The complex impact of silicon and oxygen on the n-type conductivity of high-Al-content AlGaN

Issues of major relevance to the n-type conductivity of Al0.77Ga0.23N associated with Si and O incorporation, their shallow donor or deep donor level behavior, and carrier compensation are elucidated by allying (i) study of Si and O incorporation kinetics at high process temperature and low growth rate, and (ii) electron paramagnetic resonance measurements. The Al0.77Ga0.23N composition correlates to that Al content for which a drastic reduction of the conductivity of AlxGa1-xN is commonly reported. We note the incorporation of carbon, the role of which for the transport properties of AlxGa1-xN has not been widely discussed. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4800978]