CN102024896A - Light-emitting diode epitaxial wafer and manufacturing method thereof - Google Patents
Light-emitting diode epitaxial wafer and manufacturing method thereof Download PDFInfo
- Publication number
- CN102024896A CN102024896A CN2009102153960A CN200910215396A CN102024896A CN 102024896 A CN102024896 A CN 102024896A CN 2009102153960 A CN2009102153960 A CN 2009102153960A CN 200910215396 A CN200910215396 A CN 200910215396A CN 102024896 A CN102024896 A CN 102024896A
- Authority
- CN
- China
- Prior art keywords
- body coating
- layer
- coating
- led
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 8
- 239000011248 coating agent Substances 0.000 claims abstract description 87
- 238000000576 coating method Methods 0.000 claims abstract description 87
- 238000000034 method Methods 0.000 claims abstract description 24
- 239000010410 layer Substances 0.000 claims description 111
- 239000000758 substrate Substances 0.000 claims description 53
- 229910052594 sapphire Inorganic materials 0.000 claims description 38
- 239000010980 sapphire Substances 0.000 claims description 38
- 229910052751 metal Inorganic materials 0.000 claims description 33
- 239000002184 metal Substances 0.000 claims description 33
- 239000004065 semiconductor Substances 0.000 claims description 28
- 238000009792 diffusion process Methods 0.000 claims description 20
- 238000010304 firing Methods 0.000 claims description 11
- 239000004332 silver Substances 0.000 claims description 11
- 229910052709 silver Inorganic materials 0.000 claims description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 9
- 239000002356 single layer Substances 0.000 claims description 8
- 229910052737 gold Inorganic materials 0.000 claims description 7
- 239000010931 gold Substances 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 7
- 239000011651 chromium Substances 0.000 claims description 6
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 6
- 229910052804 chromium Inorganic materials 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 4
- 239000004411 aluminium Substances 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
- 239000010936 titanium Substances 0.000 claims description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- 238000002310 reflectometry Methods 0.000 abstract description 7
- 230000005855 radiation Effects 0.000 abstract description 3
- 239000010409 thin film Substances 0.000 abstract 1
- 229910002601 GaN Inorganic materials 0.000 description 39
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 36
- 238000000151 deposition Methods 0.000 description 19
- 230000008021 deposition Effects 0.000 description 17
- 238000000605 extraction Methods 0.000 description 15
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 14
- 230000008020 evaporation Effects 0.000 description 9
- 238000001704 evaporation Methods 0.000 description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 229910004298 SiO 2 Inorganic materials 0.000 description 6
- 239000000428 dust Substances 0.000 description 6
- 238000005538 encapsulation Methods 0.000 description 6
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 6
- 241001025261 Neoraja caerulea Species 0.000 description 5
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 4
- 239000012528 membrane Substances 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 4
- 239000011241 protective layer Substances 0.000 description 4
- 235000012239 silicon dioxide Nutrition 0.000 description 4
- 239000000377 silicon dioxide Substances 0.000 description 4
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- ORUIBWPALBXDOA-UHFFFAOYSA-L magnesium fluoride Chemical compound [F-].[F-].[Mg+2] ORUIBWPALBXDOA-UHFFFAOYSA-L 0.000 description 3
- 229910052750 molybdenum Inorganic materials 0.000 description 3
- 239000011733 molybdenum Substances 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 229910010413 TiO 2 Inorganic materials 0.000 description 2
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 2
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000005496 eutectics Effects 0.000 description 2
- 239000003292 glue Substances 0.000 description 2
- 230000003760 hair shine Effects 0.000 description 2
- 230000017525 heat dissipation Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 239000004408 titanium dioxide Substances 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000005566 electron beam evaporation Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910001635 magnesium fluoride Inorganic materials 0.000 description 1
- XZWYZXLIPXDOLR-UHFFFAOYSA-N metformin Chemical compound CN(C)C(=N)NC(N)=N XZWYZXLIPXDOLR-UHFFFAOYSA-N 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Images
Abstract
The invention discloses a light-emitting diode epitaxial wafer and a manufacturing method thereof. The method comprises: growing a first back coating for reflecting emergent light, of which the incident angle is greater than 36 DEG, on the non-light-leaving surface of an LED; growing a second back coating for reflecting emergent light, of which the incident angle is smaller than 36 DEG, on the first back coating; and growing a third back coating for protection and radiation on the second back coating. In the invention, by manufacturing thin-film structures, which have high reflectivity for the corresponding wave bands of the emergent light of the LED and high heat conducting performance, on the non-light-leaving surface of the LED, the light emitting efficiency and reliability of the LED are improved.
Description
Technical field
The present invention relates to field of semiconductor manufacture, particularly a kind of LED epitaxial slice and its manufacture method.
Background technology
At present, (light emitting diode, LED) primary structure of epitaxial wafer comprises light-emitting diode: substrate, resilient coating, n type semiconductor layer, active area luminescent layer and p type semiconductor layer.Between n type semiconductor layer and p type semiconductor layer, is the PN junction that the interface of p type and n type semiconductor layer constitutes as the active area luminescent layer of LED epitaxial wafer core.Application and metal-organic chemical vapor deposition equipment (MOCVD) development of technology in the active area luminescent layer along with double heterojunction and multi-quantum pit structure is at sapphire (Al
2O
3) gallium nitride based light emitting diode (GaN basedLED) epitaxial wafer of successfully having grown on the substrate of material, produce blue-ray LED and green light LED.
In order on the LED epitaxial wafer, to apply drive current, also need to make the p electrode in the p type semiconductor layer, make the n electrode at n type semiconductor layer, and draw lead, with the counter electrode of lead connecting circuit substrate at p electrode and n electrode.After the LED epitaxial wafer that completes cuts into led chip, also must be fixed on the support.Above-mentioned making electrode, draw lead and be called encapsulation to circuit substrate and cutting, fixing process, the led chip after the encapsulation is called tube core.Different LED according to encapsulation back exiting surface is divided into formal dress (Normal) structure and upside-down mounting (Flip Chip) structure.Wherein, the exiting surface of positive assembling structure is the p type semiconductor layer, and non-exiting surface is a substrate, and the exiting surface of inverted structure is a substrate, and non-exiting surface is the current-diffusion layer on the p type semiconductor layer.LED epitaxial wafer after the encapsulation is called tube core.
Be 470 nanometers to the blue-ray LED of 430 nano wavebands with wave-length coverage be example, Sapphire Substrate gallium nitride based LED formal dress section of structure as shown in Figure 1, Sapphire Substrate 101 device growth faces be the front have successively resilient coating 102, n type gallium nitride layer 103 as n type semiconductor layer, active area luminescent layer 104 and p type gallium nitride layer 105 as the p type semiconductor layer, because the high p type doping difficulty of p type gallium nitride layer makes p type gallium nitride layer conductivity very limited.For being evenly distributed of electric current requires on p type gallium nitride layer surface deposition current diffusion layer 106 again, form by nickel and gold usually.Because Sapphire Substrate is non-conductive, electrode can't be made on substrate, usually adopt lithographic method to remove sub-fraction current-diffusion layer 106, p N-type semiconductor N 105 and active area luminescent layer 104 and expose the n type semiconductor layer, respectively p electrode 107 and n electrode 108 are placed on current-diffusion layer 106 and the n type semiconductor layer 103 then.In the formal dress construction packages, the light of active area luminescent layer outgoing takes out from uppermost p type gallium nitride layer, and the Sapphire Substrate back side links to each other with support.Though current-diffusion layer has improved the luminous efficiency of active area luminescent layer, the beam split of meeting absorbent portion reduces light extraction efficiency.In order to reduce the absorption of emergent light, the thickness of current-diffusion layer should reduce to the hundreds of nanometer.The minimizing of thickness has limited current-diffusion layer again conversely in all even ability that spreads big electric current reliably in p type gallium nitride layer surface.Simultaneously, the heat of LED mainly results from the very thin active area luminescent layer, and encapsulates the device after finishing, and its heat then mainly relies on Sapphire Substrate to scatter to the heat conduction of support.The conductive coefficient of Sapphire Substrate is very little, so the positive assembling structure of LED can make the very big temperature difference of generation between support and active area luminescent layer, causes die temperature to rise, thereby influences the performance of device.In addition, the lead that the p electrode of this structure and p electrode are drawn also can block the part emergent light, so die devices power, light extraction efficiency and the hot property of the positive assembling structure of this LED all can not be optimum.
In order to overcome the deficiency of the positive assembling structure of blue-ray LED, proposed with Sapphire Substrate 101 as exiting surface, the current-diffusion layer 106 on the p type gallium nitride layer 105 is the LED inverted structure of non-exiting surface.After finishing, the GaN-based LED epitaxial wafer growth of Sapphire Substrate makes p electrode 107 and n electrode 108, the epitaxial wafer growth is identical with positive assembling structure with method for making its electrode, the device growth face of Sapphire Substrate is linked to each other with support by heat-conducting substrate 209, finish encapsulation, obtain the inverted structure profile (support does not draw) of the gallium nitride based LED of Sapphire Substrate as shown in Figure 2.Because Sapphire Substrate is transparent, the Sapphire Substrate after the upside-down mounting becomes exiting surface up, and p electrode and the upside-down mounting of n electrode simultaneously can not blocked from the light of Sapphire Substrate exiting surface outgoing, thereby improve light extraction efficiency below.After adopting the flip chip bonding epitaxial slice structure, because silicon is the good conductor of heat, utilize its heat-conducting substrate as heat radiation, its radiating effect also will be much better than the positive assembling structure of LED.
The light extraction efficiency of LED is by luminous efficiency and the common decision of extraction efficiency, and therefore, the extraction efficiency that how to improve LED becomes an importance of further raising LED luminous efficiency.As everyone knows, the photon that LED active area luminescent layer sends is that spontaneous radiation produces each homogeny of its direction.Therefore, after the LED encapsulation, no matter formal dress or inverted structure, the heat-conducting glue that most of emergent light of the directive support that the active area luminescent layer sends can be connected support and epitaxial wafer absorbs, and has reduced the extraction efficiency of LED.Simultaneously,, can assemble a large amount of heats, further reduce light extraction efficiency and the reliability of LED because the radiating effect of heat-conducting glue is unsatisfactory.
Summary of the invention
In view of this, goal of the invention of the present invention is to improve the light extraction efficiency and the reliability of light-emitting diode.
For achieving the above object, technical scheme of the present invention specifically is achieved in that
The invention provides a kind of manufacture method of LED epitaxial slice, this method comprises:
Device side in Sapphire Substrate forms resilient coating, n type semiconductor layer, active area luminescent layer and p type semiconductor layer successively, and the n electrode on the n type semiconductor layer, behind current-diffusion layer on the p type semiconductor layer and the p electrode, growing successively at non-exiting surface is used to be reflected into first back of the body coating of firing angle greater than 36 degree emergent lights;
Growth is used to be reflected into second back of the body coating of firing angle less than 36 degree emergent lights on first back of the body coating.
This method also comprises:
The 3rd back of the body coating that growth is used to protect and dispels the heat on second back of the body coating.
The thickness range of described first back of the body coating is 1 to 5 LED outgoing light wavelength.
The total thickness of described second back of the body coating is that 200 nanometers are to 5000 nanometers.
Described second back of the body coating is the multilayer dielectricity that replaces of high low-refraction and the combination of reflective metal layer.
Described reflective metal layer is aluminium or silver.
Described the 3rd back of the body coating is single-layer metal film or the combination of metal multilayer film system.
The material of described single-layer metal film or metal multilayer film system combination is one or more the combination in gold, nickel, chromium, the titanium.
The thickness range of described the 3rd back of the body coating is that 100 nanometers are to 1000 nanometers.
A kind of LED epitaxial slice, comprise Sapphire Substrate and the resilient coating that forms successively in the Sapphire Substrate device side, n type semiconductor layer, active area luminescent layer and p type semiconductor layer, it is characterized in that, described epitaxial wafer also is included in being used on the non-exiting surface and is reflected into first back of the body coating of firing angle greater than 36 degree emergent lights, and first back of the body is used to be reflected into second back of the body coating of firing angle less than 36 degree emergent lights on the coating.
Described epitaxial wafer comprises that also second back of the body is used to the 3rd back of the body coating of protecting and dispelling the heat on the coating.
As seen from the above technical solutions, the present invention makes the membrane structure that the corresponding wave band of LED emergent light is had high reflectance and good heat conductive at the non-exiting surface of LED, has improved light extraction efficiency and the reliability of LED.
Description of drawings
Fig. 1 is the gallium nitride based LED formal dress section of structure of prior art Sapphire Substrate;
Fig. 2 is the gallium nitride based LED inverted structure profile of prior art Sapphire Substrate;
Fig. 3 is the gallium nitride based LED formal dress section of structure of Sapphire Substrate of the present invention;
Fig. 4 is the gallium nitride based LED inverted structure profile of Sapphire Substrate of the present invention;
Embodiment
For make purpose of the present invention, technical scheme, and advantage clearer, below with reference to the accompanying drawing embodiment that develops simultaneously, the present invention is described in more detail.
Make a kind of membrane structure that the corresponding wave band of light-emitting diode emergent light is had high reflectance and good heat conductive at the non-exiting surface of LED epitaxial slice, promote the light extraction efficiency and the reliability of light-emitting diode.
Specific embodiment one
The present invention is that the positive assembling structure of the gallium nitride based LED of Sapphire Substrate is an example, explanation is the step of making the membrane structure with high reflectance and good heat conductive on the Sapphire Substrate at non-exiting surface: with peak wavelength is that the blue-ray LED of 450 nanometers is an example, the preferred silicon dioxide (SiO of low refractive index dielectric
2), magnesium fluoride (MgF
2) etc.Preferred titanium dioxide (the TiO of high refractive index medium
2), ceria (CeO
2) etc.Can adopt method preparations such as PVD or CVD.High refractive index medium is selected TiO for use in the present embodiment
2, low refractive index dielectric is selected MgF for use
2And SiO
2, the reflecting metal of second back of the body coating is selected high metallic aluminium (Al) of emissivity or silver (Ag), preferred silver in the present embodiment.Concrete steps are as follows:
Step 1, be that the non-exiting surface of the GaN-based LED epitaxial wafer of substrate is the transparent medium magnesium fluoride (MgF that the Sapphire Substrate growth is lower than refractive index of substrate with sapphire 101 what provide
2) as first back of the body coating 301, be used to be reflected into firing angle greater than 36 degree emergent lights;
In this step, LED epitaxial wafer heating-up temperature is 150 degrees centigrade, and vacuum degree is 5.0*10
-3Pascal, growing method is the molybdenum boat evaporation, evaporation rate 6 dust per seconds, crystal-vibration-chip on-line monitoring deposition rate, first back of the body coating, 301 thicknesses of layers of deposition are 1220 nanometers;
In this step, the LED epitaxial wafer specifically is meant, the resilient coating 102 that has successively on Sapphire Substrate 101 device side, n type gallium nitride layer 103, active area luminescent layer 104, p type gallium nitride layer 105, and the current-diffusion layer 106 on the p type gallium nitride layer;
In this step, the physical thickness range of first back of the body coating 301 is 1 to 5 LED outgoing light wavelength;
In this step, the p type semiconductor layer is as exiting surface, the transparent sapphire substrate of active area luminescent layer emergent light by non-exiting surface shines first back of the body coating, 301, the first back of the body coating 301 and makes from the light of n type gallium nitride directive Sapphire Substrate, and incidence angle is greater than light 100% reflection of 36 degree.Incidence angle is defined as the angle of the normal of incident ray and substrate and back of the body coating.
Multilayer dielectricity and reflective metal layer that step 2, the high low-refraction of growing successively on first back of the body coating 301 replace, the effect of carrying on the back coating 302 as second back of the body coating 302, the second is to be reflected into the emergent lights of firing angle less than 36 degree;
In this step, high refractive index medium is selected TiO
2, low refractive index dielectric is selected SiO
2On first back of the body coating 301,, change the mode of Coating Materials, successively depositing Ti O by the rotation crucible
2And SiO
2Periodic structure alternately, deposition high refractive index medium TiO earlier
2, back deposition low refractive index dielectric SiO
2Sedimentary condition is: substrate heating temperature is 150 degrees centigrade, and vacuum degree is 5.0*10
-3Pascal, deposition rate 3 dust per seconds, lower deposition rate is convenient to accurately control the thickness of each layer film, crystal-vibration-chip on-line monitoring deposition rate.In this step, the number of plies scope of the multilayer dielectricity that high low-refraction replaces is 4 layers to 50 layers.If with a high low refractive index dielectric layer is one-period, periodicity is 2 to 25 integers in the cycle.It is to be noted that especially high refractive index medium thickness in each cycle and low refractive index dielectric thickness are not a definite value, reach the high reflectance of incidence angle less than all angles emergent lights of 36 degree with the high low refractive index dielectric layer combination of different-thickness.
In this step, reduce heating-up temperature to 50 degree centigrade, adopt molybdenum boat evaporation reflective metals silver, evaporation speed is 10 dust per seconds.Deposition rate helps improving the reflectivity of argent faster, and silver film thickness is 150 nanometers.Combination by argent and high low-refraction multilayer dielectric film structure can make from the incidence angle of n type gallium nitride directive Sapphire Substrate less than the average reflectance of the light of 36 degree greater than 98%.In conjunction with the effect of back of the body coating one, can make the light of directive Sapphire Substrate, reach more than 99% at the reflectivity of full angle.Near the limit of 100% reflection, the light of the non-exiting surface sapphire of different angles directive face is all reflected back.Therefore, the light that reflects back penetrates the extraction efficiency that has not only improved LED by exiting surface, and because the emergent light of the non-exiting surface of directive reduces, has reduced the gathering of heat, thereby improved light extraction efficiency and the reliability of LED.
In this step, the total thickness of second back of the body coating 302 is that 200 nanometers are to 5000 nanometers.
Step 3, growth single-layer metal film or the combination of metal multilayer film system on second back of the body coating 302; as the 3rd back of the body coating 303; the 3rd back of the body coating 303 prevents that as metal protective film the reflectivity that the reflective metal layer oxidation in second back of the body coating 302 causes from descending, simultaneously as the heat dissipation metal rete that links to each other with support.
In this step; is example to select chromium (Cr) metal as protective layer; adopt the mode of electron beam evaporation; the deposition rate of control rete is 5 dust per seconds; evaporation thickness is 300 nanometers, is used to protect reflector layer silver, if epitaxial wafer need adopt the mode of eutectic bonding to be connected with support when encapsulating; also can adopt metallic gold as protective layer, or the gold of outermost layer evaporation thickness 50 nanometer to 500 nanometers.
In this step, the material of single-layer metal film or metal multilayer film system combination is one or more the combination in gold, nickel, chromium, the titanium;
In this step, the thickness range of the 3rd back of the body coating 303 is that 50 nanometers are to 1000 nanometers.
Step 4, the appointed area of current-diffusion layer 106, p type gallium nitride layer 105 and active area luminescent layer 104 is carried out etching successively, until exposing n type gallium nitride layer, on the n type gallium nitride layer that exposes, make n electrode 108, on current-diffusion layer 106, make p electrode 107.
So far, obtain the gallium nitride based LED formal dress section of structure of Sapphire Substrate of the present invention shown in Figure 3.
Specific embodiment two
The gallium nitride based LED inverted structure of Sapphire Substrate of the present invention is an example, illustrates that at non-exiting surface be the making step of making the membrane structure with high reflectance and good heat conductive on the current-diffusion layer of p type gallium nitride layer.With peak wavelength is that the blue-ray LED of 450 nanometers is an example, the preferred silicon dioxide (SiO of low refractive index dielectric
2), magnesium fluoride (MgF
2) etc.Preferred titanium dioxide (the TiO of high refractive index medium
2), ceria (CeO
2) etc.Can adopt method preparations such as PVD or CVD.High refractive index medium is selected TiO for use in the present embodiment
2, low refractive index dielectric is selected SiO for use
2, the reflecting metal of second back of the body coating is selected high metallic aluminium (Al) of emissivity or silver (Ag), preferred silver in the present embodiment.Concrete steps are as follows:
Step 1, growth is lower than the transparent medium silicon dioxide (SiO of current-diffusion layer refractive index on the current-diffusion layer 106 of the LED epitaxial wafer that provides
2) as first back of the body coating 401, the SiO of general epitaxial wafer using plasma enhanced chemical vapor deposition (PECVD) one deck densification
2As protective layer,, perhaps in the subsequent technique preparation, consider the thickness and the surface appearance of this protective layer in PECVD so first back of the body coating 401 can prepare; In the present embodiment, first back of the body coating 401 prepares thicknesses of layers 1000 nanometers, on-line monitoring deposition rate in PECVD.First back of the body coating 401 can ensure that incident angle is reflected greater than 36 light 100% of spending from the light of non-exiting surface directive first back of the body coating 401 directions, has also played the effect of protection LED simultaneously;
In this step, the LED epitaxial wafer specifically is meant, the resilient coating 102 that has successively on Sapphire Substrate 101 device side, n type gallium nitride layer 103, active area luminescent layer 104, p type gallium nitride layer 105, and the current-diffusion layer 106 on the p type gallium nitride layer;
In this step, Sapphire Substrate is as exiting surface, and active area luminescent layer emergent light shines first back of the body coating, 401, the first back of the body coating 401 by the current-diffusion layer 106 as non-exiting surface and makes the light generation total reflection of incidence angle greater than 36 degree.
Multilayer dielectricity and reflective metal layer that step 2, the high low-refraction of growing successively on first back of the body coating 401 replace are as second back of the body coating 402; Wherein high refractive index medium is selected TiO
2, low refractive index dielectric is selected SiO2.Adopt the evaporation coating mode, on first back of the body coating 401,, change Coating Materials, depositing Ti O successively by the rotation crucible
2And SiO
2Periodic structure alternately, deposition high refractive index medium TiO earlier
2, back deposition low refractive index dielectric SiO
2Sedimentary condition is: substrate heating temperature is 150 degrees centigrade, and vacuum degree is 5.0*10
-3Pascal, deposition rate 3 dust per seconds, lower deposition rate is convenient to accurately control the thickness of each layer film, crystal-vibration-chip on-line monitoring deposition rate.In this step, the number of plies scope of the multilayer dielectricity that high low-refraction replaces is 4 layers to 50 layers.If with a high low refractive index dielectric layer is one-period, periodicity is 2 to 25 integers in the cycle.It is to be noted that especially high refractive index medium thickness in each cycle and low refractive index dielectric thickness are not a definite value, reach the high reflectance of incidence angle less than all angles emergent lights of 36 degree with the high low refractive index dielectric layer combination of different-thickness.
Reduce heating-up temperature to 50 degree, adopt molybdenum boat evaporation reflective metals silver, evaporation speed is 10 dust per seconds, and deposition rate helps improving the reflectivity of argent faster, and silver film thickness is 150 nanometers.Combination by argent and high low-refraction multilayer dielectric film structure can make incidence angle less than the average reflectance of the light of 36 degree greater than 98%.In conjunction with the effect of back of the body coating one, can make the light of directive p type gallium nitride, reach more than 99% at the reflectivity of full angle.Near the limit of 100% reflection, the light of the non-exiting surface of different angles directive is all reflected back.Therefore, the light that reflects back penetrates the extraction efficiency that has not only improved LED by exiting surface, and because the emergent light of the non-exiting surface of directive reduces, has reduced the gathering of heat, thereby improved light extraction efficiency and the reliability of LED.
In this step, the total thickness of second back of the body coating 402 is that 200 nanometers are to 5000 nanometers;
In this step, the effect of second back of the body coating 402 is to be reflected into the emergent light of firing angle less than 36 degree.
Step 3, growth single-layer metal film or the combination of metal multilayer film system on second back of the body coating 402 are as the 3rd back of the body coating 403;
In this step, the material of single-layer metal film or metal multilayer film system combination is one or more the combination among Au, Ni, Cr, the Ti;
In this step, the thickness range of the 3rd back of the body coating 403 is that 50 nanometers are to 1000 nanometers.
In this step, the 3rd back of the body coating 403 prevents that as metal protective film the reflectivity that the reflective metal layer oxidation in second back of the body coating 402 causes from descending the heat dissipation metal rete when conduct links to each other with heat-conducting substrate simultaneously.。
Step 4, with the appointed area of ICP etching successively the 3rd back of the body coating 403, second back of the body coating 402, first back of the body coating 401, up to exposing current-diffusion layer, again the appointed area of p type gallium nitride layer, current-diffusion layer and active area luminescent layer is carried out etching successively, until exposing n type gallium nitride layer; On the n type gallium nitride layer that exposes, make the n electrode; On p type gallium nitride layer, make the p electrode, and the counter electrode on p electrode and n electrode and the heat-conducting substrate is welded by the eutectic mode, need simultaneously to ensure that the 3rd back of the body coating 403 contacts with the good of heat-conducting substrate.The present invention who forms as shown in Figure 4 is the gallium nitride based LED inverted structure profile of Sapphire Substrate.
The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (11)
1. the manufacture method of a LED epitaxial slice, this method comprises:
Device side in Sapphire Substrate forms resilient coating, n type semiconductor layer, active area luminescent layer and p type semiconductor layer successively, and n type semiconductor layer, current-diffusion layer on the p type semiconductor layer, growing successively at non-exiting surface is used to be reflected into first back of the body coating of firing angle greater than 36 degree emergent lights;
Growth is used to be reflected into second back of the body coating of firing angle less than 36 degree emergent lights on first back of the body coating.
2. the method for claim 1 is characterized in that, described second back of the body coating is the multilayer dielectricity that replaces of high low-refraction and the combination of reflective metal layer.
3. the method for claim 1 is characterized in that, the thickness range of described first back of the body coating is 1 to 5 LED outgoing light wavelength.
4. the method for claim 1 is characterized in that, the total thickness of described second back of the body coating is that 200 nanometers are to 5000 nanometers.
5. method as claimed in claim 2 is characterized in that, described reflective metal layer is aluminium or silver.
6. the method for claim 1, this method also comprises:
The 3rd back of the body coating that growth is used to protect and dispels the heat on second back of the body coating.
7. method as claimed in claim 6 is characterized in that, described the 3rd back of the body coating is single-layer metal film or the combination of metal multilayer film system.
8. method as claimed in claim 6 is characterized in that, the thickness range of described the 3rd back of the body coating is that 100 nanometers are to 1000 nanometers.
9. method as claimed in claim 7 is characterized in that, the material of described single-layer metal film or metal multilayer film system combination is one or more the combination in gold, nickel, chromium, the titanium.
10. LED epitaxial slice, comprise Sapphire Substrate and the resilient coating that forms successively in the Sapphire Substrate device side, n type semiconductor layer, active area luminescent layer and p type semiconductor layer, it is characterized in that, described epitaxial wafer also is included in being used on the non-exiting surface and is reflected into first back of the body coating of firing angle greater than 36 degree emergent lights, and first back of the body is used to be reflected into second back of the body coating of firing angle less than 36 degree emergent lights on the coating.
11. LED epitaxial slice as claimed in claim 10 is characterized in that, described epitaxial wafer comprises that also second back of the body is used to the 3rd back of the body coating of protecting and dispelling the heat on the coating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009102153960A CN102024896B (en) | 2009-12-31 | 2009-12-31 | Light-emitting diode epitaxial wafer and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009102153960A CN102024896B (en) | 2009-12-31 | 2009-12-31 | Light-emitting diode epitaxial wafer and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102024896A true CN102024896A (en) | 2011-04-20 |
| CN102024896B CN102024896B (en) | 2012-03-21 |
Family
ID=43865961
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009102153960A Active CN102024896B (en) | 2009-12-31 | 2009-12-31 | Light-emitting diode epitaxial wafer and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102024896B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103904174A (en) * | 2014-04-11 | 2014-07-02 | 安徽三安光电有限公司 | Manufacturing method for LED chip |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100466310C (en) * | 2005-02-25 | 2009-03-04 | 日立电线株式会社 | Light emitting diode and method for fabricating same |
| US7573074B2 (en) * | 2006-05-19 | 2009-08-11 | Bridgelux, Inc. | LED electrode |
-
2009
- 2009-12-31 CN CN2009102153960A patent/CN102024896B/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103904174A (en) * | 2014-04-11 | 2014-07-02 | 安徽三安光电有限公司 | Manufacturing method for LED chip |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102024896B (en) | 2012-03-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8729580B2 (en) | Light emitter with metal-oxide coating | |
| US7622746B1 (en) | Highly reflective mounting arrangement for LEDs | |
| TWI819258B (en) | Light emitting diode chip | |
| TWI274427B (en) | Light-emitting devices having an antireflective layer that has a graded index of refraction and methods of forming the same | |
| US9362459B2 (en) | High reflectivity mirrors and method for making same | |
| CN101276863B (en) | LED and manufacturing method thereof | |
| US7943944B2 (en) | GaN-based radiation-emitting thin-layered semiconductor component | |
| TWI305425B (en) | ||
| KR20230021045A (en) | Light-emitting device | |
| EP1256987A2 (en) | Semiconductor LED flip-chip with high reflectivity dielectric coating on the mesa | |
| TWI601312B (en) | Optoelectronic semiconductor chip | |
| GB2542542A (en) | Vertical LED chip structure and manufacturing method therefor | |
| US20060054919A1 (en) | Light-emitting element, method for manufacturing the same and lighting equipment using the same | |
| CN102034913A (en) | Metal medium nano structure light-emitting diode and preparation method thereof | |
| TW201214780A (en) | Light emitting diode chip having distributed Bragg reflector and method of fabricating the same | |
| JP2011166146A (en) | Light-emitting diode chip having distributed bragg reflector and method of fabricating the same | |
| CN108933187A (en) | A kind of light-emitting surface is the LED chip and preparation method thereof of specific plane geometric figure | |
| TW202029534A (en) | Light-emitting element with distributed bragg reflector | |
| JP6911111B2 (en) | Manufacturing method of optoelectronic semiconductor chip and optoelectronic semiconductor chip | |
| US20110272727A1 (en) | Light-emitting diode and method for manufacturing the same | |
| CN109378372A (en) | LED chip structure and preparation method thereof | |
| JP2012525693A (en) | Optoelectronic semiconductor with a reflective layer system | |
| CN102082216A (en) | Light emitting diode chip and manufacturing method thereof | |
| US8604497B2 (en) | Radiation-emitting thin-film semiconductor chip | |
| CN102024896B (en) | Light-emitting diode epitaxial wafer and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20160901 Address after: 516083 Guangdong city of Huizhou province Dayawan xiangshuihe Patentee after: HUIZHOU BYD INDUSTRIAL Co.,Ltd. Address before: 518118 Pingshan Road, Pingshan Town, Shenzhen, Guangdong, No. 3001, No. Patentee before: BYD Co.,Ltd. |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20191128 Address after: 518119 1 Yanan Road, Kwai Chung street, Dapeng New District, Shenzhen, Guangdong Patentee after: SHENZHEN BYD MICROELECTRONICS Co.,Ltd. Address before: 516083 Guangdong city of Huizhou province Dayawan xiangshuihe Patentee before: HUIZHOU BYD INDUSTRIAL Co.,Ltd. |
|
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 518119 No.1 Yan'an Road, Kuiyong street, Dapeng New District, Shenzhen City, Guangdong Province Patentee after: BYD Semiconductor Co.,Ltd. Address before: 518119 No.1 Yan'an Road, Kuiyong street, Dapeng New District, Shenzhen City, Guangdong Province Patentee before: BYD Semiconductor Co.,Ltd. |
|
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 518119 No.1 Yan'an Road, Kuiyong street, Dapeng New District, Shenzhen City, Guangdong Province Patentee after: BYD Semiconductor Co.,Ltd. Address before: 518119 No.1 Yan'an Road, Kwai Chung street, Dapeng New District, Shenzhen City, Guangdong Province Patentee before: SHENZHEN BYD MICROELECTRONICS Co.,Ltd. |