Systems and methods for producing light emitting diode array

• US 20060154390A1
• Filed: 01/11/2005
• Published: 07/13/2006
• Est. Priority Date: 01/11/2005
• Status: Active Grant

• Current Assignee: Foshan Nationstar Semiconductor Co., Ltd. (Foshan Nationstar Optoelectronics Company Limited)
• Original Assignee: SemiLEDs Corporation (SemiLEDs Inc)
• Inventors: Tran, Chuong Anh, Doan, Trung Tri
• Granted Patent: US 7,378,288 B2
• Time in Patent Office: Days
• US Class Current: 438/22
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination

Abstract

Systems and methods are disclosed for producing vertical LED array on a metal substrate; evaluating said array of LEDs for defects; destroying one or more defective LEDs; forming good LEDs only LED array suitable for wafer level package.

Claims

1. A method for producing known good LEDs LED array, comprising:

forming LEDs on a metal substrate;

evaluating said LEDs for defects including optical and electrical non-functionality compared to preset criteria;

removing one or more defective LEDs and leaving good LEDs on the metal substrate.

2. The method of claim 1, wherein the removing comprises vaporizing a defective LED structure using laser to elevate the temperature of the LED to higher than the evaporation temperature.

3. The method of claim 1, wherein the removing of one or more defective LEDs comprises applying a laser beam along the kerfs of defective LEDs and cutting through the metal substrate.

4. The method of claim 1, wherein the evaluating process comprises performing optical and electrical functionality on testing each of said plurality of LED to identify a satisfactorily non-defective LED array.

5. The method of claim 1, comprising packaging an array of nondefective LEDs at wafer level.

6. The method of claim 1, wherein the multi layer epitaxial structure comprises:

an n-type layer made from one of;

GaN and AlGaN,

one or more quantum wells with InAlGaN/GaN layers, and

an p-type layer made from one of;

GaN and AlGaN.

7. The method of claim 1, wherein the one or more metal layers above the multi layer epitaxial structure comprises one of:

Indium Tin Oxide (ITO), Silver, Al, Cr, Pt, Ni, Au, Mo, W, a refractory metal, a metal alloy thereof.

8. A method for producing known good LED array, comprising:

forming an array of LEDs on a metal substrate;

evaluating said array of LEDs for defects for optical and electrical non-functionality compared to a preset criteria; and

removing one or more defective LEDs from the metal substrate.

9. The method of claim 8, wherein the removing process comprises vaporizing a defective LED structure using laser to elevate the temperature of the LED to higher than the evaporation temperature.

10. The method of claim 8, wherein the removing of one or more defective LEDs comprises applying a laser beam along the kerfs of defective LEDs and cutting through the metal substrate.

11. The method of claim 8, the evaluating process comprises performing optical and electrical functionality on testing each of said plurality of LED to identify a satisfactorily nondefective LED array.

12. The method of claim 8, comprising packaging a nondefective LED array at wafer level.

13. The method of claim 8, wherein the multi layer epitaxial structure comprises:

an n-type layer made from one of;

GaN and AlGaN,

one or more quantum wells with InAlGaN/GaN layers, and

an p-type layer made from one of;

GaN and AlGaN.

14. The method of claim 8, wherein the one or more metal layers above the multi layer epitaxial structure comprises one of:

Indium Tin Oxide (ITO), Silver, Al, Cr, Pt, Ni, Au, Mo, W, a refractory metal, a metal alloy thereof.

20. The method of claim 8, the metal substrate comprises depositing Copper using one of:

electro plating, electroless plating.

15. A method of manufacturing vertical LED array on metal substrate, comprising:

providing a carrier substrate;

depositing a n-GaN portion above the carrier substrate;

depositing active layers above the n-GaN portion;

depositing a p-GaN portion above the active layers;

depositing one or more metal layers applying a masking layer;

etching the metal, p-GaN layer, active layers and n-GaN layer,

removing the masking layer;

depositing a passivation layer;

removing portion of the passivation layer on top of the p-GaN to expose the metal;

depositing one or more metal layers;

depositing a metal substrate;

removing the carrier substrate to expose the n-GaN surface;

evaluating each LED sites for defect using mapping;

removing one or more defective LEDs.

16. The method of claim 15, wherein the removing process comprises vaporizing a defective LED structure using laser to elevate the temperature of the LED to higher than the evaporation temperature.

17. The method of claim 15, wherein the removing of one or more defective LEDs comprises applying a laser beam along the kerfs of defective LEDs and cutting thru the metal substrate.

18. The method of claim 15, wherein the removing of one or more defective LEDs comprises using a saw blade to cut along the kerfs of defective LEDs and cutting through the metal substrate.

19. The method of claim 15, metal substrate comprises using one of:

copper, nickel, silver, platinum, aluminum, Mo, tungsten.