Phosphor coating method for fabricating light emitting semiconductor device and applications thereof

• US 8,258,535 B2
• Filed: 03/26/2012
• Issued: 09/04/2012
• Est. Priority Date: 08/29/2007
• Status: Expired due to Fees

• Current Assignee: Everlight Electronics Company Limited
• Original Assignee: Everlight Electronics Company Limited
• Inventors: Chao, Tzu-Hao
• Primary Examiner(s): Geyer, Scott B
• Application Number:
  US13/430,663
• Publication Number:
  US 20120181564A1
• Time in Patent Office: 162 Days
• Field of Search: None
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• 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

In one aspect, a light emitting unit comprises: a first semiconductor layer having a first electric property; a second semiconductor layer having a second electric property disposed over the first semiconductor layer; an active layer disposed between the first semiconductor layer and the second semiconductor layer; a first electrode disposed on the second semiconductor layer; a second electrode disposed under the first semiconductor layer; and a phosphor layer disposed on the first semiconductor layer. The phosphor layer covers the active layer and the second semiconductor layer. The first electrode is exposed out of the phosphor layer.

Claims

1. A light emitting unit comprising:

a first semiconductor layer having a first electric property;

a second semiconductor layer having a second electric property disposed over the first semiconductor layer;

an active layer disposed between the first semiconductor layer and the second semiconductor layer;

a first electrode disposed on the second semiconductor layer;

a second electrode disposed on the first semiconductor layer; and

a phosphor layer disposed on the first semiconductor layer, wherein the phosphor layer covers the active layer and the second semiconductor layer, and wherein the first electrode and the second electrode are exposed out of the phosphor layer.

2. The light emitting unit of claim 1, wherein the first semiconductor layer includes a top surface and a bottom surface opposite to the top surface, wherein the top surface includes a first portion, a second portion lower than the first portion and a third portion lower than the second portion, wherein the active layer is disposed on the first portion, wherein the second electrode is disposed on the second portion, and wherein the first portion, part of the second portion and part of the third portion are covered by the phosphor layer.

3. The light emitting unit of claim 1, wherein the first semiconductor layer includes a top surface and a bottom surface opposite to the top surface, wherein the top surface includes a first central portion, a second central portion lower than the first central portion and a peripheral portion lower than the second central portion, wherein the active layer is disposed on the first central portion, wherein the second electrode is disposed on the second central portion, and wherein the first central portion, part of the second central portion and part of the peripheral portion are covered by the phosphor layer.

4. The light emitting unit of claim 1, wherein the first electric property is n type and the second electric property is p type.

5. The light emitting unit of claim 1, wherein the first electric property is p type and the second electric property is n type.

6. The light emitting unit of claim 1, wherein a carrier is disposed under the first semiconductor layer.

7. A light emitting unit comprising:

a first semiconductor layer having a first electric property;

a second semiconductor layer having a second electric property disposed over the first semiconductor layer;

an active layer disposed between the first semiconductor layer and the second semiconductor layer;

a first electrode in contact with the second semiconductor layer;

a second electrode in contact with the first semiconductor layer; and

a phosphor layer disposed on the first semiconductor layer, the phosphor layer covering the active layer and the second semiconductor layer with the first electrode and either or both of the second electrode and a portion of the first semiconductor layer exposed out of the phosphor layer.

8. The light emitting unit of claim 7, wherein the first semiconductor layer includes a top surface and a bottom surface opposite to the top surface, wherein the top surface includes a central portion and a peripheral portion lower than the central portion, wherein the active layer is disposed on the central portion, wherein the second electrode is disposed on the bottom surface, and wherein the central portion and part of the peripheral portion are covered by the phosphor layer.

9. The light emitting unit of claim 7, wherein the first semiconductor layer includes a top surface and a bottom surface opposite to the top surface, wherein the top surface includes a first portion and a second portion lower than the first portion, wherein the active layer is disposed on the first portion, wherein the second electrode is disposed on the bottom surface, and wherein the first portion and part of the second portion are covered by the phosphor layer.

10. The light emitting unit of claim 7, wherein the first semiconductor layer includes a top surface and a bottom surface opposite to the top surface, wherein the second semiconductor layer is disposed over the top surface of the first semiconductor layer, wherein the first electrode is disposed on the second semiconductor layer, and wherein the second electrode is disposed on the top surface of the first semiconductor layer.

11. The light emitting unit of claim 7, wherein the first semiconductor layer includes a top surface and a bottom surface opposite to the top surface, wherein the second semiconductor layer is disposed over the top surface of the first semiconductor layer, wherein the first electrode is disposed on the second semiconductor layer, and wherein the second electrode is disposed on the bottom surface of the first semiconductor layer.

12. The light emitting unit of claim 7, wherein the first electric property is n type and the second electric property is p type.

13. The light emitting unit of claim 7, wherein the first electric property is p type and the second electric property is n type.

14. The light emitting unit of claim 7, wherein a carrier is disposed under the second electrode.