The method of making a nitride semiconductor light emitting device, the epitaxial substrate and the nitride semiconductor light emitting element

A nitride-semiconductor luminescent element which includes a GaN supporting substrate having a semipolar plane and a luminescent layer disposed thereon and in which the decrease in luminescent efficiency caused by misfit dislocation can be inhibited. The nitride-semiconductor luminescent element (11) comprises a supporting substrate (13) constituted of hexagonal gallium nitride, an n-type galliumnitride semiconductor layer (15) comprising an Inx1AlY1Ga1-X1-Y1N (0luminescent layer (17), and a p-type gallium nitride semiconductor layer (19). The InAlGaN layer (21) is disposed between a semipolar main plane (13a) and the luminescent layer (17). Since the InAlGaN layer (21) has a band gap (E) equal to or higher than the band gap (E) of the gallium nitride, the effect of confining carriers and light in the luminescent layer (17) is produced. Although the c plane (Sc2) of the InAlGaN layer (21) is inclined toward the normal axis (Ax), the density of misfit dislocation in slip planes including the c plane as the main slip plane is lower than in AlGaN.