X‐ray reciprocal space mapping study on semipolar InAlN films coherently grown on ZnO substrates

Abstract We have grown semipolar InAlN films on nearly lattice‐matched ZnO $(1\bar 101)$ substrates and investigated their structural properties. Symmetric and asymmetric reciprocal space‐mapping measurements have revealed that semipolar InAlN films grow coherently on ZnO $(1\bar 101)$ at room temperature. The narrow width of the X‐ray rocking curves and the suppression of tilting of semipolar films can be attributed to this coherency. This forms a striking contrast with the case of semipolar AlN films grown on ZnO. We calculated In composition and lattice strain in the semipolar InAlN films based on a model for the lattice distortion of semipolar wurtzite crystal, and found that In_0.26Al_0.74N $(1\bar 101)$ grows on ZnO substrates with small lattice strains of less than 1%. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)