TWI662719B - Light-emitting device - Google Patents

Abstract

A light emitting element includes: a light emitting stack having a length, a width, a first electrical semiconductor layer, an active layer on the first electrical semiconductor layer, and a second electrical semiconductor layer on the above. Above the active layer, the first electrical semiconductor layer, the active layer, and the second electrical semiconductor layer are stacked along a stacking direction; a first electrode is connected to the first electrical semiconductor layer and is parallel Extending in the direction of the stacking direction; a second electrode connected to the second electrical semiconductor layer and extending in a direction parallel to the stacking direction; and an insulating layer located between the first electrode and the second electrode.

Description

Light emitting element

The present invention relates to a light-emitting element, and more particularly to a light-emitting element capable of increasing light extraction.

A schematic diagram of a general light emitting diode is shown in FIG. 1A and FIG. 1B. FIG. 1A is a top view and FIG. 1B is a side view. A general light emitting diode system forms a light emitting stack 101 on a substrate 111, and includes a first electrical semiconductor layer 101a, an active layer 101b, and a second electrical semiconductor layer 101c in this order from bottom to top. The first electrical semiconductor layer 101a and the second electrical semiconductor layer 101c are electrically different. For example, the first electrical semiconductor layer 101a is an n-type semiconductor layer, and the second electrical semiconductor layer 101c is a p-type semiconductor layer. A first electrode 104 is provided on the first electrical semiconductor layer 101a, and a second electrode 105 is provided on the second electrical semiconductor layer 101c to transmit current. In addition, a transparent conductive layer 103 is also provided on the second electrical semiconductor layer 101c as an ohmic contact layer. At present, both metal and transparent conductive materials can be applied to LED elements as ohmic contact materials. However, metal has the advantage of good current transmission but it has the disadvantage of light absorption. Although transparent conductive materials have the advantage of light transmission, current transmission is not as good as metal . Therefore, most of the current solutions are to use the transparent conductive layer 103 for ohmic contact, and then use metal wires as extension electrodes 105a to transfer current. Under the design of the extension electrode 105a with a metal line, good current diffusion can be achieved, but the shading of the metal is also increased, which results in loss of brightness.

A light emitting element includes: a light emitting stack having a length, a width, a first electrical semiconductor layer, an active layer on the first electrical semiconductor layer, and a second electrical semiconductor layer on the above. Above the active layer, the first electrical semiconductor layer, the active layer, and the second electrical semiconductor layer are stacked along a stacking direction; a first electrode is connected to the first electrical semiconductor layer and is parallel Extending in the direction of the stacking direction; a second electrode connected to the second electrical semiconductor layer and extending in a direction parallel to the stacking direction; and an insulating layer located between the first electrode and the second electrode.

101‧‧‧light emitting stack

101a‧‧‧first electrical semiconductor layer

101b‧‧‧active layer

101c‧‧‧Second electrical semiconductor layer

103‧‧‧ transparent conductive layer

104‧‧‧first electrode

105‧‧‧Second electrode

105a‧‧‧Extended electrode

111‧‧‧ substrate

201‧‧‧Light-emitting stack

201a‧‧‧first electrical semiconductor layer

201b‧‧‧active layer

201c‧‧‧Second electrical semiconductor layer

202‧‧‧ conductive layer

202a‧‧‧ (of conductive layer 202) first overlapping portion

202b‧‧‧ (of the conductive layer 202) the first extension

203‧‧‧Transparent conductive layer

203a‧‧‧ (transparent conductive layer 203) second overlapping portion

203b‧‧‧ (transparent conductive layer 203) second extension

204‧‧‧First electrode

205‧‧‧Second electrode

206‧‧‧Permanent substrate

206a‧‧‧Insulation

206b‧‧‧Si substrate

207‧‧‧Insulation

211‧‧‧ substrate

212‧‧‧Temporary substrate

213, 213’‧‧‧ dividing line

214‧‧‧laser light

215‧‧‧Joint surface

301‧‧‧luminescent stack

302‧‧‧ conductive layer

302a‧‧‧ (conducting layer 302) first overlapping portion

302b‧‧‧ (conducting layer 302) first extension

303‧‧‧Transparent conductive layer

302a‧‧‧ (of the transparent conductive layer 302) first overlapping portion

303b‧‧‧ (transparent conductive layer 303) second extension

304‧‧‧First electrode

305‧‧‧Second electrode

306‧‧‧Permanent substrate

306a, 306b ‧‧‧ (permanent substrate) where electrodes are to be formed

307‧‧‧ Insulation

307a‧‧‧ (insulation layer) where electrode is to be formed

361‧‧‧ bonding substance

362‧‧‧Temporary substrate

400‧‧‧Light-emitting element

401‧‧‧luminescent stack

402‧‧‧ conductive layer

402a‧‧‧ (conducting layer 402) first overlapping portion

402b‧‧‧ (conducting layer 402) first extension

402c‧‧‧ (Conductive layer 402 of the third extension)

403‧‧‧ transparent conductive layer

403a‧‧‧ (transparent conductive layer 403) second overlapping portion

403b‧‧‧ (transparent conductive layer 403) second extension

403c‧‧‧ (transparent conductive layer 403) fourth extension

403’‧‧‧ transparent conductive layer

404‧‧‧First electrode

405‧‧‧Second electrode

406‧‧‧Permanent substrate

407‧‧‧Insulation

408‧‧‧ bonding layer

462‧‧‧Transparent substrate

PP’‧‧‧plane

500‧‧‧light-emitting device

501,502,503‧‧‧‧Light-emitting element

501a, 501b‧‧‧electrode

502a, 502b‧‧‧ electrode

503a, 503b‧‧‧electrode

510‧‧‧ sub-mount

511,512,513,514‧‧‧Circuits

601‧‧‧luminescent stack

601a‧‧‧first electrical semiconductor layer

601b‧‧‧active layer

601c‧‧‧Second electrical semiconductor layer

603‧‧‧ transparent conductive layer

604‧‧‧contact layer

604’‧‧‧first electrode

604 "‧‧‧Second electrode

604a‧‧‧contact layer removal area

One end of 605‧‧‧ (conducting layer 686)

606‧‧‧Transparent substrate

607‧‧‧ transparent bonding substance

611‧‧‧ substrate

659‧‧‧protective layer

681‧‧‧ intermediate layer structure

682‧‧‧Temporary substrate

683‧‧‧ bonding substance

684‧‧‧ isolated area

685‧‧‧ insulation

685a‧‧‧electrical connection area

686‧‧‧ conductive layer

701‧‧‧luminescent stack

701a‧‧‧first electrical semiconductor layer

701b‧‧‧active layer

701c‧‧‧Second electrical semiconductor layer

703‧‧‧Transparent conductive layer

704‧‧‧contact layer

One end of 705‧‧‧ (conducting layer 686)

706‧‧‧Transparent substrate

707‧‧‧ transparent bonding substance

759‧‧‧protective layer

781‧‧‧ intermediate layer structure

785‧‧‧ insulation

786‧‧‧ conductive layer

Figure 1A: Top view of a light-emitting diode showing the prior art

Fig. 1B: a side view illustrating a light emitting diode of the prior art

2A to 2F: a method and structure for forming a light emitting diode according to a first embodiment of the present invention

3A to 3E: a method and structure for forming a light emitting diode according to a second embodiment of the present invention

4A to 4D: a method and structure for forming a light emitting diode according to a third embodiment of the present invention

FIG. 5: A light-emitting device formed by applying the light-emitting diode according to the embodiment of the present invention

6A to 6I: a method and structure for forming a light emitting diode according to a fourth embodiment of the present invention

FIG. 7 shows a light-emitting diode structure of a fifth embodiment of the present invention

FIG. 2 is a first embodiment of the present invention. As shown in FIG. 2A, a light-emitting stack 201 is first formed on a substrate 211. The light-emitting stack 201 includes a first electrical semiconductor layer 201a and an active layer in order from bottom to top. 201b, and a second electrical semiconductor layer 201c. The first electrical semiconductor layer 201a and the second electrical semiconductor layer 201c are electrically different. For example, the first electrical semiconductor layer 201a is an n-type semiconductor layer, and the second electrical semiconductor layer 201c is a p-type semiconductor layer. Then take a part from the light-emitting stack 201 for subsequent steps. The method can be, for example, an epitaxy lift-off (ELO) method, as shown in FIG. 2A. First, a laser is used between the C part to be accessed and the L and R parts reserved nearby. Cutting or lithography and etching are used to form division lines 213 and 213 'to facilitate subsequent tilting. A temporary substrate 212, such as glass, is then provided to bond with the part C to be accessed. The bonding method may be, for example, forming a bonding substance (not shown) between the bonding surfaces 215 (as shown in FIG. 2B), and applying heat and pressure to the temporary substrate 212 and the substrate 211 for bonding. The bonding substance may be a conductive substance or a non-conductive substance, and the conductive substance includes, for example, a metal or alloy material, such as gold, silver, or tin or an alloy thereof. Examples of the non-conductive material include polyimide (PI), benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy resin (Epoxy), and other organic bonding materials. The method of joining is well known in the technical field, so it will not be described in detail. After the bonding is formed, a laser light can be applied to the interface between the part C to be used and the substrate 211, and at the same time, the part C to be used can be lifted upwards by temporarily bonding the substrate 212. As shown in FIG. 2B, the epitaxial tilting step is completed. As shown in FIG. 2B, the removed light-emitting stack 201 has a length L and a width W, and the x-axis shown in the figure is parallel to the length L and the y-axis is parallel to the width W.

Next, as shown in FIG. 2C, a permanent substrate 206 is provided. The permanent substrate 206 may be a conductive substrate or a non-conductive substrate, and the conductive substrate may be a semiconductor material such as silicon, silicon carbide, or a metal. The non-conductive substrate may be, for example, sapphire (Al2O3), glass, or ceramic magnetic material. In this embodiment, a silicon substrate 206b commonly used in the industry is selected, and this embodiment has a horizontal structure. Therefore, an insulating layer 206a such as silicon oxide is formed thereon to form the permanent substrate 206 of this embodiment. Next, a conductive layer 202 is formed on the permanent substrate 206, and the width W 'of the conductive layer 202 is greater than the width of the light-emitting stack 201 removed as described above. W. The conductive layer 202 may be, for example, a metal or a metal oxide or a stack of both. The metal may be, for example, indium (In), gold (Au), titanium (Ti), platinum (Pt), aluminum (Al), silver (Ag), or an alloy thereof, or a laminate of the above metals. The metal oxide is, for example, indium tin oxide (ITO). Then, the light-emitting stack 201 removed as described above is bonded to the conductive layer 202. This bonding is, for example, forming a bonding layer 208 on the light emitting stack 201 first, and then bonding to the conductive layer 202. For example, the bonding layer 208 is indium tin oxide (ITO), and the conductive layer 202 is a stack of titanium (Ti) / gold (Au) / silver (Ag) / indium tin oxide (ITO) from bottom to top. In addition, the bonding layer 208 may also include a reflective metal to serve as a mirror at the same time. In this embodiment, for example, silver (Ag) / titanium (Ti) / platinum (Pt) / gold (Au) is sequentially formed on the light-emitting stack 201. ) Is used as the bonding layer 208, and the conductive layer 202 is made of titanium (Ti) / gold (Au) / indium (In) from bottom to top. Similarly, the bonding can be completed by heating and pressing, and the laser light irradiation method can be used to apply a laser light to the interface between the light-emitting stack 201 and the temporary substrate 212 to remove the temporary substrate 212. As shown in FIG. 2D, the conductive layer 202 is located under the light-emitting stack 201 (the first electrical semiconductor layer 201a (not shown in this figure, see FIG. 2A)), and because the width W 'of the conductive layer 202 is larger than the light-emitting layer The width W of the stacked layer 201, therefore, the conductive layer 202 can be regarded as including a first overlapping portion 202a overlapping the first electrical semiconductor layer 201a and a first extending portion 202b not overlapping the first electrical semiconductor layer 201a. The first extending portion 202b extends in a first direction (+ y direction) parallel to the width. Next, an insulating layer 207 is formed on the light-emitting stack by using, for example, a chemical vapor deposition (CVD) method or an electron beam (E-Gun) method in combination with lithography and etching or a lift-off method. One side wall of the layer 201 and the conductive layer 202 is shown in the figure. The material of the insulating layer 207 may be, for example, silicon dioxide (SiO2), silicon nitride (SiNx), aluminum oxide (Al2O3), or the like.

Next, as shown in FIG. 2E, a transparent conductive layer 203 is formed on the light-emitting stack 201 (the second electrical semiconductor layer 201c (not shown in this figure, see FIG. 2A)), and similarly, the transparent conductive layer 203 has a width larger than that of the second electrical semiconductor layer 201c. Therefore, the transparent conductive layer 203 can be regarded as including a second overlapping portion 203a overlapping with the second electrical semiconductor layer 201c and a second extending portion 203b not overlapping with the second electrical semiconductor layer 201c, and the second extending portion 203b is To the second direction parallel to the width (-y side Direction), and the second direction (-y direction) is opposite to the aforementioned first direction (+ y direction). The transparent conductive layer 203 is, for example, a metal oxide or a thin metal having a thickness of less than 500 angstroms. The metal oxide is, for example, indium tin oxide (ITO), aluminum zinc oxide (AZO), cadmium tin oxide, antimony tin oxide, zinc oxide (ZnO), indium zinc oxide (IZO), and oxide Materials such as zinc tin (ZTO) or the groups they form. The thin metal is, for example, aluminum, gold, platinum, zinc, silver, nickel, germanium, indium, tin, or an alloy of these metals. Finally, as shown in FIG. 2F, a first electrode 204 is formed on the first extension 202b, and a second electrode 205 is formed on the second extension 203b. In particular, as shown in the figure, the first electrode 204 is substantially only connected to the first extension 202b or a part of the conductive layer 202, and the second electrode 205 is generally only connected to the second of the transparent conductive layer 203 The extension portion 203b or a part thereof is connected, that is, the second overlapping portion 203a where the transparent conductive layer 203 and the second electrical semiconductor layer 201c overlap does not have the second electrode 205 or any extension electrode of the prior art, so The loss of brightness caused by metal shading. Therefore, the conduction in the parallel width direction (y direction) of the light emitting stack 201 in this embodiment is substantially completed only by the second overlapping portion 203a of the transparent conductive layer 203. Taking the transparent conductive layer 203 as indium tin oxide as an example, its thickness is generally between 50 nm and 1 μm, and the commonly used 120 nm is taken as an example. Under this thickness, the distance between its conductive (or charge transfer) is about 30 μm to 100 μm (that is, 0.1 mm). Therefore, the width W of the light-emitting stack 201 in this embodiment can be designed to be about 100 μm (that is, 0.1 mm), and for a light-emitting stack with an area specification of 42 mil * 42 mil (about 1 mm * 1 mm, that is, 1 mm 2) that is commonly used in general commerce. In this embodiment, the length L of the light-emitting stack 201 can be lengthened to provide the same light-emitting area. In this way, the current is transmitted using the excellent current diffusion characteristics of the second electrode 205 metal, and the transparent conductive layer 203 with high light transmission is used for transmission. The current is applied to the light-emitting stack 201 so that the current can be uniformly transmitted, and the light-emitting area is prevented from being blocked by the metal of the electrode or the extension electrode. Therefore, the length L of the light-emitting stack 201 can be designed to be about 10mm (1mm2 / 0.1mm = 10mm), so the ratio of the length L to the width W is 10mm: 0.1mm, that is, 100: 1. Generally speaking, as the thickness of the indium tin oxide of the transparent conductive layer 203 is thicker, the conductive distance is longer, so the design of the width W can be wider than the above example, or it can be adjusted on various design parameters such as the light emitting area, such as light emission. The area adjustment is smaller than the above example, and the corresponding design length L is also smaller than the above example. For example, the width W is greater than The above example is enlarged twice, and the length L is reduced to 1/10 of the above example. Then the ratio of the length L to the width W of the light-emitting stack 201 is greater than about 5: 1 to achieve the above purpose.

3A to 3E show a second embodiment of the present invention. This second embodiment is a modification of the above-mentioned first embodiment. In the first embodiment, as shown in FIG. 2F, the first electrode 204 is formed on the first extension portion 202b, and the second electrode 205 is formed on the second extension portion 203b. In the second embodiment, as shown in FIG. 3E, the first electrode 304 is formed under the first extension portion 302b, and the second electrode 305 is formed under the second extension portion 303b. In addition, in the second embodiment, the permanent substrate 206 made of the silicon substrate 206a with the insulating layer 206b above is replaced by the permanent substrate 306 made of glass. Otherwise, the second embodiment is substantially the same as the first embodiment. Therefore, referring to the method of FIG. 2A to FIG. 2E of the foregoing first embodiment, the structure of FIG. 3A similar to that of FIG. 2E can be obtained, including a permanent substrate 306 made of glass, a conductive layer 302, a light-emitting stack 301, and an insulating layer. 307 and a transparent conductive layer 303. Next, as shown in FIG. 3B, the structure of FIG. 3A is bonded to the temporary substrate 362 by a bonding substance 361 for subsequent electrode formation. Next, as shown in FIG. 3C, by forming a protective layer (not shown) such as a photoresist on the permanent substrate 306, but exposing the electrodes 306a, 306b, and lithography and etching or sandblasting or In a mixed method, the permanent substrate 306 where the electrodes 306a and 306b are to be formed is removed, and the insulating layer 307 and the place 307a where the electrodes are to be formed 307a are also removed. In this way, a part of the conductive layer 302 and a part of the transparent conductive layer 303 are exposed for subsequent formation of the first electrode 304 and the second electrode 305 thereon. As shown in FIG. 3D, the transparent conductive layer 303 and the light-emitting stack are stacked. One of the top surfaces of 301 is connected, and the first electrode 304 and the second electrode 305 are not higher than the top surface of the light-emitting stack 301 when viewed from the direction of the permanent substrate 306 toward the light-emitting stack 301. In detail, the first electrode 304 and the second electrode 305 have an upper surface that is not higher than a top surface of the light-emitting stack 301. In some applications, the bonding substance 361 and the temporary substrate 362 may remain. In this embodiment, the bonding material 361 and the temporary substrate 362 are removed in a manner such that the laser light irradiates the bonding material 361 or is etched to complete the structure of the second embodiment shown in FIG. 3E. Similarly, in this embodiment, the first electrode 304 is substantially only in contact with the first extension portion 302b or a part of the conductive layer 302, and the second electrode 305 It is generally only connected to the second extension portion 303b or a part of the transparent conductive layer 303, that is, the second overlap portion 303a of the transparent conductive layer 303 does not have the second electrode 305 or the extension electrode, so there is no metal shading The resulting loss of brightness.

4A to 4D show a third embodiment of the present invention. This third embodiment is also a modification of the first embodiment described above. In the first embodiment, as shown in FIG. 2F, the first electrode 204 is formed on the first extension portion 202b, and the second electrode 205 is formed on the second extension portion 203b. In the third embodiment, as shown in FIG. 4C, the first electrode 404 is formed under the first extension portion 402b, and the second electrode 405 is formed over the second extension portion 403b. In addition, in the third embodiment, the permanent substrate 206 made of the silicon substrate 206b with the insulating layer 206a above is changed to a permanent substrate 406 made of a transparent material. The transparent material may be glass, for example. And other dielectric materials. Otherwise, the third embodiment is substantially similar to the first embodiment. Therefore, referring to the method of FIG. 2A to FIG. 2E of the foregoing first embodiment, the structure of FIG. 4A similar to FIG. 2E can be obtained, including a permanent substrate 406 made of glass, a conductive layer 402, a light-emitting stack 401, and an insulating layer. 407, and a transparent conductive layer 403. It should be noted that the conductive layer 402 of this embodiment uses indium tin oxide (ITO), so the light-emitting stack 401 is bonded to it as mentioned in the aforementioned first embodiment. For example, an oxide layer is formed on the light-emitting stack 401 first. A bonding layer 408 of indium tin (ITO) is then bonded to the conductive layer 402. It should also be noted that the conductive layer 402 on the permanent substrate 406 is covered in a whole layer. Therefore, compared with the first embodiment, the conductive layer 402 can be regarded as including the first overlapping portion 402a and the first extending portion 402b, and other A third extension 402c. Similarly, the transparent conductive layer 403 can be regarded as including a second overlapping portion 403a, a second extending portion 403b, and another fourth extending portion 403c. In this embodiment, the first extension portion 402b and the second extension portion 403b extend in the same direction (-y direction). The third extension portion 402c and the fourth extension portion 403c extend in the same direction (+ y direction).

Next, as shown in FIG. 4B, another transparent material, such as a transparent substrate 462 of a dielectric material such as glass, is formed thereon with a transparent conductive layer 403 ', such as indium tin oxide (ITO), and then it is similar to that of FIG. 4A. Structural bonding, transparent conductive layer 403 'of indium tin oxide (ITO) and transparent conductive layer of indium tin oxide (ITO) The electrical layer 403 is combined. Next, as shown in FIG. 4C, a part of the permanent substrate 406 and a part of the transparent substrate 462 are removed by lithography and etching or sandblasting or a mixture of the two, and a part of the conductive layer 402 and a part of the conductive layer are exposed. The third embodiment is completed by forming a transparent conductive layer 403 ', forming a first electrode 404 under the first extension portion 402b, and forming a second electrode 405 over the transparent conductive layer 403'.

As shown in FIG. 4C, in the third embodiment, the first electrode 404 has a first surface (that is in contact with the PP 'plane) perpendicular to the first extension 402b, and the second electrode 405 has a perpendicular extension to the second extension The second surface of the portion 403b (those in contact with the PP 'plane), and the first surface and the second surface are substantially coplanar, that is, co-PP' plane. In this way, the first surface and the second surface can be bonded to a carrier board (not shown), and the surface of the carrier board is the PP 'plane. In application, if such a device is rotated 90 degrees, as shown in FIG. 4D, the light emitted by the light-emitting stack 401 can be transmitted in multiple directions, including a permanent substrate 406 made of a transparent material, a transparent substrate 462, and an insulating layer 407. It is transparent and has the advantages of full ambient light.

As shown in FIG. 5, the light-emitting elements of the three embodiments described above can be further combined with other elements to form a light-emitting device 500. The light-emitting device 500 includes a sub-mount 510 having at least one circuit 511, 512, 513, 514; at least one light-emitting element is located on the sub-carrier 510. In this embodiment, three light-emitting elements 501, 502, 503 are provided on the sub-carrier 510, and the light-emitting element Any of 501,502,503 can be any of the light emitting elements of the three embodiments described above, and the electrodes of the light emitting element 501,502,503 can be bonded to the circuit 511,512,513,514 of the sub-carrier 510 by solder (solder, not shown), such as a light emitting element The two electrodes 501a, 501b of 501 are respectively bonded to circuits 511, 512; the two electrodes 502a, 502b of light-emitting element 502 are respectively bonded to circuits 512, 513; the two electrodes 503a, 503b of light-emitting element 503 are respectively bonded to circuits 513, 514, so that the light-emitting elements 501, 502, 503 can be fixed On the sub-carrier 510, the light-emitting elements 501, 502, and 503 form circuits in series (such as this embodiment) or parallel or series-parallel circuits through the circuits 511, 512, 513, 514, and the conductive material structure 521, 522, such as gold or copper wires, to provide external power to This device 500. The secondary carrier 510 is, for example, ceramic, glass, fiberglass, Bakelite, or the like.

In addition to the above-mentioned implementation exceptions, the electrodes and extension electrodes on the light-emitting stack can also be moved to the light-emitting stack by a manufacturing process, leaving only a small area for electrical connection to achieve the effect of actively minimizing the light-shielding surface to solve the metal The problem of shading. The embodiment is a fourth embodiment of the present invention shown in FIGS. 6A to 6I. In FIG. 6A, a light-emitting stack 601 including a first electrical semiconductor layer 601a, an active layer 601b, and a second electrical semiconductor layer 601c is sequentially formed on a substrate 611. The light-emitting stack 601 may be selectively formed before forming the light-emitting stack 601. First, an intermediate layer structure 681 is formed, such as a buffer layer. Thereafter, a contact layer 604 is formed on the light-emitting stack 601. The contact layer 604 may be, for example, a transparent conductive oxide or a metal; the transparent conductive oxide is, for example, indium tin oxide (ITO), aluminum zinc (Aluminum Zinc) Oxide, AZO), cadmium tin oxide, antimony tin oxide, zinc oxide (ZnO), indium zinc oxide (IZO), and zinc tin oxide (ZTO) and other materials or groups thereof; metals such as aluminum, gold, Platinum, zinc, silver, nickel, germanium, indium, tin, beryllium, platinum, rhodium or alloys of these metals. When the metal is selected as a highly reflective metal, such as aluminum, silver, etc., it can also provide a mirror function; or a reflective structure (not shown) can be optionally added to the contact layer 604, such as a distributed Bragg reflective layer (Distributed Bragg Reflector (DBR) or Omni-Directional Reflector (ODR) to provide reflective functions. Then, a part of the contact layer 604 is removed by lithography and etching to form a contact layer removal area 604a. Next, as shown in FIG. 6B, a protection layer 659 is formed on the contact layer 604, and the protection layer 659 fills the contact layer removal area 604a. As shown in the figure, there are two unprotected layers 659 on the contact layer 604. The covering is reserved for use as electrodes, that is, the first electrode 604 'and the second electrode 604 ". Then, as shown in FIG. 6C, the structure of FIG. 6B is bonded to the temporary substrate 682 by a bonding substance 683 for Subsequent process. Then, a laser light (not shown) is applied to the interface between the substrate 611 and the intermediate layer structure 681 in the laser light irradiation method as described above to remove the substrate 611, and the removal of the substrate 611 can also be performed by etching. The process is completed. The structure after the substrate 611 is removed is shown in FIG. 6D.

Next, as shown in FIG. 6E, a part of the intermediate layer structure 681 and the light-emitting stack 601 are removed by lithography and etching to form an isolation region 684, and the underlying contact layer 604 and (the above-mentioned filling) are exposed. The contact layer removal region 604a) is a protection layer 659. In this way, a whole large-area light-emitting stack 601 will be divided into a plurality of light-emitting units of relatively small performance. As shown in this embodiment, it is divided into two light-emitting units of relatively small performance. The light emitting units are isolated from each other by an isolation area 684. Next, as shown in FIG. 6F, an insulating layer 685, such as silicon dioxide (SiO2), silicon nitride (SiNx), or aluminum oxide (Al2O3), is formed on the structure of FIG. 6E, and then lithography and etching are used. Remove a portion of the insulating layer 685 to form an electrical connection region 685a, and expose the underlying contact layer 604 (may also be exposed in some cases (filled in the contact layer removal region 604a) with the protective layer 659) The surface of the intermediate layer structure 681 is also substantially completely exposed, so that the light emitted by the light-emitting stack 601 can be emitted. In this way, the insulating layer 685 electrically isolates each light-emitting unit, and the light-emitting units are electrically connected in series or in parallel or in series and parallel via a conductive layer that is subsequently filled in the electrical connection area 685a. As shown in FIG. 6G, a conductive layer 686 is formed on the structure of FIG. 6F, such as aluminum, gold, platinum, zinc, silver, nickel, germanium, indium, tin and the like, or an alloy of these metals. And etching to remove a part of the conductive layer 686 to form the aforementioned electrical connection. This embodiment shows the situation of electrical connection in series. The conductive layer 686 fills the electrical connection region 685a and forms an electrical connection with the exposed contact layer 604, and the other end (ie, 605) of the conductive layer 686 is in contact with a portion of the surface of the intermediate layer structure 681. In addition, as shown in FIG. 6G, before the conductive layer 686 is formed, a transparent conductive layer 603 may be selectively formed on the intermediate layer structure 681. Therefore, the other end (605) of the conductive layer 686 in this embodiment is It is in contact with the surface of the transparent conductive layer 603. As mentioned above, since the large-area light-emitting stack 601 is divided into a plurality of relatively small-scale light-emitting units, the width (W) of each light-emitting unit becomes smaller and falls within the range of effective current transmission, so In the case of the transparent conductive layer 603, it is not necessary to provide an extension electrode on each light-emitting unit, and the terminal point (ie, 605) electrically connected to the conductive layer 686 and the light-emitting stack 601 can be designed to be very small, so that it can be uniformly transferred The current is protected from the light shielding area due to the metal of the electrode or the extension electrode. Similarly, the aspect ratio of each light-emitting unit (for example, the ratio of the length and width of the aforementioned light-emitting stack is greater than about 5: 1) can be appropriately determined as described above to provide a generally applicable light-emitting area. In addition, since this embodiment can also form different implementations such as series and parallel, even without adjusting the aspect ratio of each light-emitting unit, Appropriate number of light-emitting units in series can also provide light-emitting areas of general commercial specifications. Next, as shown in FIG. 6H, the structure of FIG. 6F is made transparent with a transparent bonding substance 607, such as polyimide (PI), benzocyclobutene (BCB), and perfluorocyclobutane (PFCB). Materials such as transparent substrates 606 such as glass are bonded to form a light emitting surface. Next, the temporary substrate 682 and the bonding substance 683 are removed by, for example, etching. As shown in FIG. 6I, this embodiment is completed. The series connection of each light-emitting unit is as described above, and the external power supply can be provided through the aforementioned first electrode 604 'and the second electrode 604 ". This embodiment is a series of implementations, and the above-mentioned FIG. 6A to FIG. The method shown in 6I, those skilled in the art can make simple adjustments to the process, such as adjusting the contact layer removal area 604a of FIG. 6A, adjusting the formation of the isolation area 684 of FIG. 6E, and the conductive layer 686 of FIG. 6G. After removing the adjustment, a fifth embodiment of the present invention in a parallel state as shown in FIG. 7 can be obtained, in which the first code of the number in FIG. 6I is changed from “6” to “7”, for example, the number 606 is a transparent substrate 606 , The reference numeral 706 is also a transparent substrate, and so on, so the fifth embodiment will not be described redundantly. It is more important to explain the contact layer 704 of the middle block (that is, the conductive layer 786 and the first electrical semiconductor) The layer 701a electrically connected to the contact layer 704) is the first electrode connected in series, and the contact layers 704 on both sides of the block (that is, the contact layer 704 located under the second electrical semiconductor layer 701c and electrically connected to it) are the first connected in series. Two electrodes (can be connected by the electrode pattern on the front) The light emitting units connected in parallel.

The above-mentioned embodiments are merely illustrative for explaining the principle of the present invention and its effects, and are not intended to limit the present invention. Any person having ordinary knowledge in the technical field to which the present invention pertains can modify and change the above embodiments without departing from the technical principles and spirit of the present invention. Therefore, the scope of protection of the rights of the present invention is listed in the scope of patent application described below.

Claims (10)

A method for manufacturing a light emitting device includes: providing a substrate; forming a conductive layer on the substrate; providing a light emitting stack on the substrate, wherein the light emitting stack has a first electrical semiconductor layer and a second electrical property The semiconductor layer and an active layer are located between the first electrical semiconductor layer and the second electrical semiconductor layer, wherein the first electrical semiconductor layer, the active layer, and the second electrical semiconductor layer are along a Stacked in the stacking direction; forming a transparent conductive layer on the light-emitting stack; forming a first electrode connected to the conductive layer; and forming a second electrode connected to the transparent conductive layer; wherein the first electrode is in the stack The direction does not overlap the light emitting stack, and the first electrode and the second electrode are not higher than a top surface of the light emitting stack when viewed from the substrate toward the light emitting stack. The method according to item 1 of the patent application scope further comprises forming an insulating layer between the light emitting stack and the second electrode. The method according to item 1 of the patent application, wherein the first electrode and the substrate are located on the same side of the conductive layer, and the second electrode and the light-emitting stack are located on the same side of the transparent conductive layer. The method according to item 2 of the scope of patent application, wherein the insulating layer has an upper surface not higher than the top surface. The method according to item 2 of the scope of patent application, wherein the transparent conductive layer has a width larger than that of the insulating layer. The method according to item 1 of the scope of patent application, wherein the second electrode has an upper surface, and the transparent conductive layer has a lower surface in direct contact with the upper surface. The method according to item 1 of the patent application scope, wherein the second electrode does not overlap the light emitting stack in the stacking direction. The method according to item 1 of the scope of patent application, wherein the second electrode has an upper surface not higher than the top surface. The method of claim 1, wherein the conductive layer includes a first overlapping portion overlapping the light emitting stack and a first extending portion not overlapping the light emitting stack, and the transparent conductive layer includes A second overlapping portion overlapping the light emitting stack and a second extending portion not overlapping the light emitting stack. The method according to item 1 of the application, wherein the transparent conductive layer has a part in direct contact with the light-emitting stack.