Micro-light-emitting diode

• US 9,105,813 B1
• Filed: 05/30/2014
• Issued: 08/11/2015
• Est. Priority Date: 05/30/2014
• Status: Active Grant

• Current Assignee: Mikro Mesa Technology Co., Ltd.
• Original Assignee: Mikro Mesa Technology Co., Ltd.
• Inventors: Chang, Pei-Yu
• Primary Examiner(s): Booth, Richard
• Application Number:
  US14/290,999
• Time in Patent Office: 438 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

A micro-light-emitting diode (micro-LED) includes a first type semiconductor layer, a second type semiconductor, a first dielectric layer, and a first electrode. The second type semiconductor layer is disposed on or above the first type semiconductor layer. The first dielectric layer is disposed on the second type semiconductor layer. The first dielectric layer has at least one opening therein to expose at least one part of the second type semiconductor layer. A first shortest distance between an edge of the opening of the first dielectric layer and a side surface of the second type semiconductor layer is greater than or equal to 1 μm. The first electrode is partially disposed on the first dielectric layer and is electrically coupled with the exposed part of the second type semiconductor layer through the opening of the first dielectric layer.

Claims

1. A micro-light-emitting diode (micro-LED), comprising:

a first type semiconductor layer;

a second type semiconductor layer disposed on or above the first type semiconductor layer;

a first dielectric layer disposed on the second type semiconductor layer, the first dielectric layer having at least one opening therein to expose at least one part of the second type semiconductor layer, wherein a first shortest distance between an edge of the opening of the first dielectric layer and a side surface of the second type semiconductor layer is greater than or equal to 1 μ

m; and

a first electrode partially disposed on the first dielectric layer and electrically coupled with the exposed part of the second type semiconductor layer through the opening of the first dielectric layer.

2. The micro-LED of claim 1, wherein a geometric weighted mean distance between the side surface of the opening of the first dielectric layer and the side surface of the second type semiconductor layer is greater than or equal to 1 μ

m.

3. The micro-LED of claim 1, wherein the first type semiconductor layer has a resistance ρ

₁ and a thickness t₁, the second type semiconductor layer has a resistance ρ

₂ and a thickness t₂, and

4. The micro-LED of claim 1, wherein the first type semiconductor layer is an n type semiconductor layer, and the second type semiconductor layer is a p type semiconductor layer.

5. The micro-LED of claim 1, wherein the current spreading length of the first type semiconductor layer is over 20 times greater than the current spreading length of the second type semiconductor layer.

6. The micro-LED of claim 1, further comprising:

a second dielectric layer disposed on the first type semiconductor layer, the second dielectric layer having at least one opening therein to expose at least one part of the first type semiconductor layer, wherein a second shortest distance between an edge of the opening of the second dielectric layer and a side surface of the first type semiconductor layer is greater than or equal to 1 μ

m; and

a second electrode partially disposed on the second dielectric layer and electrically coupled with the exposed part of the first type semiconductor layer through the opening of the second dielectric layer.

7. The micro-LED of claim 1, wherein the first type semiconductor layer has a resistance ρ

₁ and a thickness t₁, the second type semiconductor layer has a resistance ρ

₂ and a thickness t₂, and

8. The micro-LED of claim 1, wherein the first type semiconductor layer is a p type semiconductor layer, and the second type semiconductor layer is an n type semiconductor layer.

9. The micro-LED of claim 1, wherein the number of the opening of the first dielectric layer is in a range from 1 to 1000.

10. The micro-LED of claim 1, wherein the area of the opening of the first dielectric layer viewed in a direction normal to the first dielectric layer occupies 2.5%-90% of the total area of the first dielectric layer viewed in the direction normal to the first dielectric layer.

11. The micro-LED of claim 1, wherein the first dielectric layer partially covers a major surface of the second type semiconductor layer distal to the first type semiconductor layer.

12. The micro-LED of claim 11, wherein the first dielectric layer at least partially covers the side surface of the second type semiconductor layer.

13. The micro-LED of claim 12, further comprising:

an active layer disposed between the first type semiconductor layer and the second type semiconductor layer, wherein the first dielectric layer at least partially covers a side surface of the active layer.

14. The micro-LED of claim 13, wherein the first dielectric layer at least partially covers a side surface of the first type semiconductor layer.

15. The micro-LED of claim 1, further comprising:

a second electrode at least partially disposed on the first type semiconductor layer, such that at least the first type semiconductor layer and the second type semiconductor layer are disposed between the first electrode and the second electrode.

16. The micro-LED of claim 1, further comprising:

an active layer disposed between the first type semiconductor layer and the second type semiconductor layer, wherein a combination of the first type semiconductor layer, the active layer, the second type semiconductor layer, and the first dielectric layer with the opening is a solid with at least two planes.

17. The micro-LED of claim 16, wherein the combination of the first type semiconductor layer, the active layer, the second type semiconductor layer, and the first dielectric layer with the opening is a cylinder, a polyhedron, or a trapezoidal solid.

18. The micro-LED of claim 1, wherein the number of the opening of the first dielectric layer is one, two, or three.

19. The micro-LED of claim 1, wherein a plurality of the openings of the first dielectric layer have the same shape.

20. The micro-LED of claim 1, wherein a plurality of the openings of the dielectric layer have different shapes.