Anisotropically biaxial strain in non-polar (112–0) plane In(x)Ga(1−x)N/GaN layers investigated by X-ray reciprocal space mapping

In this study, the indium composition x as well as the anisotropically biaxial strain in non-polar a-plane In(x)Ga(1−x)N on GaN is studied by X-ray diffraction (XRD) analysis. In accordance with XRD reciprocal lattice space mapping, with increasing indium composition, the maximum of the In(x)Ga(1−x)N reciprocal lattice points progressively shifts from a fully compressive strained to a fully relaxed position, then to reversed tensile strained. To fully understand the strain in the ternary alloy layers, it is helpful to grow high-quality device structures using a-plane nitrides. As the layer thickness increases, the strain of In(x)Ga(1−x)N layer releases through surface roughening and the 3D growth-mode.