TWI422077B - Light-emitting diode structure and method for manufacturing the same - Google Patents

Description

Light-emitting diode structure and manufacturing method thereof

The present invention relates to a light-emitting element, and more particularly to a light-emitting diode structure and a method of fabricating the same.

Please refer to FIG. 1 , which is a cross-sectional view showing a conventional light emitting diode structure. The light emitting diode structure 100 mainly includes a substrate 102, an epitaxial structure 104, a transparent conductive layer 106, an electrode 114 and a protective layer 116. The epitaxial structure 104 is disposed on the substrate 102. The transparent conductive layer 106 is disposed on the epitaxial structure 104. The electrode 114 is disposed over a portion of the transparent conductive layer 106. The electrode 114 is generally formed by stacking three metal layers 108, 110 and 112. The protective layer 116 overlies the exposed portions of the electrode 114 and the transparent conductive layer 106. The protective layer 116 has an opening 118 in which a portion of the electrode 114 is exposed to facilitate electrical connection of the electrode 114 to an external power source.

In the conventional light-emitting diode structure 100, when the electrode 114 is defined in the process, the acid-base solution or the acid-base gas used may damage the transparent conductive layer 106, and the surface of the transparent conductive layer 106 may be defective. . Since in the light emitting diode structure 100, the electrode 114 is formed first, and then the electrode 114 is defined, the acid-base solution or the acid-base gas is easily accessible from the periphery 120 of the interface between the electrode 114 and the transparent conductive layer 106. And enter the contact interface between the two.

In addition, after the definition of the electrode 114 is completed, the plasma used for the photoresist cleaning, or the plasma used for the subsequent deposition of the protective layer 116, is also easily accessible from the periphery of the contact interface between the electrode 114 and the transparent conductive layer 106. 120, and enter the contact interface of the two.

Whether it is acid-base erosion or plasma intrusion, the adhesion of the electrode 114 to the transparent conductive layer 106 is lowered. The poor adhesion of the electrode 114 to the transparent conductive layer 106 will cause abnormal electrical characteristics of the light-emitting diode structure 100 and affect the stability of the light-emitting diode structure 100.

Accordingly, an aspect of the present invention is to provide a light emitting diode structure and a method of fabricating the same that form a protective layer and then form an electrode. In this way, the electrodes can be filled in defects formed on the surface of the transparent conductive layer during the formation of the protective layer. Therefore, the acid-base solution, the acid-base gas or the plasma can be reduced to enter through the periphery of the interface between the electrode and the transparent conductive layer, thereby reducing the damage of the interface between the electrode and the transparent conductive layer by the acid-base solution, the acid-base gas or the plasma. . Therefore, the adhesion of the electrode to the transparent conductive layer can be greatly improved.

Another aspect of the present invention provides a light emitting diode structure and a method of fabricating the same, wherein a periphery of an electrode is elevated above a protective layer, and a semiconductor layer or a transparent conductive layer not having an epitaxial structure contact. Therefore, the acid-base solution, the acid-base gas or the plasma can be effectively prevented from invading the interface between the electrode and the semiconductor layer or the transparent conductive layer of the epitaxial structure, thereby improving the stability of the electrode of the light-emitting diode structure and effectively improving the light emission. The operational performance of the diode structure.

Another aspect of the present invention provides a light emitting diode structure and a manufacturing method thereof, which can effectively improve the adhesion of an electrode to a transparent conductive layer, thereby improving the electrical quality of the light emitting diode structure and further improving The effect of the stability of the light-emitting diode structure.

According to the above object of the present invention, a light emitting diode structure is proposed. The light emitting diode structure comprises a substrate, an epitaxial structure, a protective layer and at least one electrode. The epitaxial structure is disposed on the substrate. The protective layer covers the epitaxial structure, wherein the protective layer has at least one opening, and the at least one opening is located on at least a portion of the epitaxial structure. The at least one electrode is disposed in the at least one opening and extends over the at least a portion of the epitaxial structure and the protective layer around the at least one opening.

According to an embodiment of the invention, the epitaxial structure comprises: a first electrical semiconductor layer on the substrate; a light emitting layer on the first portion of the first electrical semiconductor layer, and exposing the first electrical semiconductor layer a second portion; and a second electrically conductive semiconductor layer on the luminescent layer. The light emitting diode structure further includes a transparent conductive layer on the second electrical semiconductor layer, and the at least one opening of the protective layer includes a first transparent opening and a second opening respectively located at a portion of the transparent conductive layer and the first electrical On the second part of the semiconductor layer. The at least one electrode of the light emitting diode structure includes a first electrode and a second electrode respectively disposed in the first opening and the second opening, and the first electrode extends over the portion of the transparent conductive layer and the first opening On the surrounding protective layer, the second electrode extends over the second portion of the first electrical semiconductor layer and the protective layer around the second opening.

According to another embodiment of the present invention, the epitaxial structure includes a second electrical semiconductor layer, a light emitting layer, and a first electrical semiconductor layer sequentially stacked on the substrate, and the at least one opening exposes the first electrical Part of the semiconductor layer. In addition, the above-mentioned light emitting diode structure further includes: a mirror is located between the second electrical semiconductor layer and the substrate; and a bonding layer is located between the mirror and the substrate.

According to still another embodiment of the present invention, the protective layer may be a single layer structure or a double layer structure, and the thickness of the protective layer may be between 20 Between 20μm.

According to the above object of the present invention, a method for fabricating a light emitting diode structure is provided, which comprises the following steps. A substrate is provided. An epitaxial structure is formed on the substrate. Wherein the epitaxial structure comprises: a first electrical semiconductor layer on the substrate; a light emitting layer on the first portion of the first electrical semiconductor layer and exposing the second portion of the first electrical semiconductor layer; A second electrically conductive semiconductor layer is on the luminescent layer. A transparent conductive layer is formed on the second electrical semiconductor layer. Forming a protective layer overlying the epitaxial structure, wherein the protective layer has a first opening and a second opening respectively located on a portion of the transparent conductive layer and the second portion of the first electrical semiconductor layer. Forming a first electrode and a second electrode respectively in the first opening and the second opening, wherein the first electrode extends over the aforementioned portion of the transparent conductive layer and the protective layer around the first opening, and the second electrode extends Covering the second portion of the first electrical semiconductor layer and the protective layer around the second opening.

According to an embodiment of the invention, the step of forming the first electrode and the second electrode comprises: forming a photoresist layer over the protective layer, wherein the photoresist layer has a third opening and a fourth opening respectively exposing the first opening And a protective layer around the first opening, and a protective layer around the second opening and the second opening; forming an electrode layer covering the photoresist layer and filling the first opening, the third opening, the second opening and the fourth Opening; and performing a floating step to remove the photoresist layer and the electrode layer on the photoresist layer.

According to another embodiment of the present invention, the step of forming the photoresist layer further comprises having an undercut structure on an inner side surface of each of the third openings and an inner side surface of the fourth opening.

According to the above object of the present invention, a method for fabricating a light emitting diode structure is further provided, which comprises the following steps. A first substrate is provided. Forming an epitaxial structure on the first substrate, wherein the epitaxial structure comprises a first electrical semiconductor layer, a light emitting layer, and a second electrical semiconductor layer sequentially stacked on the first substrate. A second substrate is bonded to the second electrical semiconductor layer by a bonding layer. The first substrate is removed to expose the first electrical semiconductor layer. Forming a protective layer overlying the epitaxial structure, wherein the protective layer has an opening exposing a portion of the first electrically conductive semiconductor layer. An electrode is formed in the opening, wherein the electrode extends over the aforementioned portion of the first electrical semiconductor layer and the protective layer around the opening.

According to an embodiment of the invention, the step of forming an electrode comprises: forming a photoresist layer overlying the protective layer, wherein the photoresist layer has another opening exposing the protective layer around the opening and the opening; forming an electrode layer Covering the photoresist layer and filling the opening and the other opening; and performing a floating step to remove the photoresist layer and the electrode layer on the photoresist layer.

According to another embodiment of the present invention, between the step of forming an epitaxial structure and the step of bonding the second substrate to the second electrical semiconductor layer, the manufacturing method further includes forming a mirror for the second electrical property. On the semiconductor layer.

Please refer to FIG. 2A to FIG. 2E , which are schematic cross-sectional views showing a process of a light emitting diode structure according to an embodiment of the invention. In the present embodiment, when the light emitting diode structure is fabricated, the substrate 200 may be provided first for the epitaxial layer to grow thereon. The material of the substrate 200 may be, for example, sapphire, tantalum carbide (SiC), gallium arsenide (GaAs), or gallium nitride (GaN). Next, an epitaxial structure 208 is grown on the surface of the substrate 200 by, for example, epitaxy. In one embodiment, as shown in FIG. 2A, the first electrical semiconductor layer 202, the light-emitting layer 204, and the second electrical property may be sequentially grown on the substrate 200 by, for example, an organic metal chemical vapor deposition (MOCVD) method. The semiconductor layer 206 serves as an epitaxial structure 208. The first electrical property is, for example, an N-type, and the second electrical property is, for example, a P-type. In one example, the material of the epitaxial structure 208 may be an indium aluminum gallium phosphide (InAlGaP) series or a gallium nitride series, such as indium aluminum gallium nitride (InAlGaN).

In another embodiment, the epitaxial structure 208 may further include a buffer layer (not shown), wherein the buffer layer is interposed between the substrate 200 and the first electrical semiconductor layer 202 to serve as the substrate 200 and the first electrical property. The buffer structure between the semiconductor layers 202 avoids lattice defects of the epitaxial structure due to mismatch of lattice constants between the substrate 200 and the epitaxial structure.

Next, as shown in FIG. 2B, a portion of the second electrical semiconductor layer 206, a portion of the light-emitting layer 204, and a portion of the first electrical semiconductor layer are removed by lithography and etching, such as dry etching or wet etching. 202 to define a platform structure of the epitaxial structure 208. After being defined by the platform, the light emitting layer 204 and the second electrical semiconductor layer 206 are sequentially stacked on the first portion 210 of the first electrical semiconductor layer 202, and the second portion 212 of the first electrical semiconductor layer 202 is exposed.

Next, a transparent conductive layer 214 is formed over the second electrical semiconductor layer 206 by, for example, a vapor deposition method. In one embodiment, the material of the transparent conductive layer 214 may be indium tin oxide (ITO), indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), zinc oxide (ZnO), and aluminum zinc oxide (AZO). The transparent conductive layer 214 can provide a current dispersion effect to avoid the occurrence of a Current Crowding Effect.

Next, a protective layer 216 is formed over the epitaxial structure 208 and the transparent conductive layer 214 by a deposition method such as a plasma gain CVD (PECVD) method. The protective layer 216 is a transparent insulating material and may be, for example, cerium oxide (SiO ₂ ), cerium nitride (SiN), spin-on glass (SOG), titanium oxide (TiO ₂ ), and aluminum oxide (Al ₂ O ₃ ). In an embodiment, the protective layer 216 can be a single layer structure. In another embodiment, the protective layer 216 may be a multi-layer structure, and the layers may have different refractive indices, for example, the bottom-up refractive indices of the layers are stacked in a large and small manner to facilitate the light generated by the light-emitting layer 204. Export. The thickness of the protective layer 216 can be, for example, between 20 Between 20μm.

Then, as shown in FIG. 2C, the protective layer 216 is patterned by, for example, lithography and etching to form openings 218 and 220 in the protective layer 216. The openings 218 and 220 are respectively located on a portion of the transparent conductive layer 214 and a portion of the second portion 212 of the first electrical semiconductor layer 202. In the embodiment illustrated in FIG. 2C, openings 218 and 220 expose portions of transparent conductive layer 214 and second portion 212 of first electrically conductive semiconductor layer 202, respectively. The opening 218 has an aperture 222 and the opening 220 has an aperture 224.

Next, an electrode of a light-emitting diode structure was fabricated. In one embodiment, the electrode can be fabricated using a lift-off method. As shown in FIG. 2D, a photoresist layer 226 is applied over the protective layer 216. Next, the photoresist layer 226 is patterned by, for example, lithography to remove portions of the photoresist layer 226, and openings 228 and 230 are formed in the photoresist layer 226. The opening 228 exposes the opening 218 of the underlying protective layer 216 and the protective layer 216 around the opening 218; the opening 230 exposes the opening 220 of the underlying protective layer 216, and the protective layer 216 around the opening 220. Therefore, after patterning, the photoresist layer 226 is not filled into the openings 218 and 220 of the protective layer 216.

In a preferred embodiment, the photoresist layer 226 is a negative photoresist to facilitate the inner side of the opening 228 of the photoresist layer 226 having an undercut structure 232 and the opening 230 when the photoresist layer 226 is patterned. The inner side has an undercut structure 234 as shown in Figure 2D.

Next, an electrode layer 236 is formed over the patterned photoresist layer 226 by, for example, evaporation, and the electrode layer 236 fills the openings 218 and 220 of the protective layer 216 and the openings 228 and 230 of the photoresist layer 226. . At this time, the electrode layer 236 is in contact with the transparent conductive layer 214 exposed by the openings 218 and 220 of the protective layer 216 and the first electrical semiconductor layer 202, respectively. In an embodiment, the electrode layer 236 may be a multilayer structure composed of three metal layers stacked on the photoresist layer 226 in sequence, such as a chromium/platinum/gold (Cr/Pt/Au) structure. In an example, the first layer of metal constituting the multilayer structure of the electrode layer 236 may be, for example, chromium, nickel (Ni), titanium (Ti), and titanium tungsten alloy (TiW).

Subsequently, a floating step is performed to remove portions of the remaining photoresist layer 226 and the electrode layer 236 over the photoresist layer 226. By having the undercut structures 232 and 234 of the inner sides of the openings 228 and 230 of the photoresist layer 226, respectively, the electrode layer 236 is located in the opening 228 of the photoresist layer 226 and the opening 218 of the protective layer 216, and is located Portions of the opening 230 of the photoresist layer 226 and the opening 220 of the protective layer 216 are smoothly retained in the openings 218 and 220 after the floating step. As such, as shown in FIG. 2E, electrodes 238 and 240 can be formed in openings 218 and 220 of protective layer 216, respectively, to complete fabrication of light emitting diode structure 246. The electrodes 238 and 240 are respectively located on the exposed portion of the transparent conductive layer 214 and the exposed second portion 220 of the first electrical semiconductor layer 202.

During the floating process, the opening 228 of the photoresist layer 226 exposes the opening 218 of the underlying protective layer 216 and the protective layer 216 therearound, and the opening 230 exposes the opening 220 of the underlying protective layer 216 and the surrounding protection. Layer 216. Thus, after floating, the formed electrodes 238 and 240 are not only located in the openings 218 and 220 of the protective layer 216, respectively, but also extend over the protective layer 216 around the opening 218 and around the opening 220, respectively. Thus, referring to FIG. 2E, the dimension 242 of the electrode 238 is greater than the aperture 222 of the opening 218 of the protective layer 216, and the dimension 244 of the electrode 240 is greater than the aperture 224 of the opening 220 of the protective layer.

In this embodiment, by forming a protective layer and then fabricating an electrode, the periphery of the electrode can be raised above the protective layer, and the periphery of the electrode is not in contact with the epitaxial structure or the transparent conductive layer. Therefore, the acid-base solution, the acid-base gas or the plasma can be effectively prevented from invading the interface between the electrode and the epitaxial structure or the transparent conductive layer, thereby improving the stability of the electrode of the light-emitting diode structure and effectively improving the light-emitting diode. The operational performance of the structure.

The light emitting diode structure of the present invention may also be a vertical conductive type structure. Please refer to FIG. 3A to FIG. 3F , which are schematic cross-sectional views showing a process of a light emitting diode structure according to another embodiment of the present invention. In the present embodiment, when the light emitting diode structure is fabricated, the first substrate 300 for growing the epitaxial layer may be provided first. The material of the first substrate 300 may be, for example, sapphire, tantalum carbide, gallium arsenide or gallium nitride. Next, an epitaxial structure 308 is grown on the surface of the first substrate 300 by an epitaxial technique such as MOCVD. In an embodiment, as shown in FIG. 3A, the epitaxial structure 308 includes a first electrical semiconductor layer 302, a light emitting layer 304, and a second electrical semiconductor layer 306 stacked on the first substrate 300 in sequence. The first electrical property is, for example, an N-type, and the second electrical property is, for example, a P-type. In one example, the material of the epitaxial structure 308 may be an indium aluminum gallium phosphide series or a gallium nitride series, such as indium aluminum gallium nitride.

In another embodiment, the epitaxial structure 308 may further include a buffer layer (not shown), wherein the buffer layer is interposed between the first substrate 300 and the first electrical semiconductor layer 302 to serve as the first electrical semiconductor. The buffer structure when the layer 302 is grown avoids lattice defects of the epitaxial structure due to mismatch of lattice constants between the first substrate 300 and the epitaxial structure.

Next, as shown in FIG. 3B, a portion of the epitaxial structure 308 is removed by lithography and etching to form a plurality of exposed portions of the trench 310 of the first substrate 300 to define a plurality of crystal grains. . Of course, the procedure for defining the grain size described above can be dispensed with when only a single light-emitting diode structure is fabricated.

Then, a mirror 312 can be selectively formed on the second electrical semiconductor layer 306 by, for example, an evaporation method depending on the product requirements. In an embodiment, the mirror 312 can be, for example, a nickel/silver (Ni/Ag) structure or a decentralized Bragg mirror (DBR). Next, as shown in FIG. 3C, the bonding layer 314 can be used to bond the second substrate 316 to the second electrical semiconductor layer 306 of the epitaxial structure 308. In an embodiment, the bonding layer 314 may be formed on the second substrate 316 first, and then the bonding layer 314 is used to bond the second substrate 316 and the second electrical semiconductor layer 306. The bonding layer 314 can be, for example, a titanium/gold (Ti/Au) structure.

In an embodiment, the second substrate 316 can directly serve as one of the electrodes of the light emitting diode structure, and therefore the second substrate 316 needs to be made of a conductive material such as germanium. In addition, in order to increase the heat dissipation capability of the light emitting diode structure, a material having good electrical conductivity and good thermal conductivity can be used as the material of the second substrate 316. In another embodiment, the second substrate 316 may not be directly used as one of the electrodes of the light emitting diode structure, but an electrode may be separately formed on the other surface of the second substrate 316 with respect to the bonding layer 314.

Next, as shown in FIG. 3D, the structure of FIG. 3C is first flipped, and then the first substrate 300 is removed by, for example, laser lift off (LLO), etching or grinding, and the exposed substrate is exposed. The first electrically conductive semiconductor layer 302 of the crystal structure 308.

Next, a protective layer 318 is formed over the epitaxial structure 308 by a deposition method such as PECVD. The protective layer 318 is a transparent insulating material and may be, for example, hafnium oxide, tantalum nitride, spin-on glass, titanium dioxide, and aluminum oxide. In an embodiment, the protective layer 318 can be a single layer structure. In another embodiment, the protective layer 318 can be a multi-layered structure in which the layers can have different refractive indices, such as layers stacked in a large and small manner. The thickness of the protective layer 318 can be, for example, between 20 Between 20μm.

Next, the protective layer 318 is patterned using, for example, lithography and etching to form openings 320 in the protective layer 318. The opening 320 is located on a portion of the first electrical semiconductor layer 302. In the embodiment illustrated in FIG. 3E, the opening 320 exposes a portion of the first electrically conductive semiconductor layer 302. The opening 320 has an aperture 324. In Fig. 3E, in order to clearly illustrate the features of the present embodiment, only a cross-sectional view of a single crystal grain is shown.

Next, an electrode of a light-emitting diode structure was fabricated. In one embodiment, the electrode can be fabricated using a floating method. As shown in FIG. 3E, a photoresist layer 326 is first coated on the protective layer 318. Next, the photoresist layer 326 is patterned, for example, by lithography, to remove portions of the photoresist layer 326, and an opening 328 is formed in the photoresist layer 326. The opening 328 exposes the opening 320 of the underlying protective layer 318 and the protective layer 318 around the opening 320. In a preferred embodiment, the photoresist layer 326 is a negative photoresist, so that the inner side of the opening 328 of the photoresist layer 326 has an undercut structure 330 during the patterning of the photoresist layer 326. Figure 3E shows.

Then, the electrode layer 332 is formed on the patterned photoresist layer 326 by, for example, vapor deposition, and the electrode layer 332 is filled with the opening 320 of the protective layer 318 and the opening 328 of the photoresist layer 326. At this time, the electrode layer 332 is in contact with the first electrical semiconductor layer 302 exposed by the opening 320 of the protective layer 318. In an embodiment, the electrode layer 332 may comprise a three-layer metal layer structure sequentially stacked on the photoresist layer 326, such as a chromium/platinum/gold structure. In one example, the first layer of metal constituting the multilayer structure of electrode layer 332 can be, for example, chromium, nickel, titanium, and titanium tungsten alloy.

Subsequently, a floating step is performed to remove portions of the remaining photoresist layer 326 and the electrode layer 332 over the photoresist layer 326. The undercut structure 330 on the inner side of the opening 328 of the photoresist layer 326 allows the electrode layer 332 to be located in the opening 328 of the photoresist layer 326 and the opening 320 of the protective layer 318, and is smoothly left in the opening 320 after the floating step. in. Therefore, as shown in FIG. 3F, the electrode 334 can be formed in the opening 320 of the protective layer 318. After all the crystal grains are separated by cutting, the fabrication of the light-emitting diode structure 338 can be completed. The electrode 334 is located on the exposed portion of the first electrical semiconductor layer 302.

During the float process, the opening 328 of the photoresist layer 326 exposes the underlying opening 320 and the protective layer 318 around the opening 320. Therefore, after the floating step, the formed electrode 334 is not only located in the opening 320 of the protective layer 318 but also extends over the protective layer 318 around the opening 320. Therefore, referring to FIG. 3F, the size 336 of the electrode 334 is larger than the aperture 322 of the opening 320 of the protective layer 318.

According to the embodiment of the present invention described above, an advantage of the present invention is that the structure of the light-emitting diode of the present invention and the method of manufacturing the same are to form a protective layer and then form an electrode. Therefore, the electrode can be filled in a defect formed on the surface of the transparent conductive layer during the formation of the protective layer. Therefore, the acid-base solution, the acid-base gas or the plasma can be reduced to enter through the periphery of the interface between the electrode and the transparent conductive layer, thereby reducing the damage of the interface between the electrode and the transparent conductive layer by the acid-base solution, the acid-base gas or the plasma. . Therefore, the adhesion of the electrode to the transparent conductive layer can be greatly improved.

According to the embodiment of the present invention described above, another advantage of the present invention is that the semiconductor layer of the light-emitting diode structure of the present invention is elevated on the periphery of the protective layer and does not have a semiconductor layer with an epitaxial structure. Or a transparent conductive layer is in contact. Therefore, the acid-base solution, the acid-base gas or the plasma can be effectively prevented from invading the interface between the electrode and the semiconductor layer or the transparent conductive layer of the epitaxial structure, thereby improving the stability of the electrode of the light-emitting diode structure and effectively improving the light emission. The operational performance of the diode structure.

According to the embodiment of the present invention, another advantage of the present invention is that the structure of the light-emitting diode of the present invention and the manufacturing method thereof can effectively improve the adhesion of the electrode to the transparent conductive layer, thereby improving the structure of the light-emitting diode. The electrical quality further enhances the stability of the structure of the light-emitting diode.

While the present invention has been described above by way of example, it is not intended to be construed as a limitation of the scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100. . . Light-emitting diode structure

102. . . Substrate

104. . . Epitaxial structure

106. . . Transparent conductive layer

108. . . Metal layer

110. . . Metal layer

112. . . Metal layer

114. . . electrode

116. . . The protective layer

118. . . Opening

120. . . periphery

200. . . Substrate

202. . . First electrical semiconductor layer

204. . . Luminous layer

206. . . Second electrical semiconductor layer

208. . . Epitaxial structure

210. . . first part

212. . . the second part

214. . . Transparent conductive layer

216. . . The protective layer

218. . . Opening

220. . . Opening

222. . . Aperture

224. . . Aperture

226. . . Photoresist layer

228. . . Opening

230. . . Opening

232. . . Undercut structure

234. . . Undercut structure

236. . . Electrode layer

238. . . electrode

240. . . electrode

242. . . size

244. . . size

246. . . Light-emitting diode structure

300. . . First substrate

302. . . First electrical semiconductor layer

304. . . Luminous layer

306. . . Second electrical semiconductor layer

308. . . Epitaxial structure

310. . . ditch

312. . . Reflector

314. . . Bonding layer

316. . . Second substrate

318. . . The protective layer

320. . . Opening

324. . . Aperture

326. . . Photoresist layer

328. . . Opening

330. . . Undercut structure

332. . . Electrode layer

334. . . electrode

336. . . size

338. . . Light-emitting diode structure

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood.

Figure 1 is a schematic cross-sectional view showing a conventional light emitting diode structure.

2A to 2E are cross-sectional views showing a process of a light emitting diode structure according to an embodiment of the present invention.

3A to 3F are cross-sectional views showing a process of a light emitting diode structure according to another embodiment of the present invention.

200. . . Substrate

202. . . First electrical semiconductor layer

204. . . Luminous layer

206. . . Second electrical semiconductor layer

208. . . Epitaxial structure

214. . . Transparent conductive layer

216. . . The protective layer

218. . . Opening

220. . . Opening

222. . . Aperture

224. . . Aperture

238. . . electrode

240. . . electrode

242. . . size

244. . . size

246. . . Light-emitting diode structure

Claims (15)

An illuminating diode structure comprising: a substrate; an epitaxial structure disposed on the substrate; a protective layer overlying the epitaxial structure, wherein the protective layer has at least one opening, the at least one opening is located At least a portion of the epitaxial structure; and at least one electrode disposed in the at least one opening and extending over the at least a portion of the epitaxial structure and the protective layer surrounding the at least one opening. The light emitting diode structure of claim 1, wherein the epitaxial structure comprises: a first electrical semiconductor layer on the substrate; and a light emitting layer on the first portion of the first electrical semiconductor layer And exposing a second portion of the first electrically conductive semiconductor layer; and a second electrically conductive semiconductor layer on the luminescent layer, wherein the luminescent diode structure further comprises a transparent conductive layer at the second The at least one opening of the protective layer includes a first opening and a second opening respectively located on a portion of the transparent conductive layer and the second portion of the first electrical semiconductor layer, wherein The at least one electrode of the LED structure comprises a first electrode and a second electrode respectively disposed in the first opening and the second opening, and the first electrode extends over the portion of the transparent conductive layer And the On the protective layer around the first opening, the second electrode extends over the second portion of the first electrical semiconductor layer and the protective layer around the second opening. The light emitting diode structure of claim 1, wherein the epitaxial structure comprises a second electrical semiconductor layer, a light emitting layer and a first electrical semiconductor layer stacked on the substrate in sequence, and the at least An opening exposes a portion of the first electrically conductive semiconductor layer. The light emitting diode structure of claim 3, further comprising: a mirror between the second electrical semiconductor layer and the substrate; and a bonding layer between the mirror and the substrate. The light-emitting diode structure according to claim 1, wherein the protective layer is a single layer structure or a two-layer structure, and the thickness of the protective layer is between 20 Å and 20 μm. A method for fabricating a light emitting diode structure includes: providing a substrate; forming an epitaxial structure on the substrate, wherein the epitaxial structure comprises: a first electrical semiconductor layer on the substrate; and a light emitting layer Located on a first portion of the first electrically conductive semiconductor layer and exposing a second portion of the first electrically conductive semiconductor layer; And a second electrically conductive layer on the luminescent layer; forming a transparent conductive layer on the second electrically conductive layer; forming a protective layer overlying the epitaxial structure, wherein the protective layer has a first An opening and a second opening are respectively located on the portion of the transparent conductive layer and the second portion of the first electrical semiconductor layer; and after the protective layer is formed, a first electrode and a second electrode are respectively formed The first opening and the second opening, wherein the first electrode extends over the portion of the transparent conductive layer and the protective layer around the first opening, and the second electrode extends over the first The second portion of the electrically conductive layer and the protective layer surrounding the second opening. The method for fabricating a light emitting diode structure according to claim 6, wherein the forming the first electrode and the second electrode comprises: forming a photoresist layer over the protective layer, wherein the photoresist layer has a The third opening and a fourth opening respectively expose the protective layer around the first opening and the first opening, and the protective layer around the second opening and the second opening; forming an electrode layer covering the light And forming a first opening, a third opening, a second opening and a fourth opening; and performing a floating step to remove the photoresist layer and the electrode layer on the photoresist layer. The method for fabricating a light emitting diode structure according to claim 7, wherein the step of forming the photoresist layer further comprises: forming an inner side of each of the third openings And an inner surface of the fourth opening has an undercut structure. The method of fabricating a light-emitting diode structure according to claim 7, wherein the photoresist layer is a negative photoresist. The method for fabricating a light-emitting diode structure according to claim 6, wherein the protective layer is a single layer structure or a two-layer structure, and the thickness of the protective layer is between 20 Å and 20 μm. A method for fabricating a light emitting diode structure includes: providing a first substrate; forming an epitaxial structure on the first substrate, wherein the epitaxial structure comprises one of the first electrodes stacked on the first substrate in sequence a semiconductor layer, a light emitting layer and a second electrical semiconductor layer; bonding a second substrate to the second electrical semiconductor layer by using a bonding layer; removing the first substrate to expose the first An electrically conductive layer; forming a protective layer overlying the epitaxial structure, wherein the protective layer has an opening exposing a portion of the first electrically conductive semiconductor layer; and after forming the protective layer, forming an electrode at the opening Wherein the electrode extends over the portion of the first electrically conductive semiconductor layer and the protective layer around the opening. The method for fabricating the light emitting diode structure according to claim 11, The step of forming the electrode includes: forming a photoresist layer over the protective layer, wherein the photoresist layer has another opening exposing the opening and the protective layer around the opening; forming an electrode layer covering the light And forming a floating step on the resist layer to remove the photoresist layer and the electrode layer on the photoresist layer. The method of fabricating a light-emitting diode structure according to claim 12, wherein the step of forming the photoresist layer further comprises providing an undercut structure on an inner side surface of the other opening. The method of fabricating a light emitting diode structure according to claim 12, wherein the photoresist layer is a negative photoresist. The method for fabricating a light emitting diode structure according to claim 11, wherein the step of forming the epitaxial structure and the step of bonding the second substrate to the second electrical semiconductor layer further comprise forming a reflection Mirrored on the second electrical semiconductor layer.