【作者】 吕吉贺；

【导师】 任晓敏；

【作者基本信息】 北京邮电大学 ， 电磁场与微波技术， 2008， 博士

【摘要】 人类通信需求量的急剧增长是光纤通信系统发展的潜在驱动力,而新一代光纤通信系统的发展必然要以新型通信光电子器件作为支撑。当前通信光电子器件正处于由分立转向集成的重大变革时期,而通信光电子集成器件研究所面临的最突出问题是半导体材料兼容、结构兼容和工艺兼容。本论文工作是围绕任晓敏教授为首席科学家的国家重点基础研究发展规划（973计划）项目（No:2003CB314900）,及其课题组承担的国家863计划项目（No:2003AA31g050,2006AA032416,2007AA032418）、国家自然基金重点项目（No:90601002,60576018）和国际科技合作重点项目计划项目（No:2006DFB11110）展开的,针对GaAs/Si、InP/GaAs以及InP/GaAs/Si材料间的大失配异质外延生长开展了大量的研究工作,并在此基础上首次研制成功了单片集成的GaAs基和Si基新型波长选择性光探测器。主要研究成果如下所述:1、在InP/GaAs的异质外延生长方面取得重要进展。探索了InP低温缓冲层和InP/Ga_0.1In_0.9P应变超晶格（SLS）的最佳生长条件和结构参数,利用低压金属有机物化学气相沉积（LP-MOCVD）技术在GaAs衬底上外延生长出高质量的InP材料。在此基础上,在GaAs衬底上生长的2.6μm厚InP外延层的X射线衍射（XRD）ω-2θ扫描的半高全宽（FWHM）达到208arcsec,测试结果表明该外延层位错密度已降到了10⁷cm^-2量级。2、首次实现了单片集成的GaAs基长波长可调谐“一镜斜置三镜腔”光探测器。在GaAs衬底上,首先生长GaAs/AlAs法布里—泊罗（F-P）滤波腔,利用InP/GaAs（100）异质外延的低温缓冲层技术,继续生长出InP基的p-i-n光探测结构和斜面形成层。所制备的光探测器获得了51.5%的峰值量子效率、10.0nm的波长调谐范围、低于0.8nm的光谱响应线宽（FWHM）以及6.0GHz的3dB响应带宽。3、综合分析了引入楔形衬底导致的双波长现象,并制备出了单片集成可调谐双波长探测器。利用低温缓冲层技术,在生长完F-P腔滤波器的GaAs衬底上生长了InP基的p-i-n光探测结构。通过引入角度为3°的楔形衬底,使得探测器可以同时工作于两个波长（1537nm和1530nm）,此器件还有5nm以上的调谐范围,测试响应3dB带宽为6.4GHz,并探讨了其应用情况。4、在GaAs/Si外延方面取得突破。通过探索有偏角衬底、Al（GaAs）As低温缓冲层和循环热退火等技术的最优条件,在Si衬底上外延生长出了高质量的GaAs材料。对于1.2μm厚GaAs外延层,其XRDω-2θ扫描的FWHM仅为192.3arcsec,透射电子显微镜（TEM）图像显示外延材料层中位错能被有效弯曲、合并,测试结果表明在距GaAs/Si界面处0.5μm的位错密度为10⁷cm^-2量级。5、摸索出了一种GaAs层分两个阶段生长、中间插入刻槽工序（mid-pattern）的GaAs/Si无裂纹外延方法。先在Si衬底上生长1～3μm厚的GaAs层,然后通过刻槽（台面面积为700μm×800μm）释放热失配应力,最后进行二次外延,得到了13μm厚的无裂纹GaAs外延层。6、综合利用mid-patern无裂纹技术和低温缓冲层法实现了InP/GaAs/Si高质量外延。外延层包含13μm的GaAs基F-P腔和5μm的InP基p-i-n结构,由此制作出了Si基波长选择性、长波长光探测器,测试结果显示,选择波长为1495.5nm,线宽为2.0nm,暗电流仅为40.1nA。更多还原

【Abstract】 The increasing demand for communication is driving force behind modern fiber communication systems, which are always based on novel optoelectronic devices. It is revolutionary period that independent devices change to optoelectronic integrated devices, which have been encountered by the compatibilities of semiconductor materials, structures and processes.The research work of this doctoral thesis is mainly supported by the grants from the National Basic Research Program of China （No.2003CB314900）, which professor Xiaomin Ren is responsible for as a chief scientist, the National High Technology Research and Development Program of China（No: 2003AA31g050, 2006AA03Z416, 2007AA03Z418）, Key Program of the National Natural Science Foundation of China（No. 90601002, 60576018） and Program of Key International Science and Technology Cooperation Projects （2006DFB11110）. In this thesis, a great deal of work is demonstrated about theorical and experimental research on heteroepitaxy of large mismatched materials, including InP/GaAs, GaAs/Si and InP/GaAs/Si. Based on high quality hoteroepitaxy, the novel monolithically integrated GaAs-based and Si-based wavelength-selective photodetectors has been successfully fabricated first time. The main achievements are listed as follows:1. Important progress has been achieved on InP/GaAs heteroepitaxy. The optimum conditions of low temperature InP buffer layer and the optimum structures of InP/Ga_0.1In_0.9P strained layer superlattice （SLS） have been obtained. Based on these methods, a 2.6μm high quality InP epilayer has been grown on GaAs substrates by using low pressure metalorganic chemical vapor deposition （LP-MOCVD）. The FWHM of X-ray diffraction （XRD）ω-2θscans is only 208arcsec. Test results indicate the dislocation density of InP epilayer has been reduced to 10⁷cm^-2.2. The monolithically integrated long-wavelength tunable "One-Mirror Inclined Three-Mirror Cavity" photodetector has been realized first time. By employing a thin low-temperature buffer layer, the high quality InP-based p-i-n structures and taper-fabricated layers have been grown on a GaAs-based GaAs/AlAs Fabry-Pérot-filter. A wavelength tuning range of 10.0 nm, an external quantum efficiency of about 51.5%, a spectral linewidth of 0.8 nm and a 3-dB bandwidth of 6.0 GHz have been obtained in this device.3. Detailed analysis and fabrication of a monolithically integrated dual-wavelength tunable photodetectors has been demonstrated. The dual-wavelength character is realized first by fabricating a taper GaAs substrate with the angle of 3°. The photodetector is monolithically integrated by using a heteroepitaxy growth of InP-In0.53Ga0.47As-InP p-i-n structure on a GaAs-based GaAs/AlAs Fabry-Perot-filter structure, which can be tuned via the thermal-optic effect. High-quality heteroepitaxy was realized by employing a thin low-temperature buffer layer. The devices with a dual-peak distance of 7 nm （1530nm, 1537 nm）, a wavelength-tuning range above 5.0 nm, and a 3-dB bandwidth of 6.4 GHz are successfully fabricated. The potential applications have been discussed also.4. Important progress has been achieved on GaAs/Si heteroepitaxy. High-quality GaAs epilayer is obtained by employing the technologies of the tilted Si substrate, optimization the low temperature Al（GaAs）As buffer layer and thermal cycle annealing. The FWHM of XRDω-2θ scans is only 192.3arcsec for a 1.2μm GaAs material grown on Si substrates. Transmission Electron Microscope （TEM） shows the density of threading dislocation in epilayers has been bended and joined. These results indicate the dislocation density has been reduced to 10⁷cm^-2 in the epilayer of 0.5μm away from the interface of GaAs/Si.5. A method of GaAs epilayer grown on mid-patterned Si subatrates has been demonstrated. The large area （700μm×800μm） crack-free GaAs/Si mesas with the thickness of 13μm have been realized, which are regrown on the patterned Si substrates covered by the pregrown 1-3μm GaAs layer. The crack-free characteristic is introduced by the release of thermal stress in the epilayers.6. The epilayers including 13μm GaAs-based GaAs/AlAs Fabry-Perot-filter and 5μm InP based p-i-n structure have been grown on Si substrates by employing the methods of mid-patterned Si substrate and the InP/GaAs low temperature buffer. Then the epilayers are fabricated into Si-based wavelength-selective photodetectors operating at the wavelength of 1495.5nm, with a spectral linewidth of 2.0nm and a dark current of 40.1nA.更多还原