Epitaxial growth of wurtzite GaN on Si(111) by a vacuum reactive evaporation

A single crystalline GaN film on Si(111) with a GaN buffer layer is grown b y a simple reactive evaporation method. Scanning electron microscopy, x-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescen ce measurement (PL), and Hall measurement results indicate that the single crystalline wurtzite GaN was successfully grown on the microcrystalline GaN buffer layers on Si(111) substrate. The surface of the GaN films is mirror -like and crack-free. A pronounced GaN (0002) peak appears in the XRD patte rn. The full width at half maximum (FWHM) of the double-crystal x-ray rocki ng curve for (0002) diffraction from the GaN epilayer is 30 arcmin. The TEM reveals that a 10 nm GaN buffer layer in the microcrystalline state exists between the Si substrate and the epilayer, which dissipates most of the st ress energy. The PL spectrum shows that the GaN epilayer emits light at the wavelength of 365 nm with a FWHM of 8 nm (74.6 meV). The unintentionally d oped films were n type with a carrier concentration of 1.76 x 10(18)/cm(3) and an electron mobility of 142 cm(3)/V s. The growth technique described i s simple but very powerful for growing single crystalline GaN films on Si s ubstrates. (C) 2000 American Institute of Physics. [S0021-8979(00)03406-X].