates",2005, Journal of Crystal Growth,282,292-293
[5.1]Tavernier P R, Etzkorn E V, Wang Y, et al."Two-step growth of high-quality GaN by hydride vapor phase epitaxy", Applied Physics Letters,2000,77(12).1804-1806
[5.2]高瑛,缪国庆,吕少哲等,“用MOCVD技术在A1203衬底上外延GaN的光致发光研究”,光子学报,1997,26(11),982-986
[5.3]范隆,郝跃,冯倩等,SiC/AIN上外延GaN薄膜的黄带发光与晶体缺陷的关系”,光子学报,2003,32(8),977-980
[5.4]Cho Y H, Lee S K,. Kwack H S, et al."Carrier loss and luminescence degradation in green-light-emitting InGaN quantum wells with micron-scale indium clusters", Applied Physics Letters,2003,83(13),2578-2580
[5.5]Eastman L F, Tilak V, Smart J, et al."Undoped AlGaN/GaN HEMTs for Microwave Power Amplification", IEEE Transactions on Electron Devices.2001,48(3).479-484
[5.6]Mishra U K, Parikh P, Wu Y,"AlGaN/GaN HEMTs-An Overview of Device Operation and Applications". Proceedings of the IEEE,2002,90(6),1022-1031
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