| 摘要 |
PURPOSE:To obtain a surface emitting type light-emitting diode provided with a lens whose focal distance is sufficiently short even when a flat thin region of a light-emitting face is processed by a method wherein a concentric-circle- shaped groove is formed in a semiconductor substrate or a cap layer which is used as the light-emitting face and the light-emitting face is used as a Fresnel' s lens. CONSTITUTION:In a surface emitting type light-emitting diode where light is taken out from a semiconductor substrate 1 or a cap layer, a concentric-circle- shaped groove is formed in the semiconductor substrate 1 or the cap layer which is used as a light-emitting face; the light-emitting face is used as a Fresnel's lens 6. For example, a P-type GaInPAs active layer 2, a P-type InP clad layer 3 and an n-type GaInPAs cap layer 4 are crystal-grown epitaxially one after another on an n-type InP substrate 1. Then, a light-emitting diode is formed in such a way that one part of the GaInPAs cap layer corresponding to a part limited as a light-emitting region is transformed into a P-type by diffusing Zn. In addition, a concentric-circle-shaped Fresnel's lens 6 is formed on the surface of the InP substrate 1 so that an optical output can be converged on one point. |
