More reliable blue light emitting diode has square insulating substrate with system of nitride layers in center and extended electrodes connecting to center and edges

摘要

The diode has a preferably-square insulating substrate (21), with conducting nitride semiconductor layer (23) upon it, dividing a central (R1) and an edge surface section (R2) with edges (23c, 23d). A layered structure on the center has an active nitride layer (24) on the nitride semiconductor layer, a second conductive nitride semiconductor layer (25) above and an upper transparent metal layer (26). A first electrode (27) is constructed on part of the metal layer. A second electrode is formed on the edge section which is not covered by the layered structure. The main section (28) of the electrode has strip extensions (28a, 28b) and is near a corner where the edges intersect. The extensions border the edges so that they extend along at least one of them.