KR101364168B1 - Method of fabricating substrates for light emitting device - Google Patents

Abstract

The present invention provides a method of preparing a substrate in a reaction chamber, forming SiN islands on the substrate, etching a portion of the substrate by using SiN islands formed on the substrate as a shadow mask, and spaced apart from each other on an upper portion of the substrate. It provides a light emitting device substrate manufacturing method comprising the step of forming a protruding pattern.

According to the present invention, it is possible to omit complicated processes, such as a thin film layer forming process and a patterning etching process, which are required for forming a mask (or pattern layer) in the related art. Accordingly, the present invention can increase the mass productivity and reproducibility by omitting the conventional complicated process required for forming the mask (or pattern layer), and lowering the yield caused during the conventional complicated process for forming the pattern on the substrate. And time loss can be greatly reduced.

PSS, Substrate, Mask, Etch, Pattern, Sapphire

Description

Method for manufacturing substrate for light emitting device {METHOD OF FABRICATING SUBSTRATES FOR LIGHT EMITTING DEVICE}

1 is a view for explaining a method for manufacturing a patterned sapphire substrate according to the prior art.

2 to 4 are views for explaining a process of manufacturing a patterned substrate according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a substrate for light emitting devices, and more particularly, to a method of manufacturing a substrate for light emitting devices in which a pattern is formed on a substrate formed by using a SiN layer formed on a substrate as a mask layer without a separate photolithography process.

A light emitting diode, which is a typical light emitting device, is a photoelectric conversion semiconductor device having a structure in which an N-type semiconductor and a P-type semiconductor are bonded to each other, and are configured to emit light by recombination of electrons and holes. As such a light emitting diode, a GaN-based light emitting diode is known. GaN-based light emitting diodes are manufactured by sequentially stacking GaN-based N-type semiconductor layers, active layers (or light-emitting layers), and P-type semiconductor layers on a substrate made of a material such as sapphire or SiC, for example, and forming a transparent electrode.

In general, when light is generated, a large amount of light is lost from the inside due to total reflection and confinement.

Due to the nature of light, when light passes between two media having different refractive indices, reflection and transmission occur at the interface. When the incident angle becomes larger than any angle, transmission does not occur and total reflection occurs. The angle is called a critical angle.

As a result of the total reflection phenomenon, when light emitted from the active layer proceeds to the transparent electrode at an angle greater than or equal to the critical angle in the light emitting diode, the light is totally reflected at the transparent electrode and trapped inside the light emitting diode, thereby forming an epitaxial layer and a sapphire substrate of the light emitting diode. By being absorbed into, a problem occurs that the light efficiency of the light emitting diode is lowered.

One way to solve this problem is to use a patterned sapphire substrate (PSS: Patterned Sapphire Substrate).

1 is a view for explaining a method for manufacturing a patterned sapphire substrate according to the prior art.

Referring to FIG. 1, the bending pattern 3 of the sapphire substrate 1 is formed. The light emitting cell of the light emitting diode is grown on the curved pattern 3 of the sapphire substrate 1.

That is, before the semiconductor layer for forming the light emitting cell is grown, the sapphire substrate is patterned to make a specific shape of the bend, and then the semiconductor layer is grown on the bent shape so that the light emitting diode cannot be extracted to the outside by total reflection. The amount of light can be extracted.

In this way, the internal light amount can be extracted to the outside by designing the LED structure to have a refractive index difference in the lateral direction.

However, the conventional technique uses photolithography to form a photoresist mask film 2 for forming the pattern 3 on the substrate 10 and to remove a certain area of the mask film 2. A mask film is manufactured.

Therefore, when performing the photolithography process, defects may occur in the arrangement of the patterns, and defects may occur due to bowing of the substrate itself, making the manufacturing process difficult and expensive, and inferior in productivity and reproducibility. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the present invention, and an object of the present invention is to provide a method for manufacturing a substrate for a light emitting device, which is easy to process and has high productivity and high reproducibility.

According to an aspect of the present invention for achieving the technical problem, the step of preparing a substrate in the reaction chamber, forming the SiN islands on the substrate, the SiN islands formed on the substrate as a shadow mask of the substrate It provides a method for manufacturing a substrate for a light emitting device comprising etching a portion to form a pattern spaced apart from each other on the upper portion of the substrate.

Preferably, the substrate may be any one of a sapphire substrate, a spinel substrate, a Si substrate, a SiC substrate, a ZnO substrate, a GaAs substrate, and a GaN substrate.

Preferably, the SiN island forming step includes introducing monomethyl silane gas and ammonia (NH ₃ ) into the reaction chamber on which the substrate is mounted and maintaining the temperature at 400 ° C. to 500 ° C., and maintaining the temperature of the reaction chamber at 1000 ° C. To 1150 ° C. may be included.

The pattern may be formed at irregular intervals on the substrate.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

2 to 4 are diagrams for explaining a process of manufacturing a patterned substrate according to an embodiment of the present invention.

Referring to FIG. 2, a substrate 10 is prepared in a reaction chamber.

The substrate 10 may be a c-side sapphire substrate or a-side sapphire substrate. In addition to the sapphire substrate, other kinds of substrates, such as a spinel substrate, a Si substrate, a SiC substrate, a ZnO substrate, a GaAs substrate, and a GaN substrate, may be used.

The SiN layer 20 is formed on the substrate 10.

In this case, before forming the SiN layer 20 on the substrate 10, a process of heat-treating the substrate 10 in a hydrogen atmosphere may be performed.

The SiN layer 20 may be formed of metal organic chemical vapor deposition (MOCVD), hydride vapor phase epitaxy (HVPE) or molecular beam epitaxy (MBE), metal organic chemical vapor deposition. It can be formed using a growth method (metalorganic chemical vapor phase epitaxy, MOCVPE) and the like.

The SiN layer 20 may be grown using any of the above-described crystal growth methods at a pressure of about 10 torr to about 780 torr at 400 ° C to 500 ° C.

As the source gas for forming the SiN layer 20, monomethyl silane gas is used, and ammonia (NH ₃ ) is used as the reaction gas. The source gas and the reaction gas for forming the SiN layer 20 are not limited thereto. These source gases and reaction gases are introduced into the reaction chamber, and the SiN layer 20 is formed at a low temperature of 400 to 500 ° C.

At this time, the SiN layer 20 formed on the substrate 10 is deposited in the form of fine particles without a continuous growth of a single crystal directly on the substrate by reacting the source gas and the reaction gas.

In this case, when the temperature condition is raised from 400 to 500 ° C. to 1000 to 1150 ° C., the SiN layer 20 deposited in the form of particles on the substrate 10 is agglomerated with adjacent particles to grow in the form of particles on the substrate 10. do. If the growth is continued, as shown in FIG. 3, the substrate 10 is spaced apart from each other in an island shape.

In the figure, the SiN islands 21 are shown as being formed in a regular pattern on the substrate 10, but are actually formed at irregular intervals on the substrate 10. Therefore, the substrate 10 has a region covered by the SiN island 21 and a region not covered by the SiN island 21 and exposed.

Thus, the plurality of SiN islands 21 formed on the substrate 10 serve as shadow masks in subsequent processes.

The surface of the exposed substrate 10 is etched to a predetermined depth by using the SiN island 21 formed on the substrate 10 as a shadow mask. The surface etching of the substrate 10 may be a suitable method such as dry or wet.

Then, etching is performed until the SiN island 21 on the substrate 10 is completely removed. As shown in FIG. 4, a protruding pattern 11 is formed on the substrate 10.

In the exemplary embodiment of the present invention, the substrate 10 is etched by the SiN islands 21 formed on the substrate 10 to form the protruding pattern on the substrate 10. The explanation was made.

However, the SiN island 21 forming process may be continuously performed on the substrate 10 to cover the entire region of the substrate 10. When the formation process of the SiN island 21 is performed until the entire area of the substrate 10 is covered, the SiN islands 21 are rugged on the substrate 10. In this case, even when etching the substrate 10, since the SiN islands 21 are unevenly formed on the substrate 10, uneven patterns may also be formed on the substrate 10.

That is, the shape of the shadow mask for etching the substrate 10 may be determined according to the time for forming the SiN island 21 on the substrate 10, and thus the shape of the pattern formed on the substrate 10 may be determined. .

The invention being thus described, it will be obvious that the same way may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention as defined by the appended claims.

According to the present invention, it is possible to omit complicated processes, such as a thin film layer forming process and a patterning etching process, which are required for forming a mask (or pattern layer) in the related art. Therefore, the present invention can increase the mass productivity and reproducibility by omitting the conventional complicated process required for forming the mask (or pattern layer), and lower the yield caused during the conventional complicated process for forming the pattern on the substrate. And time loss can be greatly reduced.

Claims (7)

Preparing a substrate in the reaction chamber, Forming SiN islands on the substrate; Etching a portion of the substrate by using SiN islands formed on the substrate as a shadow mask to form a pattern spaced apart from each other on the top of the substrate, The SiN island forming step, Introducing monomethyl silane gas and ammonia (NH ₃ ) into the reaction chamber on which the substrate is mounted and maintaining the temperature at 400 ° C. to 500 ° C .; Method of manufacturing a light emitting device substrate comprising the step of maintaining the temperature of the reaction chamber at 1000 ℃ to 1150 ℃. The method according to claim 1, wherein the substrate, A method for manufacturing a light emitting device substrate, which is any one of a sapphire substrate, a spinel substrate, a Si substrate, a SiC substrate, a ZnO substrate, a GaAs substrate, and a GaN substrate. delete The method according to claim 1, The pattern is a substrate manufacturing method for a light emitting device formed on the substrate irregularly spaced apart. The method according to claim 1, After preparing the substrate, before forming the SiN islands, Method of manufacturing a light emitting device substrate comprising the step of heat-treating the substrate in a hydrogen atmosphere. The method according to claim 1, The SiN islands are formed by metal organic chemical vapor deposition (MOCVD) substrate manufacturing method for a light emitting device. The method according to claim 1, The etching method of manufacturing a substrate for a light emitting device comprising a dry and wet method.

Images