In this thesis , we grow hexagonal gan on c - plane sapphire substrates in a horizontal mocvd reactor equipped with an in situ normal incidence reflectance monitoring , and the focus has been turned to improve the quality of unintentionally doped gan epilayer . listed below are the main contents of this thesis . ( 1 ) a single - wavelength normal incidence reflectance monitoring system was installed 本文利用配有近垂直入射激光反射在位监测的卧式mocvd在c面蓝宝石衬底上生长六方相的gan薄膜，围绕提高本征gan外延层质量的目的，开展了具体如下的工作： ( 1 )在mocvd设备上搭建了一套单波长近垂直入射激光反射在位监测系统。
The experiment results showed we had got well nanowires on si and sapphire substrate and the au and ag act catalyst respectively , we got zno nanowires array on si and sapphire substrate using the ag as catalyst . 2 . we measured the pl spectrum of zno nanowires samples excited by an ultraviolet fluorescence spectrophotometer in different wavelength 实验结果显示分别采用金和银为催化剂在硅衬底和蓝宝石衬底上制备出结晶质量较好的纳米线,其中在银催化的硅基片和蓝宝石基片上制备出排列整齐的纳米线阵列。
The defect and interface in sapphire and gan were observed by afm . we found that when the dislocation density in sapphire was lower thanl05 / cm2 , the dislocation density in gan was 108 ~ 109 / cm2and not linear with the dislocation in sapphire . the impurity of mo in sapphire and gan was measured by sem xps epma and uvf we found the mo content in sapphire was 10 - 4 , and the mo content in gan was lower than ppm . so it was concluded that low - cost mo crucible is viable 用扫描电镜( sem ) 、 xps 、电子探针和紫外荧光光谱仪测量了蓝宝石衬底和gan外延层中的mo杂质的含量，发现蓝宝石衬底中含有mo杂质，含量约为10 ~ ( - 4 ) (质量含量) ；而在外延层gan中没有检测到mo杂质，即mo杂质含量小于ppm级。
Furthermore , the growth and the study of self - organized quantum dots structures become more and more important recently , and the application of self - organization technique become wider and wider in this thesis , we address the theory of film growth and the growth technique firstly more , the ways and characteristics of surface detection are prescribed we mainly report the growth process , results and discuss of self - organized quantum dots structures in the a12o3 substrates by s - k mode using ecr - mocvd , in the espd - u device the growth art of ain epilayer which is the preliminary foundation of self - organized gan / ain quantum dots structures , including the substrate cleaning , nitridation , the growth of buffer and the growth of gan and ain epilayer , is discussed we deliberately compare the test result of rheed xrd and afm and achieved the optimalized condition of ain at last we have successfully realized the growth of ain which is much smooth and better crystal quality moreover , we grow the self - organized gan / ain quantum dots structure in s - k mode because the limits of the heater temperature , we can not grow the atom - smooth epilayer of ain until now so we could not grow better quantum dots which have small diameter and big density but the self - organized quantum dots structures with better quality will be realized successfully if the substrate temperature is increased the thesis study belong to my tutor subject of national nature science foundation ( 69976008 ) 本论文主要论述了在espd - u装置上，采用电子回旋共振等离子体增强mocvd ( ecr - pamocvd )方法，在蓝宝石衬底上通过s - k模式自组装生长gan aln量子点结构的生长工艺、结果及讨论。而重点分析了自组装生长量子点之前的aln外延层生长工艺，包括衬底清洗、氮化、缓冲层的生长和gan 、 aln外延层的生长；通过高能电子衍射、 x射线衍射和原子力显微镜测试，并且对这些测试结果进行了详细的比较研究，得出了较优化的工艺条件，生长出了晶质较好、表面较平整的aln外延层；进而采用s - k模式自组装生长了gan aln量子点结构。由于实验装置加热炉温度的限制，我们没有能够生长出原子级平滑的aln外延层表面，因而没能够生长出密度比较大和直径比较小的量子点。
