Light emitting devices having current reducing structures

• US 8,704,240 B2
• Filed: 04/04/2013
• Issued: 04/22/2014
• Est. Priority Date: 06/30/2004
• Status: Expired due to Term

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Emerson, David Todd, Haberern, Kevin, Bergmann, Michael John, Slater, David B. Jr., Donofrio, Matthew, Edmond, John
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): PATTON, PAUL E
• Application Number:
  US13/856,928
• Publication Number:
  US 20130292639A1
• Time in Patent Office: 383 Days
• Field of Search: 257/E33.005, 257/79
• US Class Current: 257/79
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• CPC Class Codes: H01L 33/38 with a particular shape

Abstract

A light emitting device includes a p-type semiconductor layer, an n-type semiconductor layer and an active region between the p-type semiconductor layer and the n-type semiconductor layer. A bond pad is provided on one of the p-type semiconductor layer or the n-type semiconductor layer, opposite the active region, the bond pad being electrically connected to the one of the p-type semiconductor layer or the n-type semiconductor layer. A conductive finger extends from and is electrically connected to the bond pad. A reduced conductivity region is provided in the light emitting device that is aligned with the conductive finger. A reflector may also be provided between the bond pad and the reduced conductivity region. A reduced conductivity region may also be provided in the light emitting device that is not aligned with the bond pad.

Claims

1. A light emitting device, comprising:

a semiconductor diode having first and second opposing semiconductor surfaces of opposite conductivity type;

a non-transparent feature on the first semiconductor surface;

a reduced conductivity region in the light emitting device that is aligned with the non-transparent feature, the reduced conductivity region and the non-transparent feature including surfaces that face one another; and

a reflector between the surfaces of the non-transparent feature and the reduced conductivity region that face one another.

2. A light emitting device according to claim 1 wherein the reflector is directly on the non-transparent feature.

3. A light emitting device according to claim 1 wherein the reflector is aligned with the non-transparent feature.

4. A light emitting device according to claim 1 wherein the reduced conductivity region is in the semiconductor diode.

5. A light emitting device according to claim 1 wherein the reduced conductivity region forms a rectifying junction or a Schottky junction with a region of the light emitting device that is adjacent thereto.

6. A light emitting device according to claim 1 wherein the reduced conductivity region comprises a high resistivity region or an insulating region in the light emitting device.

7. A light emitting device, comprising:

a p-type semiconductor layer, an n-type semiconductor layer and an active region between the p-type semiconductor layer and the n-type semiconductor layer;

a bond pad on one of the p-type semiconductor layer or the n-type semiconductor layer, opposite the active region, the bond pad being electrically connected to the one of the p-type semiconductor layer or the n-type semiconductor layer;

a conductive finger that extends from and is electrically connected to the bond pad; and

a reduced conductivity region in the light emitting device that is aligned with the conductive finger.

8. A light emitting device according to claim 7 wherein the reduced conductivity region is further aligned with the bond pad.

9. A light emitting device according to claim 7 wherein the bond pad is a first bond pad, the conductive finger is a first conductive finger, the reduced conductivity region is a first reduced conductivity region and wherein the light emitting device further comprises:

a second bond pad that is electrically connected to the other of the p-type semiconductor layer or the n-type semiconductor layer;

a second conductive finger that extends from and is electrically connected to the second bond pad; and

a second reduced conductivity region in the light emitting device that is aligned with the second conductive finger.

10. A light emitting device according to claim 9 wherein the second reduced conductivity region is further aligned with the second bond pad.

11. A light emitting device according to claim 9 wherein the second bond pad and the second conductive finger are on the other of the p-type semiconductor layer or the n-type semiconductor layer, opposite the active region.

12. A light emitting device according to claim 9 wherein the second bond pad and the second conductive finger are on the other of the p-type semiconductor layer or the n-type semiconductor layer, adjacent the active region.

13. A light emitting device according to claim 11 further comprising a substrate on the other of the p-type semiconductor layer or the n-type semiconductor layer, opposite the active region and wherein the second bond pad and the second conductive finger are on the substrate opposite the active region.

14. A light emitting device according to claim 9 further comprising a substrate on the other of the p-type semiconductor layer or the n-type semiconductor layer, opposite the active region and wherein the first and second bond pads are on an exposed surface of the light emitting device that is opposite the substrate.

15. A light emitting device according to claim 14 wherein the substrate includes beveled sidewalls.

16. A light emitting device according to claim 13 further comprising a reflective layer between the other of the p-type semiconductor layer or the n-type semiconductor layer and the substrate, and a bonding layer between the reflective layer and the substrate.

17. A light emitting device according to claim 9 further comprising a transparent conductive layer between the one of the p-type semiconductor layer or the n-type semiconductor layer and the first bond pad and the first conductive finger.

18. A light emitting device, comprising:

a semiconductor diode having first and second opposing semiconductor surfaces of opposite conductivity type;

a non-transparent feature on the first semiconductor surface; and

a reduced conductivity region in the light emitting device that is not aligned with the non-transparent feature.

19. A light emitting device according to claim 18 wherein the reduced conductivity region is a first reduced conductivity region, the light emitting device further comprising:

a second reduced conductivity region in the light emitting device that is aligned with the non-transparent feature.

20. A light emitting device according to claim 18 wherein the reduced conductivity region is configured to shape a light emission pattern of the light emitting device.