Background technology
Semiconductor lighting is as new and effective solid light source, there is the remarkable advantages such as life-span length, energy-saving and environmental protection, safety, by the leap again becoming the mankind and throw light in history after incandescent lamp, fluorescent lamp, its application expands rapidly, just driving the upgrading of the industry such as traditional lighting, display, its economic benefit and social benefit huge.Just because of this, semiconductor lighting is generally regarded as one of new industry that 21 century is most with prospects, is also one of most important commanding elevation of the optoelectronic areas coming years.LED is by three four compounds, as GaAs(GaAs), GaP(gallium phosphide), GaAsP(gallium arsenide phosphide) etc. semiconductor make, its core is PN junction.Therefore it has the I-N characteristic of general P-N junction, i.e. forward conduction, oppositely cut-off, breakdown characteristics.In addition, under certain condition, it also has the characteristics of luminescence.Under forward voltage, electronics injects P district by N district, and N district is injected by P district in hole.Minority carrier (few son) part entering the other side region and majority carrier (how son) compound and luminous.
The early stage product luminous efficiency of LED illumination light source is low, and light intensity generally can only reach several to dozens of mcd, is useful in indoor scenarios, applies in household electrical appliances, instrument and meter, communication apparatus, microcomputer and toy etc.Directly target is that LED light source substitutes incandescent lamp and fluorescent lamp at present, and this alternative trend develops from topical application field.
Along with the development of semiconductor illumination technique, GaN base light-emitting diode demonstrates the advantage of its uniqueness gradually, the light emission rate how improving GaN base LED is one of problem of being concerned about most of current people, because the light extraction efficiency of GaN base LED is limited by refringence huge between GaN and air, according to snell law, light is from GaN(n ≈ 2.5) be about 23 ° to the critical angle of air (n=1.0), only can shine in air at the light of incidence angle within critical angle, and light beyond critical angle can only at the inner roundtrip of GaN, until by self-absorption.
Fig. 1 is traditional quadrangle chip light-emitting design sketch, traditional light-emitting diode, when the shooting angle of chip is greater than 23.5 °, when being less than 66.5 °, the light of chip will only be confined to the inside roundtrip of chip, photon can not be escaped out chip exterior, and that causes chip goes out light loss, causes the reduction of light extraction efficiency.
Therefore, provide a kind of effectively can improve light-emitting diode light extraction efficiency light emitting diode construction and manufacture method be necessary.
Summary of the invention
The shortcoming of prior art in view of the above, the object of the present invention is to provide a kind of light-emitting diode and manufacture method thereof, for solving the problem that in prior art, light-emitting diode light extraction efficiency is lower.
For achieving the above object and other relevant objects, the invention provides a kind of manufacture method of light-emitting diode, at least comprise the following steps:
1) growth substrates is provided, forms in described growth substrates surface the epitaxial light emission structure at least comprising N-type layer, quantum well layer and P-type layer;
2) P-type layer of removal part, quantum well layer and N-type layer form the sidewall formed when N electrode prepares the P-type layer of region and removal part, quantum well layer and N-type layer;
3) prepare region surface in described P-type layer, sidewall and N electrode and form transparent insulating layer, etch described transparent insulating layer and form spaced pattern structure;
4) in described P-type layer and pattern structure surface and N electrode prepare region surface formed current extending;
5) prepare the current extending surface making N electrode of region surface in described N electrode, make P electrode in the current extending surface on described P-type layer and pattern structure surface.
As a kind of preferred version of the manufacture method of light-emitting diode of the present invention, described growth substrates is Sapphire Substrate, and described N-type layer is N-GaN layer, and described quantum well layer is InGaN/GaN multiple quantum well layer, and described P-type layer is P-GaN layer.
Further, form described N-GaN layer before also comprise the step forming u-GaN layer.
As a kind of preferred version of the manufacture method of light-emitting diode of the present invention, described sidewall is the inclined-plane tilted in predetermined angle with described N-type layer surface.
As a kind of preferred version of the manufacture method of light-emitting diode of the present invention, in step 3), using plasma strengthens chemical vapour deposition technique PECVD and forms described transparent insulating layer, and thickness is 120 ~ 960nm.
As a kind of preferred version of the manufacture method of light-emitting diode of the present invention, described pattern structure is column construction or the pyramidal structure of periodic arrangement.
The present invention also provides a kind of light-emitting diode, at least comprises:
Growth substrates;
Epitaxial light emission structure, at least comprise the N-type layer, quantum well layer and the P-type layer that stack gradually, described epitaxial light emission structure has the sidewall formed when N electrode that the P-type layer, quantum well layer and the N-type layer that eliminate part formed prepares the P-type layer of region and removal part, quantum well layer and N-type layer;
Pattern structure, is formed by transparent insulation material, is incorporated into described P-type layer, sidewall and N electrode and prepares region surface;
Current extending, is covered in described P-type layer and described pattern structure surface and described N electrode and prepares region surface;
N electrode, is formed at the current extending surface that described N electrode prepares region surface, and P electrode, is formed at the current extending surface on described P-type layer and described pattern structure surface.
As a kind of preferred version of light-emitting diode of the present invention, described growth substrates is Sapphire Substrate, and described N-type layer is N-GaN layer, and described quantum well layer is InGaN/GaN multiple quantum well layer, and described P-type layer is P-GaN layer.
As a kind of preferred version of light-emitting diode of the present invention, between described growth substrates and described N-GaN layer, also there is u-GaN layer.
As a kind of preferred version of light-emitting diode of the present invention, described sidewall is the inclined-plane tilted in predetermined angle with described N-type layer surface.
As a kind of preferred version of light-emitting diode of the present invention, described pattern structure is column construction or the pyramidal structure of periodic arrangement.
As a kind of preferred version of light-emitting diode of the present invention, the height of described pattern structure is 120 ~ 960nm.
As mentioned above, the invention provides a kind of light-emitting diode and manufacture method thereof, described manufacture method comprises: 1) provide a growth substrates, forms in described growth substrates surface the epitaxial light emission structure at least comprising N-type layer, quantum well layer and P-type layer; 2) P-type layer of removal part, quantum well layer and N-type layer form the sidewall formed when N electrode prepares the P-type layer of region and removal part, quantum well layer and N-type layer; 3) prepare region surface in described P-type layer, sidewall and N electrode and form transparent insulating layer, etch described transparent insulating layer and form spaced pattern structure; 4) in described P-type layer and pattern structure surface and N electrode prepare region surface formed current extending; 5) prepare the current extending surface making N electrode of region surface in described N electrode, make P electrode in the current extending surface on described P-type layer and pattern structure surface.The present invention effectively can improve the light extraction efficiency of light-emitting diode, thus improves the brightness of light-emitting diode.Present invention process is simple, is applicable to industrial production.
Embodiment
Below by way of specific instantiation, embodiments of the present invention are described, those skilled in the art the content disclosed by this specification can understand other advantages of the present invention and effect easily.The present invention can also be implemented or be applied by embodiments different in addition, and the every details in this specification also can based on different viewpoints and application, carries out various modification or change not deviating under spirit of the present invention.
Refer to Fig. 2 ~ Fig. 7.It should be noted that, the diagram provided in the present embodiment only illustrates basic conception of the present invention in a schematic way, then only the assembly relevant with the present invention is shown in graphic but not component count, shape and size when implementing according to reality is drawn, it is actual when implementing, and the kenel of each assembly, quantity and ratio can be a kind of change arbitrarily, and its assembly layout kenel also may be more complicated.
As shown in Figure 2 to 7, the present embodiment provides a kind of manufacture method of light-emitting diode, at least comprises the following steps:
As shown in Figure 2, first carry out step 1), a growth substrates 101 is provided, form in described growth substrates 101 surface the epitaxial light emission structure at least comprising N-type layer 102, quantum well layer 103 and P-type layer 104.
Exemplarily, described growth substrates 101 is Sapphire Substrate, graphical sapphire substrate or GaN substrate.Certainly, in other embodiments, described growth substrates 101 also can be as Si substrate, SiC substrate etc., can select according to different process requirements, is not limited to cited several herein.
Exemplarily, chemical vapour deposition technique is adopted to form described epitaxial light emission structure.
Exemplarily, described N-type layer 102 is N-GaN layer, and described quantum well layer 103 is InGaN/GaN multiple quantum well layer 103, and described P-type layer 104 is P-GaN layer.Certainly, described epitaxial light emission structure also can be as GaAs(GaAs), GaP(gallium phosphide), GaAsP(gallium arsenide phosphide) etc. the epitaxial light emission structure made of semiconductor, can select according to the performance of required product, and be not limited to cited several herein.
Certainly, in other embodiments, in order to improve the growth quality of described epitaxial light emission structure, before forming described N-GaN layer, u-GaN layer can be formed prior to growth substrates 101 surface, to reduce the defect that lattice mismatch etc. causes, improve the performance of light-emitting diode.
As shown in Figure 3, then carry out step 2), the P-type layer 104 of removal part, quantum well layer 103 and N-type layer 102 form the sidewall 106 formed when N electrode prepares the P-type layer 104 of region 105 and removal part, quantum well layer 103 and N-type layer 102.
Exemplarily, adopt the P-type layer 104 of inductively coupled plasma ICP lithographic technique removal part, quantum well layer 103 and N-type layer 102 to form N electrode to prepare region 105 and be connected to by described P-type layer 104 surface the sidewall 106 that described N electrode prepares region 105.
In the present embodiment, described N electrode prepares N-type layer 102 platform that region 105 obtains for eliminating part N-type layer 102.
In the present embodiment, described sidewall 106 is the inclined-plane tilted in predetermined angle with described N-type layer 102 surface,
As shown in Fig. 4 ~ Fig. 5, then carry out step 3), prepare surface, region 105 in described P-type layer 104, sidewall 106 and N electrode and form transparent insulating layer 107, etch described transparent insulating layer 107 and form spaced pattern structure 108.
Exemplarily, using plasma strengthens chemical vapour deposition technique PECVD and forms described transparent insulating layer 107, and the thickness of described transparent insulating layer 107 is 120 ~ 960nm.
Exemplarily, adopt dry etching or wet etching method to carry out process to described transparent insulating layer 107 and form described pattern structure 108, wherein, the transparent insulating layer 107 at each interval of pattern structure 108 is carved completely to be worn.
Exemplarily, described pattern structure 108 is column construction or the pyramidal structure of periodic arrangement, and the shape of the cross section of described pattern structure 108 can be rectangle, trapezoidal, triangle, semicircle etc.
Exemplarily, described transparent insulating layer 107 is silicon dioxide layer.
As shown in Figure 6, then carry out step 4), prepare region surface 105 form current extending 109 in described P-type layer 104 and pattern structure 108 surface and N electrode.
Exemplarily, described current extending 109 can be ITO transparency conducting layer, metal level etc.
As shown in Figure 7, finally carry out step 5), current extending 109 surface of preparing region 105 in described N electrode makes N electrode 111, makes P electrode 110 in current extending 109 surface on described P-type layer 104 and pattern structure 108 surface.
As shown in Figure 7, the present embodiment also provides a kind of light-emitting diode, at least comprises:
Growth substrates 101;
Epitaxial light emission structure, at least comprise the N-type layer 102, quantum well layer 103 and the P-type layer 104 that stack gradually, described epitaxial light emission structure has the sidewall 106 formed when N electrode that the P-type layer 104, quantum well layer 103 and the N-type layer 102 that eliminate part formed prepares the P-type layer 104 of region 105 and removal part, quantum well layer 103 and N-type layer 102;
Pattern structure 108, is formed by transparent insulation material, is incorporated into described P-type layer 104, sidewall 106 and N electrode and prepares surface, region 105;
Current extending 109, is covered in described P-type layer 104 and described pattern structure 108 surface and described N electrode and prepares region surface;
N electrode 111, is formed at current extending 109 surface that described N electrode prepares surface, region 105, and P electrode 110, is formed at current extending 109 surface on described P-type layer 104 and described pattern structure 108 surface.
Exemplarily, described growth substrates 101 is Sapphire Substrate, graphical sapphire substrate or GaN substrate.Certainly, in other embodiments, described growth substrates 101 also can be as Si substrate, SiC substrate etc., can select according to different process requirements, is not limited to cited several herein.
Exemplarily, described N-type layer 102 is N-GaN layer, and described quantum well layer 103 is InGaN/GaN multiple quantum well layer 103, and described P-type layer 104 is P-GaN layer.Certainly, described epitaxial light emission structure also can be as GaAs(GaAs), GaP(gallium phosphide), GaAsP(gallium arsenide phosphide) etc. the epitaxial light emission structure made of semiconductor, can select according to the performance of required product, and be not limited to cited several herein.
Certainly, in other embodiments, in order to improve the quality of described epitaxial light emission structure, between described N-GaN layer and described growth substrates 101, u-GaN layer can also be formed with, to reduce the defect that lattice mismatch etc. causes, improve the performance of light-emitting diode.
Exemplarily, described sidewall 106 is the inclined-plane tilted in predetermined angle with described N-type layer 102 surface.In the present embodiment, described sidewall 106 is 20 ~ 70 degree with the angle on described N-type layer 102 surface, can increase the bright dipping probability of the sidewall 106 of light-emitting diode.
Exemplarily, described pattern structure 108 is column construction or the pyramidal structure of periodic arrangement, and the shape of the cross section of described pattern structure 108 can be rectangle, trapezoidal, triangle, semicircle etc.
Exemplarily, the height of described pattern structure 108 is 120 ~ 960nm.
Exemplarily, the material of described pattern structure 108 is silicon dioxide.
Exemplarily, described current extending 109 can be ITO transparency conducting layer, metal level etc.
In sum, the invention provides a kind of light-emitting diode and manufacture method thereof, described manufacture method comprises: 1) provide a growth substrates, forms in described growth substrates surface the epitaxial light emission structure at least comprising N-type layer, quantum well layer and P-type layer; 2) P-type layer of removal part, quantum well layer and N-type layer form the sidewall formed when N electrode prepares the P-type layer of region and removal part, quantum well layer and N-type layer; 3) prepare region surface in described P-type layer, sidewall and N electrode and form transparent insulating layer, etch described transparent insulating layer and form spaced pattern structure; 4) in described P-type layer and pattern structure surface and N electrode prepare region surface formed current extending; 5) prepare the current extending surface making N electrode of region surface in described N electrode, make P electrode in the current extending surface on described P-type layer and pattern structure surface.The present invention effectively can improve the light extraction efficiency of light-emitting diode, thus improves the brightness of light-emitting diode.Present invention process is simple, is applicable to industrial production.So the present invention effectively overcomes various shortcoming of the prior art and tool high industrial utilization.
Above-described embodiment is illustrative principle of the present invention and effect thereof only, but not for limiting the present invention.Any person skilled in the art scholar all without prejudice under spirit of the present invention and category, can modify above-described embodiment or changes.Therefore, such as have in art usually know the knowledgeable do not depart from complete under disclosed spirit and technological thought all equivalence modify or change, must be contained by claim of the present invention.