KR20140029037A - Thermal chemical vapor deposition system for low temperature growth of oxide-based nanorods - Google Patents

Abstract

The present invention provides a thermochemical vapor deposition apparatus capable of growing high-grade nanorods. According to the present invention, the inner space of a reaction chamber is separated into a growth area, on which a substrate is mounted, and a vaporization area which vaporizes a source material; the temperature of the growth area is controlled to be relatively low and the temperature of the vaporization area is controlled to be relatively high; a reaction product from vaporized source material is formed at high temperatures and then grows to nanorods by vapor deposition on the substrate with the low temperature; and thereby the nanorods having a mono-crystal structure can be obtained without damaging the substrate.

Description

Technical Field [0001] The present invention relates to a thermal chemical vapor deposition apparatus capable of growing a high-quality nano-rod,

The present invention relates to a thermal chemical vapor deposition apparatus capable of growing a high-quality nano-rod. More specifically, the inner space of the reaction chamber is divided into a growth region in which a substrate is placed and a vaporization region in which a source material is vaporized, and independently controlling each region at a low temperature and a high temperature, To a thermal chemical vapor deposition apparatus capable of growing a high-quality nano-rod having a single crystal structure.

Nanotechnology is a technology that physically or chemically controls materials at the atomic and molecular levels to express useful structures and functions. Through this, it is possible to realize devices with different principles from the conventional ones, and the possibilities of their applications are expected to be unlimited have. Nanotechnology is expected to become a key area of future science and technology, and it is growing much more rapidly in terms of infrastructure and speed than other technologies.

At the same time, studies are being actively made to develop functional devices such as new electronic devices and optical devices by using nanostructures of materials. Nanometer-sized structures such as nano-powders, nanowires, nanotubes, nanorods, and nanocomposites exhibit completely different optical, electrical, magnetic, and genetic properties than conventional thin-film or bulk structures. Various attempts have been made to improve the operation efficiency or improve the performance of the functional device with low power using these characteristics.

A one-dimensional nanostructure having a large aspect ratio can have a large surface area, a small dislocation density, a high crystallinity, and a physical property such as a quantum size effect due to a nano-size. In addition, it can be applied to environment-related materials. In particular, in the case of semiconductor nanostructures, it can be applied not only to single electron transistor devices but also to new optical device materials.

In particular, oxide nano-rods such as ZnO and ITO have been widely spotlighted as optoelectronic devices such as light emitting diodes (LEDs), electronic devices, display transparent electrodes and transparent sensors because of their excellent optical and electrical properties.

In recent years, such oxide nanorods have been applied to gallium nitride (LED) light emitting diodes (LEDs) to improve light extraction efficiency, or oxide nano-rods have been utilized as a buffer layer on a substrate to be utilized in vertical light emitting diode research and development.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view showing a structure of a general gallium nitride (GaN) light emitting diode. FIG.

A typical GaN LED device 1 is a method of sequentially epitaxially growing an n-type cladding layer 20, an active layer 30 and a p-type cladding layer 40 on a GaN substrate 10 as shown in Fig. . The clad layers 20 and 40 and the active layer 30 constitute the light emitting structure of the LED element. An ITO electrode layer 50 is formed on the p-type clad layer 40 and an oxide nano rod 60 such as ZnO is grown on the ITO electrode layer 50. The nanorods 60 serve to increase the external photon efficiency of the LED element by scattering light, and since the size and density of the nanorods 60 are controlled with a very uniform distribution, the surface roughness of the light exit surface becomes uniform The external photon efficiency of the LED element can be further improved.

At this time, the n-type cladding layer 20 and the p-type cladding layer 40 are formed at a temperature of about 1000 ° C. to 1100 ° C., and the active layer 30 is formed at a relatively low temperature of about 620 ° C. to 720 ° C. .

In order to form the oxide nanorod 60, a method having a Vapor-Liquid-Vapor (VLS) mechanism using a metal catalyst is mainly used. The liquid catalyst used in the VLS method is a metal cluster such as Au In order to form the vaporization, a method of reducing the oxide by heat-treating the metal oxide and the garphite together at a high temperature has been mainly used.

However, such a VLS method can be performed in a laboratory unit and is not suitable for a mass production method in an industrial field. Thermal CVD (Thermal Chemical Vapor Deposition) is currently being used as a mass production method for forming oxide nanorods.

When the oxide nano-rods are formed using the thermal chemical vapor deposition method, the source material must be vaporized at a high temperature of 700 ° C or higher, preferably 900 ° C or higher, in order to grow the high-quality oxide nano-rods. However, as described above, in the case of the GaN LED element 1, since the active layer 30 is formed at a temperature of about 620 캜 to 720 캜, the active layer 30 is damaged at a temperature higher than about 620 캜 to 720 캜. It is very difficult to form oxide nano-rods and thus it is not widely used.

On the other hand, oxide nano-rods can be formed by thermal chemical vapor deposition even at a low temperature of 600 ° C or lower under certain conditions, but oxide nano-rods formed in this case can not maintain high quality. For example, oxide nanorods formed at a low temperature of 600 ° C or less have a poly-cristal structure and do not have a single-crystal structure. Therefore, in order to form a high-quality oxide nano-rod having a single crystal structure, a thermal chemical vapor deposition method must be performed at a high temperature of 700 ° C or more as described above. In this case, Despite its excellent properties, the vapor deposition method is severely limited in its use.

The present invention has been made to solve the problems of the prior art, and it is an object of the present invention to provide a method and apparatus for separating the inner space of a reaction chamber into a growth region in which a substrate is placed and a vaporization region in which a source material is vaporized, Is controlled at a relatively low temperature and the temperature of the vaporization region is controlled at a relatively high temperature so that a reaction material through vaporization of the source material is formed at a high temperature and then deposited and grown as a nano-rod on a substrate at a low temperature, Structure having a high-quality nano-rod structure.

It is another object of the present invention to provide a method and apparatus for forming a buffer region between a vaporization region and a growth region of a reaction chamber and setting the temperature of the buffer region between the temperature of the vaporization region and the temperature of the growth region, And to provide a thermochemical vapor deposition apparatus capable of more stably growing a high-quality nano-rod by buffering the difference in partial pressure.

A reaction chamber in which a gas injection port and an exhaust port are formed on both sides so that a reaction gas and a carrier gas can be supplied therein, and a substrate is disposed on one side of the internal space; And a first heater and a second heater for partially heating an inner space of the reaction chamber by an area, the reaction chamber being formed to be positioned adjacent to the gas inlet, a source material disposed within the region, Wherein the substrate is disposed in the region adjacent to the exhaust port so as to be spaced apart from the vaporization region, and the substrate is disposed in the region by the second heater, Wherein the source material vaporized in the vaporization region is reacted with the reaction gas to produce a reaction material and the reaction material is moved by the carrier gas Wherein the substrate is deposited and grown on the substrate by a nano-rod. It provides.

At this time, the reaction chamber is formed to be positioned between the vaporization region and the growth region, and the space inside the region is heated by a third heater to a third temperature between the first temperature and the second temperature, And the like.

Further, the source material may be disposed inside the buffer region so as to be vaporized by heating the third heater.

In addition, the buffer region may be formed so that the heating temperature at each position gradually decreases from a position adjacent to the vaporization region to a position adjacent to the growth region.

A plurality of buffer regions are formed between the vaporization region and the growth region, and a plurality of buffer regions are formed so that the heating temperature is sequentially lowered from the vaporization region to the growth region. .

In addition, the source material may be disposed in at least one of the plurality of buffer regions to be vaporized by heating the third heater.

In addition, the source material may include any one of In, Zn, Sn and Al having a powder or pillar structure, and graphite.

In addition, the carrier gas may include Ar or N ₂ gas, the reaction gas may include O ₂ gas, and the reaction gas may be injected into the reaction chamber together with the carrier gas.

Also, the second temperature may be set to 400 ° C to 650 ° C.

Also, the first temperature may be set to 700 ° C or higher.

According to the present invention, the inner space of the reaction chamber is divided into a growth region in which a substrate is seated and a vaporization region in which a source material is vaporized, respectively, and the temperature of the growth region is controlled to be relatively low and the temperature of the vaporization region is relatively high The reactive material through vaporization of the source material is formed at a high temperature, and then is deposited and grown as a nano-rod on a substrate at a low temperature, so that a high-quality nano-rod having a single crystal structure can be grown without damaging the substrate.

In addition, a buffer region is formed between the vaporization region and the growth region of the reaction chamber, and the temperature of the buffer region is set between the temperature of the vaporization region and the temperature of the growth region, thereby buffering the temperature gradient and the partial pressure difference So that it is possible to grow a high-quality nano-rod more stably.

In addition, by forming a plurality of buffer regions, it is possible to more precisely control the temperature gradient of the internal space of the reaction chamber in a multistage manner, thereby enabling to grow a high-quality nano-rod with higher quality.

1 schematically shows a structure of a general gallium nitride (GaN) light emitting diode,
2 is a conceptual diagram conceptually showing a configuration of a thermal chemical vapor deposition apparatus according to an embodiment of the present invention;
3 is a conceptual diagram conceptually illustrating a principle of nano-rod growth of a thermal chemical vapor deposition apparatus according to an embodiment of the present invention.
FIG. 4 is a conceptual view conceptually showing still another embodiment of a thermal chemical vapor deposition apparatus according to an embodiment of the present invention. FIG.
FIGS. 5 and 6 are photographs showing experimental results of nano-rods grown at a low temperature through a thermal chemical vapor deposition apparatus according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

FIG. 2 is a conceptual diagram conceptually showing a configuration of a thermochemical vapor deposition apparatus according to an embodiment of the present invention, and FIG. 3 conceptually illustrates a nanorod growth principle of a thermochemical vapor deposition apparatus according to an embodiment of the present invention. 4 is a conceptual diagram illustrating another embodiment of a thermochemical vapor deposition apparatus according to an embodiment of the present invention, and FIGS. 5 and 6 are thermochemical vapor phases according to an embodiment of the present invention. A diagram showing photographs of experimental results of nanorods grown at low temperature through a deposition apparatus.

A thermal CVD apparatus according to an embodiment of the present invention is an apparatus capable of growing a high-quality oxide nano-rod on a substrate. The apparatus includes a reaction chamber 100 in which a substrate 300 to be deposited is disposed in an inner space, The first heater 210 and the second heater 220 partially heat the inner space of the first heater 210 and the second heater 230, respectively. The heaters 210, 220, and 230 may be independently temperature controlled through a separate controller 500.

The reaction chamber 100 is formed in a closed structure so that a deposition process can be performed therein, like a conventional thermal chemical vapor deposition apparatus. The reaction chamber 100 is provided with a gas inlet 101 and an exhaust port 101 on both sides thereof, (102) are formed. That is, the carrier gas and the reactive gas are continuously supplied through the gas inlet 101 into the inner space of the reaction chamber 100 and then discharged through the exhaust port 102.

At this time, it is preferable that the gas injection port 101 is formed at the upper end side of the reaction chamber 100 as shown in FIG. 2 and the exhaust port 102 is formed at the lower end side of the reaction chamber 100. The reaction gas flowing through the gas inlet 101 there is is capable of generating a new reactants (R1) in response to the source which will be described later material 400, gas applications, the oxygen (O ₂ in accordance with an embodiment of the invention ) May be applied. The reactive gas diffuses into the entire area of the inner space of the reaction chamber 100 and reacts with the source material 400.

The carrier gas flows through the gas inlet 101 to have a constant flow, and carries the above-mentioned reactant R1. That is, the carrier gas has a flow flowing from the gas injection port 101 toward the exhaust port 102, and the reaction material R 1 is moved through the flow of the carrier gas to be deposited and grown on the substrate 300.

2, the vaporization region 110 and the growth region 120 may be formed in the reaction chamber 100, and a buffer layer may be formed between the vaporization region 110 and the growth region 120, The region 130 may be formed.

The vaporization region 110 is formed at a position adjacent to the gas inlet 101 and the source material 400 is disposed within the region and is heated to the first temperature T1 by a separate first heater 210 . The source material 400 is vaporized by the heating of the first heater 210 and the vaporized source material 400 reacts with the reaction gas to produce the reactive material R1. At this time, the first temperature T1 is set such that the reacted material R1 generated by reacting the reacted gas with the vaporized source material 400 has a high quality, that is, a single crystal structure.

The growth region 120 is formed at a position adjacent to the exhaust port 102 so as to be spaced apart from the vaporization region 110 and the substrate 300 is disposed within the region and is separated by a second heater 220 And is heated to a second temperature T2 lower than the first temperature T1. At this time, the second temperature T2 is set to a temperature at which the substrate 300 is not damaged.

According to this structure, in the vaporization region 110, the source material 400 is vaporized and reacted with the reaction gas to generate a reaction material R 1. The reaction material R 1 is transported and transported by the carrier gas, Is deposited on the substrate 300 of the substrate 120 and grows into the nano-rod 310 through continuous deposition. At this time, the heating temperature in the vaporization region 110 is set to the first temperature T1 so that the reactive material R1 has a single crystal structure as described above, and the heating temperature in the growth region 120 is set to the substrate (T2) to such an extent that it does not cause damage to the first and second heat exchangers (300, 300). Accordingly, the reactive material R 1 has a single crystal structure and is deposited and grown on the substrate 300 without damaging the substrate 300. That is, the high-quality oxide nano-rod 310 is deposited and grown on the substrate 300 at a low temperature.

At this time, a buffer region 130 may be further formed between the vaporization region 110 and the growth region 120 as shown in FIG. 2 and FIG. The buffer region 130 is formed such that the inner space of the region is heated by the third heater 230 to a third temperature T3 between the first temperature T1 and the second temperature T2. The source material 400 may be disposed within the region of the buffer region 130 to be vaporized by heating the third heater 230 as shown in FIGS. 2 and 3, It is preferable to apply the same as the source material 400 disposed in the vaporization region 110.

The abrupt temperature gradient between the vaporization region 110 and the growth region 120 can be buffered within the reaction chamber 100 by the buffer region 130 and a constant saturation pressure can be maintained, Can move more smoothly toward the substrate 300, and thus the nano-rod 310 can be more uniformly and stably deposited and grown on the substrate 300.

More specifically, a typical thermal chemical vapor deposition apparatus is formed by combining a vaporized source material with a reaction gas at a high temperature of 700 ° C or higher, and then depositing and growing the substrate on a nano-rod. At such a high temperature, The thermal chemical vapor deposition apparatus according to an embodiment of the present invention includes an inner space of the reaction chamber 100 in a region where the substrate 300 is seated, that is, a growth region 120, The nano-rods 310 are configured to be deposited and grown without damaging the substrate 300 through a method of separating the region for vaporizing the source material 400, that is, the vaporization region 110.

3, the source material 400 is vaporized by the heating of the first heater 210 in the vaporization region 110 and the vaporized source material 400 is injected into the gas inlet 101 And reacted with the reacted gas to produce a reaction product R1. The reactant R1 thus generated moves to the growth region 120 through the carrier gas and is deposited and grown on the substrate 300 mounted on the growth region 120 with the nano-rod 310.

At this time, it is preferable that the first temperature T1, which is the heating temperature of the vaporization region 110, is set to 700 ° C or higher, preferably 900 ° C or higher, The reaction is active and stable.

The second temperature T2, which is the heating temperature of the growth region 120, is preferably set to a temperature in the range of 400 deg. C to 650 deg. C at a temperature at which damage to the substrate 300 is not caused. For example, as described in the related art, damage to the active layer is prevented in a range lower than the temperature of about 620 캜 to 720 캜, which is the active layer formation temperature of the GaN LED device.

In other words, the source material 400 is vaporized at a high temperature in the vaporization region 110 to generate a reactive material R 1, and the reactive material R 1 is introduced into the growth region portion through which the substrate 300 is placed, The high temperature nano rod of the single crystal structure can be deposited and grown without damaging the substrate 300 by maintaining the heating temperature of the growth region 120 at a relatively low temperature.

At this time, the vaporization region 110 and the growth region 120 are kept apart from each other and an abrupt temperature gradient occurs between the vaporization region 110 and the growth region 120, The reactive material R1 generated in the nano rod 110 may not move stably to the substrate 300 due to the loss of energy in the process of moving to the growth region 120 and the deposition growth efficiency of the nano rod 310 may be very low. In addition, the temperature control may be very difficult due to the rapid temperature gradient in the inner space of the reaction chamber 100.

In order to solve this problem, a buffer region 130 is formed between the vaporization region 110 and the growth region 120 according to an embodiment of the present invention. The buffer zone 130 not only exhibits an effect of buffering a sudden temperature gradient, but also buffers the partial pressure difference in each zone 110 and 120, and maintains a constant saturation pressure in the reaction chamber 100.

At this time, the source material 400 is also disposed in the buffer region 130 and the source material 400 of the buffer region 130 is also vaporized at the third temperature T3 by the heating of the third heater 230 And is vaporized in the same manner as the region 110. The vaporized source material 400 reacts with the reaction gas to generate a new reaction material R2. The generated reaction material differs from the reactant material generated in the vaporization region 110. That is, the reactive material R2 generated in the buffer region 130 has a relatively small number of particles and a low energy, and therefore falls mostly in the region of the buffer region 130 and does not rise, It can not move to the growth region 120 through the carrier gas and remains at the bottom of the reaction chamber 100.

In detail, the total pressure of the reaction chamber 100 can be controlled by an externally injected carrier gas and a reactive gas. Alternatively, the partial pressures formed in the respective regions 110, 120 and 130 can be controlled by the ideal gas equation PV = nRT .

When the volume V is constant, the temperature T and the pressure P are proportional, so that the size of the partial pressure in each region is formed to the same size as the temperature. That is, the partial pressure P1 in the vaporization region 110 is the largest, the partial pressure P2 in the buffer region 130 is the smallest, and the partial pressure P3 in the growth region 120 is the smallest.

Since the large partial pressure means that the number of particles per unit volume is large, the number of particles of the source material 400 vaporized in the vaporization region 110 is large, and accordingly, the number of particles of the reactive substance R 1 is also relatively large. On the other hand, in the buffer region 130, the number of particles of the vaporized source material 400 and the number of particles of the reactive material R2 are relatively small.

Since the heating temperature T3 in the buffer region 130 is lower than the heating temperature T1 in the vaporization region 110, the vaporized source material 400 and the reactive material R1 are relatively low Energy.

For this reason, the reactive materials Rl generated in the buffer region 130 can not move to the growth region 120 through the carrier gas, and fall down directly on the bottom of the region.

According to this principle, the reaction material R2 generated in the buffer region 130 does not substantially grow directly into the nano-rods 310, but the reaction material R1 generated in the vaporization region 110 is smoothly grown in the growth region And moves to the nano-rod 120 to function as a nano-rod 310 to grow. This is accomplished through the function of buffering the temperature gradient and partial pressure difference as described above.

The reaction material R2 having a relatively low energy generated in the buffer region 130 is excluded on the substrate 300 of the growth region 120 and the reactive material R2 in the high energy state generated in the vaporization region 110 is removed Only the nano rod 310 having the single crystal structure can be uniformly and stably grown without damaging the substrate 300 because the nano rod 310 having the single crystal structure reaches only the nano rod 310 having the single crystal structure. Since the nano rod 310 is grown by the reactive material R1 generated in the high-temperature vaporization region 110, it has excellent electrical and optical characteristics.

3, the buffer region 130 may be formed as one unit. However, as shown in FIG. 4, the buffer region 130 may be formed in two have. Although FIG. 4 shows two buffer regions 130, a plurality of buffer regions 130 may be provided in this manner.

That is, a plurality of buffer regions 130 may be formed between the vaporization region 110 and the growth region 120, and a plurality of buffer regions 130 may be grown from the vaporization region 110 And the heating temperature may be sequentially lowered as it is positioned adjacent to the region 120. For example, when two buffer regions 130 and 130 'are formed as shown in FIG. 4, the buffer region 130 adjacent to the vaporization region 110 is separated from the buffer region 130 by a third heater 230, And the buffer region 130 'adjacent to the growth region 120 may be formed to be heated to a T3-2 temperature lower than the T3-1 temperature by another third heater 230'.

With this structure, the temperature gradient between the vaporization region 110 and the growth region 120 can be further divided into a plurality of stages, thereby buffering the temperature gradient.

At this time, the source material 400 which is vaporized by the heating of the third heater 230 is disposed in at least one of the plurality of buffer regions 130 and 130 '. That is, the source material 400 may be disposed within the regions of both the buffer regions 130 and 130 ', and the buffer region 130' adjacent to the growth region 120 as shown in FIG. The source material 400 may not be disposed. In this case, the buffer region 130 'in which the source material 400 is not disposed concentrates the function of buffering the temperature gradient rather than buffering the partial pressure difference.

4, the source material 400 may be simultaneously disposed in the vaporization region 110 and the buffer region 130 in an integrated manner, 110 and the buffer area 130, respectively.

In addition, when the buffer region 130 is formed as one unit as shown in FIG. 3, in order to perform the multi-stage division type temperature gradient buffering function through the buffer regions 130, The heating temperature at each position gradually decreases from a position adjacent to the growth region 120 to a position adjacent to the growth region 120.

The source material 400 may be applied to any one of In, Zn, Sn and Al having a powder or pillar structure and graphite (C). The carrier gas may be doped with Ar or N ₂ Gas, and the reaction gas can be applied as O ₂ gas.

For example, when a zinc oxide (ZnO) nano rod is formed on a substrate to be used as a GaN LED device, the source material 400 is mixed with Zn and graphite (C). The source material 400 is vaporized in the vaporization region 110 and reacted to form ZnC, and ZnC reacts with the reaction gas O ₂ to produce CO ₂ and ZnO. The ZnO thus generated moves to the growth region 120 together with the carrier gas Ar and is deposited and grown on the substrate 300 with the nano-rod 310.

FIGS. 5 and 6 are photographs showing experimental results of deposition and growth of zinc oxide nano-rods through a thermal chemical vapor deposition apparatus according to an embodiment of the present invention. ° C. and T3: 700 ° C., and the distance between the area sections 110, 120 and 130 was maintained at 3 cm. The photographs shown in FIG. 6 show experimental results under the conditions that T1: 830.degree. C., T2: 600.degree. C. and T3: 700.degree. C., and the distance between the regions 110, 120 and 130 was maintained at 3 cm.

As shown in the photographs, the thermal CVD apparatus according to an embodiment of the present invention allows stable deposition of the nano-particles on the substrate 300 without damaging the substrate 300 in a state where the temperature of the growth region 120 is relatively low. It can be seen that the rod 310 is deposited and grown.

The foregoing description is merely illustrative of the technical idea of the present invention and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

100: reaction chamber 101: gas inlet
102: exhaust port 110:
120: Growth area 130: Buffer area
210: first heater 220: second heater
230: third heater 300: substrate
400: source material 500:

Claims (10)

A reaction chamber in which a gas injection port and an exhaust port are formed on both sides so that a reaction gas and a carrier gas can be supplied into the reaction chamber, and a substrate is disposed on one side of the internal space; And
A first heater and a second heater for partially heating the inner space of the reaction chamber by region,
The reaction chamber
A vaporization zone formed to be adjacent to the gas inlet, the vaporization zone being heated to a first temperature by the first heater so that a source material is disposed within the zone and the source material is vaporized;
A growth region portion formed adjacent to the exhaust port so as to be spaced apart from the vaporization region portion, the substrate being disposed in the region and heated to a second temperature lower than the first temperature by the second heater,
High-quality nanorod growth, characterized in that the source material vaporized in the vaporization region portion reacts with the reaction gas to generate a reaction material, and the reaction material is moved by the carrier gas and deposited by nanorods on the substrate. This is possible thermal chemical vapor deposition apparatus.
The method of claim 1,
The reaction chamber
It is formed so as to be located between the vaporization region portion and the growth region portion, further comprising a buffer region portion is heated to a third temperature between the first temperature and the second temperature by a separate third heater. Thermal chemical vapor deposition apparatus capable of high quality nanorod growth.
3. The method of claim 2,
And the source material is disposed in the buffer region so as to be vaporized by heating of the third heater.
The method of claim 3, wherein
Wherein the buffer region is formed so that the heating temperature at each position gradually decreases from the position adjacent to the vaporization region to the position adjacent to the growth region.
3. The method of claim 2,
A plurality of buffer regions are formed between the vaporization region and the growth region and a plurality of buffer regions are formed so that the heating temperature is sequentially lowered from the vaporization region toward the growth region A thermal chemical vapor deposition system capable of growing high-quality nano-rods.
The method of claim 5, wherein
Wherein the source material is disposed in at least one of the plurality of buffer regions to be vaporized by heating the third heater.
7. The method according to any one of claims 2 to 6,
Wherein the source material comprises any one of In, Zn, Sn, Al having a powder or pillared structure, and graphite.
The method of claim 7, wherein
Wherein the carrier gas includes Ar or N ₂ gas, the reaction gas includes O ₂ gas, and the reaction gas is injected into the reaction chamber together with the carrier gas. Thermal chemical vapor deposition apparatus.
7. The method according to any one of claims 2 to 6,
Wherein the second temperature is set to 400 ° C to 650 ° C.
The method of claim 9,
Wherein the first temperature is set to 700 DEG C or higher. ≪ RTI ID = 0.0 > 11. < / RTI >

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