LIGHT-EMITTING DEVICE AND MANUFACTURING METHOD THEREOF

• US 20170025567A1
• Filed: 07/24/2015
• Published: 01/26/2017
• Est. Priority Date: 07/24/2015
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: TSAI, Chun-Fu, LU, Shao-Ping, CHEN, Yi-Ming, PENG, Yu-Ren, LIN, Chun-Yu, HSU, Tzu-Chieh
• Granted Patent: US 9,825,088 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence

Abstract

A light-emitting device comprises a carrier; and a first semiconductor element comprising a first semiconductor structure and a second semiconductor structure, wherein the second semiconductor structure is closer to the carrier than the first semiconductor structure is to the carrier, the first semiconductor structure comprises a first MQW structure configured to emit a first light having a first dominant wavelength during normal operation, and the second semiconductor structure comprises a second MQW structure configured not to emit light during normal operation.

Claims

1. A light-emitting device, comprising:

a carrier; and

a first semiconductor element formed on the carrier and comprising a first semiconductor structure and a second semiconductor structure, wherein the second semiconductor structure is closer to the carrier than the first semiconductor structure is to the carrier, the first semiconductor structure comprises a first MQW structure configured to emit a first light having a first dominant wavelength during normal operation, and the second semiconductor structure comprises a second MQW structure configured not to emit light during normal operation.

2. The light-emitting device of claim 1, wherein the first semiconductor structure comprises a first n-type semiconductor layer, a first p-type semiconductor layer, and the first MQW structure is between the first n-type semiconductor layer and the first p-type semiconductor layer;

and the second semiconductor structure comprises a second n-type semiconductor layer, a second p-type semiconductor layer, and the second MQW structure is between the second n-type semiconductor layer and the second p-type semiconductor layer.

3. The light-emitting device of claim 1, further comprising a first top electrode formed on the first semiconductor structure, a bottom electrode formed on the carrier, and a third top electrode formed on the second semiconductor structure of the first semiconductor element, wherein the third top electrode and the bottom electrode form a main current path bypassing the second MQW structure during normal operation.

4. The light-emitting device of claim 3, wherein the third top electrode provides a series electrical connection between the first top electrode and the bottom electrode.

5. The light-emitting device of claim 1, wherein an electrical current flowing in series through the first MQW structure and the second MQW structure.

6. The light-emitting device of claim 3, wherein current flows through the first top electrode and the bottom electrode to forward bias the first MQW structure to emit the first light during normal operation.

7. The light-emitting device of claim 3, wherein the second MQW structure is permanently broken down to conduct current between the first top electrode and the bottom electrode during normal operation.

8. The light-emitting device of claim 1, further comprising a second semiconductor element formed on the carrier, wherein the first semiconductor element is physically spaced apart from the second semiconductor element.

9. The light-emitting device of claim 8, wherein the second semiconductor element comprises a third semiconductor structure, the third semiconductor structure comprises a third MQW structure having the same layer sequence and the same material composition as that of the second MQW structure of the first semiconductor element.

10. The light-emitting device of claim 9, wherein the first semiconductor element comprises a first top electrode, the second semiconductor element comprises a second top electrode, the first MQW structure emits the first light by conducting a first driving current between the carrier and the first top electrode, and the third MQW structure emits a second light having a second dominant wavelength by conducting a second driving current between the carrier and the second top electrode.

11. The light-emitting device of claim 10, wherein the first dominant wavelength is different from the second dominant wavelength.

12. The light-emitting device of claim 10, wherein the first light is infrared light and the second light is red light.

13. The light-emitting device of claim 1, wherein a first well layer in the first MQW structure comprises a composition or a composition ratio different from that of a second well layer in the second MQW structure.

14. The light-emitting device of claim 13, wherein the first well layer comprises In_xGa_yAl_1-x-yAs (0≦

x, y≦

1), the second well layer comprises In_aGa_bAl_1-a-bP (0≦

a, b≦

1).

15. The light-emitting device of claim 1, further comprising a tunnel junction formed between the first semiconductor structure and the second semiconductor structure.

16. The light-emitting device of claim 1, further comprising an etching stop layer formed between the first semiconductor structure and the second semiconductor structure.

17. The light-emitting device of claim 1, further comprising a distributed bragg reflector formed between the first semiconductor structure and the second semiconductor structure.

18. A method of manufacturing a light-emitting device, comprising:

providing a growth substrate;

growing a first semiconductor stack on the growth substrate;

growing a second semiconductor stack on the first semiconductor stack;

providing a carrier;

bonding the second semiconductor stack to the carrier, wherein the carrier comprises a first region and a second region next to the first region;

removing the first semiconductor stack over the second region of the carrier to expose the second semiconductor stack while retaining the first semiconductor stack over the first region of the carrier;

forming a groove by removing a portion of the second semiconductor stack to divide the second semiconductor stack into two separate parts;

forming a first top electrode on the first semiconductor stack over the first region of the carrier; and

forming a second top electrode on the second semiconductor stack over the second region of the carrier;

wherein the carrier is commonly electrically connected to the first top electrode and the second top electrode.

19. The method of claim 18, wherein the first semiconductor stack comprises a first MQW structure and the second semiconductor stack comprises a second MQW structure.

20. The method of claim 19, further comprising inactivating the second MQW structure on the first region of the carrier.

21. The method of claim 18, further comprising forming a bottom electrode such that the carrier is between the bottom electrode and the second semiconductor stack.

22. The method of claim 19, wherein the first MQW structure on the first region is forward bias to be luminous by electrically connecting the first MQW structure and the second MQW structure on the first region in series.

23. The method of claim 19, wherein the second MQW structure on the first region is breakdown to be non-luminous prior to forward bias the first MQW structure on the first region.