Concaves and convexes 1a are formed by
processing the
surface layer of a first layer 1, and second layer 2 having a different
refractive index from the first layer is grown while burying the concaves and convexes (or first
crystal 10 is grown as concaves and convexes on
crystal layer S to be the base of the growth, and second
crystal 20 is grown, which has a different
refractive index from the first crystal). After forming these concavo-convex
refractive index interfaces 1a (10a), an element structure, wherein
semiconductor crystal
layers containing a light-emitting layer A are laminated, is formed. As a result, the light in the lateral direction, which is generated in the light-emitting layer changes its direction by an influence of the concavo-convex refractive index interface and heads toward the outside. Particularly, when an
ultraviolet light is to be emitted using InGaN as a material of a light-emitting layer, a
quantum well structure is employed and all the
layers between the
quantum well structure and the low temperature buffer layer are formed of a GaN crystal, removing AlGaN. The
quantum well structure preferably consists of a well layer made of InGaN and a
barrier layer made of GaN, and the thickness of the
barrier layer is preferably 6 nm–30 nm.