MOVPE growth of InAsN films on GaAs(001) substrates with an InAs buffer layer

InAsN films of N content up to 3.5% without phase separation were grown on GaAs(001) substrates with a 1.9 μm-thick InAs buffer layer by metalorganic vapor phase epitaxy (MOVPE). In order to grow the InAsN films with a high N content at low temperature that assures a non-equilibrium growth environment, 1,1-dimetylhydrazine (DMHy) and tertiarybutylarsine (TBAs), which can be efficiently decomposed at low temperatures, were adopted as the N and As precursors, respectively. The electron concentration evaluated by the Hall measurement increased with increasing N content and the electrons were degenerated, while the fundamental absorption edge which was determined by the FT-IR absorption spectroscopy showed a blue-shift with increasing N content. These results indicate that the Burstein-Moss effect (or band filling effect) is dominant over the bandgap reduction expected from the bandgap bowing. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)