CN102255023A

CN102255023A - Light emitting diode (LED) and manufacturing method thereof

Info

Publication number: CN102255023A
Application number: CN2010101763007A
Authority: CN
Inventors: 沈佳辉; 洪梓健
Original assignee: Rongchuang Energy Technology Co ltd; Zhanjing Technology Shenzhen Co Ltd
Current assignee: Rongchuang Energy Technology Co ltd; Zhanjing Technology Shenzhen Co Ltd
Priority date: 2010-05-19
Filing date: 2010-05-19
Publication date: 2011-11-23

Abstract

The invention relates to a manufacturing method of a light emitting diode (LED). The manufacturing method comprises the following steps of: providing a substrate, wherein the substrate is provided with a first surface and a second surface opposite to the first surface; forming at least one luminous structure on the first surface of the substrate; grinding the second surface of the substrate to make the second surface of the substrate ground into an irregular rough surface; and forming a reflecting layer on the ground second surface of the substrate. The invention also relates to the LED.

Description

Light-emitting diode and manufacture method thereof

Technical field

The present invention relates to a kind of semiconductor structure, relate in particular to a kind of light-emitting diode and manufacture method thereof.

Background technology

Light-emitting diode (Light Emitting Diode, luminous efficiency LED), main relevant with light-emitting diode internal quantum (Internal Quantum Efficiency) and external quantum efficiency (ExternalQuantum Efficiency).The former depend on electron hole in the lumination of light emitting diode layer in conjunction with so that discharge the probability of photon.Then successfully to break away from the probability of light-emitting diode relevant with photon for the latter.

See also Fig. 1, a kind of light-emitting diode 50 that prior art provides comprises a substrate 51, a resilient coating 52, a n type semiconductor layer 53, a luminescent layer 54, a p type semiconductor layer 55, a transparency conducting layer 56, a N type electrode 57, a P type electrode 58 and a reflector 59.Described substrate 51 has a first surface 51a and one and described first surface opposing second surface 51b, and this first surface 51a and second surface 51b are smooth flat.Described resilient coating 52, n type semiconductor layer 53, luminescent layer 54, p type semiconductor layer 55 and transparency conducting layer 56 are formed on the first surface 51a of described substrate 51 successively.Described N type electrode 57 and P type electrode 58 are respectively formed on n type semiconductor layer 53 and the transparency conducting layer 56.Described reflector 59 is formed on the second surface 51b of described substrate 51.This reflector 59 can reflex to the light of luminescent layer 54 generations the direction of transparency conducting layer 56, thereby penetrates from transparency conducting layer 56 surfaces, increases the luminous efficiency of light-emitting diode 50.Yet for some light of being returned by total reflection at transparency conducting layer 56, because the second surface 51b of described substrate 51 is a smooth flat, these light still can be returned by total reflection at transparency conducting layer 56 after second surface 51b is reflected back toward transparency conducting layer 56.Finally, these light are most of can be absorbed by each layer in the light-emitting diode 50, and can't reach the purpose that increases luminous efficiency.

Summary of the invention

In view of this, be necessary to provide higher light-emitting diode of a kind of luminous efficiency and manufacture method thereof.

A kind of manufacturing method for LED may further comprise the steps: a substrate is provided, and this substrate has a first surface and one and described first surface opposing second surface; On the first surface of described substrate, form at least one ray structure; Grind the second surface of substrate, make the second surface of this substrate be worn into irregular matsurface; And on the second surface of the substrate after the described grinding, form the reflector.

A kind of light-emitting diode, it comprises substrate, ray structure and reflector.This substrate has a first surface and one and described first surface opposing second surface.Described ray structure is formed on the first surface of described substrate.The second surface of described substrate is an irregular matsurface, and described reflector is formed on the second surface of this substrate.

In the light-emitting diode that embodiment of the present invention provides,, can carry out scattering to the light that shines on it, thereby can improve the light extraction efficiency of whole light-emitting diode because the second surface of substrate is irregular matsurface.In the method for manufacturing light-emitting that embodiment of the present invention provides, because being ground the back by lapped face, substrate only need obtain a matsurface, need not further to polish, thereby can shorten milling time, reduce the light-emitting diode manufacturing cost.

Description of drawings

Fig. 1 is a kind of light emitting diode construction schematic diagram that prior art provides.

Fig. 2 is a kind of light emitting diode construction schematic diagram that embodiment of the present invention provides.

Fig. 3 is a kind of manufacturing method for LED flow chart that embodiment of the present invention provides.

Fig. 4 is each step schematic diagram of manufacturing method for LED of Fig. 3.

The main element symbol description

Light-

emitting diode

10,50

Substrate

11,21,51

Resilient coating

12,52

Ray structure 13

Reflector

14,59

Separator 15

N type semiconductor layer 53

P type semiconductor layer 55

N type electrode 57

P type electrode 58

First surface 111,211,51a

Second surface 112,212,51b

First semiconductor layer 131

Luminescent layer

132,54

Second semiconductor layer 133

Transparency conducting

layer

134,56

First electrode 135

Second electrode 136

Embodiment

Below with reference to the drawings, the present invention is described in further detail.

See also Fig. 2, a kind of light-emitting diode 10 that embodiment of the present invention provides comprises: substrate 11, resilient coating 12, ray structure 13 and reflector 14.

Described substrate 11 has a first surface 111 and one and described first surface 111 opposing second surface 112.Described second surface 112 is an irregular matsurface, and its surface roughness (Ra) is greater than 100A (angstrom).Described substrate 11 thickness can be between the 50-200 micron.Described substrate 11 can be selected from sapphire, zinc selenide, zinc oxide, carborundum, glass, gallium phosphide, gallium arsenide phosphide, zinc sulphide or selenium zinc sulphide etc.In the present embodiment, the thickness of substrate 11 is 100 microns.

Described resilient coating 12 is formed on the first surface 111 of described substrate 11, its role is to improve the of heap of stone brilliant quality of the luminescent layer 14 that subsequent growth comes out.In other embodiments, light-emitting diode 10 also can not comprise this resilient coating 12.

In the present embodiment, described ray structure 13 comprises: first semiconductor layer 131, luminescent layer 132, second semiconductor layer 133, transparency conducting layer 134, first electrode 135 and second electrode 136.The structure that is appreciated that described ray structure 13 should be not limited to present embodiment, as long as it can realize luminous.

Described first semiconductor layer 131, luminescent layer 132, second semiconductor layer 133 are formed on the described resilient coating 12 successively.This first semiconductor layer 131 is different doping type semiconductor layers with second semiconductor layer 133.In the present embodiment, this first semiconductor layer 131 Si that can mix forms N type nitride layer.But second semiconductor layer, 133 doped with Mg form P type nitride layer.Luminescent layer 132 is single heterojunction structure, double-heterostructure, single quantum well layer or multiple quantum trap layer structure.This nitride is aluminum indium nitride gallium (Al _xIn _yGa _1-x-yN), 0≤x≤1,0≤y≤1 wherein, x+y≤1.

Described first electrode 135 and second electrode 136 respectively with described first semiconductor layer 131 and second semiconductor layer, 133 electrical couplings.This first electrode 135 and second electrode 136 all can adopt metal material to make.

Described transparency conducting layer 134 is formed between described second semiconductor layer 133 and second electrode 136.Described transparency conducting layer 134 can be an including transparent conducting oxide layer, and its material can be indium oxide, tin oxide, indium oxide molybdenum, zinc oxide, indium zinc oxide, magnesium oxide zinc, tin indium oxide or nickel/gold etc.In other embodiments, light-emitting diode 10 also can not comprise this transparency conducting layer 134.

Described reflector 14 is formed on the second surface 112 of described substrate 11.Because the second surface 112 of described substrate 11 is an irregular matsurface, thereby can increase the bonded area and the adhesion in substrate 11 and reflector 14, make this reflector 14 be not easy to come off from substrate 11.The thickness in this reflector 14 is not limit, and its material can be selected from one or more the alloy in silver, aluminium, nickel, titanium, gold, the platinum.

Described light-emitting diode 10 also can comprise a separator 15.This separator 15 coats described ray structure 13, only exposes the upper surface of first electrode 135 and second electrode 136.The material of this separator 15 can be silicon dioxide.

In the light-emitting diode 10 that embodiment of the present invention provides,, can carry out scattering to the light that shines on it, thereby can improve the light extraction efficiency of whole light-emitting diode 10 because the second surface 112 of substrate 11 is irregular matsurface.

See also Fig. 3 and Fig. 4, embodiment of the present invention also provides a kind of manufacturing method for LED.This manufacturing method for LED may further comprise the steps:

Step 1 provides a substrate 21.This substrate 21 has a first surface 211 and one and described first surface 211 opposing second surface 212.The thickness of this substrate 21 generally should be greater than 350 microns, and in the present embodiment, the thickness of this substrate is 430 microns.This substrate 21 can be selected from sapphire, zinc selenide, zinc oxide, carborundum, glass, gallium phosphide, gallium arsenide phosphide, zinc sulphide or selenium zinc sulphide etc.

Step 2 forms at least one ray structure 13 on the first surface 211 of substrate 21.Be formed with two ray structures 13 on the first surface 211 of the substrate 21 among Fig. 4, be appreciated that, the quantity of the ray structure 13 that forms on the first surface 211 of substrate 21 is not limited to shown in Figure 4, the quantity of the ray structure 13 that forms on the first surface 211 of described substrate 21 can be according to actual conditions, as substrate 21 sizes etc., be provided with.In other embodiments, on substrate 21, form ray structure 13 before, can on substrate 21 described first surfaces 211, form as shown in Figure 2 resilient coating 12 earlier to improve the quality of follow-up crystalline substance of heap of stone.The concrete structure of described ray structure 13 has been done explanation before, so repeat no more.

Step 3 forms separator 15 to coat described ray structure 13.This step can determine whether to keep according to actual needs, if light-emitting diode does not comprise separator 15, then need not this step 3.Preferably, described manufacturing method for LED comprises step 3, to avoid in successive process ray structure 13 surfaces contaminated.

Step 4, the second surface 212 of grinding substrate 21, this substrate 21 of wear down also make the second surface 212 of this substrate 21 be worn into irregular matsurface.The surface roughness of described irregular matsurface (Ra) is greater than 100A.The thickness of the substrate 21 after the described grinding can be between the 50-200 micron.In the present embodiment, the thickness of the substrate 21 after the grinding is 100 microns.

Step 5 forms reflector 14 on the second surface 212 of the substrate after the described grinding 21.Described reflector 14 can be formed on the second surface 212 after the described grinding by methods such as evaporation, sputter or plating.

Step 6 is cut described substrate 21, obtains a plurality of light-emitting diodes.Be appreciated that if in step 2 only be formed with a ray structure 13 on the first surface 211 of substrate 21, then described manufacturing method for LED can not comprise step 6.

In the method for manufacturing light-emitting that embodiment of the present invention provides, because substrate 21 is by wear down, thereby can reduce the absorptivity of the light that 21 pairs of light-emitting diodes of substrate send, in addition, because being ground the back by lapped face, substrate 21 only need obtain a matsurface, need not further to polish, thereby can shorten milling time, reduce the light-emitting diode manufacturing cost.

Be understandable that, for the person of ordinary skill of the art, can make change and the distortion that other various pictures are answered by technical conceive according to the present invention, and all these change the protection range that all should belong to claim of the present invention with distortion.

Claims

1. manufacturing method for LED may further comprise the steps:

One substrate is provided, and this substrate has a first surface and one and described first surface opposing second surface;

On the first surface of described substrate, form at least one ray structure;

Grind the second surface of substrate, make the second surface of this substrate be worn into irregular matsurface; And on the second surface of the substrate after the described grinding, form the reflector.

2. manufacturing method for LED as claimed in claim 1 is characterized in that: the thickness of the substrate after the described grinding is between the 80-200 micron.

3. manufacturing method for LED as claimed in claim 1 is characterized in that: the surface roughness of described irregular matsurface (Ra) is greater than 100A.

4. manufacturing method for LED as claimed in claim 1, it is characterized in that: be formed with a plurality of ray structures on the first surface of described substrate, after forming the reflector, this manufacturing method for LED also comprises step: cut described substrate, obtain a plurality of light-emitting diodes.

5. manufacturing method for LED as claimed in claim 1 is characterized in that: before the second surface that grinds described substrate, this manufacturing method for LED also comprises step: form separator to coat described ray structure.

6. manufacturing method for LED as claimed in claim 1 is characterized in that: the material in described reflector is one or more the alloy in silver, aluminium, nickel, titanium, gold, the platinum.

7. light-emitting diode, it comprises substrate, ray structure and reflector, this substrate has a first surface and one and described first surface opposing second surface, described ray structure is formed on the first surface of described substrate, it is characterized in that: the second surface of described substrate is an irregular matsurface, and described reflector is formed on the second surface of this substrate.

8. light-emitting diode as claimed in claim 7 is characterized in that: the thickness of described substrate is between the 50-200 micron.

9. light-emitting diode as claimed in claim 7 is characterized in that: the surface roughness of the second surface of described substrate (Ra) is greater than 100A.

10. light-emitting diode as claimed in claim 7 is characterized in that: the material in described reflector is one or more the alloy in silver, aluminium, nickel, titanium, gold, the platinum.