Nitride Light Emitting Diode Structure

Abstract

A nitride light-emitting diode (LED) structure includes a substrate, a buffer layer, an N-type layer, a stress release layer, a quantum well light-emitting layer and a P-type layer, wherein, between the N-type layer and the stress release layer, an electric field distribution layer is inserted, which is an n-doped multi-layer GaN structure with growth temperature equaling to or lower than that of the quantum well light-emitting layer; and GaN layers of different doping concentrations are applied to gradually reduce electric field concentration and make uniform spreading of current, thus enhancing electrostatic voltage endurance, reducing failure rate during usage, improving operational reliability and extending service life of the nitride semiconductor component.

Claims

1. A nitride light-emitting diode (LED), comprising: a substrate; a buffer layer; an N-type layer; a stress release layer; a quantum well light-emitting layer; and a P -type layer; wherein: between the N-type layer and the stress release layer, an electric field distribution layer is inserted; and the electric field distribution layer comprises a multi-layer GaN structure grown with a growth temperature equal to or lower than a growth temperature of the quantum well light-emitting layer.

2. The nitride LED of claim 1, wherein the electric field distribution layer has a number of n layers, where n>3.

3. The nitride LED of claim 1, wherein the electric field distribution layer is an n-type doped layer.

4. The nitride LED of claim 1, wherein the electric field distribution layer comprises a first GaN layer A with a doping concentration of 510.sup.18-110.sup.19/cm.sup.3.

5. The nitride LED of claim 1, wherein the electric field distribution layer comprises a second GaN layer B with a doping concentration of 110.sup.18-510.sup.18/cm.sup.3.

6. The nitride LED of claim 1, wherein the electric field distribution layer comprises a third GaN layer with a doping concentration of 110.sup.17-110.sup.18/cm.sup.3.

7. The nitride LED of claim 1, wherein the electric field distribution layer comprises at least one layer with an impurity concentration higher than an impurity concentration of the stress release layer.

8. The nitride LED of claim 1, wherein the electric field distribution layer is 50-800 thick.

9. The nitride LED of claim 1, wherein the growth temperature of the electric field distribution layer is 700 C.-900 C.

10. The nitride LED of claim 1, wherein the stress release layer is an InGaN or an InGaN/GaN super lattice structure.

11. A light-emitting system comprising a plurality of nitride light-emitting diodes (LEDs), each LED comprising: a substrate; a buffer layer; an N-type layer; a stress release layer; a quantum well light-emitting layer; and a P -type layer; wherein: between the N-type layer and the stress release layer, an electric field distribution layer is inserted; and the electric field distribution layer comprises a multi-layer GaN structure grown with a growth temperature equal to or lower than a growth temperature of the quantum well light-emitting layer.

12. The system of claim 11, wherein the electric field distribution layer has a number of n layers, where n>3.

13. The system of claim 11, wherein the electric field distribution layer is an n-type doped layer.

14. The system of claim 11, wherein the electric field distribution layer comprises a first GaN layer A with a doping concentration of 510.sup.18-110.sup.19/cm.sup.3.

15. The system of claim 11, wherein the electric field distribution layer comprises a second GaN layer B with a doping concentration of 110.sup.18-510.sup.18/cm.sup.3.

16. The system of claim 11, wherein the electric field distribution layer comprises a third GaN layer with a doping concentration of 110.sup.17-110.sup.18/cm.sup.3.

17. The system of claim 11, wherein the electric field distribution layer comprises at least one layer with an impurity concentration higher than an impurity concentration of the stress release layer.

18. The system of claim 11, wherein the electric field distribution layer is 50-800 thick.

19. The system of claim 11, wherein the growth temperature of the electric field distribution layer is 700 C.-900 C.

20. The system of claim 11, wherein the stress release layer is an InGaN or an InGaN/GaN super lattice structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are included to provide a further understanding of the disclosure and constitute a part of this specification, together with the embodiments, are therefore to be considered in all respects as illustrative and not restrictive. In addition, the drawings are merely illustrative, which are not drawn to scale.

[0019] FIG. 1 is a side view of a nitride light emitting diode structure according to Embodiment 1 of the present disclosure.

[0020] FIG. 2 is partial structural diagrams of a nitride light emitting diode structure according to some embodiments.

[0021] FIG. 3 illustrates a first variation of the LED structure illustrated in FIG. 2.

[0022] FIG. 4 illustrates a second variation of the LED structure illustrated in FIG. 2.

[0023] FIG. 5 illustrates a third variation of the LED structure illustrated in FIG. 2.

[0024] FIG. 6 illustrates a fourth variation of the LED structure illustrated in FIG. 2.

[0025] FIG. 7 illustrates a fifth variation of the LED structure illustrated in FIG. 2.

[0026] In the drawings: 1: substrate; 2: buffer layer; 3: N-type layer; 4: electric field distribution layer; 401: GaN layer A; 402: GaN layer B; 403: GaN layer C; 5: stress release layer; 6: quantum well light-emitting layer; 7: P-type layer.

DETAILED DESCRIPTION

[0027] The embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and embodiments.

Embodiment 1

[0028] Referring to FIGS. 1 and 2, some embodiments disclosed herein provide a nitride light emitting diode structure, comprising: a substrate 1, on which a buffer layer 2, an N-type layer 3, an electronic field distribution layer 4, a stress release layer 5, a quantum well light emitting layer 6 and a P-type layer 7 are formed in sequence, wherein, the substrate 1 is made of any one of Al.sub.2O.sub.3 monocrystal (sapphire), SiC (6HSiC or 4HSiC), Si, GaAs, GaN or a single crystalline oxide with lattice constant approximate to that of the nitride semiconductor layer; the buffer layer 2 is composed of Al.sub.1-x-yIn.sub.yGa.sub.xN, where OX<1, and O<Y<1; the N-type layer 3 is composed of Si-doped GaN, with growth temperature of 900 C.-1,100 C. and Si doping concentration higher than that of the electronic field distribution layer 4; the electronic field distribution layer 4 is an n-type GaN-doped structure having at least 3 layers (number of layers: n), in which, impurity concentration of at least one layer is higher than that of the stress release layer 5. In this embodiment, Si doping is preferred with thickness of 50 -800 , and growth temperature is 700 C.-900 C., equaling to or higher than that of the quantum well light emitting layer 6; the stress release layer 5 is an InGaN or InGaN/GaN super-lattice structure with doping concentration of 510.sup.17-110.sup.18/cm.sup.3, and growth temperature of 800 C.-900 C.; the quantum well light emitting layer 6 is alternatively formed by a Si-doped quantum barrier (n-GaN) layer and an In-doped quantum well (InGaN) layer under growth temperature of 800 C.-880 C. and with periods of 1-50; and the P -type layer 7 is 100-4,000 thick with compositions of Mg-doped GaN under growth temperature of 800 C.-1,000 C.

[0029] In this embodiment, the electronic field distribution layer 4 at least comprises a GaN layer A 401 with doping concentration of 510.sup.18-110.sup.19/cm.sup.3, a GaN layer B 402 with doping concentration of 110.sup.18-510.sup.18/cm.sup.3 and a GaN layer C 403 with doping concentration of 110.sup.17-110.sup.18/cm.sup.3, and these three GaN layers 401, 402 and 403 are stacked on the N-type layer 3 in descending order of doping concentration; as the electronic field distribution layer 4 comprises GaN layers in variety of doping concentrations, when a light emitting diode having this structure is applied with electronic field, the GaN layers with various doping concentrations can effectively scatter and buffer the electronic field to enhance electrostatic voltage endurance.

[0030] In addition, referring to FIGS. 3-7, variations of this embodiment is provided, wherein stacking sequence of three GaN layers 401, 402 and 403 of different doping concentrations on the N-type layer 3 can be adjusted flexible according to production requirements so that the electronic field is scattered and the LED component characteristics are enhanced. For example, FIG. 2 is partial structural diagrams of a nitride light emitting diode structure according to some embodiments, FIG. 3 illustrates a first variation of the LED structure illustrated in FIG. 2, FIG. 4 illustrates a second variation of the LED structure illustrated in FIG. 2, FIG. 5 illustrates a third variation of the LED structure illustrated in FIG. 2, FIG. 6 illustrates a fourth variation of the LED structure illustrated in FIG. 2, and FIG. 7 illustrates a fifth variation of the LED structure illustrated in FIG. 2.

[0031] All references referred to in the present disclosure are incorporated by reference in their entirety. Although specific embodiments have been described above in detail, the description is merely for purposes of illustration. It should be appreciated, therefore, that many aspects described above are not intended as required or essential elements unless explicitly stated otherwise. Various modifications of, and equivalent acts corresponding to, the disclosed aspects of the exemplary embodiments, in addition to those described above, can b e made by a person of ordinary skill in the art, having the benefit of the present disclosure, without departing from the spirit and scope of the disclosure defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures.