Light emitting element, method of manufacturing the same, and semiconductor device having light emitting element
View Patent ↗An InGaN active layer is formed on a sapphire substrate. A p-side electrode is formed on the InGaN active layer to supply an electric current to this InGaN active layer. The p-side electrode includes {circle around (1)} an Ni layer for forming an ohmic contact with a p-GaN layer, {circle around (2)} an Mo layer having a barrier function of preventing diffusion of impurities, {circle around (3)} an Al layer as a high-reflection electrode, {circle around (4)} a Ti layer having a barrier function, and {circle around (5)} an Au layer for improving the contact with a submount on a lead frame. The p-side electrode having this five-layered structure realizes an ohmic contact and high reflectance at the same time.
1. A light emitting element comprising:
a substrate;
a light emitting layer formed on said substrate to emit light, wherein said light emitting layer includes a first semiconductor layer of a first conductivity type, an active layer formed on said first semiconductor layer to emit the light and a second semiconductor layer of a second conductivity type formed on said active layer;
a first electrode contacting said second semiconductor layer;
a second electrode contacting said substrate and being only located at a place which is below the center of the light emitting layer, such that a center line drawn vertically through the light emitting layer will pass through the second electrode; and
a light reflecting layer contacting said substrate and being only located at a place which is along an edge of said substrate.
2. The light emitting element according to claim 1 , wherein an area of said light reflecting layer is larger than that of said second electrode.
3. The light emitting element according to claim 1 , wherein said substrate is a conductive substrate.
4. The light emitting element according to claim 3 , wherein said substrate includes Ga.
5. The light emitting element according to claim 1 , wherein said first semiconductor layer and said second semiconductor layer include Ga.
6. The light emitting element according to claim 1 , wherein said first electrode is located at a place except a place which is above the center of said substrate.
7. The light emitting element according to claim 1 , further comprising a current limiting layer formed on said substrate, wherein said current limiting layer is located at a place except a place at which said light emitting layer is formed.
8. The light emitting element according to claim 7 , wherein said light reflecting layer is located at a place which is below the current limiting layer.