Nitride compound semiconductor light emitting element and its

Abstract

A nitride compound semiconductor light emitting element comprises a substrate, a nitride compound semiconductor n-type layer, a mask layer having a predetermined opening, a nitride compound semiconductor buffer layer epitaxially grown on said n-type layer exclusively at said opening. The buffer layer has a recess on its top face so that a thickness of said buffer layer is thinner above a central portion of the opening and thicker above edge portions of the opening. A nitride compound semiconductor active layer is selectively formed on the recess of the buffer layer to be thicker at the central portion of the recess and thinner at the edges of the recess. A nitride compound semiconductor burying layer overlays the mask layer and the active layer to cover the active layer. By selectively growing the buffer layer and the active layer in the opening of the mask layer formed on the substrate and by growing additional layers to bury the entire structure and to flatten the surface, a planar-type, stripe-buried structure is realized. The active layer has a distribution of refractive index due to the distribution of thickness resulting from the selective growth and can confine light with high efficiency. Additionally, by using an insulation film, highly efficient confinement of current is realized to provide a light emitting element for a shorter wavelength with a high luminous intensity and a low oscillation threshold value.