Semiconductor light emitting devices with applied wavelength conversion materials

• US 7,863,635 B2
• Filed: 08/07/2007
• Issued: 01/04/2011
• 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., Ibbetson, James, Le Toquin, Ronan P.
• Primary Examiner(s): Tran; Minh-Loan T
• Assistant Examiner(s): Sengdara; Vongsavanh
• Application Number:
  US11/835,044
• Publication Number:
  US 20090039365A1
• Time in Patent Office: 1,246 Days
• Field of Search: 257/98, 257/99, 257/100, 257/E33.061, 257/E33.074, 372/50.1, 372/50.121
• US Class Current: 257/98
• 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:

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 the plurality of discrete phosphor-containing regions containing phosphor particles of a first type of phosphor particle 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

wherein the phosphor-containing regions comprise recesses that extend into and/or through the window layer; and

wherein a first plurality of the recesses have a first diameter smaller than or about equal to an average diameter of the first type of phosphor particle in the discrete phosphor-containing regions so that the first plurality of recesses are configured to trap the first type of phosphor particle.

2. The semiconductor device of claim 1, wherein a second plurality of the recesses have a second diameter larger than the first diameter.

3. The semiconductor device of claim 2, wherein the discrete phosphor-containing regions further contain phosphor particles of a second type of phosphor particle, and wherein the second diameter is smaller than or about equal to an average diameter of the second type of phosphor particle in the discrete phosphor-containing regions so that the second plurality of recesses are configured to trap the second type of phosphor particle.

4. A semiconductor device, comprising:

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 phosphor-containing regions on the window layer and containing a plurality of phosphor particles of a first type of phosphor particle 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;

wherein the plurality of discrete phosphor containing regions are spaced apart from the active region by the window layer;

wherein the window layer comprises a plurality of recesses that extend into and/or through the window layer, and wherein the discrete phosphor containing regions are in the plurality of recesses; and

wherein a first plurality of the recesses have a first diameter smaller than or about equal to an average diameter of the first type of phosphor particle in the discrete phosphor-containing regions so that the first plurality of recesses are configured to trap the first type of phosphor particle.

5. The semiconductor device of claim 4, wherein a second plurality of the recesses have a second diameter larger than the first diameter.

6. The semiconductor device of claim 5, wherein the discrete phosphor-containing regions further contain phosphor particles of a second type of phosphor particle, and wherein the second diameter is smaller than or about equal to an average diameter of the second type of phosphor particle in the discrete phosphor-containing regions so that the second plurality of recesses are configured to trap the second type of phosphor particle.