CN104078545A

CN104078545A - Light emitting diode and manufacturing method thereof

Info

Publication number: CN104078545A
Application number: CN201310101615.9A
Authority: CN
Inventors: 赖志成
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2013-03-27
Filing date: 2013-03-27
Publication date: 2014-10-01

Abstract

The invention provides a light emitting diode which comprises a substrate, a first electrode and a second electrode, wherein a first semiconductor layer, an active layer and a second semiconductor layer are sequentially laminated on a surface of the substrate; the first semiconductor layer is close to the substrate; the first electrode is electrically connected with the first semiconductor layer; the second electrode is electrically connected with the second semiconductor layer; and a plurality of nanoscale holes are formed at a combining part between the surface of the substrate and the first semiconductor layer. The nanoscale holes are formed at the combining part between the substrate and the first semiconductor layer and can exert a scattering effect, and when partial light rays generated in the active layer are incident to the nanoscale holes at large angles, the nanoscale holes can change motion directions of the light rays and effectively reduce total reflection of light, so that the light extraction efficiency of the light emitting diode can be improved. The invention further provides a method for manufacturing the light emitting diode.

Description

Light-emitting diode and manufacture method thereof

Technical field

The present invention relates to a kind of light-emitting diode and manufacture method thereof.

Background technology

The blue light of being made by semi-conducting materials such as gallium nitride, green glow and white light emitting diode have the distinguishing features such as long, energy-conservation, environmental protection of life-span, be widely used in the fields such as large-sized solor demonstration, automotive lighting, traffic signals, multimedia display and optical communication, particularly at lighting field, there is wide development potentiality.

Existing light-emitting diode generally include n type semiconductor layer, p type semiconductor layer and be arranged on n type semiconductor layer and p type semiconductor layer between active layer.When light-emitting diode is in running order, on p type semiconductor layer and n type semiconductor layer, apply respectively positive and negative voltage, like this, be present in hole in p type semiconductor layer and be present in electronics in n type semiconductor layer and in active layer, occur compound and produce light and penetrate from light-emitting diode.

Yet, the light extraction efficiency of existing light-emitting diode (light extraction efficiency typically refers to the efficiency that the light that produces in active layer discharges from light-emitting diode inside) is lower, its main cause is due to semi-conductive refractive index, to be greater than the refractive index of air, in the interface of semiconductor and air, there is total reflection in the wide-angle light from active layer, thereby most of wide-angle light is limited in the inside of light-emitting diode, until absorbed completely by the material in light-emitting diode.

Summary of the invention

In view of this, be necessary the light-emitting diode and the manufacture method thereof that provide a kind of smooth extraction efficiency higher.

A light-emitting diode, it comprises: a substrate; One first semiconductor layer, an active layer and one second semiconductor layer are cascadingly set on a surface of this substrate, and described the first semiconductor layer arranges near this substrate; One first electrode is electrically connected to described the first semiconductor layer; One second electrode is electrically connected to described the second semiconductor layer; Described substrate surface is being offered a plurality of nano level holes with the first semiconductor layer place of combining.

A method for manufacturing light-emitting, it comprises step: the first step, a substrate is provided, on this substrate, form one deck mask, make this mask cover this substrate; Second step, this mask of pattern etched, this mask forms a plurality of nanoscale holes that run through this mask after etching, exposes the substrate that is positioned at mask below with part; The 3rd step, the substrate surface that pattern etched is not covered by mask, this substrate surface forms a plurality of nanoscale holes after etching; The 4th step, removes this mask; The 5th step, epitaxial growth one first semiconductor layer, an active layer and one second semiconductor layer successively on this substrate surface; The 6th step, forms one first electrode on the surface of the first semiconductor layer, on the surface of the second semiconductor layer, forms one second electrode.

Compared with prior art, in light-emitting diode of the present invention, substrate is being offered a plurality of nano level holes with the first semiconductor layer place of combining, the plurality of nano level hole can play the effect of scattering, when the part light producing in active layer incides the plurality of nano level hole with wide-angle, the plurality of nano level hole can change the direction of motion of light, effectively reduces the total reflection of light, thereby can improve the light extraction efficiency of described light-emitting diode.

With reference to the accompanying drawings, in conjunction with embodiment, the invention will be further described.

Accompanying drawing explanation

The schematic diagram of the manufacture method of the light-emitting diode that Fig. 1 to Fig. 9 provides for one embodiment of the invention.

Main element symbol description

Light-emitting diode	100
		Substrate	10
Mask	20
		Hole	22、32
Scattering layer	30
		Resilient coating	40
The first semiconductor layer	50
		Active layer	60
The second semiconductor layer	70
		The first electrode	52
The second electrode	72
		Substrate	80
Weld pad	82

Following embodiment further illustrates the present invention in connection with above-mentioned accompanying drawing.

Embodiment

Please refer to shown in Fig. 1 to Fig. 9, the manufacture method of a kind of light-emitting diode 100 that one embodiment of the invention provides, it comprises the following steps:

The first step, provides a substrate 10, on this substrate 10, forms one deck mask 20, makes this mask 20 cover this substrate 10(and please refer to Fig. 1).

In the present embodiment, the material of this substrate 10 is sapphires, and the material of this mask 20 is polysilicon (polysilicon).This mask 20 is by adopting the method for chemical vapor deposition (CVD) to be grown in the upper surface of this substrate 10, and the thickness that forms mask 20 is 2 microns.

Second step, this mask 20 of pattern etched, this mask 20 forms a plurality of nano level holes 22 that run through this mask 20 after etching, exposes the substrate 10(that is positioned at mask 20 belows please refer to Fig. 2 with part).

In the present embodiment, this step adopts this mask 20 of mixing material etching of hydrofluoric acid and nitric acid, time is 10 ~ 60 minutes, on mask 20 after etching, form patterned structures, so-called " patterned structures " refers to that it is nano level hole 22 that mask 20 forms a plurality of apertures of running through this mask 20 after etching, and this nanoscale hole 22 is randomness disorder distribution on mask 20.The pore size of this nanoscale hole 22 is 20 ~ 200 nanometers.

The 3rd step, substrate 10 surfaces that pattern etched is not covered by mask 20, these substrate 10 surfaces form a plurality of nanoscale hole 32(and please refer to Fig. 3 after etching).

In the present embodiment, this step is that substrate 10 and mask 20 are placed in an induction coupled plasma system, boron chloride (BCl3) and chlorine (Cl2) the nano level hole 22 as etching gas along mask 20 of take infiltrates substrate 10 surfaces that etching is not covered by mask 20, these substrate 10 surfaces form shown in some nanoscale hole 32(Fig. 5 of institute that are random disorder distribution after etching, Fig. 5 is the vertical view of Fig. 4), these substrate 10 upper skims that run through by the plurality of nanoscale hole 32 in surface form a scattering layer 30.The pore size of this nanoscale hole 32 is 20 ~ 200 nanometers.

The 4th step, removes mask 20(and please refer to Fig. 4).

In the present embodiment, this mask 20 is by adopting the etching of potassium hydroxide (KOH) solution to remove.

The 5th step, is formed with at this substrate 10 that on the surface of a plurality of nanoscale holes 32, epitaxial growth one resilient coating 40, one first semiconductor layer 50, an active layer 60 and one second semiconductor layer 70(please refer to Fig. 6 successively).

Described resilient coating 40, the first semiconductor layer 50, active layer 60, the second semiconductor layer 70 form the active layer of light-emitting diode.The first semiconductor layer 50 arranges near substrate 10, and the second semiconductor layer 70 arranges away from substrate 10.

Described the first semiconductor layer 50 can be n type semiconductor layer or p type semiconductor layer, and described the second semiconductor layer 70 can be n type semiconductor layer or p type semiconductor layer, and described the first semiconductor layer 50 and the second semiconductor layer 70 adhere to two kinds of dissimilar semiconductor layers separately.In the present embodiment, the n type gallium nitride that the material of the first semiconductor layer 50 is silicon doping, the material of the second semiconductor layer 70 is the P type gallium nitride of magnesium doping.

Because the first semiconductor layer 50 has different lattice constants from substrate 10, therefore resilient coating 40 is set between the first semiconductor layer 50 and substrate 10 for reducing the lattice mismatch of the first semiconductor layer 50 growth courses, reduces the dislocation density of the first semiconductor layer 50 of growth.In the present embodiment, the material of this resilient coating 40 is gallium nitride, and its thickness is 80 ~ 150 nanometers.

Described active layer 60 is the quantum well structure that comprises one or more layers quantum well layer.In the present embodiment, the material of described active layer 60 is InGaN.

The 6th step, the subregion of this active layer 60 of etching and the second semiconductor layer 70 please refer to Fig. 7 with expose portion the first semiconductor layer 50().

In the present embodiment, adopt the subregion of gold-tinted micro-photographing process this active layer 60 of etching and the second semiconductor layer 70 with expose portion the first semiconductor layer 50.

The 7th step, forms one first electrode 52 on the surface of the first semiconductor layer 50, forms one second electrode 72(please refer to Fig. 8 on the surface of the second semiconductor layer 70).

The 8th step, provides a substrate 80, forms at intervals two weld pads 82 on this substrate 80, and by two weld pads 82 on substrate 80, corresponding and the first electrode 52 and the second electrode 72 welding, please refer to Fig. 9 from being shaped as described light-emitting diode 100().

As shown in Figure 9, for the light-emitting diode 100 that adopts above-mentioned manufacture method to obtain, it comprises a substrate 10, a scattering layer 30, a resilient coating 40, one first semiconductor layer 50, an active layer 60, one second semiconductor layer 70, one first electrode 52, one second electrode 72, two weld pads 82 and a substrate 80.Described scattering layer 30, resilient coating 40, the first semiconductor layer 50, active layer 60 and the second semiconductor layer 70 are cascadingly set on a side of described substrate 10.Described resilient coating 40, the first semiconductor layer 50, active layer 60, the second semiconductor layer 70 form the active layer of light-emitting diode 100.Described the first semiconductor layer 50 arranges near substrate 10.Described scattering layer 30 is arranged between substrate 10 and the first semiconductor layer 50.Scattering layer 30 is offered a plurality of nanoscale holes 32 that are random disorder distribution that run through this scattering layer 30.Described the first electrode 52 is electrically connected to described the first semiconductor layer 50, and described the second electrode 72 is electrically connected to described the second semiconductor layer 70.

In the present invention, on the surface that described substrate 10 contacts with the first semiconductor layer 50, offer a plurality of nano level holes 32, the plurality of nano level hole 32 can play the effect of scattering, when the part light producing in active layer 60 incides the plurality of nano level hole 32 with wide-angle, the plurality of nano level hole 32 can change the direction of motion of light, effectively reduce the total reflection of light, thereby can improve the light extraction efficiency of described light-emitting diode 100.

Be understandable that, for the person of ordinary skill of the art, can make other various corresponding changes and distortion by technical conceive according to the present invention, and all these change and distortion all should belong to the protection range of the claims in the present invention.

Claims

1. a light-emitting diode, it comprises:

Substrate;

The first semiconductor layer, active layer and the second semiconductor layer are cascadingly set on a surface of this substrate, and described the first semiconductor layer arranges near this substrate;

The first electrode being electrically connected to described the first semiconductor layer; And

The second electrode being electrically connected to described the second semiconductor layer;

It is characterized in that: on the surface that described substrate contacts with the first semiconductor layer, be formed with a plurality of nano level holes.

2. light-emitting diode as claimed in claim 1, is characterized in that: the lip-deep nano level hole of this substrate is randomness disorder distribution.

3. light-emitting diode as claimed in claim 1, is characterized in that: the pore size of the lip-deep nano level hole of this substrate is 20 ~ 200 nanometers.

4. light-emitting diode as claimed in claim 1, is characterized in that: described light-emitting diode also comprises substrate, forms at intervals two weld pads on this substrate, this two weld pads correspondence and the first electrode and the second electrode welding.

5. a method for manufacturing light-emitting, it comprises the following steps:

The first step, provides a substrate, forms one deck mask on this substrate, makes this mask cover this substrate;

Second step, this mask of pattern etched, this mask forms a plurality of nanoscale holes that run through this mask after etching, exposes the substrate that is positioned at mask below with part;

The 3rd step, the substrate surface that pattern etched is not covered by mask, this substrate surface forms a plurality of nanoscale holes after etching;

The 4th step, removes this mask;

The 5th step, is formed with on the surface of a plurality of nanoscale holes epitaxial growth one first semiconductor layer, an active layer and one second semiconductor layer successively at this substrate; And

The 6th step, forms one first electrode on the surface of the first semiconductor layer, on the surface of the second semiconductor layer, forms one second electrode.

6. method for manufacturing light-emitting as claimed in claim 5, is characterized in that: described mask is by adopting the method for chemical vapour deposition (CVD) to be grown in the upper surface of this substrate.

7. method for manufacturing light-emitting as claimed in claim 5, is characterized in that: this mask of mixing material etching of described second step employing hydrofluoric acid and nitric acid 10 ~ 60 minutes.

8. method for manufacturing light-emitting as claimed in claim 5, is characterized in that: the nanoscale hole of this mask is random disorder distribution, and the pore size of the nanoscale hole of this mask is 20 ~ 200 nanometers.

9. method for manufacturing light-emitting as claimed in claim 5, is characterized in that: the nanoscale hole on this substrate surface is random disorder distribution, and the pore size of the nanoscale hole on this substrate surface is 20 ~ 200 nanometers.

10. method for manufacturing light-emitting as claimed in claim 5, it is characterized in that: described the 3rd step is that substrate and mask are placed in an induction coupled plasma system, the substrate surface that boron chloride and the chlorine nano level hole as etching gas along mask of take infiltrates etching not covered by mask.