| 摘要 |
PURPOSE: To reduce the area impeding the taking out of light by arranging the surface electrode to be superposed, by a specific percent or more, on the rear electrode with the thickness of an element, being cut from a substrate into a square shape having four sides of length L, satisfying specific requirements. CONSTITUTION: N type circular electrodes 1 (diameter: 130μmϕ) are formed on the entire surface of a wafer at an interval of 350μm in the longitudinal and lateral directions. A rear electrode, i.e., a p-type electrode 2, is formed in a circle having diameter of 250μm in the center of the rear surface. It corresponds to about 50% of the rear surface area of the element. Since the rear electrode is located directly under the surface electrode and they are aligned in the vertical direction, the area impeding the taking out of light can be decreased. When the thickness D of the element is set such that D>=L/3, conventionally unavailable emission intensity can be attained. The effect is not damaged so long as the D exceeds L/3 but a thick epitaxial layer can not be grown when the D is too thick. D is optimally set in the range of (1/3-1.0)L. |
