Semiconductor light emitting devices with applied wavelength conversion materials and methods for forming the same

• US 9,054,282 B2
• Filed: 12/22/2010
• Issued: 06/09/2015
• Est. Priority Date: 08/07/2007
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Andrews, Peter S., Le Toquin, Ronan P., Ibbetson, James
• Primary Examiner(s): Sengdara, Vongsavanh
• Application Number:
  US12/976,769
• Publication Number:
  US 20110089456A1
• Time in Patent Office: 1,630 Days
• Field of Search: 257/98, 257/E33.059, 257/E33.061
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material

Abstract

A semiconductor structure includes an active region configured to emit light upon the application of a voltage thereto, a window layer configured to receive the light emitted by the active region, and a plurality of discrete phosphor-containing regions on the window layer and configured to receive light emitted by the active region and to convert at least a portion of the received light to a different wavelength than a wavelength of light emitted by the active region. Methods of forming a semiconductor structure including an active region configured to emit light and a window layer include forming a plurality of discrete phosphor-containing regions on the window layer.

Claims

1. A semiconductor device, comprising:

a diode structure configured to emit light upon the application of a voltage thereto;

a plurality of discrete phosphor-containing regions spaced apart laterally on an external surface of the diode structure and configured to receive light emitted by the diode structure and to convert at least a portion of the received light to a different wavelength than a wavelength of light emitted by the diode structure; and

an overlayer comprising a phosphor-loaded material on the diode structure, wherein the plurality of discrete phosphor containing regions are between the overlayer and the diode structure, wherein the plurality of discrete phosphor-containing regions comprise a first plurality of spaced apart phosphor-containing regions comprising a first type of phosphor configured to convert light emitted by the diode structure to a first wavelength and a second plurality of spaced apart phosphor-containing regions comprising a second type of phosphor configured to convert light emitted by the diode structure to a second wavelength that is different from the first wavelength, wherein the second plurality of spaced apart phosphor containing regions are free of the first type of phosphor;

wherein adjacent ones of the first plurality of phosphor-containing regions are spaced apart from one another on the external surface of the diode structure with intervening ones of the second plurality of phosphor containing regions therebetween.

2. The semiconductor device of claim 1, wherein the first plurality of spaced apart phosphor containing regions are in direct contact with respective ones of the second plurality of spaced apart phosphor containing regions.

3. The semiconductor device of claim 2, further comprising a third plurality of spaced apart phosphor-containing regions comprising a phosphor configured to convert light emitted by the diode structure to a third wavelength, wherein the third wavelength comprises a wavelength in the blue portion of the spectrum.

4. The semiconductor device of claim 1, wherein the first plurality of spaced apart phosphor containing regions and the second plurality of spaced apart phosphor containing regions form a continuous layer of phosphor containing regions on the surface of the diode structure.

5. The semiconductor device of claim 1, wherein the first wavelength comprises a wavelength in the yellow portion of the spectrum, the second wavelength comprises a wavelength in the red portion of the spectrum, and the diode structure is configured to emit light in the blue or UV portions of the spectrum.

6. The semiconductor device of claim 1, wherein the first wavelength comprises a wavelength in the red portion of the spectrum, the second wavelength comprises a wavelength in the green portion of the spectrum, and the diode structure is configured to emit light in the blue or UV portions of the spectrum.

7. The semiconductor device of claim 1, wherein the overlayer comprises light scattering particles.

8. The semiconductor device of claim 1, wherein the overlayer comprises a phosphor that is different from phosphors in the discrete phosphor-containing regions.

9. The semiconductor device of claim 1, wherein the overlayer has a roughened surface opposite the diode structure.

10. The semiconductor device of claim 1, further comprising a light scattering layer, wherein the plurality of discrete phosphor-containing regions are on the light scattering layer.

13. The semiconductor device of claim 1, wherein a distribution of the first plurality of spaced apart phosphor containing regions laterally adjacent to the second plurality of spaced apart phosphor containing regions is uniform.

14. The semiconductor device of claim 1, wherein the overlayer comprises a third type of phosphor that is different than the first type of phosphor in the first plurality of spaced apart phosphor-containing regions.

15. The semiconductor device of claim 14, wherein the overlayer comprises light scattering particles in addition to the third type of phosphor.

16. The semiconductor device of claim 14, wherein the overlayer comprises a textured surface.

17. The semiconductor device of claim 14, wherein the overlayer comprises a patterned surface.

11. The semiconductor device of claim I, wherein the first plurality of spaced apart phosphor containing regions and the second plurality of spaced apart phosphor containing regions are arranged in an alternating pattern on the surface of the diode structure.

12. The semiconductor device of claim 11, wherein each of the first plurality of spaced apart phosphor containing regions is in direct contact with a neighboring one of the second plurality of spaced apart phosphor containing regions.