Thick AlN epilayer grown by using the HVPE method

A thick AlN epilayer is grown directly on a c-plane sapphire substrate by using the hydride vapor phase epitaxy (HVPE) method with a small quantity of Al. The new type (RF + hot-wall) flow HVPE reactor used in the AlN epilayer growth is custommade. The growth temperatures of the source and the growth zones are set at 950 °C and 1145 °C, respectively. The characteristics of the AlN layer grown on a sapphire substrate are investigated by using energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The value of the full width at half maximum (FWHM) for the (002) peak from the AlN layer on the sapphire substrate is observed at 790 arcsec. From the small value of the FWHM, the AlN layer seems to be a well-arranged plane with a uniform (002) growth direction on a sapphire substrate.