AlN:Si Buffer Layer on Si(111) Substrate Effect on GaN Film

AlN is generally used as buffer layer for the epitaxial growth of GaN on Si(111) substrate. In this paper , we wok on the AlN buffer layer and investigated the crystal quality the doped and undoped Si. Compared with the sample without Si doped, AlN:Si could improve the GaN layer crystal quality. Whereas, the coefficient of doped Si could be found. With suitable the coefficient, crack-free 2.0μm GaN was obtained and the full-width at half-maximum (FWHM) of (002) plane measured by X-ray diffraction (XRD) was as low as 680arcsec. In the image of cross-section measured by scanner electron microscope, we could not find the "wedge groove "crack.