中文摘要：

采用在A1N缓冲层后原位沉积SiN掩膜层，然后横向外延生长GaN薄膜。通过该法在硅衬底上获得了1．7μm无裂纹的GaN薄膜，并在此基础上外延生长出了GaN基发光二极管（LED）外延片，其外延片的总厚度约为1．9μm。采用高分辨率双晶X-射线衍射（DCXRD）、原子力显微镜（AFM）测试分析。结果表明，GaN薄膜（0002）面的半峰全宽（FWHM）降低到403arcsee，其表面平整度得到了很大的改善；InGaN／GaN多量子阱的界面较平整，结晶质量良好。光致发光谱表明，GaN基LED峰值波长为469．2nm。

英文摘要：

The SiN mask layer which is deposited on A1N buffer layer in situ is used to grow GaN films laterally. The crack-free GaN film with thickness over 1.7 micron is grown on Si（111） substrate successfully. On the basis of it, the GaN-based LEDs with the thickness of 1.9 μm have been prepared epitaxiatly. The microstructures of samples are analyzed by atomic force microscopy （AFM） and high-resolution double crystal X-ray diffraction （DCXRD）. These results indicate that the full-width at half-maximum （FWHM） on （0002） plane of GaN film is decreased to 403 arcsec, and the surface quality has been improved. The crystal quality of InGaN/GaN multiple quantum wells （MQWs） is preferable, and the interface of MQWs is level, too. The peak wavelength of GaN-based LED on silicon substrate is 469.2 nm, based on the Photoluminescence （PL） spectra.