TWI440219B - Led substrate, method of manufacturing the same and led - Google Patents

Description

Light-emitting diode substrate, manufacturing method thereof and light-emitting diode

The present invention relates to a light-emitting diode substrate, and more particularly to a light-emitting diode substrate capable of improving light-emitting luminance, a method of manufacturing the same, and a light-emitting diode using the same.

A light-emitting diode is a light-emitting element made of a compound semiconductor, which can be converted into light by means of a combination of electrons and holes. The light-emitting diode is cold-emitting, so it has the advantages of low power consumption, no pre-warm time, long component life, fast reaction speed, etc., plus its small size, impact resistance, mass production, and easy to match the application. It can be made into very small or array components.

In order to make the LEDs have more application space and prospects in the future, how to improve the luminance of the LEDs is one of the most important studies in the world. At present, there is a method in which a mask having a plurality of protrusion structures is formed as a light-emitting diode substrate by means of wet etching in combination with a mask layer. The light-emitting diode substrate can effectively improve the luminous efficiency of the light-emitting diode. However, the surface of the protruding structure formed by the wet etching leaves a partial crystal face, and a heterostructure which affects the epitaxial quality is easily generated.

The invention provides a light-emitting diode substrate, which can improve the luminous efficiency of the light-emitting diode.

The present invention further provides a light emitting diode having the above light emitting diode substrate.

The present invention further provides a method of manufacturing a light-emitting diode substrate, and fabricating the light-emitting diode substrate.

The invention provides a light-emitting diode substrate having a plurality of protrusion structures formed by a first processing procedure on one side, and a surface of each protrusion structure is a defect surface formed by a second processing procedure. In the cross section of each of the protruding structures, the length of the defect surface is in a range of not less than 0.5 μm, and the surface height difference of the defect surface formed by the second processing procedure is larger than the surface of each of the protrusion structures through the first processing procedure. Height difference.

In an embodiment of the invention, the surface height difference of the defect surface formed by the second processing procedure is, for example, between 0.1 nm and 50 nm.

In an embodiment of the invention, the bottom of the face having the protrusion structure includes a c-plane, an a-plane, an r-plane or an m-plane.

In an embodiment of the invention, the protrusion structure comprises a pyramid structure, a ridge structure, a conical structure, a cylindrical structure, a corner column structure or a polygonal structure.

In an embodiment of the invention, the pitch of the protrusion structure is, for example, between 0.1 μm and 10 μm.

In an embodiment of the invention, the height of the protrusion structure is, for example, between 1 μm and 2 μm.

The invention further provides a light-emitting diode having the above-mentioned light-emitting diode substrate.

The invention further provides a method for manufacturing a light-emitting diode substrate by first performing a first processing procedure on one side of a sapphire substrate to form a plurality of protrusion structures; and then performing a second processing procedure on the protrusion structure to make Has a defective surface.

In another embodiment of the invention, the first processing procedure includes wet etching, wet etching, and dry etching, or dry etching.

In another embodiment of the invention, the second processing procedure includes dry etching, machining, or ion implantation. For example, dry etching of the second process includes inductively coupled plasma (ICP) etching, reactive ion etching (RIE), or ICP-RIE. The machining of the second process includes a polishing process.

In another embodiment of the invention, the dry etching reaction gas of the second processing step is, for example, BCl ₃ , Cl ₂ , Ar, O ₂ or CF ₄ .

Based on the above, since the surface of the protruding structure of the light-emitting diode substrate of the present invention is a defective surface, it is possible to prevent a heterostructure that affects the epitaxial quality from being generated on the surface of the protruding structure, so as to improve the brightness and light emission of the light-emitting diode. effectiveness.

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

1 is a schematic cross-sectional view of a light-emitting diode substrate according to a first embodiment of the present invention, and FIG. 2 is an enlarged schematic view of a first portion of FIG.

Referring to FIG. 1 , one side 100 a of the LED substrate 100 in this embodiment has a plurality of protrusion structures 102 formed by a first processing procedure, and the surface of each protrusion structure 102 is formed through a second processing procedure. A defective surface 104. The above-described light-emitting diode substrate 100 is, for example, a sapphire substrate, and the first processing procedure and the second processing procedure will be described in detail below.

Then, referring to FIG. 2, under the cross section of each of the protrusion structures 102, the length of the defect surface 104 of the light-emitting diode substrate 100 has a suricial height difference d1 in a range of not less than 0.5 μm. The so-called "surface height difference" in this paper refers to the difference between the lowest point and the highest point in a specific range of the same plane. For example, the surface height difference d1 of the defect surface 104 formed by the second processing procedure in this embodiment ranges, for example, between 0.1 nm and 50 nm; preferably between 1 nm and 10 nm. Moreover, the surface height difference d1 is larger than the surface height difference of each of the protrusion structures 102 after the first processing procedure, so as to prevent the heterogeneous structure affecting the epitaxial quality from being generated on the surface of the protrusion structure 102, thereby improving the light emitting diode. Brightness and luminous efficiency.

In the present embodiment, the bottom surface of the surface 100a having the protrusion structure 102 may be a c-plane, an a-plane, an r-plane or an m-plane, and the protrusion structure 102 formed according to the axial direction of the light-emitting diode substrate 100 may be different. For example, using a C-axis sapphire substrate, the protrusion structure formed by a first processing procedure such as wet etching is a pyramid structure 300, as shown in FIG. The pyramid structure 300 may be in the shape of a triangular pyramid, a hexagonal cone or the like. The pattern p of the protrusion structure 300 is, for example, between 0.1 μm and 10 μm, and has a preferable light-emitting efficiency. The so-called "pattern period" means the distance between each of the protrusion structures 300.

Further, if the light-emitting diode substrate 100 is a non-C-axis sapphire substrate, a sapphire substrate such as an A-axis, an R-axis or an M-axis can be applied to the present invention. If an R-axis sapphire substrate is used, the protrusion structure formed by the first processing procedure such as wet etching will be the ridge structure 400, as shown in FIG. In the present embodiment, the height h of the protrusion structure 400 is between 1 μm and 2 μm, preferably between 1.5 μm and 2 μm. The "height" here is the distance from the top to the bottom of the protruding structure 400.

Further, the protruding structure on the surface 100a may be a corner post structure 500 (please refer to FIG. 5), or a conical structure, a cylindrical structure, or a polygonal structure in addition to the structures shown in FIGS.

The above FIGS. 3 to 5 are structures which are presented after the first processing procedure, and thus only the protrusion structure is displayed, and the defect surface 104 formed by the subsequent second processing procedure is not shown.

Figure 6 is a schematic illustration of a light emitting diode in accordance with a second embodiment of the present invention.

Referring to FIG. 6 , the light emitting diode of the present embodiment includes the light emitting diode substrate 100 of the first embodiment (see FIG. 1 ), a first semiconductor layer 600 disposed on the LED substrate 100 , and a configuration. a light emitting layer 602 on the first semiconductor layer 600, a second semiconductor layer 604 disposed on the light emitting layer 602, a first ohmic electrode 606 contacting the first semiconductor layer 600, and a first semiconductor layer 604 contacting the first semiconductor layer 600 Second ohmic electrode 608. Since the surface of the protrusion structure 102 on the light-emitting diode substrate 100 is a defect surface (see FIG. 2 for details), it is possible to prevent the generation of a heterostructure that affects the epitaxial quality. The protruding structure 102 of the above-described light-emitting diode substrate 100 can also be replaced with any of the protruding structures as shown in FIGS.

In this embodiment, the first semiconductor layer 600, the light emitting layer 602, and the second semiconductor layer 604 may be a III-V semiconductor, such as a gallium nitride based semiconductor. As for the first and second ohmic electrodes 606 and 608, for example, each selected from the group consisting of nickel, lead, cobalt, iron, titanium, copper, ruthenium, gold, rhenium, tungsten, zirconium, molybdenum, niobium, silver, and the like, At least one alloy or multilayer film selected from the group consisting of nitrides. In addition, the first and second ohmic electrodes 606 and 608 may each be selected from an alloy or a multilayer film selected from the group consisting of ruthenium, osmium, silver, and aluminum.

FIG. 7 is a process diagram of a light emitting diode substrate according to a third embodiment of the present invention.

In FIG. 7, step 700 is first performed to perform a first processing procedure on one side of a sapphire substrate to form a plurality of protrusion structures. The first processing procedure is, for example, wet etching, wet etching, and dry etching, or dry etching. For example, if the first treatment procedure is performed by wet etching, a mixed solution such as sulfuric acid and phosphoric acid can be used as the etching liquid. The surface of the protrusion structure formed by wet etching may have a specific crystal plane, so that a heterostructure that affects the epitaxial quality may be generated when the substrate is subsequently epitaxial. Therefore, the next step is required.

Next, in step 710, a second processing procedure is performed on the protrusion structure to make it a defect surface. This step is to make the surface height difference of the defect surface larger than the surface height difference of the protrusion structure formed in the previous step 700, so as to greatly reduce the specific crystal plane of the surface of the protrusion structure, thereby preventing the occurrence of epitaxial quality during subsequent epitaxy. Heterogeneous structure. The second processing procedure is, for example, dry etching, machining, or ion implantation. For example, if the second processing procedure is dry etching, inductively coupled plasma (ICP) etching, reactive ion etching (RIE), or ICP-RIE may be selected; for example, BCl ₃ , Cl ₂ , Ar, A reaction gas such as O ₂ or CF ₄ . If the damage to the bottom surface of the substrate is less than that for the protrusion structure, it is preferred to use BCl ₃ as the reaction gas. In addition, the second processing program, such as mechanical processing, may include a polishing process such as hard throwing, soft throwing, fine polishing, and the like.

In summary, the present invention designs the surface of the protruding structure of the light-emitting diode substrate as a defective surface, thereby preventing the heterogeneous structure that affects the epitaxial quality from being generated on the surface of the surface structure without the surface treatment, so as to simultaneously Improve the brightness and luminous efficiency of the light-emitting diode.

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. . . Light-emitting diode substrate

102, 300, 400, 500. . . Protrusion structure

104. . . Defect surface

600. . . First semiconductor layer

602. . . Luminous layer

604. . . Second semiconductor layer

606. . . First ohmic electrode

608. . . Second ohmic electrode

700~710. . . step

L. . . length

d ₁ . . . Surface height difference

p. . . cycle

h. . . height

1 is a schematic cross-sectional view of a light emitting diode substrate in accordance with a first embodiment of the present invention.

Figure 2 is an enlarged schematic view of the first portion of Figure 1.

3 is a schematic perspective view of a light-emitting diode substrate of the first embodiment after a first processing procedure.

4 is a schematic perspective view of another LED substrate of the first embodiment after a first processing procedure.

FIG. 5 is a schematic perspective view of still another light-emitting diode substrate of the first embodiment after a first processing procedure.

Figure 6 is a schematic illustration of a light emitting diode in accordance with a second embodiment of the present invention.

FIG. 7 is a process diagram of a light emitting diode substrate according to a third embodiment of the present invention.

102. . . Protrusion structure

104. . . Defect surface

L. . . length

d ₁ . . . Surface height difference

Claims (12)

A light-emitting diode substrate, wherein one surface of the light-emitting diode substrate has a plurality of protrusion structures formed by a first processing procedure, and a surface of each protrusion structure is formed by a second processing program. a defect surface, wherein a length of the defect surface is in a range of not less than 0.5 μm in a cross section of each of the protrusion structures, and a surface height difference of the defect surface formed by the second processing procedure is larger than each protrusion structure The surface of the first processing program has a height difference, and the surface height difference of the defect surface formed by the second processing procedure is between 0.1 nm and 50 nm. The light-emitting diode substrate according to claim 1, wherein the bottom surface of the surface having the protrusion structures includes a c-plane, an a-plane, an r-plane or an m-plane. The light-emitting diode substrate of claim 1, wherein the protruding structures comprise a pyramid structure, a ridge structure, a corner column structure, a conical structure, a cylindrical structure or a polygonal structure. The light-emitting diode substrate of claim 1, wherein the protrusion structures have a period of between 0.1 μm and 10 μm. The light-emitting diode substrate of claim 1, wherein the height of the protrusion structures is between 1 μm and 2 μm. A light-emitting diode comprising the light-emitting diode substrate according to any one of claims 1 to 5. A method of manufacturing a light-emitting diode substrate, comprising: performing a first processing procedure on one side of a sapphire substrate to form a plurality of protrusion structures; and performing a second processing procedure on the protrusion structures to make the protrusion structures A defect surface having a surface height difference ranging from 0.1 nm to 50 nm in a length range of not less than 0.5 μm. The method of manufacturing a light-emitting diode substrate according to claim 7, wherein the first processing procedure comprises wet etching, wet etching, dry etching, or dry etching. The method of manufacturing a light-emitting diode substrate according to claim 7, wherein the second processing procedure comprises dry etching, machining, or ion implantation. The method of fabricating a light-emitting diode substrate according to claim 9, wherein the dry etching comprises inductively coupled plasma (ICP) etching, reactive ion etching (RIE) or ICP-RIE. The method for producing a light-emitting diode substrate according to claim 9, wherein the dry etching reaction gas comprises BCl ₃ , Cl ₂ , Ar, O ₂ or CF ₄ . The method of manufacturing a light-emitting diode substrate according to claim 9, wherein the mechanical processing comprises a polishing process.