Embodiments of the invention relate to methods of fabricating semiconductor structures, and to semiconductor structures fabricated by such methods. In some embodiments, the methods may be used to fabricate semiconductor structures of III-V materials, such as InGaN. A semiconductor layer is fabricated by growing sublayers using differing sets of growth conditions to improve the homogeneity of the resulting layer, to improve a surface roughness of the resulting layer, and/or to enable the layer to be grown to an increased thickness without the onset of strain relaxation.