Backside transparent substrate roughening for uv light emitting diode
AssigneeRayVio Corporation
InventorsYitao LIAO, Douglas A. COLLINS
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Abstract
In the present invention, a fabrication process for epitaxy onto back-side patterned substrate, where the substrate patterns were defined prior to epitaxy and therefore simplify post growth processing. Specifically, for LED devices, said fabrication process reduces the post growth processing steps required to obtain high LEE due to strong scattering of the back-side features defined on the substrate. The features defined on the back-side patterned substrate scatters strongly with light emitted from the LED devices. Methods of obtaining such features include wet and dry etching.
Claims21
A method for fabricating an optical diode device configured to emit electromagnetic radiation in an ultraviolet range, the method comprising:
- providing a transparent substrate member having a growth surface and a backside surface;
- treating the backside surface to a polishing process to remove contaminants from the backside surface;
- subjecting the backside surface to a treatment process to cause the backside surface to be characterized by a roughness having a periodic spatial pattern overlying the backside surface;
- forming a thickness of metal on the backside surface, the plurality of periodic spatial patterns being selected from one of a plurality of stripe grids, a plurality of square grids, a checker board, or other regular spatial configurations;
- transferring the transparent substrate member into a reactor chamber for deposition of epitaxial materials;
- forming a buffer material overlying the growth surface while exposing the backside surface;
- processing the substrate at a temperature greater than 100 degrees to less than 1,500 degrees;
- and
- removing the thickness of metal to expose the backside surface including the roughness having the periodic spatial pattern.
A semiconductor device configured to emit electromagnetic radiation in the ultraviolet light range grown onto a substrate, the substrate comprising a front side surface configured for growth of a plurality of epitaxial materials, and a back-side surface configured for a plurality of periodic spatial patterns formed prior to growth of the plurality of epitaxial materials, the plurality of periodic spatial patterns being selected from one of a plurality of stripe grids, a plurality of square grids, a checker board, or other regular spatial configurations.
Dependencies are inferred from the claim text.