UV emitting LED having mesa structure

• US 20050264172A1
• Filed: 05/26/2004
• Published: 12/01/2005
• Est. Priority Date: 05/26/2004
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: LeBoeuf, Steven F., Wojnarowski, Robert, Weaver, Stanton E.
• Granted Patent: US 7,683,391 B2
• Time in Patent Office: Days
• US Class Current: 313/498
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction

Abstract

The present invention is directed towards a source of ultraviolet energy, wherein the source is a UV-emitting LED. In an embodiment of the invention, the UV-LED is characterized by a base layer material including a substrate, a p-doped semiconductor material, a multiple quantum well, a n-doped semiconductor material, upon which base material a p-type metal resides and wherein the LED'"'"'s are provided with a rounded mesa configuration. In a specific embodiment, the p-type metal is positioned upon a rounded mesa, such as a parabolic mesa, formed out of the base structure materials.

Claims

1. A LED emitting UV energy comprised of a substrate having:

a base layer;

an active region;

a p-doped region;

a n-doped region;

wherein the substrate is formed into a mesa;

a p-metallization region is positioned on the mesa;

a n-metallization region is positioned in a depression on the substrate;

wherein the p-metallization layer and n-metallization layer are in contact with electrical contacts;

wherein the mesa is provided with a rounded surface contour.

2. The LED of claim 1 wherein p-metallization region and n-metallization have edges and the distance between the edges of the p-metallization region and n-metallization region is about twice the edge-to-edge distance of the p-metallization region.

3. The LED of claim 1 wherein the rounded surface contour of the mesa has a height of about 0.5 to about 5000 μ

m.

4. The LED of claim 1 wherein the mesa is provided with edges and the edge-to-edge distance of the mesa is about 50 to about 5000 μ

m.

5. The LED of claim 1 wherein the p-metallization layer is embedded within an encapsulated layer selected from Ti—

W alloy, W, Co, Mo, Cr, and other refractory metals.

6. The LED of claim 1 wherein the LED is further comprised of a passivation layer encasing at least a portion of a region including the p-metallization layer, mesa, and n-metallization layer.

7. The LED of claim 5 wherein the LED is further comprised of a passivation layer encasing at least a portion of a region including the encapsulating layer, mesa, and n-metallization layer.

8. The LED claim 1 wherein the mesa is circular in shape and has a diameter selected from about 25 μ

m, about 50 μ

m, and about 100 μ

m.

9. A plurality of LED'"'"'s of claim 1 arranged in a linear array.

10. The linear array of claim 9 wherein the LED'"'"'s have a circular diameter of about 25 μ

m and about 10 μ

m of n-metallization layer is present between LEDs.

11. The linear array of claim 9 wherein the LED'"'"'s have a circular diameter of about 50 μ

m and about 10 μ

m of n-metallization layer is present between LEDs.

12. The linear array of claim 9 wherein the LED'"'"'s have a circular diameter of about 100 μ

m and about 20 μ

m of n-metallization layer is present between LEDs.

13. A plurality of LEDs of claim 1 arranged in a triple array.

14. The triple array of claim 13 wherein the LEDs have a circular diameter of about 25 μ

m and about 20 μ

m of n-metallization is present between LEDs.

15. The triple array of claim 13 wherein the LEDs have a circular diameter of about 50 μ

m and about 20 μ

m of n-metallization is present between LEDs.

16. The triple array of claim 13 wherein the LEDs have a circular diameter of about 100 μ

m and about 30 μ

m of n-metallization is present between LEDs.

17. A plurality of LEDs of claim 1 arranged in a compact array.

18. The compact array of claim 17 wherein the LEDs have a circular diameter of about 25 μ

m and wherein about 20 μ

m of n-metallization is present between LEDs.

19. The compact array of claim 17 wherein the LEDs have a circular diameter of about 50 μ

m and wherein about 25 μ

m of n-metallization is present between LEDs.

20. The compact array of claim 17 wherein the LEDs have a circular diameter of about 100 μ

m and wherein about 35 μ

m of n-metallization is present between LEDs.

21. A plurality of LED'"'"'s of claim 1 wherein the n-metallization layer and p-metallization layer are spaced by about 12 μ

m.