Summary of the invention
The technical problem to be solved in the present invention is that the substrate of existing light-emitting diode absorbs photon, influence the luminous efficiency of light-emitting diode component, and light-emitting diode chip for backlight unit is peeled off on substrate directly or when utilizing metal to be engaged in other substrates as engagement medium, must or fit the alignment of chip chamber lattice direction and easily peel off, cause qualification rate to descend.
For solving the problems of the technologies described above, the invention provides a kind of light-emitting diode, comprise at least: a transparency carrier; One is positioned at the reflector on the one side of transparency carrier; One is positioned at the following layer on the another side of transparency carrier; One is positioned at the semiconductor epitaxial structure on the following layer; An and transparency conducting layer that is positioned on the semiconductor epitaxial structure.
The material in reflector is a metal among the present invention, and the material of following layer is high temperature resistant and the conduction or the electrically non-conductive material of the high-temperature coefficient of conductivity, and the material of following layer can be organic material or metal.
The present invention also provides this kind manufacturing method for LED, it comprises the following steps: a kind of manufacturing method for LED at least, at least comprise: a primary substrate is provided, wherein comprises the resilient coating and the etch stop layer (Etching Stop Layer) that pile up in regular turn on this primary substrate at least; On etch stop layer, form the semiconductor epitaxial structure; Remove described primary substrate, resilient coating and etch stop layer; One transparency carrier is provided, and wherein the one side of this transparency carrier comprises a reflector at least, and the another side of this transparency carrier comprises a following layer at least; Carry out a chip join step so as to the semiconductor epitaxial structure being fitted on the following layer of transparency carrier; And on the semiconductor epitaxial structure, form a transparency conducting layer.
The present invention is after this chip join step, comprise that also the n N-type semiconductor N contact layer to semiconductor structure carries out etched step, so as to making n N-type semiconductor N contact layer form nonplanar continuous structure or noncontinuous surface structure, thus, can improve the electric current dispersion effect.
Light-emitting diode of the present invention and manufacture method thereof by removing primary substrate, can significantly be reduced the loss of light intensity that the substrate absorbing light is caused.Secondly, utilize then that material carries out chip join, can not need consider the direction configuration of joint chip, thereby can improve qualification rate and reduce production costs.In addition, the reflector on the transparency carrier can provide photon to utilize again, and then can improve the quantity that photon is taken out by the assembly side.In addition, deposit transparent conductive layer on the n N-type semiconductor N contact layer after the etching not only can improve light and take out efficient, and n type contact mat is positioned at the front of assembly, also can take into account the effect that electric current disperses.
Embodiment
Hereinafter, will describe the present invention in detail.
In semiconductor luminous assembly, AlGaInP (AlGaInP) is common material.Because AlGaInP is a direct gap material, therefore, can make the lattice constant match of AlGaInP material and GaAs substrate by suitably adjusting the ratio of indium/(aluminium+gallium) in the AlGaInP material.If the ratio of aluminium and gallium can make emission wavelength between 550nm (green glow)~680nm (ruddiness) in adjusting the AlGaInP material.Because the adjustment of AlGaInP material on assembly crystalline substance of heap of stone is quite simple and easy, can be easily obtain wanting luminous wavelength, so be highly suitable for making the luminescence component of visible region in the mode of linearity.
In addition, owing to increase the energy gap that the content of aluminium in the AlGaInP material can increase the AlGaInP material.Therefore, generally can be used as coating layer with the high AlGaInP of aluminium content, drop to the center luminescent layer carrier of (have another name called and be active layer) so as to limitation, penetrate combined efficiency with the injection efficiency and the width of cloth that improve carrier, and form the light-emitting diode of the double-heterostructure (Double Heterostructure) of tool high-luminous-efficiency.Wherein, because that the energy gap of above-mentioned coating layer sends photon energy is big, therefore can not absorb the light that active layer sends.
Please refer to Fig. 2 to Fig. 5 a, Fig. 2 to Fig. 5 a is the processing procedure profile of the light-emitting diode of a preferred embodiment of the present invention.The manufacture process of light-emitting diode of the present invention is: substrate 200 at first is provided, and wherein this substrate 200 is a primary substrate, and the material of substrate 200 can be the n p type gallium arensidep.Utilize for example Metalorganic chemical vapor deposition (Metal Organic Chemical Vapor Deposition again; MOCVD) mode forms resilient coating 202 and etch stop layer 204 in regular turn on substrate 200.Next, utilize Metalorganic chemical vapor deposition method for example to form the semiconductor epitaxial structure of this light-emitting diode, and on etch stop layer 204, form n N-type semiconductor N contact layer 206, n N-type semiconductor N coating layer 208, multi-layer quantum well active layer (Multiple Quantum Well Active Layer) 210, p N-type semiconductor N coating layer 212 and p N-type semiconductor N contact layer 214 in regular turn in regular turn, and form structure as shown in Figure 2.In this preferred embodiment, the material of resilient coating 202 can be the n p type gallium arensidep; The material of etch stop layer 204 can be n type AlGaInP; The material of n N-type semiconductor N contact layer 206 can be the n p type gallium arensidep; The material of n N-type semiconductor N coating layer 208 can be AlGaInP; The material of multi-layer quantum well active layer 210 can be AlGaInP/InGaP (GaInP); The material of p N-type semiconductor N coating layer 212 can be AlGaInP; And the material of p N-type semiconductor N contact layer 214 can be AlGaInP arsenic (AlGaInAsP).
After waiting to finish the semiconductor epitaxial structure of light-emitting diode, can utilize etched mode to remove etch stop layer 204, so as to removing resilient coating 202 and substrate 200, and stay the epitaxial structure of light-emitting diode, as shown in Figure 3.
At the same time, provide transparency carrier 300, wherein the material of this transparency carrier 300 can be aluminium oxide (Al
2O
3), zinc selenide (ZnSe), zinc oxide (ZeO), gallium phosphide (GaP) or glass etc.Then, for example utilizing, the mode of deposition forms reflector 304 in the one side of transparency carrier 300, and utilize for example coating (Coating), deposition or evaporation modes such as (Evaporation) to form following layer 302 at the another side of transparency carrier 300, and form structure as shown in Figure 4.Wherein, reflector 304 is preferably the metal into high light reflectivity, for example aluminium (Al), gold (Au), silver (Ag), and the alloy of described metal, and the material of following layer 302 is conduction or nonconducting high temperature resistant and high-temperature coefficient of conductivity material, for example organic material or metal.
Then, utilize for example chip join technology, the epitaxial structure of the light-emitting diode of Fig. 3 and transparency carrier 300 structures of Fig. 4 are fitted, and following layer 302 is engaged with p N-type semiconductor N contact layer 214.Utilization is carried out chip join by following layer 302 high temperature resistant and that high-temperature coefficient of conductivity material is constituted, does not need to consider to engage the direction configuration of light-emitting diode chip for backlight unit, therefore can improve qualification rate, and can reduce production costs.Secondly, behind transparency carrier 300 replacement substrates 200, not only can effectively reduce the loss of substrate light absorption, the light that also can improve light-emitting diode takes out efficient.Moreover, the reflector 304 of transparency carrier 300, the photon that can provide multi-layer quantum well active layer 210 to be produced utilizes again, and improves the quantity that photon is taken out by the side of light-emitting diode component.
After waiting to finish the chip join of light-emitting diode, for example utilize electron gun vapour deposition method (E-GunEvaporation), hot vapour deposition method or sputtering method (Sputtering) to form transparency conducting layer 216 and cover on the n N-type semiconductor N contact layer 206, take out efficient with the light that improves light-emitting diode.Wherein, the material of transparency conducting layer 216 can be alloy, titanyl compound or the nitride [for example titanium nitride (TiN)] of titanium (Ti), titanium, the oxide of tantalum (Ta) [tantalum pentoxide (Ta for example
2O
5)] or nitride, platinum (Pt), the alloy of platinum, tin indium oxide (Indium Tin Oxide; ITO), indium oxide (Indium Oxide), tin oxide (Tin Oxide) or cadmium tin (Cadmium Tin Oxide) etc.
After transparency conducting layer 216 forms, utilize for example little shadow and etching mode to define, so as to the n N-type semiconductor N contact layer 206 that removes transparency conducting layer 216 partly, part, the n N-type semiconductor N coating layer 208 of part, the multi-layer quantum well active layer 210 of part and the p N-type semiconductor N coating layer 212 of part, and expose p N-type semiconductor N contact layer 214 partly.Then, for example utilize deposition and little shadow to form n type contact mat 218 respectively or simultaneously on transparency conducting layer 216 partly with etched definition technology, and form on the part of p N-type semiconductor N contact layer 214 that p type contact mat 220 is positioned at exposure, thereby finish the making of light-emitting diode component, shown in Fig. 5 a.Because the doping content of n N-type semiconductor N is higher than the p N-type semiconductor N, so n type contact mat 218 can provide preferable electric current dispersion effect in the front of light-emitting diode component.
For realizing that high light takes out efficient and improves CURRENT DISTRIBUTION (Current Spreading) effect, after transparency carrier 300 structures of the light-emitting diode epitaxial structure of applying Fig. 3 and Fig. 4, can utilize for example development and dry type or Wet-type etching technology definition n N-type semiconductor N contact layer 222 earlier, and form the n N-type semiconductor N contact layer 222 of surface irregularity.Wherein, formed n N-type semiconductor N contact layer 222 can expose the n N-type semiconductor N coating layer 208 of part after etching, also can not expose n N-type semiconductor N coating layer 208.In a preferred embodiment of the present invention, n N-type semiconductor N contact layer 222 can be the cylinder or the corner structure of tool noncontinuous surface, or the netted or list structure of tool continuous surface.Next, for example utilizing, electron gun vapour deposition method, hot vapour deposition method or sputtering method formation transparency conducting layer 224 cover on the n N-type semiconductor N contact layer 222.Wherein, the material of transparency conducting layer 224 can be alloy, tin indium oxide, indium oxide, tin oxide or the cadmium tin etc. of the oxide of alloy, titanyl compound or nitride, tantalum of titanium, titanium or nitride, platinum, platinum.When n N-type semiconductor N contact layer 222 exposed the n N-type semiconductor N coating layer 208 of part, transparency conducting layer 224 covered on the n N-type semiconductor N coating layer 208 of n N-type semiconductor N contact layer 222 and exposure; And when n N-type semiconductor N contact layer 222 did not expose n N-type semiconductor N coating layer 208, transparency conducting layer 224 only covered on the n N-type semiconductor N contact layer 222.
Similarly, after transparency conducting layer 224 forms, shown in Fig. 5 b, utilize for example little shadow and etching mode to define, so as to the n N-type semiconductor N contact layer 222 that removes transparency conducting layer 224 partly, part, the n N-type semiconductor N coating layer 208 of part, the multi-layer quantum well active layer 210 of part and the p N-type semiconductor N coating layer 212 of part, thereby expose p N-type semiconductor N contact layer 214 partly.Then, for example utilize deposition and little shadow to form n type contact mat 218 respectively or simultaneously on transparency conducting layer 224 partly with etched definition technology, and form on the part of p N-type semiconductor N contact layer 214 that p type contact mat 220 is positioned at exposure, thereby finish the making of light-emitting diode component.
Please refer to Fig. 6, Fig. 6 is the light removing direction schematic diagram of a preferred embodiment of the present invention light-emitting diode.Light-emitting diode of the present invention also has the light removing direction of a plurality of increases such as direction 2, direction 3, direction 4, direction 5 and direction 6 except the light of direction 1 with traditional light-emitting diode takes out, therefore can obtain catch light output brightness.
By the invention described above preferred embodiment as can be known, an advantage of the present invention is exactly because the present invention utilizes the then material of high temperature resistant and the high-temperature coefficient of conductivity to carry out the chip join of light-emitting diode, so must not consider to engage the direction configuration of light-emitting diode chip for backlight unit.Therefore, can improve qualification rate, and then reach the purpose that reduces production costs.
By the invention described above preferred embodiment as can be known, another advantage of the present invention is exactly because remove the primary substrate of GaAs and the light-emitting diode epitaxial structure is fitted in transparency carrier, therefore not only can significantly reduce the loss of substrate light absorption, also can improve light and take out efficient.
By the invention described above preferred embodiment as can be known, another advantage of the present invention is exactly because therefore the light-emitting diode chip for backlight unit surface deposition transparency conducting layer of the present invention after applying can improve light and take out efficient.And deposition of transparent conductive film on the n N-type semiconductor N contact layer after the etching is taken out the efficient except providing high, can also take into account the electric current dispersion effect.
By the invention described above preferred embodiment as can be known, another advantage of the present invention is exactly because the present invention forms the reflector in the one side of transparency carrier, therefore can provide photon to utilize again, and improves the quantity that photon is taken out by the side of light-emitting diode component.
By the invention described above preferred embodiment as can be known, an advantage more of the present invention is exactly because the n type contact mat of light-emitting diode of the present invention is positioned at the front of assembly, therefore more traditional p type contact mat has better electric current dispersion effect at the light-emitting diode in assembly front.
Be understandable that; for the person of ordinary skill of the art; can make other various corresponding changes and distortion according to technical scheme of the present invention and technical conceive, and all these changes and distortion all should belong to the protection range of accompanying Claim of the present invention.