Light-emitting device

• US 10,361,342 B2
• Filed: 06/26/2017
• Issued: 07/23/2019
• Est. Priority Date: 06/28/2016
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Chen, Chao-Hsing, Wang, Jia-Kuen, Chuang, Wen-Hung, Tseng, Tzu-Yao, Lu, Cheng-Lin, Hsu, Chi-Shiang, Chiang, Tsung-Hsun, Hu, Bo-Jiun
• Primary Examiner(s): Naraghi, Ali
• Application Number:
  US15/633,264
• Publication Number:
  US 20170373226A1
• Time in Patent Office: 757 Days
• Field of Search: None
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/237 Details of housings or cases, i.e. the parts between the light-generating element and the bases; Arrangement of components within housings or cases F21K9/238 takes precedence
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 29/77 with essentially identical diverging planar fins or blades, e.g. with fan-like or star-like cross-section
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/16245 the item being metallic
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light-emitting device comprises a semiconductor stack comprising a first semiconductor layer, a second semiconductor layer, and an active layer formed between the first semiconductor layer and the second semiconductor layer; a first pad electrically connected to the first semiconductor layer; a second pad comprising multiple sidewalls electrically connected to the second semiconductor layer; and a metal layer formed on the semiconductor stack, wherein the metal layer surrounds the multiple sidewalls of the second pad and the metal layer is separated from the second pad.

Claims

1. A light-emitting device, comprising:

a semiconductor stack comprising a first semiconductor layer, a second semiconductor layer and an active layer between the first semiconductor layer and the second semiconductor layer;

a first contact layer formed on the semiconductor stack and contact the first semiconductor layer;

a second contact layer formed on the second semiconductor layer, wherein the second contact layer comprises multiple sidewalls and a size smaller than a size of the first contact layer, and the first contact layer is formed at the multiple sidewalls of the second contact layer;

a first pad comprising a side formed on the first contact layer;

a second pad formed on the semiconductor stack, wherein the second contact layer is between the second semiconductor layer and the second pad; and

an insulating layer comprising a first portion covered by the first pad and a connecting portion adjacent to the side of the first pad, wherein the insulating layer comprises an opening between the first portion and the connecting portion to expose the first contact layer, the opening is constituted by a first side of the first portion and one side of the connecting portion, a distance smaller than 100 μ

m is between the side of the first pad and the first side of the first portion or between the side of the first pad and the one side of the connecting portion.

2. The light-emitting device of claim 1, wherein the distance is smaller than 50 μ

m.

3. The light-emitting device of claim 1, wherein the distance is smaller than 20 μ

m.

4. The light-emitting device of claim 1, wherein the opening of the insulating layer is formed along the side of the first pad.

5. The light-emitting device of claim 1, further comprising multiple vias penetrating the second semiconductor layer and the active layer to expose the first semiconductor layer, wherein the multiple vias are formed outside the first pad and the second pad in a top view of the light-emitting device.

6. The light-emitting device of claim 1, further comprising a pin region formed between the first pad and the second pad, wherein the pin region comprises a shape comprising rectangular, oval or circular.

7. The light-emitting device of claim 1, further comprising a pin region formed between the first pad and the second pad, wherein the pin region is covered by the insulating layer.

8. The light-emitting device of claim 1, further comprising a transparent conductive layer formed on the second semiconductor layer, a reflective layer formed on the transparent conductive layer, and a barrier layer formed on the reflective layer wherein the barrier layer comprises a metal material comprising titanium (Ti), tungsten (W), aluminum (Al), indium (In), tin (Sn), nickel (Ni), platinum (Pt), or an alloy of the above materials.

9. The light-emitting device of claim 8, wherein the material of the reflective layer and the barrier layer comprises a metal material other than gold (Au) or copper (Cu).

10. The light-emitting device of claim 8, wherein the barrier layer comprises titanium (Ti)/tungsten (W) on one side closer to the reflective layer and titanium (Ti)/aluminum (Al) on another side away from the reflective layer.

11. The light-emitting device of claim 8, wherein the reflective layer comprises a metal material comprising silver (Ag), aluminum (Al), rhodium (Rh), or an alloy of the above materials.

12. The light-emitting device of claim 8, wherein the second contact layer is formed on the barrier layer and separated from the first contact layer, and the first contact layer and the second contact layer comprise aluminum (Al) or platinum (Pt).

13. The light-emitting device of claim 1, further comprising a first insulating layer covering a sidewall of the active layer, and a second insulating layer comprising multiple openings exposing the first semiconductor layer and the second semiconductor layer.

14. The light-emitting device of claim 1, wherein the second pad contacts the second contact layer.

15. The light-emitting device of claim 14, wherein the second contact layer comprises a side contacting the second pad, and the side of the second contact layer comprises a metal material comprising titanium (Ti) or platinum (Pt).

16. The light-emitting device of claim 1, wherein the second contact layer is surrounded by the first contact layer from a top view of the light-emitting device.

17. The light-emitting device of claim 1, wherein the first contact layer comprises a side contacting the first semiconductor layer, and the side of the first contact layer comprises a metal material comprising chromium (Cr) or titanium (Ti).

18. The light-emitting device of claim 1, wherein the insulating layer comprises a second portion covered by the second pad and formed on the second contact layer.

19. The light-emitting device of claim 18, wherein the first portion, the second portion and the connecting portion of the insulating layer are separated from each other.