EPITAXIAL-GROWTH OF GAN ON SI (100) SAPPHIRE (0001) USING RF PLASMA-ASSISTED IONIZED SOURCE BEAM EPITAXY

A new approach to epitaxial GaN growth utilizing radiofrequency plasma -assisted ionized source beam epitaxy (PAISBE) is described. To facili tate the reaction between Ga and atomic nitrogen, the Ga beam was part ially ionized and accelerated. The reactive atomic nitrogen flux was o btained from an RF discharge nitrogen plasma with controllable power a nd frequency. A grid was placed at the exit of the plasma tube to prev ent N2- from hitting the substrate. The growth parameters were chosen to systematically investigate the effects of Ga-beam ionization and gr id bias. The crystal quality of the PAISBE-grown GaN was analysed by R HEED and x-ray diffraction. The FWHM of a 0.4-mum-thick GaN epilayer g rown with ionized Ga beam and RF nitrogen plasma with 140 W power was measured to be 25 min at (0002) diffraction peak. This and other preli minary data from the present study indicate that PAISBE is a promising technique for GaN growth.