2.6 mu m/h high-speed growth of GaN by RF-molecular beam epitaxy and improvement of crystal quality by migration enhanced epitaxy

High-quality GaN films were grown by molecular beam epitaxy (MBE) using ele mental Ga and rf-plasma nitrogen as source with 1.2 mu m/h growth rate. GaN films were grown on the migration enhanced epitaxy (MEE)-GaN buffers depos ited on (0001) sapphire substrates. The room temperature (RT) mobility was 372 cm(2)/Vs at 1.2 x 10(17) cm(-3). Furthermore, extreme high-speed GaN gr owth of 2.6 mu m/h was also demonstrated by increase of radical nitrogen su pply at the substrates. The electron density of Si-doped GaN films was cont rolled in the range of 5.3 x 10(15) to 4.9 x 10(20) cm(-3) and the room tem perature mobility was 252 cm(2)/Vs at 3.4 x 10(17) cm(-3). The narrowest fu ll width at half maximum (FWHM) of photoluminescence at 15 K was 10.5 meV.