Coaxial rf-magnetron nitrogen activator for GaN MBE growth

Novel compact coaxial magnetron nitrogen activator with a radio frequency ( rf) capacitively-coupled discharge has been used for the first time for GaN molecular beam epitaxial growth on different substrates, including GaAs(11 3). Optical emission spectra of the discharge have been studied as a Functi on of nitrogen flow rate, rf power, and magnetic field, focusing on first n egative (391 nm) and second positive (380 nm) lines associated with nitroge n molecular ions and excited molecules, respectively. Optimization of the a ctivator parameters and distance of the discharge zone from the substrate r esulted in GaN growth rate as high as 0.5 mu m h(-1) at a 350 l s(-1) pumpi ng speed. (C) 1999 Elsevier Science S.A. All rights reserved.