KR100659897B1 - Method of manufacturing substrate having nano rod structure - Google Patents

Abstract

A method fot manufacturing a substrate having nano rod structure is provided to prevent the pollution of a nano rod caused by a metal catalyst without using the metal catalyst. A substrate(100) is loaded in a chamber of an MOCVD(Metal Organic Chemical Vapor Deposition) apparatus. The substrate is then heated. Crystalline nucleuses(210) are formed on the substrate by injecting a Ð -group precursor in the chamber. A plurality of nano rods(220) are grown on the crystalline nucleuses. The nano rods are spaced apart from each other.

Description

Method of manufacturing substrate having nano rod structure

1 is a process flow diagram of manufacturing a substrate having a nanorod structure according to a first embodiment of the present invention.

2 is a process flow diagram of manufacturing a substrate having a nanorod structure in accordance with a second embodiment of the present invention.

3 is a conceptual diagram illustrating a process of forming nanorod structures on a substrate by an organometallic chemical vapor deposition method according to the present invention.

4 is a schematic perspective view of a state in which nanorods are formed on a substrate according to the present invention;

5 is a schematic perspective view for explaining a method of forming a light emitting structure using a nanorod formed on the substrate according to the present invention;

6 is a schematic perspective view of a light emitting structure according to the present invention;

7 is a schematic perspective view for explaining a method for controlling the length of a nanorod structure according to the present invention.

8a to 8d is a scanning electron micrograph of the nanorod structure in a length controlled state in accordance with the present invention

9 is a scanning electron micrograph of the nanorod structure grown in accordance with the present invention.

10 is a light emission characteristic of the light emitting structure grown using the nano-rod structure according to the present invention

<Description of the symbols for the main parts of the drawings>

100 substrate 210 crystal nuclei

220221: Nanorod 220: Multi Quantum Well Layer

223: nitride semiconductor layer 300: chamber

The present invention relates to a method for manufacturing a substrate having a nanorod structure, and more particularly, because it does not use a metal catalyst, it is possible to prevent the contamination of the nanorods by the catalyst, and using the nanorod structure of the light emitting device When the light emitting structure is formed, the light emitting surface is increased, and the present invention relates to a method of manufacturing a substrate having a nano rod structure capable of improving light output.

At present, the technology based on the semiconductor of silicon (Si) or gallium arsenide (GaAs) is mainly used in the technology of information communication.

However, silicon semiconductors do not have a forbidden bandgap structure, and thus are limited in use as optical devices. Gallium arsenide has a direct bandgap structure, but gallium nitride and III Since the energy bandgap is smaller than that of the -V nitride, the application of the visible light into the blue wavelength band is impossible.

However, gallium nitride is a semiconductor with a direct transition type band width, and has an electron band band width of 3.4 eV corresponding to the blue and violet wavelength bands, as well as indium nitride (InN) or aluminum nitride (AlN) and perfect solid solution (Perfect). Solid Solution), and thus the width of the direct transition inhibiting band can be continuously adjusted to 0.7 to 6.2 eV, thereby enabling application to a full color display device and a white light emitting device.

In addition to these excellent properties, gallium nitride and group III-V nitride materials have a large ban band, very high electron mobility, and are stable at high temperatures and chemically very stable, so that they are not only optical devices but also high frequency devices and high temperature stable semiconductors. It is attracting attention as an element.

Research into applying this physical and chemical excellence to nanotechnology has been carried out by many of the world's leading researchers.

In particular, nano-sized materials with small diameters have emerged as a very important field in the scientific community because of their new physical and chemical properties, namely their unique electrical, optical, and mechanical properties. Research shows that new phenomena, such as the quantum size effect, suggest the potential of semiconductor nanomaterials as a new optical device material in the future.

In particular, nanorods can have a large surface area because they have one-dimensional morphological characteristics with high aspect ratios, and because they have physical properties such as quantum size effects due to nano-size, small dislocation density, high crystallinity, and nanoelectronic devices and semiconductors. It can be applied not only to optical devices including light emitting devices and optical communication devices, but also to environmental materials. In particular, in the case of semiconductor nano-compounds, application to new optical device materials as well as single electronic transistor (SET) devices is possible.

In particular, the manufacturing technology of nanorods which are vertically or unidirectionally oriented and whose diameters and lengths are adjustable has great significance in terms of development of important device materials that are the basis of nanotechnology.

Since the semiconductor nanomaterial manufacturing technology can solve many problems of the existing electronic device of several micrometers in size, it will greatly affect the basic research development for the development of nano devices in the 21st century.

In addition, nanomaterials such as nanorods can be applied to a wider field, given that nanotechnology and science are still unexplored.

To date, research on the synthesis of various nanomaterials, including nanorods, is being actively conducted, including silicon (Si), germanium (Ge), gallium nitride (GaN), gallium arsenide (GaAs) gallium phosphide (GaP), and oxidation. Nanowires and nanorods made of various materials such as zinc (ZnO) have been reported.

The nanowires are mainly made of a vapor-phase transport process using a metal such as gold, iron, cobalt, or nickel as a catalyst, or a method using a physical vapor deposition method. A method for synthesizing nanorods and nanowires having a thickness of 150 nm to 150 nm has been developed.

In such a method of synthesizing nanorods and nanowires using a metal catalyst, the metal is heat-treated at an appropriate temperature to form nanometer-sized liquid droplets and used as a catalyst.

In this method, since it is synthesized through the precipitation process after being solidified by the liquid metal catalyst of the nanowires, it is impossible to prevent trace metal catalysts from entering the nanorods and nanowires in this process.

These unwanted or inevitable impurities degrade the inherent properties of the nanorods and nanowires, and in semiconductors, these impurities form an unintended defect energy level, which can drastically degrade the electrical and optical properties. Works.

Accordingly, the present invention has been made to solve the problems described above, and because it does not use a metal catalyst to provide a method for manufacturing a substrate having a nano rod structure that can prevent the contamination of the nanorods by the catalyst The purpose is.

Another object of the present invention is to provide a method of manufacturing a substrate having a nano-rod structure that can increase the light output when the light emitting structure of the light emitting device is formed using the nano-rod structure.

Still another object of the present invention is a method of manufacturing a substrate having a nanorod structure that can control the growth rate of the nanorods with a gas that inhibits the growth of the nanorods, and thus can freely control the length, diameter, and aspect ratio of the nanorods. To provide.

A preferred aspect for achieving the above objects of the present invention,

Heating the substrate;

Forming a plurality of crystal nuclei of a Group 3 material on the substrate;

Provided is a method of manufacturing a substrate having a nanorod structure comprising the steps of forming a nanorod made of a nitride semiconductor on the plurality of crystal nuclei to be spaced apart from each other.

Another preferred aspect for achieving the above object of the present invention,

Heating the substrate;

Forming a plurality of crystal nuclei formed of a nitride semiconductor on the substrate;

Provided is a method of manufacturing a substrate having a nanorod structure comprising the steps of forming a nanorod consisting of a nitride semiconductor on the plurality of crystal nuclei on top of each other.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a process flowchart of manufacturing a substrate having a nanorod structure according to the first embodiment of the present invention. First, the substrate is heated.

Here, the heating of the substrate is a method of heating the substrate by heating the inside of the chamber when the substrate is inside the chamber, or directly heating the substrate.

And as for the temperature which heats a board | substrate, 500-1200 degreeC is preferable.

That is, it is difficult to decompose the Group 3 precursor at a temperature of 500 ° C. or lower, and it is difficult to grow high quality materials, and it is difficult to grow each of the separated nano bars at 1200 ° C. or higher.

The substrate may be a silicon (Si) substrate, a germanium (Ge) substrate, a gallium nitride (GaN) substrate, an aluminum nitride (AlN) substrate, a gallium phosphide (GaP) substrate, an indium phosphide (InP) substrate, or gallium arsenide (GaAs). Substrate, silicon carbide (SiC) substrate, glass, quartz substrate, silicon oxide / silicon (SiO ₂ / Si) substrate, aluminum oxide (Al ₂ O ₃ ) substrate, lithium aluminum oxide (LiAl ₂ O ₃ ) substrate One of the magnesium peroxide (MgO) substrates is used.

Thereafter, a plurality of crystal nuclei formed of Group 3 material is formed on the substrate.

At this time, the plurality of crystal nuclei consisting of the Group 3 material is preferably formed of a Group 3 material separated from the Group 3 precursor.

Here, the group 3 material is any one of Ga, In, and Al.

Such a Group III precursor, the aluminum (Al) precursor is trimethylaluminum (Trimethylaluminum), triethylaluminum (Triethylaluminum), dimethylethylamine, Alaninerimethylamine (Alane), dimethylaluminum It is one of hydride (Dimethylaluminum Hydride) and tritetia butylaluminum.

Indium (In) precursor is trimethylindium or triethylindium.

In addition, the gallium (Ga) precursor is any one of trimethylgallium (Trimethylgallium), Triethylgallium (Triethylgallium) and triisopropylgallium (Triisopropylgallium).

Finally, nanorods made of nitride semiconductors are formed on the plurality of crystal nuclei to be spaced apart from each other.

The nanorod formed of the nitride semiconductor is preferably formed by reacting a Group 3 material and a Group 5 material separated from the Group 3 precursor and the Group 5 precursor.

Here, the Group 5 material is nitrogen (N), and the Group 5 precursor is ammonia (NH ₃ ).

Therefore, nanorods made of nitride semiconductors are formed on top of the group nuclei.

At this time, the nitride semiconductor is preferably any one of InN, AlN, InGaN, AlGaN and AlGaInN.

2 is a flowchart illustrating a process of manufacturing a substrate having a nanorod structure according to a second embodiment of the present invention, in which the substrate is heated (step S11).

Thereafter, a plurality of crystal nuclei formed of a nitride semiconductor are formed on the substrate (step S21).

Finally, nanorods made of nitride semiconductors are formed on the plurality of crystal nuclei so as to be spaced apart from each other.

Here, the plurality of crystal nuclei and nanorods made of the nitride semiconductor may be formed by reacting a Group 3 material and a Group 5 material separated from the Group 3 precursor and the Group 5 precursor.

In addition, the nitride semiconductor is preferably any one of InN, AlN, InGaN, AlGaN and AlGaInN.

Therefore, as described above, since the first and second embodiments of the present invention do not use a metal catalyst, there is an advantage of preventing contamination of the nanorods by the catalyst.

3 is a conceptual diagram illustrating a process of forming nanorod structures on a substrate by an organometallic chemical vapor deposition method according to the present invention, and the substrate 100 is placed inside the chamber 300 of the organometallic chemical vapor deposition apparatus. The substrate 100 is heated.

Here, not only an organometallic chemical vapor deposition apparatus but also a chemical vapor deposition apparatus are possible.

Thereafter, as in the first and second embodiments of the present invention, nano-spaced on the substrate 100 by injecting a group 3 precursor and a group 5 precursor into the chamber 300 or by injecting a group 3 precursor. The seed growth nuclei 210 are formed.

Finally, a nanorod is grown on the spaced apart crystal nuclei 210 formed on the substrate 100 by injecting a group 3 precursor and a group 5 precursor into the chamber 300.

As a result, a plurality of nanorods 220 spaced apart from each other are formed on the substrate 100.

Such nanorod structures are formed of nitride semiconductor, which is one of indium nitride (InN), gallium nitride (GaN) and aluminum nitride (AlN), indium gallium nitride (InGaN), and gallium aluminum nitride (AlGaN).

At this time, the composition of indium, gallium, and aluminum can be arbitrarily changed by reaction conditions as needed.

In addition, gallium nitride, indium nitride or aluminum nitride, which is binary, as well as indium gallium nitride (In _1-x Ga _x N, 0 ≦ _X ≦ 1) and gallium aluminum nitride (Al _{1- x} Ga _x N, 0≤X≤1) can be formed.

In addition, nanorods such as quaternary indium gallium nitride (Al _y Ga _x In _{1- (xy)} N, 0 ≦ X + Y ≦ 1) may also be formed.

Meanwhile, when the nanorods are grown on various surface substrates, the nanorods are cultured in each side direction.

For example, when nanorods are grown on a substrate having a C-plane, the nanorods are oriented in the C-plane direction, and depending on the substrate, the nanorods are cultured perpendicular to the substrate, or oriented in one direction other than vertical.

Therefore, the present invention is not only capable of vertical culture, but can also grow nanorods in the plane direction of the substrate selected as desired.

4 is a schematic perspective view of a state in which nanorods are formed on a substrate according to the present invention, and the nanorods 221 formed on the substrate 100 have a hexagonal pillar shape as illustrated in FIG. 4, Or it has a triangular prism shape.

FIG. 5 is a schematic perspective view illustrating a method of forming a light emitting structure using nanorods formed on a substrate according to the present invention. The nanorods having a first polarity on the substrate 100 and made of a nitride semiconductor are shown in FIG. 221, and a plurality of quantum well layers 222 and a nitride semiconductor layer 223 having a second polarity opposite to the first polarity are sequentially formed on the nanorods 221.

Therefore, the nanorod 221, the multi-quantum well layer 222 formed of a nitride semiconductor, and the nitride semiconductor layer 223 having a second polarity opposite to the first polarity have a first polarity on the substrate 100. It can form a light emitting structure consisting of.

Therefore, when the light emitting structure of the light emitting device is formed by using the nanorod structure, the light emitting surface is increased to improve the light output.

6 is a schematic perspective view of a light emitting structure according to the present invention, in which the light emitting structure formed by the method of FIG. 5 has a first polarity and comprises a nanorod 221 made of a nitride semiconductor; Multiple quantum well layers 222; The nitride semiconductor layer 223 has a second polarity opposite to the first polarity.

Here, the multi quantum well layer 222 may be a multi quantum well layer made of gallium nitride and indium gallium nitride or a multi quantum well layer made of gallium nitride and aluminum gallium nitride.

The first polarity is N type or P type.

That is, if the first polarity is N type, the second polarity is P type.

FIG. 7 is a schematic perspective view illustrating a method for controlling the length of a nanorod structure according to the present invention, in which the chlorine (Cl ₂ ) gas and hydrogen chloride (N ₂ ) are grown while the nanorod 220 is grown on the substrate 100. When at least one gas of HCl) gas and boron trichloride (BCl ₃ ) gas is injected, the injected gas may hinder the growth of the nanorods 220, thereby reducing the length of the nanorods 220.

Therefore, the gases injected in the middle of the growth of the nanorods 220 can control the length of the nanorods 222.

For example, as shown in FIG. 7, in order to control the length of the nanorod 220 to have an 'L' value, the chlorine (Cl ₂ ) may be added to the height of the 'L' value from the top of the substrate 100. When the at least one gas of hydrogen chloride (HCl) gas or boron trichloride (BCl ₃ ) gas is injected, the nanorod 222 component grown in a region higher than the height of the 'L' value is injected by the injected gas. Removed.

At this time, when the growth of the nanorods 220 is stopped, the nanorods 222 having a length of 'L' value can be grown.

As such, adjusting the length of the nanorods grown by the method of FIG. 7 is merely one of various methods of controlling.

That is, the present invention can control the length, diameter, aspect ratio, density, etc. of the nanorods by controlling the growth rate of the nanorods by injecting a gas that interferes with the growth of the nanorods while the nanorods are growing.

Here, the gas that prevents the growth of the nanorods is injected from the beginning of the growth or in the middle of the growth in the substrate.

As described above, the gas that inhibits the growth of the nanorods is at least one gas of chlorine (Cl ₂ ) gas, hydrogen chloride (HCl) gas, and boron trichloride (BCl ₃ ) gas.

In addition, in order to control the growth rate of the furnace rod, the gas that hinders the growth of the nanorods is injected with the same gas amount from the start of gas injection to the end, or injected while changing the gas amount.

Therefore, the present invention can control the growth rate of the nanorods with a gas that prevents the growth of the nanorods, there is an advantage that can freely control the length, diameter and aspect ratio of the nanorods.

8A to 8D are scanning electron micrographs of the nanorod structure in a length-controlled state according to the present invention, wherein the nanorods are grown when a gas that interferes with the growth of the nanorods is injected while the nanorods are growing. The length of the can be controlled, the greater the amount of gas injected, the length of the grown nanorods is reduced.

That is, the injected gas is thereby interfere with the reaction product of a Group III material and group V material is deposited over the nano-rods, the gas injection amount increases, the length of the nanorods triazine small.

8A to 8D are photographs in which the length of the nanorods is controlled by hydrogen chloride (HCl), and in FIG. 8A, the nanorods are grown without hydrogen chloride injection, and nanorods having a length of 750 nm were grown.

When 5 sccm of hydrogen chloride was injected while the nanorods were growing, nanorods having a length of 600 nm were grown (FIG. 8B), and 50sccm of hydrogen chloride was injected, and nanorods having a length of 580 nm were grown (FIG. 8C). When 100 sccm of hydrogen chloride was injected, nanorods having a length of 110 nm were grown as shown in FIG. 8D.

As a result, the growth of the nanorods was prevented by the injection of a gas that prevented the growth of the nanorods, and the length of the grown nanorods was reduced by injecting the gas rather than the length of the nanorods grown without the gas injection. .

9 is a scanning electron micrograph of the nanorod structure grown in accordance with the present invention, the gallium nitride nanorods were grown at a temperature of 550 ~ 650 ℃ and pressure conditions of 0.5 ~ 20torr.

At this time, trimethylgallium (TMGa) was used as the Group ₃ precursor, and ammonia (NH ₃ ) gas was used as the Group 5 precursor.

Here, trimethylgallium was injected with 3-20 μmol / min and ammonia was injected with 15-200 sccm.

In addition, 99.999% high purity nitrogen and purified 99.99995% or more high purity hydrogen were used as a carrier gas of the atmosphere gas and the Group 3 precursor.

At this time, the transport gas of the Group 3 precursor uses an inert gas such as hydrogen, nitrogen and argon.

20 to 200 sccm of nitrogen was injected into the atmosphere gas, and 0 to 500 sccm of hydrogen was injected to control the shape.

Under these conditions, gallium nitride nanorods oriented vertically from the substrate could be formed as shown in the photograph of FIG. 9.

FIG. 10 is a light emission characteristic diagram of a light emitting structure grown using a nanorod structure according to the present invention, and is an X-ray diffraction peak of gallium nitride nanorods grown on a C-plane sapphire single crystal substrate.

As shown in FIG. 10, the peak of sapphire (Al ₂ O ₃ ) appears at 42 degrees of the crystal angle (2θ), and the peak of gallium nitride (GaN) appears at 34.5 degrees of the crystal angle (2θ). It can be seen that gallium nitride was grown vertically on the surface sapphire substrate.

As described above, since the present invention does not use a metal catalyst, it is possible to prevent contamination of the nanorods by the catalyst.

In addition, when the light emitting structure of the light emitting device is formed by using the nanorod structure, the light emitting surface is increased, thereby improving the light output.

In addition, the present invention can control the growth rate of the nanorods by the gas to hinder the growth of the nanorods, there is an effect that can freely control the length, diameter and aspect ratio of the nanorods.

Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (18)

Heating the substrate; Forming a plurality of crystal nuclei of a Group 3 material on the substrate; Forming a nanorod formed of a nitride semiconductor on the plurality of crystal nuclei to be spaced apart from each other. The method of claim 1, A plurality of crystal nuclei made of the Group 3 material, A method of manufacturing a substrate having a nanorod structure, characterized in that formed of a Group 3 material separated from the Group 3 precursor. Heating the substrate; Forming a plurality of crystal nuclei formed of a nitride semiconductor on the substrate; Forming a nanorod formed of a nitride semiconductor on the plurality of crystal nuclei to be spaced apart from each other. The method of claim 3, wherein A plurality of crystal nuclei and nanorods made of the nitride semiconductor, A method of manufacturing a substrate having a nanorod structure, characterized in that formed by reacting a Group 3 material and a Group 5 material separated from Group 3 and Group 5 precursors, respectively. The method according to any one of claims 1 to 4, The nitride semiconductor, A method of manufacturing a substrate having a nanorod structure, characterized in that any one of InN, AlN, InGaN, AlGaN and AlGaInN. The method according to any one of claims 1, 2 and 4, The Group 3 material, Ga, In and Al any one of a method for manufacturing a substrate having a nano-rod structure. The method according to claim 2 or 4, The Group 3 precursor is an aluminum (Al) precursor, The aluminum (Al) precursor, Trimethylaluminum, Triethylaluminum, Dimethylethylamine, AlaneTrimethyl amine Alanine, Dime thylaluminum Hydride and Tritetia Method of manufacturing a substrate having a nano-rod structure, characterized in that any one of the tritium (Tritertiary butylaluminum). The method according to claim 2 or 4, The Group 3 precursor is an indium (In) precursor, The indium (In) precursor, Trimethylindium or Triethylindium, the method of manufacturing a substrate having a nanorod structure, characterized in that. The method according to claim 2 or 4, The Group 3 precursor is a gallium (Ga) precursor, The gallium (Ga) precursor, Trimethylgallium (Trimethylgallium), Triethylgallium (Triethylgallium) and triisopropylgallium (Triisopropylgallium) is a method for producing a substrate having a nano-rod structure, characterized in that any one of (Triisopropylgallium). The method according to any one of claims 1 to 4, During the initial growth or growth of the nanorods, A method of making a substrate having a nanorod structure, the method comprising injecting a gas into the substrate that interferes with the growth of the nanorod. The method of claim 10, The gas that hinders the growth of the nanorods, At least one gas of chlorine (Cl ₂ ) gas, hydrogen chloride (HCl) gas and boron trichloride (BCl ₃ ) gas. The method of claim 10, With gas injection to hinder the growth of the nanorods, Any one of a length, a diameter and an aspect ratio of the nanorods is controlled. The method according to any one of claims 1 to 4, The temperature for heating the substrate is a method for manufacturing a substrate having a nano-rod structure, characterized in that 500 ~ 1200 ℃. The method according to any one of claims 1 to 4, The substrate, Silicon (Si) substrates, germanium (Ge) substrates, gallium nitride (GaN) substrates, aluminum nitride (AlN) substrates, gallium phosphide (GaP) substrates, indium phosphide (InP) substrates, gallium arsenide (GaAs) substrates, silicon carbide (SiC) substrate, glass, quartz substrate, silicon oxide / silicon (SiO ₂ / Si) substrate, aluminum oxide (Al ₂ O ₃ ) substrate, lithium aluminum oxide (LiAlO ₃ ) substrate and magnesium oxide (MgO) substrate Method of manufacturing a substrate having a nano-rod structure, characterized in that any one of. The method according to claim 2 or 4, The Group 3 precursor, Injected into a carrier gas, The transport gas, A method of making a substrate having a nanorod structure, characterized in that it is an inert gas. The method of claim 4, wherein The Group 5 precursor is And ammonia (NH ₃ ). The method according to any one of claims 1 to 4, The nanorods, Having a first polarity and formed of a nanorod made of a nitride semiconductor, On top of the nanorods, And forming a multiple quantum well layer and a nitride semiconductor layer having a second polarity opposite to said first polarity. The method of claim 17, The first polarity is a method of manufacturing a substrate having a nano-rod structure, characterized in that the N type or P type.

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