Effects of plasma species on the N incorporation of GaAsSbN grown by plasma-assisted gas-source molecular-beam epitaxy

We report the effects of plasma species on the N incorporation of GaAsSbN. Optical emission spectroscopy and quadruple mass spectroscopy were used to characterize the plasma source. We found a simple correlation between the atomic N species and meta-stable molecular N2⁎ species that is independent of plasma power and N2 flow rate. In order to achieve atomic-N-rich growth conditions, we place a PBN shutter in front of our plasma source, rich in meta-stable N2* molecules, to facilitate the relaxation of N2* and turn the growth condition into an atomic-N-dominant one. When an atomic-N-rich condition is used, N incorporation rate decreases when Sb flux increases and increases as growth temperature increases. This behavior is well explained by a surface kinetics model. When a N2*-rich condition is used, the N incorporation in GaAsSbN is enhanced by increase in Sb flux and growth temperature.