To reduce the threading dislocation density in (00•1) GaN grown on c-plane sapphire, a series of samples were grown using scandium oxynitride (ScOxNy) interlayers on AlN-on-sapphire templates. Scanning capacitance microscopy was used to investigate the unintentional doping in GaN with varying ScOxNy interlayer thicknesses. The use of ScOxNy interlayers decreases the threading dislocation density. An unintentionally n-doped layer was identified, by scanning capacitance microscopy, close to the GaN/ScOxNy interface. The average width of this conductive layer was quantified and found to increase as the ScOxNy interlayer thickness increased up to 13nm.

The Impact of ScOxNy Interlayers on Unintentional Doping and Threading Dislocations in GaN. T.Zhu, M.A.Moram, D.V.Sridhara Rao, H.Li, M.J.Kappers, R.A.Oliver: Journal of Physics - Conference Series, 2010, 209[1], 012067