LIGHT EMITTING DIODE STRUTURE

• US 20120025237A1
• Filed: 11/08/2010
• Published: 02/02/2012
• Est. Priority Date: 08/02/2010
• Status: Active Grant

• Current Assignee: Foxsemicon Integrated Technology Incorporated
• Original Assignee: Foxsemicon Integrated Technology Incorporated
• Inventors: LAI, CHIH-MING
• Granted Patent: US 8,513,690 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

A light emitting diode structure includes an electrically conductive substrate, a first lighting structure having a first n-type semiconductor layer, a first active layer and a first p-type semiconductor layer and a second lighting structure having a second n-type semiconductor layer, a second active layer and a second p-type semiconductor layer. The first n-type semiconductor layer is electrically connected with the second p-type semiconductor layer and the first p-type semiconductor layer is electrically connected with the second n-type semiconductor layer. A first transparent, conductive layer is formed on the first lighting structure and a second transparent, conductive layer is formed on the second lighting structure. The first transparent, conductive layer and the second transparent, conductive layer are connected together to combine the first lighting structure with the second lighting structure.

Claims

1. A light emitting diode structure comprising:

an electrically conductive substrate;

a first lighting structure formed on the electrically conductive substrate, the first lighting structure including a first n-type semiconductor layer, a first active layer and a first p-type semiconductor layer;

a second lighting structure formed on the first lighting structure, the second lighting structure including a second n-type semiconductor layer, a second active layer and a second p-type semiconductor layer, the second n-type semiconductor layer being electrically connected with the first p-type semiconductor layer and the second p-type semiconductor layer being electrically connected with the first n-type semiconductor layer;

a first transparent, conductive layer formed on the first lighting structure; and

a second transparent, conductive layer formed on the second lighting structure, wherein the first transparent, conductive layer and the second transparent, conductive layer being connected together to combine the first lighting structure with the second lighting structure.

2. The light emitting diode structure of claim 1, wherein the first transparent, conductive layer and the second transparent, conductive layer are connected together by conductive adhesive.

3. The light emitting diode structure of claim 1, wherein the first transparent, conductive layer and the second transparent, conductive layer are connected together by wafer bonding.

4. The light emitting diode structure of claim 1, wherein a wavelength of the light emitted by the first active layer is greater than that of the light emitted by the second active layer.

5. The light emitting diode structure of claim 1, wherein a thickness of each of the first lighting structure and the second lighting structure is less than or equal to 3 μ

m.

6. The light emitting diode structure of claim 1, wherein the first transparent, conductive layer is selected from the group consisting of ITO film, ZnO film doped with Ga, Al or In, mixture of In₂O₃ and SnO₂, mixture of ZnO and Ga₂O₃, mixture of ZnO and Al₂O₃ and mixture of ZnO and In₂O₃.

7. The light emitting diode structure of claim 1, wherein the second transparent, conductive layer is selected from the group consisting of ITO film, ZnO film doped with Ga, Al or In, mixture of In₂O₃ and SnO₂, mixture of ZnO and Ga₂O₃, mixture of ZnO and Al₂O₃ and mixture of ZnO and In₂O₃.

8. The light emitting diode structure of claim 1 further comprising a third transparent, conductive layer formed on a top surface of the second lighting structure away from the second transparent, conductive layer.

9. The light emitting diode structure of claim 8 further comprising a first electrode pad formed on a top surface of the third transparent, conductive layer and a second electrode pad formed on the first transparent, conductive layer, wherein the first electrode pad is electrically connected with the electrically conductive substrate.

10. The light emitting diode structure of claim 1, wherein a material of the electrically conductive layer is selected from the group consisting of copper, tungsten, molybdenum, nickel, aluminum, gold and an alloy thereof.

11. The light emitting diode structure of claim 1 further comprising a light conversion layer formed on the surface of the first lighting structure and the second lighting structure.

12. The light emitting diode structure of claim 11, wherein a material of the light conversion layer is selected from the group consisting of sulfides, nitrides, oxides, silicates and aluminates.

13. The light emitting diode structure of claim 12, wherein of the light conversion layer contains one or more of following materials:

Ca₂Al₁₂O₁₉;

Mn, Y₃Al₅O₁₂;

Ce³⁺, Tb₃Al₅O₁₂;

Ce³⁺, Ca₂Si₅N₈;

Eu²⁺, BaMgAl₁₀O₁₇;

Eu²⁺, Ca_aSr_bBa_(1-a-b)S;

Eu²⁺, (Mg_aCa_bSr_cBa_(1-a-b-c))₂SiO₄;

Eu²⁺, (Mg_aCa_bSr_cBa_(1-a-b-c))₃Si₂O₇;

EU²⁺, Ca₈Mg(SiO₄)₄Cl₂;

EU²⁺, (Ca_aSr_bBa_(1-a-b)Al₂O₄;

Eu²⁺, (Ca_aSr_bBa_(1-a-b))Si_xO_yN_z;

Eu²⁺, Y₂O₂S;

EU³⁺, (Ca_aMg_bY_(1-a-b))Si_xAl_wO_yN_z;

Eu²⁺, CdS, CdTe and CdSe.

14. The light emitting diode structure of claim 1 further comprising an optical adjusting layer formed between the first active layer and the second active layer, light emitted from the first active layer to the second lighting structure passing through the optical adjusting layer and emitting to an environment through the second lighting structure, and light emitted from the second active layer to the first lighting structure being reflected by the optical adjusting layer and emitting to the environment through the second lighting structure.

15. The light emitting diode structure of claim 14, wherein the optical adjusting layer comprises a plurality of first layers and second layers, the first and second layers have different refraction coefficients, the first and second layers are alternately stacked between the first active layer and the second active layer, and a thickness of each of the first and second layers is one fourth of the wavelength of the light emitted from the second active layer.

16. The light emitting diode structure of claim 14, wherein the optical adjusting layer comprises a plurality of grooves formed on the second n-type semiconductor layer of the second lighting structure, and the grooves are adjacent to the second transparent, conductive layer.

17. The light emitting diode structure of claim 16, wherein a cross section of each of the grooves is triangle.