硅衬底GaN基LED外延生长的研究

采用在AlN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1.7 μm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1.9 μm.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403 arcsec,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469.2 nm.

Study on the Epitaxial Growth of GaN-based LEDs on Silicon Substrate

The SiN mask layer which is deposited on AlN 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 epitaxially. 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.