The method of fabricating a nitride semiconductor of this invention
includes the steps of forming, on a substrate, a first nitride
semiconductor layer of Al.sub.u Ga.sub.v In.sub.w N, wherein 0.ltoreq.u,
v, w .ltoreq.1 and u+v+w=1; forming, in an upper portion of the first
nitride semiconductor layer, plural convexes extending at intervals along
a substrate surface direction; forming a mask film for covering bottoms of
recesses formed between the convexes adjacent to each other; and growing,
on the first nitride semiconductor layer, a second nitride semiconductor
layer of Al.sub.x Ga.sub.y In.sub.z N, wherein 0.ltoreq.x, y, z.ltoreq.1
and x+y+z=1, by using, as a seed crystal, Cplanes corresponding to top
faces of the convexes exposed from the mask film.
