UV light emitting devices and systems and methods for production
A method of fabricating an ultraviolet (UV) light emitting device includes receiving a UV transmissive substrate, forming a first UV transmissive layer comprising aluminum nitride upon the UV transmissive substrate using a first deposition technique at a temperature less than about 800 degrees Celsius or greater than about 1200 degrees Celsius, forming a second UV transmissive layer comprising aluminum nitride upon the first UV transmissive layer comprising aluminum nitride using a second deposition technique that is different from the first deposition technique, at a temperature within a range of about 800 degrees Celsius to about 1200 degrees Celsius, forming an n-type layer comprising aluminum gallium nitride layer upon the second UV transmissive layer, forming one or more quantum well structures comprising aluminum gallium nitride upon the n-type layer, and forming a p-type nitride layer upon the one or more quantum well structures.
1. A method of fabricating an ultraviolet (UV) light emitting device comprising:
receiving a UV transmissive substrate;
forming a UV transmissive layer upon the UV transmissive substrate, comprising:
forming a first UV transmissive layer comprising aluminum nitride upon the UV transmissive substrate using a first deposition technique at a temperature less than about 800 degrees Celsius or greater than about 1200 degrees Celsius; and
forming a second UV transmissive layer comprising aluminum nitride upon the first UV transmissive layer comprising aluminum nitride using a second deposition technique that is different from the first deposition technique, at a temperature within a range of about 800 degrees Celsius to about 1200 degrees Celsius; and
forming a UV light emitting layer structure on the UV transmissive layer, comprising:
forming an n-type layer comprising aluminum gallium nitride layer upon the UV transmissive layer;
forming one or more quantum well structures comprising aluminum gallium nitride upon the n-type layer; and
forming a p-type nitride layer upon the one or more quantum well structures.
2. The method of claim 1 wherein the UV transmissive layer has a thickness within a range of about 10 nm to about 3 microns.
3. The method of claim 1 wherein the UV transmissive layer has a thickness of about 3 microns to 10 microns.
4. The method of claim 1 wherein the UV transmissive layer has transmissivity in the UV wavelength range within a transmissivity range of about 50% to about 99%.
5. The method of claim 1 wherein the method of forming the first UV transmissive layer uses a deposition process selected from a group consisting of: hydride vapor phase epitaxy, atomic layer deposition, liquid phase epitaxy, physical vapor deposition, sputtering, solid source solution epitaxy.
6. The method of claim 1 wherein the method of forming the second UV transmissive layer uses a deposition process selected from a group consisting of:
metalorganic chemical vapor deposition, metalorganic vapor phase epitaxy, molecular beam epitaxy, chemical beam epitaxy.
7. The method of claim 1
wherein the first UV transmissive layer comprises polycrystalline aluminum nitride; and
wherein the second UV transmissive layer comprises single crystal aluminum nitride.
8. The method of claim 1 wherein the receiving the UV transmissive substrate comprises receiving a substrate selected from a group consisting of: a quartz substrate, a sapphire substrate, and a free standing single crystal aluminum nitride substrate.