Vertical type light emitting diode and manufacture method thereof
Technical field
The present invention relates to a kind of light-emitting diode and manufacture method thereof, particularly relate to a kind of vertical type light emitting diode and manufacture method thereof with local substrate of removing.
Background technology
Fig. 1 a to Fig. 1 d is for showing the process section of traditional vertical type light emitting diode.At first, provide sapphire substrate 100.Next, utilize extensional mode, on the surface of sapphire substrate 100, form epitaxial light emission structure 102, as shown in Figure 1a.In general, epitaxial light emission structure 102 mainly comprises the first electrical semiconductor layer, active layers and the second electrical semiconductor layer that piles up in regular turn.Because sapphire substrate 100 is insulating materials, therefore when making the electrode structure of vertical conducting, another substrate with conduction property 104 need be provided usually, and the sapphire substrate 100 of original electric insulation is removed.After epitaxial light emission structure 102 is finished, utilize the mode of pasting (Bonding), epitaxial light emission structure 102 is pasted on the conductive substrate 104, shown in Fig. 1 b.
After epitaxial light emission structure 102 pasted substrate 104, utilize laser lift-off technique, full wafer sapphire substrate 100 is removed from epitaxial light emission structure 102, thereby expose the surface of epitaxial light emission structure 102, shown in Fig. 1 c.Then, on the surface of epitaxial light emission structure 102 and substrate 104, form the first electrical electrode 106 and the second electrical electrode 108 respectively.Then, can utilize cutting mode to be partitioned into many light-emitting diode chip for backlight unit 110, shown in 1d figure.
Yet, in above-mentioned light-emitting diode manufacturing process, because when using laser lift-off technique to remove full wafer sapphire substrate 100, the reason of the normal or temperature difference caused stress too high because of temperature in the laser treatment process, cause light-emitting diode structure to be damaged, and when peeling off chip is produced too high energy and shift, cause the deterioration of component characteristic.Thus, will cause the operating characteristic of light-emitting diode component and production qualification rate all therefore to be had a greatly reduced quality.In addition, whole component process also can be slow excessively because of the peeling rate of substrate, and the full wafer strippable substrate is quite consuming time, and cause the technology cost to increase, and also can influence output.Moreover such arts demand affixes to epitaxial light emission structure on the extra substrate 104 again, therefore can increase cost, and causes qualification rate to descend.
Summary of the invention
Therefore, the object of the present invention is to provide a kind of manufacture method of vertical type light emitting diode, it is after the growth of finishing epitaxial structure, sapphire substrate is carried out the part to be removed, therefore not only can reduce substrate extinction problem, and, can further improve light and take out efficient because light can be taken out by sapphire substrate.
Another object of the present invention is that a kind of manufacture method of vertical type light emitting diode is being provided, only the part removes sapphire substrate, add the additional process that does not need epitaxial structure is affixed to another substrate, therefore can improve the technology qualification rate, and can effectively reduce production costs.
Another object of the present invention provides a kind of vertical type light emitting diode, owing to utilize the laser technology part to peel off sapphire substrate, thus, the high heat of reason and destroy light-emitting diode structure not, so the operation reliability of assembly is good.
Another object of the present invention provides a kind of vertical type light emitting diode, has the metal electrode of high reflectance, and the light that therefore can improve assembly takes out efficient.
Another object of the present invention provides a kind of vertical type light emitting diode, has good CURRENT DISTRIBUTION effect, therefore can be applicable on big electric current or the powerful light-emitting diode component, and then can enlarge application.
According to above-mentioned purpose of the present invention, a kind of vertical type light emitting diode is proposed, comprise at least: an epitaxial light emission structure has opposite first and second surface; One first electrical electrode is positioned on the first surface of epitaxial light emission structure; The sapphire substrate that one part removes is positioned in the first of epitaxial light emission structure second surface, and exposes the second portion of epitaxial light emission structure second surface; And one second electrical electrode, be positioned on the second portion of epitaxial light emission structure second surface, wherein the first electrical electrode and the second electrical electrode is electrical opposite.
According to preferred implementation of the present invention, above-mentioned vertical type light emitting diode can be gallium nitride based (GaN-based) light-emitting diode.In addition, the sapphire substrate that removes of part can be for utilizing the sapphire substrate of the formed local laser lift-off of laser cutting technique.
The described first electrical electrode and the described second electrical electrode are a plurality of metal electrodes.The material of described these metal electrodes is the metal of high reflectance.
According to purpose of the present invention, a kind of manufacture method of vertical type light emitting diode is proposed, comprise the following steps: at least at first, a sapphire substrate is provided; On this sapphire substrate, form an epitaxial light emission structure; On the surface of above-mentioned epitaxial light emission structure, form one first electrical electrode; Carry out the part and remove step, so that part sapphire substrate another surface from epitaxial light emission structure is removed, thereby expose another surperficial part of epitaxial light emission structure, wherein another surface of epitaxial light emission structure surperficial relative with the first electrical electrode place; Then, form one second electrical electrode on another surperficial expose portion of epitaxial light emission structure, wherein the first electrical electrode and the second electrical electrode is electrical opposite.
Described vertical type light emitting diode is a GaN series LED.Described part removes step and comprises at least and utilize a laser cutting technique and a laser lift-off technique.The described first electrical electrode and the described second electrical electrode are a plurality of metal electrodes.The material of described these metal electrodes is the metal of high reflectance.
According to preferred implementation of the present invention, above-mentioned part removes step can utilize laser lift-off technique, and the material of the first electrical electrode can be the metal of high reflectance.
A kind of manufacture method of vertical type light emitting diode comprises the following steps: to provide a sapphire substrate at least, and wherein, described sapphire substrate is preset with a plurality of lines of cut; On described sapphire substrate, form an epitaxial light emission structure; On a surface of described epitaxial light emission structure, form one first electrical electrode layer; Carry out first cutting step along described these lines of cut, be divided into a plurality of light-emitting diode chip for backlight unit with the light-emitting diode disk that described sapphire substrate, described epitaxial light emission structure and the described first electrical electrode layer are constituted; Carry out the part and remove step, remove the described sapphire substrate of part with another surface from described epitaxial light emission structure, thereby expose described another surperficial part of epitaxial light emission structure described in each described light-emitting diode chip for backlight unit, wherein, described another surface of described epitaxial light emission structure is relative with described surface; And on described another surperficial expose portion of epitaxial light emission structure described in each described light-emitting diode chip for backlight unit, form one second electrical electrode layer, wherein, the described first electrical electrode layer is electrical opposite with the described second electrical electrode layer.
Wherein, described first cutting step comprises at least and utilizes laser cutting technique.And described part removes step and comprises at least: carry out second cutting step, cut out the described part of described sapphire substrate thus; And carry out strip step, described another surface of thus the described part of described sapphire substrate being peeled off described epitaxial light emission structure.Wherein, described second cutting step comprises at least and utilizes laser cutting technique.And described strip step comprises at least and utilizes laser lift-off technique.
Owing to come the part to divest sapphire substrate by laser cutting and lift-off technology, therefore not only can improve substrate extinction phenomenon, and light can take out from sapphire substrate, thereby can promote light and take out efficient, also do not need to carry out again extra substrate sticking technology, thereby can reduce cost, and can improve the technology qualification rate.In addition,, therefore can avoid light emitting diode construction to be subjected to the destruction of the high heat of technology, thereby can guarantee the operation reliability of assembly, more can improve the production qualification rate, reduce cost because only the part divests sapphire substrate.
Below, with preferred implementation of the present invention purpose of the present invention, structure, feature and function thereof are described in further detail in conjunction with the accompanying drawings.
Description of drawings
Fig. 1 a to Fig. 1 d is the process section that shows traditional vertical type light emitting diode; And
Fig. 2 a to Fig. 2 e shows a kind of process section of vertical type light emitting diode according to the preferred embodiment of the present invention.
Wherein, Reference numeral:
100: sapphire substrate 102: epitaxial light emission structure
104: 106: the first electrical electrodes of substrate
108: the second electrical electrodes 110: light-emitting diode chip for backlight unit
200: sapphire substrate 202: epitaxial light emission structure
204: the first electrical electrodes 206: the part of desiring to remove
208: 210: the second electrical electrodes of part that desire keeps
212: 214: the first road cutting actions of light-emitting diode disk
216: the second road cutting actions 218: light-emitting diode chip for backlight unit
220: stripping process
Embodiment
The invention discloses a kind of vertical type light emitting diode and manufacture method thereof, it is after epitaxial light emission structure forms, only the part removes sapphire substrate, therefore can improve the technology qualification rate, reduces the technology cost, improve the operation reliability that light takes out efficient and improves assembly.In order to make narration of the present invention more detailed and complete, can be with reference to the diagram of following description and cooperation Fig. 2 a to Fig. 2 e.
Fig. 2 a to Fig. 2 e is for showing a kind of process section of vertical type light emitting diode according to the preferred embodiment of the present invention.In the present invention, when making vertical type light emitting diode, at first provide sapphire substrate 200.Utilize for example extensional mode again, growth epitaxial light emission structure 202 on a surface of sapphire substrate 200.In some instances, epitaxial light emission structure 202 can comprise the second electrical semiconductor layer, active layers and the first electrical semiconductor layer that piles up in regular turn at least.For instance, vertical type light emitting diode of the present invention can be GaN series LED, and the active layers material of epitaxial light emission structure 202 is a gallium nitride series material.Next, utilize mode as vapor deposition, on another surface relative of epitaxial light emission structure 202, form the first electrical electrode 204, thereby the first electrical electrode 204 is positioned on the first electrical semiconductor layer of epitaxial light emission structure 202, shown in Fig. 2 a with surface, sapphire substrate 200 places.In the present embodiment, the material of the first electrical electrode 204 preferably adopts metal, is more preferably to adopt to have the metal of high reflectance, so that more effectively reflect the light that epitaxial light emission structure 202 is sent.Wherein, sapphire substrate 200, epitaxial light emission structure 202 and the first electrical electrode 204 constitute light-emitting diode disk (wafer) 212, shown in Fig. 2 a.
Simultaneously with reference to Fig. 2 b and Fig. 2 c, treat that the first electrical electrode 204 forms after, light-emitting diode disk 212 is overturn, again light-emitting diode disk 212 is carried out the first road cutting action 214, thereby makes sapphire substrate 200 surperficial as cutting.In the first road cutting action 214, can utilize for example technology of laser cutting, line of cut (Scribing Lines) along light-emitting diode disk 212 cuts, thereby light-emitting diode disk 212 is divided into a plurality of light-emitting diode chip for backlight unit 218, shown in Fig. 2 c.At this moment, can carry out the part and remove operation.At first, for example can utilize the technology of laser cutting to carry out the second road cutting action 216, wherein, part of desiring to remove in the sapphire substrate 200 206 and the part 208 that desire keeps can be cut out, shown in Fig. 2 b and Fig. 2 c by the first road cutting action 214 and the second road cutting action 216.Finish after the first road cutting action 214 and the second road cutting action 216, since with sapphire substrate 200 desire remove part 206 and cut out, can utilize for example technology of laser lift-off this moment, carry out local stripping process 220, thereby the part of desiring to remove 206 of sapphire substrate 200 on each light-emitting diode chip for backlight unit 218 is peeled off from epitaxial light emission structure 202, and expose the surface of the epitaxial light emission structure 202 of these part of desiring to remove 206 belows, shown in Fig. 2 d.
More noticeablely be, in the present embodiment, though along line of cut the light-emitting diode disk is divided into a plurality of light-emitting diode chip for backlight unit earlier, carry out sapphire substrate again and desire to remove the cutting action of part, right the present invention also can carry out the cutting action that sapphire substrate desires to remove part earlier, carry out the light-emitting diode disk is divided into the cutting action of a plurality of light-emitting diode chip for backlight unit again, so the present invention is not limited to the foregoing description.
Because the present invention only removes sapphire substrate 200 in the part, but not full wafer sapphire substrate 200 is removed fully, therefore not only the processing time can be shortened, significantly reduce impact to the assembly operation characteristic, more can effectively improve the production qualification rate, and then can increase output, and can reduce production costs.In addition, because the part removes sapphire substrate 200, therefore can improve the problem of substrate extinction.On the other hand, more owing to can adopt laser technology, and only the part removes sapphire substrate 200, therefore can avoid producing high heat during the lift-off processing and destroys epitaxial light emission structure 202, so can improve the operation reliability of assembly.
After the part removes sapphire substrate 200, can utilize for example mode of vapor deposition, on the surface that the epitaxial light emission structure 202 of each light-emitting diode chip for backlight unit 218 is exposed, be on the surface of the second electrical semiconductor layer of epitaxial light emission structure 202, form the second electrical electrode 210, thereby finish the making of light-emitting diode chip for backlight unit 218, shown in Fig. 2 e.Wherein, the material of the second electrical electrode 210 adopts metal relatively good, adopts the metal with high reflectance better.In the present invention, first is electrically electrical electrical opposite with second, that is to say, when first electrical when being the P type, second electrical be the N type; And when first electrically was the N type, second electrically then was the P type.In this light-emitting diode chip for backlight unit 218, the first electrical electrode 204 and the second electrical electrode 210 lay respectively on two relative surfaces of epitaxial light emission structure 202, constitute vertical conducting type light-emitting diode.
One of the present invention only is characterised in that and need removes nonconducting sapphire substrate by the part, to expose the part of conductive epitaxial light emission structure, electrode can be arranged on the surface that epitaxial light emission structure exposes, thereby produce the light emitting diode construction of vertical conducting type.Therefore, use the present invention, not only need not expend the tediously long time and peel off the primary substrate of full wafer, and can additionally use another substrate, more can save epitaxial light emission structure is pasted the operation of extra substrate so far.Thus, can reduce stripping process the energy that chip produced is shifted, alleviate negative impact, and can save the technology cost, increase output and improve qualification rate component characteristic.In addition, because the light that epitaxial light emission structure sent mainly can take out from sapphire substrate, therefore light-emitting diode of the present invention has quite good light taking-up efficient.Moreover because light-emitting diode of the present invention has vertical conducting type structure, so CURRENT DISTRIBUTION is effective, thereby can be applicable on the high-power or big galvanoluminescence diode.
By the preferred implementation of the invention described above as can be known, an advantage of LED production method of the present invention is exactly because after the growth of finishing epitaxial structure, only sapphire substrate being carried out the part removes, not only can reduce substrate extinction problem, and because light can be taken out by sapphire substrate, the light that therefore can improve assembly greatly takes out efficient.
By the preferred implementation of the invention described above as can be known, another advantage of LED production method of the present invention is exactly because can only remove sapphire substrate by the part, can exempt the additional process that epitaxial structure is affixed to another substrate, therefore can effectively reduce production costs, and can realize improving the purpose of technology qualification rate.
By the preferred implementation of the invention described above as can be known, another advantage of light-emitting diode of the present invention is exactly because utilize the laser technology part to peel off sapphire substrate, not only the strippable substrate processing time can be reduced significantly, and high hot the or too high energy of reason does not shift and destroys light-emitting diode structure, so the operation reliability of assembly is good.
By the preferred implementation of the invention described above as can be known, another advantage of light-emitting diode of the present invention is exactly because it has the metal electrode of high reflectance, so assembly has higher light and takes out efficient.
By the preferred implementation of the invention described above as can be known, another advantage of light-emitting diode of the present invention is exactly because it has vertical conducting type structure, have good CURRENT DISTRIBUTION effect, therefore can be applicable on big electric current or the powerful light-emitting diode component, have application very widely.
Though disclose preferred implementation of the present invention as mentioned above; yet it is not to be used to limit the present invention; for those of ordinary skill in the art; under the premise without departing from the spirit and scope of the present invention; can make various changes and improvements for the present invention, so protection scope of the present invention must limit by the present invention appended claim and equivalent thereof.