TWI395349B - Light emitting diode chip and fabricating method thereof - Google Patents

Description

Light-emitting diode chip and method of manufacturing same

The present invention relates to a light-emitting diode wafer and a method of fabricating the same, and more particularly to a light-emitting diode wafer that retains a portion of a grown substrate and a method of fabricating the same.

Because the light-emitting diode has the advantages of long life, small volume, high shock resistance, low heat generation and low power consumption, the light-emitting diode has been widely used in home appliances and indicators or light sources of various instruments. In recent years, due to the development of multi-color and high-brightness of light-emitting diodes, the application range of light-emitting diodes has been extended to large-scale outdoor display billboards and traffic lights, etc. In the future, tungsten filament lamps and mercury lamps can be replaced to become A lighting source with power saving and environmental protection functions.

In the prior art, a gallium nitride (GaN) epitaxial layer can be formed on a sapphire substrate to form a light emitting diode, which can produce a large amount of gallium nitride on a sapphire substrate by using a semiconductor process technology. Light-emitting diode. However, since the gallium nitride light-emitting diode fabricated in this manner is located on the sapphire substrate, there is still room for improvement in the insulation and heat dissipation effect of the gallium nitride light-emitting diode. To solve this problem, a solution is to separate the gallium nitride epitaxial layer from the sapphire substrate and transfer the gallium nitride epitaxial layer to the laser lift-off process and the wafer bonding process. A permanent substrate, the detailed process of which is as follows.

1A to 1D are a conventional method of fabricating a light emitting diode wafer. Referring to FIG. 1A, a first type doped semiconductor layer 112, a light emitting layer 114, and a second type doped semiconductor layer 116 are sequentially formed on the growth substrate 110, and the transfer substrate 120 is bonded to the second type doped semiconductor layer 116. . The growth substrate 110 is, for example, a sapphire substrate, and the first type doped semiconductor layer 112, the light emitting layer 114, and the second type doped semiconductor layer 116 are, for example, a gallium nitride epitaxial layer. Referring to FIG. 1B, the first type doped semiconductor layer 112 is separated from the growth substrate 110 by a laser lift-off process. Referring to FIG. 1C, next, the permanent substrate 130 is bonded to the first type doped semiconductor layer 112 and the transfer substrate 120 is removed. Referring to FIG. 1D, the first electrode 140 and the second electrode 150 are formed on the first type doped semiconductor layer 112 and the second type doped semiconductor layer 116, respectively, to complete the fabrication of the LED array 100. In the above method, the permanent substrate 130 having good conductivity and thermal conductivity successfully replaces the growth substrate 110 (such as a sapphire substrate) having poor conductivity and thermal conductivity, thereby greatly improving the conductivity and heat dissipation of the LED wafer 100.

However, since the lattice constant between the gallium nitride epitaxial layer and the sapphire substrate is extremely different, when the gallium nitride series material is grown on the sapphire substrate, there is a great stress accumulation in the generated gallium nitride epitaxial crystal. In the layer. As a result, when the gallium nitride epitaxial layer is separated from the sapphire substrate, the gallium nitride epitaxial layer loses the support of the sapphire substrate, causing a large stress change of the gallium nitride epitaxial layer, and the aforementioned stress change causes nitrogen. The gallium nitride epitaxial layer undergoes lattice defects such as lattice rupture or dislocation when it is separated from the substrate, resulting in poor yield, antistatic capability, and reliability of the luminescent diode chip.

The present invention provides a method of fabricating a light-emitting diode wafer, which produces a light-emitting diode wafer having better yield, antistatic capability, reliability, component characteristics, and lower manufacturing cost.

The present invention further provides a light emitting diode wafer having better yield, antistatic capability, reliability, component characteristics, and lower manufacturing cost.

The present invention provides a method of fabricating a light emitting diode wafer. First, a first type doped semiconductor layer, a light emitting layer, and a second type doped semiconductor layer are sequentially formed on a growth substrate. Next, the second type doped semiconductor layer is bonded to the transfer substrate, wherein the growth substrate and the transfer substrate are respectively located on both sides of the second type doped semiconductor layer. Then, the growth substrate is thinned and patterned to form a plurality of protrusion structures on the first type doped semiconductor layer. Thereafter, a conductive layer is formed on the first type doped semiconductor layer to cover the protrusion structure and the first type doped semiconductor layer. Then, the transfer substrate is separated from the second type doped semiconductor layer. And forming a first electrode and a second electrode on the first type doped semiconductor layer and the second type doped semiconductor layer, wherein the first electrode is electrically connected to the first type doped semiconductor layer and the second electrode is electrically connected The second type is doped with a semiconductor layer.

In one embodiment of the present invention, the step of thinning the substrate is performed after bonding the second type doped semiconductor layer and the transfer substrate, and patterning the growth substrate after thinning the substrate.

In one embodiment of the present invention, the step of patterning the growth substrate is performed after bonding the second type doped semiconductor layer and the transfer substrate, and thinning the substrate after patterning the growth substrate.

In an embodiment of the invention, the step of patterning the growth substrate is performed before forming the first type doped semiconductor layer, and the step of thinning the growth substrate is to bond the second type doped semiconductor layer and the transfer substrate. After that.

In an embodiment of the invention, the transfer substrate is bonded to the second type doped semiconductor layer by the first bonding layer.

In one embodiment of the invention, the transfer substrate is separated from the second type doped semiconductor layer by removing the first bonding layer.

In an embodiment of the invention, the first electrode is disposed on the conductive layer and the second electrode is disposed on the second type doped semiconductor layer.

In an embodiment of the invention, the method further includes bonding the permanent substrate to the conductive layer, wherein the permanent substrate and the protruding structure are respectively located on opposite sides of the conductive layer.

In an embodiment of the invention, the permanent substrate is bonded to the conductive layer by the second bonding layer.

In an embodiment of the invention, the first electrode is disposed on the permanent substrate and the second electrode is disposed on the second type doped semiconductor layer.

In an embodiment of the invention, the step of forming the first electrode and the second electrode includes: removing the second type doped semiconductor layer and a portion of the light emitting layer to expose the first type doped semiconductor layer; Forming a first electrode on the exposed first type doped semiconductor layer and forming a second electrode on the second type doped semiconductor layer.

In an embodiment of the invention, the step of forming the first electrode and the second electrode is performed after separating the transfer substrate from the second type doped semiconductor layer.

In an embodiment of the invention, the step of forming the first electrode and the second electrode is performed before bonding the second type doped semiconductor layer and the transfer substrate.

In an embodiment of the invention, the transfer substrate is bonded to the second type doped semiconductor layer by the first bonding layer, and the first bonding layer covers the exposed first type doped semiconductor layer, the luminescent layer, and the The doped semiconductor layer, the first electrode, and the second electrode.

In one embodiment of the invention, the transfer substrate is separated from the second type doped semiconductor layer by removing the first bonding layer.

In an embodiment of the invention, the first type of doped semiconductor layer is provided with an insulating layer.

In an embodiment of the invention, the surface of the first type doped semiconductor layer has a plurality of recesses, the protrusion structure is located on a surface between the recesses, and the conductive layer extends into the recess.

In an embodiment of the invention, the surface of the first type doped semiconductor layer has a plurality of recesses, and the protrusion structure is located in the recess.

The present invention further provides a light emitting diode chip including a first type doped semiconductor layer, a second type doped semiconductor layer, a light emitting layer, a plurality of protruding structures, a conductive layer, a first electrode, and a second electrode. The light emitting layer is between the first type doped semiconductor layer and the second type doped semiconductor layer. The protrusion structure is disposed on the first type doped semiconductor layer, wherein the height of the protrusion structure is between 1 μm and 100 μm, and the protrusion structure and the light emitting layer are located on both sides of the first type doped semiconductor layer. The conductive layer is disposed on the first type doped semiconductor layer and covers the protrusion structure. The first electrode is disposed on the first type doped semiconductor layer and electrically connected to the first type doped semiconductor layer, and the second electrode is disposed on the second type doped semiconductor layer and electrically connected to the second type doped semiconductor layer connection.

In an embodiment of the invention, the height of the protruding structure is less than 5 μm.

In an embodiment of the invention, the conductive layer has a thickness greater than or equal to 50 μm.

In an embodiment of the invention, the first electrode is disposed on the conductive layer and the second electrode is disposed on the second type doped semiconductor layer.

In an embodiment of the invention, the method further includes a permanent substrate disposed on the conductive layer, wherein the permanent substrate and the protruding structure are respectively located on opposite sides of the conductive layer.

In an embodiment of the invention, the conductive layer has a thickness of less than or equal to 50 μm.

In an embodiment of the invention, a bonding layer is further disposed between the permanent substrate and the conductive layer.

In an embodiment of the invention, the first electrode is disposed on the permanent substrate and the second electrode is disposed on the second type doped semiconductor layer.

In an embodiment of the invention, one of the first portions of the doped semiconductor layer is exposed to the outside, and the first electrode is disposed on the exposed first type doped semiconductor layer.

In an embodiment of the invention, an insulating layer is further disposed, and the insulating layer is disposed in the first type doped semiconductor layer.

In an embodiment of the invention, the surface of the first type doped semiconductor layer has a plurality of recesses, the protrusion structure is located on a surface between the recesses, and the conductive layer extends into the recess.

In an embodiment of the invention, the surface of the first type doped semiconductor layer has a plurality of recesses, and the protrusion structure is located in the recess.

Based on the above, in the method of manufacturing a light-emitting diode wafer of the present invention, the protrusion structure is formed by thinning and patterning the grown substrate. Therefore, it is not necessary to use an expensive laser stripping machine in the process of the light emitting diode wafer, and problems such as lattice defects due to separation of the first type doped semiconductor layer from the growth substrate can be avoided. Therefore, the light-emitting diode wafer formed by the method for manufacturing a light-emitting diode wafer of the present invention has better yield, antistatic property, reliability, component characteristics, and lower manufacturing cost.

The above described features and advantages of the present invention will be more apparent from the following description.

[First Embodiment]

2A to 2H are cross-sectional views showing the flow of a method of manufacturing a light-emitting diode wafer according to a first embodiment of the present invention.

Referring to FIG. 2A , first, a first type doped semiconductor layer 212 , a light emitting layer 214 , and a second type doped semiconductor layer 216 are sequentially formed on the growth substrate 210 . In the present embodiment, the growth substrate 210 is, for example, a sapphire substrate, and has a thickness of, for example, 450 μm or more. The light-emitting layer 214 is a multiple quantum well light-emitting layer, and the first-type doped semiconductor layer 212 is, for example, an N-type semiconductor layer, and the second-type doped semiconductor layer 216 is, for example, a P-type semiconductor layer, and the material thereof is, for example, gallium nitride (GaN). . Of course, in another embodiment, the first type doped semiconductor layer 212 may also be a P type semiconductor layer, and the second type doped semiconductor layer 216 is an N type semiconductor layer. The forming method of the first type doped semiconductor layer 212, the light emitting layer 214, and the second type doped semiconductor layer 216 is, for example, a metal organic chemical vapor deposition (MOCVD) method or a molecular beam epitaxy (molecular beam). Epitaxial, MBE) or other suitable epitaxial growth method.

Referring to FIG. 2B , the second type doped semiconductor layer 216 is bonded to the transfer substrate 220 , wherein the growth substrate 210 and the transfer substrate 220 are respectively located on opposite sides of the second type doped semiconductor layer 216 . In the present embodiment, the transfer substrate 220 is bonded to the second type doped semiconductor layer 216 by, for example, the first bonding layer 218. The transfer substrate 220 is, for example, a sapphire substrate, a tantalum carbide substrate, a tantalum substrate, a gallium arsenide substrate, a gallium oxide substrate, a gallium nitride substrate, a lithium aluminate substrate, a lithium gallate substrate, or an aluminum nitride substrate. The material of the first bonding layer 218 is, for example, wax, a low melting point metal or an adhesive. Therefore, for example, the first bonding layer 218 is formed on the second type doped semiconductor layer 216, and then the transfer substrate 220 is bonded to the first bonding layer 218 by heating or pressing.

Referring to FIG. 2C, the substrate 210 is then thinned to have a thickness of the growth substrate 210a. In the present embodiment, after bonding the second-type doped semiconductor layer 216 and the transfer substrate 220, the growth substrate 210 is thinned so that the thickness of the growth substrate 210a is less than or equal to 100 μm, and preferably the growth substrate 210a is grown. The thickness is less than or equal to 5 μm. The method of thinning the growth substrate 210 is, for example, a polishing process or an etching process.

Referring to FIG. 2D and FIG. 2E simultaneously, a patterned mask layer 222 is formed on the growth substrate 210a, and the growth substrate 210a is patterned by using the patterned mask layer 222 as a mask to the first type. A plurality of protrusion structures 224 are formed on the doped semiconductor layer 212. The patterned mask layer 222 is then removed. In the present embodiment, the plurality of protrusion structures 224 are, for example, arranged in an array, and the protrusion structure 224 is, for example, a columnar protrusion structure. The patterned mask layer 222 is, for example, a hard mask layer, and the method of patterning the substrate 210a includes a dry etching process or a wet etching process, wherein the dry etching process may be an inductively coupled plasma (ICP) process or a reactive process. Ion etching (RIE) process. It is noted that, in this embodiment, patterning the growth substrate 210a may simultaneously remove a portion of the first type doped semiconductor layer 212 such that the surface of the first type doped semiconductor layer 212 has a plurality of recesses 226. And the protrusion structure 224 is located on the surface between the recesses 226. Of course, in other embodiments, it is also possible for the first type doped semiconductor layer 212 to have a flat surface, as shown by the dashed line in FIG. 2E.

Referring to FIG. 2F, a conductive layer 228 is formed on the first type doped semiconductor layer 212 to cover the protrusion structure 224 and the first type doped semiconductor layer 212. In the present embodiment, the thickness of the conductive layer 228 is, for example, greater than or equal to 50 μm, and the conductive layer 228 extends into the recess 226 of the first type doped semiconductor layer 212. The material of the conductive layer is, for example, a metal, a conductive oxide or a multilayer composite composed of the above two, wherein the metal may be a material such as nickel, copper, tin, gold, tungsten, aluminum or chromium, and the conductive oxide may be indium oxide. Materials such as tin, zinc aluminum oxide, zinc gallium oxide, zinc indium oxide, etc., which have both transparent and conductive properties. The method for forming the metal is, for example, a plating method, a sputtering method, or a vapor deposition method, and a method of forming the conductive oxide is, for example, a vapor deposition method, a sputtering method, a chemical deposition method, a sol-gel method, or a coating method.

Referring to FIG. 2F and FIG. 2G simultaneously, the transfer substrate 220 is separated from the second type doped semiconductor layer 216. In this embodiment, the first bonding layer 218 and the second doping semiconductor layer 216 may be separated by heating or other means according to the material properties of the first bonding layer 218, thereby causing the transfer substrate 220 and the second type to be doped. The hetero semiconductor layer 216 is separated.

Referring to FIG. 2H, a first electrode 240 and a second electrode 250 are formed on the conductive layer 228 and the second type doped semiconductor layer 216, respectively, to form a light emitting diode wafer 200. The first electrode 240 is electrically connected to the first type doped semiconductor layer 212 and the second electrode 250 is electrically connected to the second type doped semiconductor layer 216. In this embodiment, the first electrode 240 is disposed on the conductive layer 228 and the second electrode 250 is disposed on the second type doped semiconductor layer 216. Furthermore, in another embodiment (not shown), a transparent conductive layer may be formed on the second type doped semiconductor layer 216, and an electrode 250 may be formed on the transparent conductive layer.

In the method of manufacturing the light-emitting diode wafer 200 of the present embodiment, a part of the growth substrate 210 is left to form the protrusion structure 224, so that it is not necessary to completely remove the growth substrate 210. In this way, it is not necessary to use an expensive laser stripping machine in the process of the light-emitting diode wafer 200, and problems such as lattice defects of the first-type doped semiconductor layer 212 due to separation from the growth substrate 210 can be avoided. In addition, the protrusion structure 224 can reduce the chance of total reflection of the light emitted by the light-emitting layer 214 in the light-emitting diode wafer 200, and the light extraction efficiency of the light-emitting diode wafer 200 is greatly increased. Therefore, the formed light-emitting diode wafer 200 has better yield, antistatic ability, reliability, and component characteristics as well as lower manufacturing cost.

[Second embodiment]

3A to 3C are partial cross-sectional views showing a method of manufacturing a light-emitting diode wafer according to a second embodiment of the present invention. In this embodiment, the manufacturing process of the LED wafer is substantially the same as the manufacturing process described in the first embodiment, and the main difference is that in this embodiment, the growth substrate is thinned first, and then thinned. The growth substrate is patterned, and only the differences will be described below.

Referring to FIG. 2B and FIG. 3A simultaneously, after bonding the second type doped semiconductor layer 216 and the transfer substrate 220, a patterned mask layer 222 is formed on the growth substrate 210. The patterned mask layer 222 is, for example, a hard mask layer.

Referring to FIG. 3B, the growth substrate 210 is patterned by using the patterned mask layer 222 as a mask to form a plurality of initial protrusion structures 224' on the first type doped semiconductor layer 212. The patterned mask layer 222 is then removed. The method of patterning the growth substrate 210 includes a dry etching process or a wet etching process, wherein the dry etching process may be an inductively coupled plasma (ICP) process or a reactive ion etching (RIE) process.

Referring to Figures 3B and 3C simultaneously, a portion of the initial raised structure 224' is then removed to form a raised structure 224 having a smaller height. In the present embodiment, the method of removing a portion of the initial protrusion structure 224' is, for example, a grinding or etching process such that the height of the protrusion structure 224 is, for example, less than or equal to 100 μm, and the height of the protrusion structure 224 is preferably less than or equal to 5 μm.

The following steps are shown in FIG. 2F to FIG. 2H. Please refer to the description of FIG. 2F to FIG. 2H of the first embodiment, and details are not described herein again. In other words, the light-emitting diode wafer 200 can also be produced through the steps of FIGS. 3A to 3C described above.

[Third embodiment]

4A to 4D are partial cross-sectional views showing a method of manufacturing a light-emitting diode wafer according to a third embodiment of the present invention. In the present embodiment, the manufacturing flow of the light-emitting diode wafer is substantially the same as that of the first embodiment, and the main difference is that the permanent substrate is bonded to the conductive layer, which will be described in detail below.

Referring to FIG. 2E and FIG. 4A, after forming a plurality of protrusion structures 224 on the first type doped semiconductor layer 212, a conductive layer 228 is formed on the first type doped semiconductor layer 212 to cover the protrusion structure 224 and the first The doped semiconductor layer 212 is doped. In the present embodiment, the thickness of the conductive layer 228 is, for example, between 1 μm and 50 μm. That is, the conductive layer 228 in the present embodiment has a smaller thickness than the conductive layer 228 of the first embodiment having a larger thickness. For the method and material for forming the conductive layer 228, reference may be made to the first embodiment, and details are not described herein.

Referring to FIG. 4B, the permanent substrate 232 is bonded to the conductive layer 228, wherein the permanent substrate 232 and the protruding structure 224 are respectively located on both sides of the conductive layer 228. In the present embodiment, the permanent substrate 232 is bonded to the conductive layer 228 by, for example, the second bonding layer 230. The permanent substrate 232 is, for example, a tantalum carbide substrate, a tantalum substrate, a gallium arsenide substrate, a gallium oxide substrate, a gallium nitride substrate, a lithium aluminate substrate, a lithium gallate substrate, an aluminum nitride substrate, or a metal substrate. The material of the second bonding layer 230 is, for example, a eutectic metal, a low melting point metal or a conductive adhesive. Therefore, for example, the second bonding layer 230 is formed on the conductive layer 228, and then the permanent substrate 232 is bonded to the second bonding layer 230 by heating or the like.

Referring to FIG. 4C, the transfer substrate 220 is separated from the second type doped semiconductor layer 216. In this embodiment, the first bonding layer 218 and the second doping semiconductor layer 216 may be separated by heating or other means according to the material properties of the first bonding layer 218, thereby causing the transfer substrate 220 and the second type to be doped. The hetero semiconductor layer 216 is separated.

Referring to FIG. 4D, the first electrode 240 and the second electrode 250 are formed on the permanent substrate 232 and the second electrode 250 respectively disposed on the second type doped semiconductor layer 216 to form the LED array 200a. The first electrode 240 is electrically connected to the first type doped semiconductor layer 212 and the second electrode 250 is electrically connected to the second type doped semiconductor layer 216.

The light-emitting diode wafer 200a of the present embodiment has a conductive layer 228 having a smaller thickness and a permanent substrate 232 bonded to the conductive layer 228 than the light-emitting diode wafer 200 in the first embodiment. In other words, depending on the process conditions and the desired product, the structure of the LED wafer can be adjusted, and the same yield, antistatic capability, reliability and component characteristics as well as lower manufacturing cost can be produced. Light-emitting diode chip.

In the above embodiments, the vertical type of light-emitting diode wafers are exemplified. Next, the manufacturing process of the planar light-emitting diode wafers will be described in the fourth embodiment and the fifth embodiment.

Fourth Embodiment

5A to 5C are partial cross-sectional views showing a method of manufacturing a light-emitting diode wafer according to a fourth embodiment of the present invention. In the present embodiment, the front-end process of the light-emitting diode wafer is substantially the same as the manufacturing process of FIGS. 2A to 2G described in the first embodiment, and the main difference is that the first-type doped semiconductor layer is formed with insulation. The layer and the first electrode and the second electrode are disposed on the same side of the light-emitting diode wafer, and the differences will be described in detail below.

Referring to FIG. 5A, in the embodiment, the conductive layer 228 is disposed with a plurality of protrusion structures 224, a first type doped semiconductor layer 212, a light emitting layer 214, and a second type doped semiconductor layer 216, wherein the first type is doped An insulating layer 260 is disposed in the hetero semiconductor layer 212. The material of the insulating layer 260 is, for example, aluminum nitride, low-growth gallium nitride or aluminum gallium nitride (Al _X Ga _1-X N (0.001≦X≦0.999)) or doped carbon or magnesium gallium nitride or nitrogen. Aluminum gallium (Al _X Ga _1-X N (0.001≦X≦0.999)).

Referring to FIG. 5B, next, the second type doped semiconductor layer 216, the light emitting layer 214, and a portion of the first type doped semiconductor layer 212 are removed to expose the first type doped semiconductor layer 212. The method of removing the second type doped semiconductor layer 216, the light emitting layer 214, and the first type doped semiconductor layer 212 is, for example, a dry etching process or a wet etching process.

Referring to FIG. 5C, a first electrode 240 is formed on the exposed first type doped semiconductor layer 212 and a second electrode 250 is formed on the second type doped semiconductor layer 216 to form a horizontal light emitting diode. Body wafer 200b. The first electrode 240 is electrically connected to the first type doped semiconductor layer 212 and the second electrode 250 is electrically connected to the second type doped semiconductor layer 216.

It can be seen from the present embodiment that the method for manufacturing the light-emitting diode wafer of the present invention is also applicable to a horizontal light-emitting diode wafer, and further, since the insulating layer 260 is disposed in the first-type doped semiconductor layer 212, the light-emitting diode is The bulk wafer 200b has thermoelectric separation characteristics, so that the light-emitting diode wafer 200b has better heat dissipation capability. In other words, the method of manufacturing the light-emitting diode wafer of the present embodiment can produce a light-emitting diode wafer having better yield, antistatic ability, reliability, and element characteristics as well as lower manufacturing cost.

In the present embodiment, the step of forming the first electrode 240 and the second electrode 250 is performed after separating the transfer substrate 220 from the second type doped semiconductor layer 216. In other words, the first type doped semiconductor layer 212 is exposed after the transfer substrate 220 is separated from the second type doped semiconductor layer 216. However, the step of forming the first electrode 240 and the second electrode 250 may also be performed before bonding the second type doped semiconductor layer 216 and the transfer substrate 220, please refer to the fifth embodiment.

[Fifth Embodiment]

6A to 6E are cross-sectional views showing the flow of a method of manufacturing a light-emitting diode wafer according to a fifth embodiment of the present invention.

Referring to FIG. 6A, first, a first type doped semiconductor layer 212, a light emitting layer 214, and a second type doped semiconductor layer 216 are sequentially formed on the growth substrate 210, wherein the first type doped semiconductor layer 212 is provided with insulation. Layer 260. The materials of the first type doped semiconductor layer 212, the light emitting layer 214, the second type doped semiconductor layer 216, and the insulating layer 260 can be referred to the foregoing, and will not be described herein.

Referring to FIG. 6B, next, the second type doped semiconductor layer 216, the light emitting layer 214, and a portion of the first type doped semiconductor layer 212 are removed to expose the first type doped semiconductor layer 212. The method of removing the second type doped semiconductor layer 216, the light emitting layer 214, and the first type doped semiconductor layer 212 is, for example, a dry etching process or a wet etching process.

Then, a current dispersion layer 270 is formed on the exposed first type doped semiconductor layer and the first electrode 240 is formed on the first type doped semiconductor layer, and a second electrode 250 is formed on the second type doped semiconductor layer. The material of the current dispersion layer 270 is, for example, indium tin oxide, indium zinc oxide, indium tin zinc oxide, antimony oxide, zinc oxide, aluminum oxide, aluminum tin oxide, aluminum zinc oxide, cadmium tin oxide, cadmium zinc. Oxide, or other suitable material.

Referring to FIG. 6C , a first bonding layer 218 is formed on the growth substrate 210 to cover the exposed first-type doped semiconductor layer 212 , the light-emitting layer 214 , the second-type doped semiconductor layer 216 , and the first electrode 240 . And a second electrode 250. Next, the transfer substrate 220 is bonded to the second type doped semiconductor layer 216 by the first bonding layer 218. The material of the first bonding layer 218 and the transfer substrate 220 can be referred to in the first embodiment, and details are not described herein.

Referring to FIG. 6D, the growth substrate 210 is thinned and patterned to form a plurality of protrusion structures 224 on the first type doped semiconductor layer 212. The method of thinning and patterning the growth substrate 210 can be referred to the description in the first embodiment, and details are not described herein.

Thereafter, a conductive layer 228 is formed on the first type doped semiconductor layer 212 to cover the protrusion structure 224 and the first type doped semiconductor layer 212. The thickness of the conductive layer 228 is, for example, greater than or equal to 50 μm.

Referring to FIG. 6E, the first bonding layer 218 is removed to separate the transfer substrate 220 from the second type doped semiconductor layer 216 to form the LED array 200c. The method of removing the first bonding layer 218 can be referred to the description in the first embodiment, and details are not described herein.

In particular, as shown in FIG. 7, in another embodiment, when the thickness of the conductive layer 228 is small (for example, between 5 μm and 50 μm), the permanent substrate can be used by the second bonding layer 230. 232 is bonded to the conductive layer 228 to form the light emitting diode wafer 200d. The method of bonding the permanent substrate 232 and the conductive layer 228 by the second bonding layer 230 can be referred to in the third embodiment, and details are not described herein.

In the light-emitting diode wafers 200c and 200d, the protrusion structure 224 formed by the growth substrate 210 can improve the light extraction efficiency of the light-emitting diode wafer 200, and the insulating layer 260 has the light-emitting diode structure 200 having thermoelectric separation characteristics. Therefore, the light-emitting diode wafer formed by the above method has better yield, antistatic ability, reliability, and element characteristics as well as lower manufacturing cost.

[Sixth embodiment]

In the above embodiments, the thinning and patterning of the grown substrate after bonding the second type doped semiconductor layer and the transfer substrate are exemplified, but in the present embodiment, the first type will be described. A process of patterning a grown substrate before doping the semiconductor layer.

8A to 8F are cross-sectional views showing the flow of a method of manufacturing a light-emitting diode wafer according to a sixth embodiment of the present invention.

Referring to FIG. 8A , first, the growth substrate 210 is patterned to form a plurality of recesses 211 on the surface of the growth substrate 210 . The depth of the recess 211 is, for example, less than or equal to 5 μm. The method of patterning the growth substrate 210 includes a dry etching process or a wet etching process, wherein the dry etching process may be an inductively coupled plasma (ICP) process or a reactive ion etching (RIE) process.

Referring to FIG. 8B , a first type doped semiconductor layer 212 , a light emitting layer 214 , and a second type doped semiconductor layer 216 are sequentially formed on the growth substrate 210 . In the present embodiment, the first type doped semiconductor layer 212 is, for example, a surface recess 211 that is not filled with the growth substrate 210, and thus a plurality of holes 282 are present. In particular, in the present embodiment, the first type doped semiconductor layer 212 is represented by a uniform point only for the reader to clearly distinguish the first type doped semiconductor layer 212 from other material layers, and is not used. The material defining the first type doped semiconductor layer 212, that is, the first type doped semiconductor layer 212 herein is not significantly different in material and formation method from the first type doped semiconductor layer 212 described above. .

Referring to FIG. 8C, the second type doped semiconductor layer 216 is bonded to the transfer substrate 220 by the first bonding layer 218, for example, the growth substrate 210 and the transfer substrate 220 are respectively located on the second type doped semiconductor layer 216. side.

Referring to FIG. 8D, the substrate 210 is thinned to form a plurality of protrusion structures 224 on the first type doped semiconductor layer 212. In the present embodiment, for example, the growth substrate 210 is thinned by a polishing process, and the thinning process is performed by exposing the holes 282 as a polishing end point, thereby forming a plurality of depressions on the surface of the first type doped semiconductor layer 212. 226. In other words, in terms of structure, the surface of the first type doped semiconductor layer 212 has a plurality of recesses 226, and the protrusion structures 224 are located on the surface between the recesses 226. The height of the protrusion structure 224 is, for example, less than or equal to 5 μm.

Referring to FIG. 8E, a conductive layer 228 is formed on the first type doped semiconductor layer 212 to cover the protrusion structure 224 and the first type doped semiconductor layer 212. Wherein, the conductive layer 228 extends into the recess 226.

Referring to FIG. 8F, the transfer substrate 220 is separated from the second type doped semiconductor layer 216 by, for example, removing the first bonding layer 218.

Then, the first electrode 240 and the second electrode 250 are formed on the first type doped semiconductor layer 212 and the second type doped semiconductor layer 216, respectively, to form the light emitting diode wafer 200e. In particular, as shown in FIG. 9, in another embodiment, when the thickness of the conductive layer 228 is small (for example, between 1 μm and 50 μm), the permanent substrate can be made by the second bonding layer 230. 232 is bonded to the conductive layer 228, and then the first electrode 240 and the second electrode 250 are formed on the permanent substrate 232 and the second type doped semiconductor layer 216, respectively, to form the light emitting diode wafer 200f. The method of bonding the permanent substrate 232 and the conductive layer 228 by the second bonding layer 230 can be referred to in the third embodiment, and details are not described herein.

In the above embodiment, the growth substrate 210 is first patterned, and then the protrusion structure 224 is simultaneously formed by thinning the substrate 210 and the holes 282 formed when the first type doped semiconductor layer 212 is formed are removed. In this way, not only the luminous efficiency of the LED wafer can be improved, but also the reliability of the LED 252 is affected by the hole 282, so that the LED chips 200d and 200e have better yield. Antistatic ability, reliability and component characteristics.

[Seventh embodiment]

10A to 10E are cross-sectional views showing the flow of a method of manufacturing a light-emitting diode wafer according to a seventh embodiment of the present invention. The main difference between the manufacturing method of the light-emitting diode wafer of the present embodiment and the process described in the sixth embodiment is that the first type doped semiconductor layer 212 formed on the growth substrate 210 fills the surface recess 211 of the growth substrate 210. The following will explain this situation.

Referring to FIG. 10A, first, a first type doped semiconductor layer 212, a light emitting layer 214, and a second type doped semiconductor layer 216 are sequentially formed on the patterned growth substrate 210, and the first type doped semiconductor layer 212 is filled. The surface of the substrate 210 is fully recessed 211. In the present embodiment, the depth of the recess 211 is, for example, less than or equal to 5 μm. In particular, in the present embodiment, the first type doped semiconductor layer 212 is indicated by oblique lines only for the reader to clearly distinguish the first type doped semiconductor layer 212 from other material layers, and is not intended to be limited. The material of the first type doped semiconductor layer 212, that is, the first type doped semiconductor layer 212 herein is not significantly different in material and formation method from the first type doped semiconductor layer 212 described above.

Referring to FIG. 10B, the second type doped semiconductor layer 216 is bonded to the transfer substrate 220, for example, by the first bonding layer 218, wherein the growth substrate 210 and the transfer substrate 220 are respectively located in the second type doped semiconductor layer 216. side.

Referring to FIG. 10C, the substrate 210 is thinned to form a plurality of protrusion structures 224 on the first type doped semiconductor layer 212. In the present embodiment, for example, the growth substrate 210 is thinned by a polishing process, and the first type doped semiconductor layer 212 that fills the recess 211 is exposed as a polishing end point. In terms of structure, in the present embodiment, the surface of the first type doped semiconductor layer 212 has a plurality of recesses 227, and the protrusion structures 224 are located in the recesses 227 and fill the recesses 227.

Referring to FIG. 10D, a conductive layer 228 is then formed on the first type doped semiconductor layer 212 to cover the protrusion structure 224 and the first type doped semiconductor layer 212.

Referring to FIG. 10E, the transfer substrate 220 is separated from the second type doped semiconductor layer 216.

Then, the first electrode 240 and the second electrode 250 are formed on the first type doped semiconductor layer 212 and the second type doped semiconductor layer 216, respectively, to form the light emitting diode wafer 200g. In particular, as shown in FIG. 11, in another embodiment, when the thickness of the conductive layer 228 is small (for example, between 1 μm and 50 μm), the permanent substrate can be used by the second bonding layer 230. 232 is bonded to the conductive layer 228, and then the first electrode 240 and the second electrode 250 are formed on the permanent substrate 232 and the second type doped semiconductor layer 216, respectively, to form the light emitting diode wafer 200h. The method of bonding the permanent substrate 232 and the conductive layer 228 by the second bonding layer 230 can be referred to in the third embodiment, and details are not described herein.

In the present embodiment, the growth substrate 210 is patterned before the first type doped semiconductor layer 212 is formed, and the growth substrate 210 is grown after the first type doped semiconductor layer 212 fills the surface recess 211 of the growth substrate 210. Thinning is performed to form a protrusion structure 224 that is located in the surface recess 227 of the first type doped semiconductor layer 212 and fills the recess 227. In other words, depending on the process conditions and the desired product, the timing of thinning and patterning the substrate can be selected, and the structure of the LED wafer can be adjusted to produce a better yield and antistatic. Light-emitting diode wafers with capability, reliability, and component characteristics, as well as lower manufacturing costs.

Furthermore, in the sixth embodiment and the seventh embodiment, a vertical light-emitting diode chip is taken as an example, but those skilled in the art should understand the sixth embodiment and the seventh embodiment. The described process can also be applied to the fabrication of horizontal light-emitting diode wafers.

As described above, in the method of manufacturing a light-emitting diode wafer of the present invention, the growth structure is thinned and patterned to form a protrusion structure, so that it is not necessary to completely remove the growth substrate. In this way, it is not necessary to use an expensive laser stripping machine to peel off the grown substrate, and problems such as lattice defects occurring in the first type doped semiconductor layer due to separation from the grown substrate can be avoided. In addition, the protruding structure between the first type doped semiconductor layer and the conductive layer can reduce the chance of the light emitted by the light emitting layer generating total reflection in the light emitting diode wafer, so that the light extraction efficiency of the light emitting diode chip is greatly improved. increase. Therefore, the light-emitting diode wafer formed by the method for fabricating the light-emitting diode wafer of the present invention has better yield, antistatic property, reliability, component characteristics, and lower manufacturing cost.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100, 200, 200a, 200b, 200c, 200d, 200e, 200f, 200g, 200h. . . Light-emitting diode chip

110, 210, 210a. . . Growth substrate

112, 212. . . First type doped semiconductor layer

114,214. . . Luminous layer

116,216. . . Second type doped semiconductor layer

120, 220. . . Transfer substrate

130, 232. . . Permanent substrate

140, 240. . . First electrode

150, 250. . . Second electrode

218, 230. . . Bonding layer

222. . . Patterned mask layer

224. . . Protrusion structure

224’. . . Initial protrusion structure

211, 226, 227. . . Depression

228. . . Conductive layer

260. . . Insulation

270. . . Current dispersion layer

282. . . Hole

1A to 1D are a conventional method of fabricating a light emitting diode wafer.

2A to 2H are cross-sectional views showing the flow of a method of manufacturing a light-emitting diode wafer according to a first embodiment of the present invention.

3A to 3C are partial cross-sectional views showing a method of manufacturing a light-emitting diode wafer according to a second embodiment of the present invention.

4A to 4D are partial cross-sectional views showing a method of manufacturing a light-emitting diode wafer according to a third embodiment of the present invention.

5A to 5C are partial cross-sectional views showing a method of manufacturing a light-emitting diode wafer according to a fourth embodiment of the present invention.

6A to 6E are cross-sectional views showing the flow of a method of manufacturing a light-emitting diode wafer according to a fifth embodiment of the present invention.

Figure 7 is a cross-sectional view showing another light emitting diode wafer of a fifth embodiment of the present invention.

8A to 8F are cross-sectional views showing the flow of a method of manufacturing a light-emitting diode wafer according to a sixth embodiment of the present invention.

Figure 9 is a cross-sectional view showing another light emitting diode wafer of a sixth embodiment of the present invention.

10A to 10E are cross-sectional views showing the flow of a method of manufacturing a light-emitting diode wafer according to a seventh embodiment of the present invention.

Figure 11 is a cross-sectional view showing another light emitting diode wafer of a seventh embodiment of the present invention.

200. . . Light-emitting diode chip

212. . . First type doped semiconductor layer

214. . . Luminous layer

216. . . Second type doped semiconductor layer

224. . . Protrusion structure

226. . . Depression

228. . . Conductive layer

240. . . First electrode

250. . . Second electrode

Claims (30)

A method for fabricating a light-emitting diode wafer includes: sequentially forming a first type doped semiconductor layer, a light emitting layer, and a second type doped semiconductor layer on a growth substrate; and causing the second type doped semiconductor The layer is bonded to a transfer substrate, wherein the growth substrate and the transfer substrate are respectively located on two sides of the second type doped semiconductor layer; the growth substrate is thinned and patterned to form a plurality of layers on the first type doped semiconductor layer a protruding structure; forming a conductive layer on the first type doped semiconductor layer to cover the protruding structures and the first type doped semiconductor layer; separating the transfer substrate from the second type doped semiconductor layer; And forming a first electrode and a second electrode on the first type doped semiconductor layer and the second type doped semiconductor layer, wherein the first electrode is electrically connected to the first type doped semiconductor layer and The second electrode is electrically connected to the second type doped semiconductor layer. The method for manufacturing a light-emitting diode wafer according to claim 1, wherein the step of thinning the growth substrate is performed after bonding the second-type doped semiconductor layer and the transfer substrate, and thinning the The growth substrate is patterned after the substrate is grown. The method for manufacturing a light-emitting diode wafer according to claim 1, wherein the step of patterning the grown substrate is performed after bonding the second-type doped semiconductor layer and the transfer substrate, and patterning The growth substrate is thinned after the substrate is grown. The method for manufacturing a light-emitting diode wafer according to claim 1, wherein the step of patterning the grown substrate is performed before forming the first-type doped semiconductor layer, and the step of thinning the grown substrate is It is performed after bonding the second type doped semiconductor layer and the transfer substrate. The method of manufacturing a light-emitting diode wafer according to claim 1, wherein the transfer substrate is bonded to the second-type doped semiconductor layer by a first bonding layer. The method of manufacturing a light-emitting diode wafer according to claim 5, wherein the transfer substrate is separated from the second-type doped semiconductor layer by removing the first bonding layer. The method of manufacturing a light-emitting diode wafer according to claim 1, wherein the first electrode is disposed on the conductive layer and the second electrode is disposed on the second-type doped semiconductor layer. The method for fabricating a light-emitting diode wafer according to claim 1, further comprising bonding a permanent substrate to the conductive layer, wherein the permanent substrate and the protruding structures are respectively located on opposite sides of the conductive layer. The method of fabricating a light-emitting diode wafer according to claim 8, wherein the permanent substrate is bonded to the conductive layer by a second bonding layer. The method of manufacturing a light-emitting diode wafer according to claim 8, wherein the first electrode is disposed on the permanent substrate and the second electrode is disposed on the second-type doped semiconductor layer. The method for manufacturing a light-emitting diode wafer according to claim 1, wherein the forming the first electrode and the second electrode comprises: removing the second-type doped semiconductor layer and a portion of the light-emitting layer And exposing the first type doped semiconductor layer; and forming the first electrode on the exposed first type doped semiconductor layer and forming the second electrode on the second type doped semiconductor layer. The method of manufacturing a light-emitting diode wafer according to claim 11, wherein the step of forming the first electrode and the second electrode is performed after separating the transfer substrate from the second-type doped semiconductor layer. The method for manufacturing a light-emitting diode wafer according to claim 11, wherein the step of forming the first electrode and the second electrode is performed before the step of bonding the second-type doped semiconductor layer and the transfer substrate . The method for manufacturing a light-emitting diode wafer according to claim 13, wherein the transfer substrate is bonded to the second-type doped semiconductor layer by a first bonding layer, and the first bonding layer is exposed by the coating. The first type doped semiconductor layer, the light emitting layer, the second type doped semiconductor layer, the first electrode, and the second electrode. The method of manufacturing a light-emitting diode wafer according to claim 14, wherein the transfer substrate is separated from the second-type doped semiconductor layer by removing the first bonding layer. The method of manufacturing a light-emitting diode wafer according to claim 11, wherein an insulating layer is disposed in the first type doped semiconductor layer. The method for fabricating a light-emitting diode wafer according to claim 1, wherein the surface of the first type doped semiconductor layer has a plurality of recesses, the protrusion structures being located on a surface between the recesses, and The conductive layer extends into the recesses. The method of manufacturing a light-emitting diode wafer according to claim 1, wherein the surface of the first type doped semiconductor layer has a plurality of recesses, and the protrusion structures are located in the recesses. A light emitting diode chip includes: a first type doped semiconductor layer, a second type doped semiconductor layer, and a light emitting layer, wherein the light emitting layer is located in the first type doped semiconductor layer and the second type doped a plurality of protrusion structures disposed on the first type doped semiconductor layer, wherein the protrusion structures have a height between 1 μm and 100 μm, and the protrusion structures and the light emitting layer are located at the first a type of doped semiconductor layer on both sides; a conductive layer disposed on the first type doped semiconductor layer and covering the protrusion structures; and a first electrode and a second electrode, the first electrode being disposed on the first The second doped semiconductor layer is electrically connected to the first type doped semiconductor layer, and the second electrode is disposed on the second type doped semiconductor layer and electrically connected to the second type doped semiconductor layer. The illuminating diode chip of claim 19, wherein the protrusion structures have a height of less than 5 μm. The light-emitting diode wafer according to claim 19, wherein the conductive layer has a thickness greater than or equal to 50 μm. The illuminating diode chip according to claim 19, wherein the first electrode is disposed on the conductive layer and the second electrode is disposed on the second type doped semiconductor layer. The illuminating diode chip of claim 19, further comprising a permanent substrate disposed on the conductive layer, wherein the permanent substrate and the protruding structures are respectively located on opposite sides of the conductive layer. The light-emitting diode wafer according to claim 23, wherein the conductive layer has a thickness of less than or equal to 50 μm. The illuminating diode chip of claim 23, wherein a bonding layer is further disposed between the permanent substrate and the conductive layer. The illuminating diode chip according to claim 23, wherein the first electrode is disposed on the permanent substrate and the second electrode is disposed on the second doped semiconductor layer. The light-emitting diode chip of claim 19, wherein a portion of the first-type doped semiconductor layer is exposed, and the first electrode is disposed on the exposed first-type doped semiconductor layer . The illuminating diode chip of claim 27, further comprising an insulating layer disposed in the first type doped semiconductor layer. The illuminating diode chip according to claim 19, wherein the surface of the first type doped semiconductor layer has a plurality of recesses, the protruding structures are located on a surface between the recesses, and the conductive layer Extending into the depressions. The illuminating diode chip according to claim 19, wherein the surface of the first type doped semiconductor layer has a plurality of recesses, and the protrusion structures are located in the recesses.