Inverted LED structure with improved light extraction
AssigneeBridgelux, Inc.
InventorGhulam Hasnain
Life of this patent
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Abstract
A light source and method for fabricating the same are disclosed. The light source includes a substrate and a light emitting structure. The substrate has a first surface and a second surface, the second surface including a curved, convex surface with respect to the first surface of the substrate. The light emitting structure includes a first layer of a material of a first conductivity type overlying the first surface, an active layer overlying the first layer, the active layer generating light when holes and electrons recombine therein, and a second layer includes a material of a second conductivity type overlying the active layer and a second surface opposite to the first surface. A mirror layer overlies the light emitting structure.
Claims3
A method of fabricating a light emitting device comprising:
- providing a substrate having a first surface and a second surface that are substantially parallel to one another;
- fabricating a light emitting structure on said first surface, said light emitting structure comprising:
- a first layer of semiconductor material of a first conductivity type deposited on said substrate;
- an active layer overlying said first layer;
- and
- a second layer of semiconductor material of an opposite conductivity type from said first conductivity type overlying said active layer;
- and
- etching said second surface of said substrate to provide a curved, convex surface with respect to said first surface, wherein said substrate comprises sapphire or silicon carbide.
A method of fabricating a light emitting device comprising
- providing a substrate having a first surface and a second surface that are substantially parallel to one another;
- fabricating a light emitting structure on said first surface, said light emitting structure comprising:
- a first layer of semiconductor material of a first conductivity type deposited on said substrate;
- an active layer overlying said first layer;
- and
- a second layer of semiconductor material of an opposite conductivity type from said first conductivity type overlying said active layer;
- and
- etching said second surface of said substrate to provide a curved, convex surface with respect to said first surface,
- wherein etching said second surface of said substrate comprises:
- depositing a layer of photoresist on said second surface;
- patterning said deposited photoresist layer;
- heating said photoresist to a temperature at which a surface of said photoresist layer assumes a curved convex shape;
- and
- etching said photoresist layer and said substrate.
Dependencies are inferred from the claim text.