Vertical light emitting diode device structure

• US 7,615,789 B2
• Filed: 05/09/2006
• Issued: 11/10/2009
• Est. Priority Date: 05/09/2006
• Status: Active Grant

• Current Assignee: Lumens Co., Ltd.
• Original Assignee: Semileds Optoelectronics Company Limited (SemiLEDs Inc)
• Inventors: TRAN, ANH CHUONG
• Primary Examiner(s): Nguyen, Cuong Q
• Assistant Examiner(s): Tran, Trang Q
• Application Number:
  US11/382,392
• Publication Number:
  US 20070278506A1
• Time in Patent Office: 1,281 Days
• Field of Search: 257/79, 257/103, 257/98, 257/99, 257/100, 257/101, 257/102, 257/94, 257/E21.089, 257/E33.001, 257/E33.055, 438/21
• US Class Current: 257/79
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials

Abstract

A vertical light-emitting diode (VLED) structure that may impart increased luminous efficiency over conventional LEDs and VLEDs is described. As additional benefits, some embodiments may have less susceptibility to electrostatic discharge (ESD) and higher manufacturing yields than conventional devices. To accomplish these benefits, embodiment of the invention may utilize a spacer or other means to separate the p-doped layer from the active layer, thereby increasing the distance between the active layer and the reflective layer within the VLED structure.

Claims

1. A vertical light-emitting diode (VLED) structure comprising:

a metal layer;

a reflective layer disposed above the metal layer;

a p-doped layer disposed above the reflective layer;

a spacer disposed above the p-doped layer, wherein the spacer comprises a slightly Mg-doped chemical compound with n-type conduction characteristics;

an active layer disposed above the spacer; and

an n-doped layer disposed directly above the active layer, wherein the n-doped layer has an n-electrode for external connection.

2. The VLED structure of claim 1, wherein the chemical compound is a combination of aluminum (Al), gallium (Ga), indium (In), and nitrogen (N) with a ratio of Al_xGa_yIn_zN where 0≦

x, y, z≦

1.

3. The VLED structure of claim 1, wherein the spacer comprises multiple layers.

5. The VLED structure of claim 1, wherein the spacer has a thickness between 1 Å

and 10000 Å

.

6. The VLED structure of claim 1, wherein the p-doped layer has a thickness between 10 Å

and 10000 Å

.

7. The VLED structure of claim 1, wherein the p-doped layer comprises p-doped gallium nitride (p-GaN).

8. The VLED structure of claim 1, wherein the n-doped layer comprises n-doped gallium nitride (n-GaN).

9. The VLED structure of claim 1, wherein the metal layer comprises at least one of a metal and a metal alloy.

10. The VLED structure of claim 1, wherein the metal layer comprises multiple layers.

11. The VLED structure of claim 1, further comprising a p-electrode for external connection disposed below the metal layer.

4. A vertical light-emitting diode (VLED) structure comprising:

a metal layer;

a reflective layer disposed above the metal layer;

a p-doped layer disposed above the reflective layer;

a spacer disposed above the p-doped layer, wherein the spacer comprises an undoped or an n-doped compound, wherein the spacer comprises multiple undoped or n-doped layers, wherein the multiple layers comprise different materials;

an active layer disposed above the spacer; and

an n-doped layer disposed directly above the active layer, wherein the n-doped layer has an n-electrode for external connection.

12. A vertical light-emitting diode (VLED) structure comprising:

a housing for encapsulating at least a portion of the structure;

a metal layer having a p-electrode for external connection;

a reflective layer disposed above the metal layer;

a p-doped layer disposed above the reflective layer;

a spacer disposed above the p-doped layer, wherein the spacer comprises a slightly Mg-doped chemical compound with n-type conduction characteristics;

an active layer disposed above the spacer; and

an n-doped layer disposed directly above the active layer, wherein the n-doped layer has an n-electrode for external connection.

13. The VLED structure of claim 12, wherein the chemical compound comprises a combination of aluminum (Al), gallium (Ga), indium (In), and nitrogen (N) with a ratio of Al_xGa_yIn_zN where 0≦

x, y, z≦

1.

14. The VLED structure of claim 12, wherein the spacer comprises multiple layers.

16. The VLED structure of claim 12, wherein the spacer has a thickness between 1 Å

and 10000 Å

.

15. A vertical light-emitting diode (VLED) structure comprising:

a housing for encapsulating at least a portion of the structure;

a metal layer having a p-electrode for external connection;

a reflective layer disposed above the metal layer;

a p-doped layer disposed above the reflective layer;

a spacer disposed above the p-doped layer, wherein the spacer comprises an undoped or an n-doped compound, wherein the spacer comprises multiple undoped or n-doped layers, wherein the multiple layers comprise different materials;

an active layer disposed above the spacer; and

an n-doped layer disposed directly above the active layer, wherein the n-doped layer has an n-electrode for external connection.

17. A vertical light-emitting diode (VLED) structure comprising:

a metal layer;

a reflective layer disposed above the metal layer;

a p-doped layer disposed above the reflective layer;

an active layer disposed above the p-doped layer;

a means for separating the p-doped layer and the active layer, wherein the means for separating is a multilayered undoped or n-doped compound; and

an n-doped layer disposed directly above the active layer, wherein the n-doped layer has an n-electrode for external connection.

18. The VLED structure of claim 17, wherein the means for separating the p-doped layer and the active layer has a thickness between 1 Å

and 10000 Å

.