共查询到20条相似文献,搜索用时 15 毫秒
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采用化学方法腐蚀部分 c-面蓝宝石衬底,在腐蚀区域形成一定的图案,利用 LP-MOCVD 在此经过表面处理的蓝宝石衬底上外延生长 GaN 薄膜.采用高分辨率双晶X射线衍射(DCXRD)、光致发光光谱(PL)、透射光谱分析GaN薄膜的晶体质量和光学质量.分析结果表明,CaN 薄膜透射谱反映出的 CaN 质量与 X射线双晶衍射测量的结果一致,即透射率越大,半高宽越小,结晶质量越好;对蓝宝石衬底进行前处理可以大大改善GaN薄膜的晶体质量和光学质量,其(0002)面及(1012)面XRD半高宽(FWHM)分别降低到 208.80arcsec 及 320.76arcsec,而且其光致发光谱中的黄光带几乎可以忽略. 相似文献
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本文研究了在Si(111)衬底上生长GaN外延层的方法。相比于直接在AlN缓冲层上生长GaN外延层,引入GaN过渡层显著地提高了外延层的晶体质量并降低了外延层的裂纹密度。使用X射线双晶衍射仪、光学显微镜以及在位监测曲线分析了GaN过渡层对外延层的晶体质量以及裂纹密度的影响。实验发现,直接在AlN缓冲层上生长外延层,晶体质量较差, X射线(0002)面半高宽最优值为0.686°,引入GaN过渡层后,通过调整生长条件,控制岛的长大与合并的过程,从而控制三维生长到二维生长过渡的过程,外延层的晶体质量明显提高, (0002)面半高宽降低为0.206°,并且裂纹明显减少。研究结果证明,通过生长合适厚度的GaN过渡层,可以得到高质量、无裂纹的GaN外延层。 相似文献
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采用光调制反射光谱(PR)研究了(0001)晶向蓝宝石村底上MOCVD方法生长的单晶六角GaN薄膜的室温光学性质。测得六角GaN薄膜的禁带宽度为3.400eV,对PR谱的调制机理进行了分析,发现信号来自缺陷作用下的表面电场调制。光吸收增和光反射谱的测量,得到3.39eV的光学吸收边和3.3eV的反射峰,证实了光调制反射光谱的结果。 相似文献
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在Si(111)衬底上采用金属有机化合物化学气相沉积(MOCVD)技术外延生长GaN薄膜,对外延生长所得GaN薄膜的晶体结构和表面形貌进行表征,并研究SiNx插入层对GaN薄膜的晶体质量和表面形貌的影响.结果表明,在Si衬底上生长GaN薄膜过程中引入SiNx插入层可使GaN薄膜的(10-12)面的X-射线回摆曲线的半峰宽(FWHM)值从974.01减小到602.01arcsec;表面凹坑等缺陷减少、表面平整度提高.可见,SiNx插入层对在Si衬底上外延生长GaN薄膜的晶体质量和表面形貌有着重要的影响. 相似文献
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研究了采用MOCVD技术分别在100与500Torr反应室压力下生长的非故意掺杂GaN薄膜的光学与电学性能。研究表明,低压100Torr外延生长条件可以有效地降低Ga与NH3气相反应造成GaN薄膜的碳杂质沾污,从而抑制造成光致发光中黄光峰与蓝光峰的深受主的形成,所制备的材料表现出较好的光学性能。同时,不同生长压力下的GaN薄膜表现出相异的电学性能,即在500Torr下生长的样品通常表现出更高的载流子浓度((4.6-6.4)×1016 cm-3)与更高的迁移率(446-561cm2/(V.s)),而100Torr下生长的样品通常表现为更低的载流子浓度(1.56-3.99)×1016 cm-3与更低迁移率(22.9-202cm2/(V.s))。 相似文献
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D. Zhi U. Tisch S. H. Zamir M. Wei E. Zolotoyabko J. Salzman 《Journal of Electronic Materials》2000,29(4):457-462
Thin GaN films, grown by metal organic chemical vapor deposition on the basal plane of sapphire substrates, were characterized
by x-ray pole figures, high-resolution x-ray diffraction and transmission electron microscopy. This combination was found
sensitive to small amounts (down to 0.1%) of cubic GaN phase in specimens subjected to surface nitridation treatment prior
to epitaxial growth. The presence of the cubic phase and its orientation relations to the hexagonal GaN matrix was established
by means of pole figures and selected area electron diffraction. The amount of cubic phase was determined by comparing the
integrated x-ray diffraction intensities of the (311) cubic GaN and the (11.2) hexagonal GaN reflections. Optimum nitridation
duration was found, which corresponds to almost complete suppression of the cubic phase formation. 相似文献
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DENG Dong-mei WANG Jin-yan ZHAO De-gang WEN Zheng 《半导体光子学与技术》2006,12(2):77-80
The persistent photoconductivity(PPC) phenomena in n-type GaN Films grown by metalorganic chemical vapor deposition(MOCVD) have been studied. After using some testing and analysis methods, such as the double crystal X-ray diffraction(DCXRD), the photolumineseence(PL) spectra, etc, it is found that the issue which influences PPC in n-type GaN is not relative to the dislocations and yellow band (YB), and is caused by the doping level of Si most likely. 相似文献
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第三代半导体材料GaN由于具有优良性质使其在微电子和光电子领域有广阔的应用前景,目前制备GaN的方法主要有分子束(MBE)、氯化物气相外延(HVPE)、金属有机物化学气相沉积(MOCVD)。其中HVPE技术制备GaN的速度最快,适合制备衬底材料;MBE技术制备GaN的速度最慢;而MOCVD制备速度适中。因而MOCVD在外延生长GaN材料方面得到广泛应用。介绍了MOCVD法外延生长GaN材料的基本理论、发展概况、利用MOCVD法外延生长GaN材料的技术进展。认为应结合相关技术发展大面积、高质量GaN衬底的制备技术,不断完善缓冲层技术,改进和发展横向外延技术,加快我国具有国际先进水平的MOCVD设备的研发速度,逐步打破进口设备的垄断。 相似文献
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Si衬底与GaN之间较大的晶格失配和热失配引起的张应力使GaN外延层极易产生裂纹,如何补偿GaN所受到的张应力是进行Si基GaN外延生长面临的首要问题.采用金属有机化合物化学气相沉积(MOCVD)技术在4英寸(1英寸=2.54 cm)Si (111)衬底上制备了GaN外延材料并研究了不同AlGaN缓冲层结构对Si基GaN外延材料性能的影响,并采用高分辨X射线衍射仪(HRXRD)、原子力显微镜(AFM)、喇曼光谱以及光学显微镜对制备的GaN材料的性能进行了表征.采用3层A1GaN缓冲层结构制备了表面光亮、无裂纹的GaN外延材料,其(002)晶面半高宽为428 arcsec,表面粗糙度为0.194 nm.结果表明,采用3层A1GaN缓冲层结构可以有效地降低GaN材料的张应力和位错密度,进而遏制表面裂纹的出现,提高晶体质量. 相似文献
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LI Chao ZHOU Xun ZOU Ze-ya DU Jiang-feng JI Hong State key Laboratory of Electronic Thin Films Integrated Devices University of Electronic Science Technology of China Chengdu CHN YANG Mo-hua ZHAO HongChongqing Optoelectronics Research Institute Chongqing CHN ZHAO Jin-xia ZHU Yan-ling YU Zhi-wei YU Qi 《半导体光子学与技术》2008,14(2):80-84
The residual strain and the damage induced by Si implantation in GaN samples have been studied, as well as the electronic characteristics. These as-grown samples are implanted with different doses of Si(1 × 10^14 cm^-2, 1×10^15 cm^-2 or ] × 10^16 cm^-2, ]00 keV) and following annealed by rapid thermal anneal(RTA) at 1 000℃ or 1 100℃ for 60 s. High resolution X-ray diffractometer(HRXRD) measurement reveals that the damage peak induced by the implantation appears and increases with the rise of the impurity dose, expanding the crystal lattice. The absolute value of biaxial strain decreases with the increase of the annealing temperature for the same sample. RT-Hall test reveals that the sample annealed at 1 100℃ acquires higher mobility and higher carrier density than that annealed at 1 000 ℃, which reflects that the residual strain(or residual stress) is the main scattering factor. And the sample C3(1 × 10^16 cm^-2 and annealed at 1100 ℃) acquires the best electronic characteristic with the carrier density of 3.25 × 10^19 cm^-3 and the carrier mobility of 31 cm2/(V·S). 相似文献