The properties of low dislocation density a-plane (11•0) GaN films grown on sapphire using 2 to 15nm ScN interlayers were reported. The dislocation densities decreased with increasing ScN interlayer thickness and the surface roughness for coalesced films remained low at 0.7nm. X-ray diffraction data revealed a reduction in ω-scan full-width at half-maximum at all rotational positions and luminescence intensities increased compared to a control sample without a ScN interlayer. However, a slight increase in the prismatic stacking fault density was observed, compared to the control sample.

Low Dislocation Density Nonpolar (11-20) GaN Films Achieved Using Scandium Nitride Interlayers. M.A.Moram, M.J.Kappers, C.J.Humphreys: Physica Status Solidi C, 2010, 7[7-8], 1778–80