CN105304780A

CN105304780A - P-GaN blue light LED epitaxy structure with high hole concentration

Info

Publication number: CN105304780A
Application number: CN201410285900.5A
Authority: CN
Inventors: 田宇; 余登永; 郑建钦; 曾欣尧; 童敬文; 吴东海; 李鹏飞
Original assignee: NANTONG TONGFANG SEMICONDUCTOR CO Ltd; Tongfang Co Ltd
Current assignee: NANTONG TONGFANG SEMICONDUCTOR CO Ltd; Tsinghua Tongfang Co Ltd; Tongfang Co Ltd
Priority date: 2014-06-25
Filing date: 2014-06-25
Publication date: 2016-02-03

Abstract

A P-GaN blue light LED epitaxy structure with a high hole concentration is disclosed, relating to field of a light-emitting diode epitaxy technology. The P-GaN blue light LED epitaxy structure comprises a sapphire substrate, an AlN buffering layer, a U type GaN layer, an N type GaN layer, an active region, an electronic barrier layer and a P type GaN layer from the bottom up in sequence; the P-GaN blue light LED epitaxy structure is characterized in that the P type GaN layer comprises an AlxGal-xN layer and an MgN-In layer that are alternatively growing from the bottom up in sequence; and a P-AIGaN layer is arranged above the MgN-In layer in the topmost layer. Compared with the prior art, the P-GaN blue light LED epitaxy structure has a higher barrier height and enables carriers to be more easily to jump to the active region, so that the hole concentration and the migration rate can be effectively improved, the crystalline quality is improved, and the LED luminance is improved consequently.

Description

A kind of P-GaN blue-ray LED epitaxial structure with high hole concentration

Technical field

The present invention relates to LED epitaxial technical field, particularly there is high hole concentration P-GaN blue-ray LED epitaxial structure.

Background technology

At present, along with LED industry develops fast, the demand of people to brightness is more and more higher.Determine LED luminance very more crucial be the Mg concentration, mobility, crystal mass etc. of P-GaN, a lot of experts and scholars, successively propose two one-step growth methods, P-AlGaN, high pressure growth etc. for P-GaN and improve the brightness that P-GaN improves LED.

In prior art, blue-ray LED epitaxial structure comprises Sapphire Substrate 1, AlN resilient coating 2, U-shaped GaN layer 3, N-type GaN layer 4, active area 5, electronic barrier layer 6 and P type GaN layer 7, as shown in Figure 1.But there is following shortcoming in the P-GaN layer 7 of said structure: first, and the relative concentration of P-GaN is lower; Secondly, its mobility is also lower; Again, in the barrier height of P-GaN lower than P-AlGaN, limit certain charge carrier and move; Finally, the crystal mass of P-GaN compares poor, has certain defect concentration.Therefore, P-GaN can affect the photoelectric characteristic of LED.

Summary of the invention

For above-mentioned the deficiencies in the prior art, the object of this invention is to provide one and there is high hole concentration P-GaN blue-ray LED epitaxial structure.It has higher barrier height, makes charge carrier more easily transit to active area, can effectively improve hole concentration and mobility, improve crystal mass, thus improves the brightness of LED.

In order to reach foregoing invention object, technical scheme of the present invention realizes as follows:

Have a P-GaN blue-ray LED epitaxial structure for high hole concentration, it comprises Sapphire Substrate, AlN resilient coating, U-shaped GaN layer, N-type GaN layer, active area, electronic barrier layer and P type GaN layer from bottom to up successively.Its design feature is, described P type GaN layer comprises AlxGa1-xN layer and the MgN-In layer of alternating growth from bottom to up successively, is equipped with P-AlGaN layer above the MgN-In layer being positioned at most top layer.

In above-mentioned blue-ray LED epitaxial structure, described AlxGa1-xN layer and MgN-In layer alternating growth cycle are 1-50 cycle, and the thickness of growth AlxGa1-xN layer is 10-1000 dust, and wherein Al component is 0<x<1.The thickness of growth MgN-In layer is 5-500 dust, and wherein In concentration is 5x10 ¹⁷~ 1x10 ²³cm ³.Growth P-AlGaN layer thickness is 5-500nm, and wherein, the doping content of Mg is 5x10 ¹⁷~ 1x10 ²³cm ³.

In above-mentioned blue-ray LED epitaxial structure, described P type GaN layer growth temperature is 800-1200 DEG C, and growth pressure is 75-1000mbar, grows in nitrogen, hydrogen or hydrogen nitrogen mixed gas environment.

In above-mentioned blue-ray LED epitaxial structure, described P type GaN layer adopt Pss substrate, flat substrate, non-polar substrate, Si substrate or SiC substrate any one.

In above-mentioned blue-ray LED epitaxial structure, described AlxGa1-xN layer adopt P-AlGaN layer, P-AlGaInN layer, AlGaInN layer, P-AlInN layer or AlInN layer any one.

P type GaN layer, owing to have employed said structure, is changed into the structure of AlxGa1-xN layer and MgN-In layer alternating growth by the present invention, because AlGaN material characteristic overallly can improve barrier height, although mobility decreases.But, have more carrier transition to active area, improve the efficiency of electronics and hole-recombination.Meanwhile, the present invention, by AlxGa1-xN layer and MgN-In layer alternating growth, can improve crystal mass, improve mobility, increase hole concentration, thus improve the light extraction efficiency of LED further.

Below in conjunction with the drawings and specific embodiments, the present invention will be further described.

Accompanying drawing explanation

Fig. 1 is LED epitaxial structure schematic diagram in prior art;

Fig. 2 is LED epitaxial structure schematic diagram in the present invention.

Embodiment

Referring to Fig. 2, of the present invention have high hole concentration P-GaN blue-ray LED epitaxial structure and comprise Sapphire Substrate 1, AlN resilient coating 2, U-shaped GaN layer 3, N-type GaN layer 4, active area 5, electronic barrier layer 6 and P type GaN layer 7 from bottom to up successively, and P type GaN layer 7 wherein comprises AlxGa1-xN layer 8, MgN-In layer 9 and P-AlGaN layer 10.

Embodiment one:

P type GaN layer 7 comprises AlxGa1-xN layer 8, MgN-In layer 9 and P-AlGaN layer 10, AlxGa1-xN layer 8 and MgN-In layer 9 alternating growth from bottom to up successively.AlxGa1-xN layer 8 and MgN-In layer 9 alternating growth cycle are 1-50 cycle, and the thickness of growth AlxGa1-xN layer 8 is 10 dusts, and wherein Al component is 0<x<1; The thickness of growth MgN-In layer 9 is 5 dusts, and In concentration is 5x10 ¹⁷cm ³; Growth P-AlGaN layer 10 thickness is 5nm, and wherein, the doping content of Mg is 5x10 ¹⁷cm ³.P type GaN layer 7 growth temperature is 800 DEG C, and growth pressure is 75mbar, grows in nitrogen, hydrogen or hydrogen nitrogen hybird environment.P type GaN layer 7 uses the substrates such as Pss substrate, flat substrate, non-polar substrate, Si substrate or SiC.AlxGa1-xN layer 8 also can be P-AlGaN layer, P-AlGaInN layer or AlGaInN layer, P-AlInN layer or AlInN layer etc.

Embodiment two:

With embodiment one unlike: the thickness growing AlxGa1-xN layer 8 is 500 dusts, and the thickness of growth MgN-In layer 9 is 200 dusts, and In concentration is 5x10 ²⁰cm ³, growth P-AlGaN layer 10 thickness is 300nm, and wherein, the doping content of Mg is 5x10 ¹⁹cm ³.P type GaN layer 7 growth temperature is 1000 DEG C, and growth pressure is 400mbar.

Embodiment three:

With embodiment one unlike: the thickness growing AlxGa1-xN layer 8 is 1000 dusts, and the thickness of growth MgN-In layer 9 is 500 dusts, and In concentration is 1x10 ²³cm ³, growth P-AlGaN layer 10 thickness is 500nm, and wherein, the doping content of Mg is 1x10 ²³cm ³.P type GaN layer 7 growth temperature is 1200 DEG C, and growth pressure is 1000mbar.

The foregoing is only three kinds of embodiments in embodiment of the present invention, but do not limit the present invention with this.All within the scope of technical solution of the present invention, the apparent technical schemes such as any amendment that those skilled in the art does, equivalent replacement, all should belong to the scope of protection of the invention.

Claims

1. one kind has the P-GaN blue-ray LED epitaxial structure of high hole concentration, it comprises Sapphire Substrate (1), AlN resilient coating (2), U-shaped GaN layer (3), N-type GaN layer (4), active area (5), electronic barrier layer (6) and P type GaN layer (7) from bottom to up successively, it is characterized in that: described P type GaN layer (7) comprises AlxGa1-xN layer (8) and the MgN-In layer (9) of alternating growth from bottom to up successively, MgN-In layer (9) top being positioned at most top layer is equipped with P-AlGaN layer (10).

2. the P-GaN blue-ray LED epitaxial structure with high hole concentration according to claim 1, it is characterized in that: described AlxGa1-xN layer (8) and MgN-In layer (9) alternating growth cycle are 1-50 cycle, the thickness of growth AlxGa1-xN layer (8) is 10-1000 dust, and wherein Al component is 0<x<1; The thickness of growth MgN-In layer (9) is 5-500 dust, and wherein In concentration is 5x10 ¹⁷~ 1x10 ²³cm ³; Growth P-AlGaN layer (10) thickness is 5-500nm, and wherein, the doping content of Mg is 5x1017 ~ 1x10 ²³cm ³.

3. the P-GaN blue-ray LED epitaxial structure with high hole concentration according to claim 1 and 2, it is characterized in that: described P type GaN layer (7) growth temperature is 800-1200 DEG C, growth pressure is 75-1000mbar, grows in nitrogen, hydrogen or hydrogen nitrogen mixed gas environment.

4. the P-GaN blue-ray LED epitaxial structure with high hole concentration according to claim 3, is characterized in that: described P type GaN layer (7) adopt Pss substrate, flat substrate, non-polar substrate, Si substrate or SiC substrate any one.

5. the P-GaN blue-ray LED epitaxial structure with high hole concentration according to claim 4, is characterized in that: described AlxGa1-xN layer (8) adopt P-AlGaN layer, P-AlGaInN layer, AlGaInN layer, P-AlInN layer or AlInN layer any one.