KR101205426B1 - METHOD AND CVD FOR THE GROWTH OF GaN-BASED LED - Google Patents

Abstract

The present invention relates to a chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, the process tube containing a boat containing a plurality of substrates; A heater assembly installed to surround the process tube; Nozzles installed vertically in the process tube; The nozzles sequentially inject a source gas mixed with an organometallic compound, and the remaining nozzles that do not inject the source gas inject a reaction gas or a purge gas.

Description

Chemical vapor deposition apparatus and method for growing gallium nitride based LED thin film {METHOD AND CVD FOR THE GROWTH OF GaN-BASED LED}

The present invention relates to a chemical vapor deposition apparatus, and more particularly to a chemical vapor deposition apparatus and method for the growth of gallium nitride-based LED thin film.

In recent years, as the demand for miniaturization of semiconductor devices, development of high efficiency, and high-power LEDs is increasing in various industrial fields, there is a demand for chemical vapor deposition (CVD) equipment capable of mass production without deterioration of quality or performance. to be.

Particularly, in the thin film deposition process of nitride (GaN) thin film deposited by CVD equipment, a substance attached with methyl group to gallium (Ga) called trimethylgallium (TMGa), which is an organometallic material, is added to the carrier gas (N2 or H2). On one side, ammonia (NH3) is blown and gallium (Ga) of trimethylgallium (TMGa) and nitrogen (N) of ammonia (NH3) react on the surface of the substrate to form a nitride (GaN) thin film. Chemical reactions usually require high temperatures above 1000 degrees. However, in the case of trimethylgallium (TMGa), an organometallic material used to deposit nitride (GaN) thin film, pyrolysis occurs at a temperature of 400-700 degrees, so that trimethylgallium (TMGa) is actively pyrolyzed in the nozzle before being sprayed onto the substrate. Is generated and a problem of clogging the nozzle has arisen.

An object of the present invention is to provide a chemical vapor deposition apparatus and method for growing a gallium nitride-based LED thin film that can prevent the organometallic compound used in the nitride thin film deposition to thermally decompose in the nozzle to block the nozzle.

The problem to be solved by the present invention is not limited thereto, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

Chemical vapor deposition apparatus for the growth of the gallium nitride-based LED thin film of the present invention for achieving the above object is a process tube that accommodates a boat containing a plurality of substrates; A heater assembly installed to surround the process tube; Nozzles installed vertically in the process tube; It is connected to each of the nozzles, the nozzles include a gas supply for supplying the source gas to sequentially spray the source gas mixed with the organometallic compound.

According to an embodiment of the present invention, the gas supply unit supplies the reaction gas so that the remaining nozzles, except the nozzles for injecting the source gas, inject the reaction gas reacting with the organometallic compound of the source gas.

According to an embodiment of the present invention, the gas supply unit supplies a purge gas to purge the source gas remaining in the nozzle after the nozzle injects the source gas and before the reaction gas is injected.

According to an embodiment of the present invention, the gas supply unit may include a gas supply line connected to each of the nozzles; At least two branching lines branching from the gas supply line and provided with an on / off valve; A source gas supply source connected to any one of the at least two branch lines; A reaction gas supply source connected to another branch line of the at least two branch lines; And a controller for controlling the on / off valves installed in the at least two branch lines.

According to an embodiment of the present invention, the gas supply unit further includes a purge gas supply source connected to another branch line of the at least two branch lines.

According to an embodiment of the present invention, the source gas is a metal source such as trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), trichloride (GaCl3) organometallic compounds as hydrogen gas The reaction gas is ammonia gas, and the purge gas is H2 gas and N2 gas.

According to an embodiment of the present invention, each of the nozzles may be hydrogen gas containing a metal source such as trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), or trichloride (GaCl3), which are organometallic compounds. A first nozzle pipe supplied with the raw material gas bubbled to the substrate and sprayed onto the substrates; And a second nozzle tube installed to surround the first nozzle tube to prevent the organometallic compound from being thermally decomposed in the first nozzle tube and having a reaction gas therein.

Chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film for achieving the above object is a process tube that is accommodated in a boat containing a plurality of substrates; A heater assembly installed to surround the process tube; Nozzles installed vertically in the process tube; The nozzles sequentially inject a source gas mixed with an organometallic compound, and the remaining nozzles that do not inject the source gas inject a reaction gas or a purge gas.

The gallium nitride based LED thin film growth method for achieving the above object comprises the steps of loading a boat containing the substrate in the process tube; Supplying a source gas mixed with an organometallic compound and a reaction gas to the process tube through nozzles to form a gallium nitride based LED thin film; In the thin film forming step, the nozzles sequentially spray the source gas in order to prevent the inside of the nozzles from being blocked by the source gas, and the remaining nozzles that do not inject the source gas inject the reaction gas.

According to the exemplary embodiment of the present invention, the thin film forming step may inject a purge gas after the nozzles inject the raw material gas and before spraying the reaction gas.

According to an embodiment of the present invention, the thin film forming step may overlap some injection time when the injection of the source gas is changed from one of the nozzles to another nozzle.

The present invention can improve the quality of the thin film formed on the substrate by preventing the organometallic compound used for nitride thin film deposition to thermally decompose in the nozzle before reaching the substrate.

In addition, according to the present invention, susceptors having a plurality of stages are loaded into the boat, so that a large number of substrates can be processed in one process. Therefore, the present invention can greatly improve the productivity compared to the conventional, it is possible to more easily match the production quantity to the delivery date required by the customer.

In addition, the present invention can increase the throughput per unit time.

1 is a side cross-sectional view showing a schematic configuration of a chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film according to an embodiment of the present invention.
2 is a plan sectional view showing a schematic configuration of a chemical vapor deposition apparatus for growing a gallium nitride based LED thin film according to an embodiment of the present invention.
3 is an enlarged view illustrating main parts of the gas supply unit illustrated in FIG. 2.
4 and 5 are graphs showing that the source gas is sequentially sprayed through the seven nozzles.
6 is a cross-sectional view showing a modification of the nozzle.

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to FIGS. 1 to 6. The embodiments of the present invention can be modified in various forms, and the scope of the present invention should not be construed as being limited to the following embodiments. This embodiment is provided to more completely explain the present invention to those skilled in the art. Thus, the shape of the elements in the figures has been exaggerated to emphasize a clearer description. In the drawings, the same reference numerals are given to components that perform the same function.

The basic feature of the present invention is that the organometallic compound used in the nitride (GaN) thin film deposition process has a nozzle and a gas supply unit that can prevent the nozzle from clogging by being thermally decomposed inside the nozzle due to the temperature rise of the nozzle. It has its features.

1 and 2 are cross-sectional views showing a schematic configuration of a chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film according to an embodiment of the present invention. 3 is an enlarged view illustrating main parts of the gas supply unit illustrated in FIG. 2.

1 to 3, the chemical vapor deposition apparatus 10 according to the present invention includes a boat 200 in which substrates w for manufacturing an LED are loaded, and an inner tube 102 in which the boat 200 is accommodated. A seal cap supporting the process tube 100 having the outer and outer tubes 104, the heater assembly 110 surrounding the process tube 100, the boat 200, and coupled to the flange 120 of the process tube 100. (7) and seven nozzles 300 for injecting gases contributing to thin film deposition on the surface of the substrate through the process tube 100, and a gas supply unit for supplying source gas, reactant gas and purge gas to the nozzles. 400).

Process tube

The process tube 100 has an outer tube 104 having a dome-shaped cylindrical tube shape, and an inner tube 102 provided inside the outer tube 104. The inner tube 102 provides an interior space in which the boat 200 on which the substrate S is loaded is loaded to perform a nitride (GaN) thin film deposition process on the substrates. Process tube 100 may be made of a material that can withstand high temperatures, such as quartz. One side of the flange 120 of the process tube 100 is provided with an exhaust port 122 for forcibly suctioning and exhausting the internal air to reduce the pressure inside the process tube 100, and an opposite side of the corresponding inner tube 102 is provided on the opposite side of the exhaust port 122. In the internal space, seven nozzles 300 are provided for injecting a source gas in which an organometallic compound is mixed and a reaction gas reacting with the organometallic compound of the source gas. The exhaust port 122 is provided to exhaust the air in the process tube 100 to the outside during the process. The exhaust port 122 is connected to an exhaust line (not shown), and exhaust and internal pressure reduction of the process gas supplied to the process tube 100 through the exhaust port 122 are performed.

Boat

The bow 200 has slots into which 50 (or more) support plates 210 are inserted. At least one substrate S is placed on the support plate 210. In this embodiment, a support plate 210 is shown on which four substrates are placed. The bolt 200 is mounted on the seal cap 220, and the seal cap 220 is loaded into the process tube 100 or unloaded out of the process tube 100 by the drive unit 230, which is an elevator device. In the case of a large substrate, the substrate may be inserted and stacked in the slot of the boat 200.

Support Plate

As shown in Figure 1 and 2, the support plate 210 for supporting the substrates in the boat 200, consisting of a disk-shaped plate, the upper surface is provided with four stages on the same plane . Substrate S is placed in each stage, and the stage may have a wide opening (not shown) in the center for loading / unloading of the substrate. Although not shown, the loading / unloading of the substrate is done in a separate device. The number of stages installed in the support plate 210 may be changed to two, three or five.

Although not shown, the support plate 210 waits in a load lock chamber adjacent to a process chamber (not shown) in which the process tube 100, the seal cap 220, and the like are located, and the substrate storage container (aka cassette). The stored substrates are placed on stages of the support plate 210 waiting in the load lock chamber by a substrate transport device (not shown). The support plate 210 having stages on which the substrates are placed is carried by the same conveying apparatus as the substrate conveying apparatus and loaded on the boat 200 waiting under the process tube 100. After the process is completed, the substrates are transferred to the load lock chamber by conveying the support plate 210 in the state of being placed on the stages, and the support 200 is loaded with the other support plates 210 waiting in the load lock chamber. As described above, in the present invention, since the support plate 210 on which four substrates are placed is loaded on the boat by one conveyance of the conveying apparatus, the time can be shortened compared to conveying the substrates one by one in the conventional vertical substrate processing equipment. In the case of using the support plate 210, it is used to process a substrate having a small size.

Seal cap

The seal cap 220 is moved to open and close the opening of the process tube 100 by the driving unit 230 which is an elevator device. The boat 200 placed on the seal cap 220 is loaded into the process tube 100 by the raising operation of the seal cap 220, and the boat placed on the seal cap 220 by the lowering operation of the seal cap 220. 200 is unloaded out of process tube 100. When the bolt 200 is loaded into the process tube 100, the seal cap 220 is coupled to the flange 120 of the process tube 100.

Meanwhile, a sealing member such as an O-ring for sealing is provided at a portion where the flange 130 and the seal cap 220 of the process tube 100 come into contact with each other so that the process gas is provided with a process tube ( 100) and seal cap 220 to prevent leakage.

7 nozzles

The seven nozzles 300 spray raw gas mixed with an organometallic compound for forming a nitride (GaN) thin film, a reaction gas and a purge gas reacting with the organometallic compound of the raw material gas to the substrates loaded on the boat 200. do. In the present exemplary embodiment, seven nozzles are installed, but the number of installation of the nozzles may be smaller or larger.

The nozzles 300 are supplied with source gas, reaction gas, and purge gas through the external gas supply unit 302, respectively.

The nozzles 300 have gas injection holes 312, and the gas injection holes 312 are formed to inject gas between the support plates 210 placed on the boat 200, thereby improving responsiveness on the substrate. By optimizing the amount of gas used, the consumption of unnecessary gas can be reduced.

Gas supply

The gas supply unit 400 includes a gas supply line 402 connected to each of the nozzles, three branch lines 404 branched from the gas supply line 402, and a raw material connected to each of the three branch lines 404. Gas source 412, reactant gas source 414, purge gas source 416, and controller 420. The controller 420 controls the opening / closing valves 406 installed in the branch lines 404 to sequentially supply the source gas, the purge gas, and the reaction gas mixed with the organometallic compound to each of the nozzles 300. The remaining nozzles, except the nozzles for injecting the gas, supply the reaction gas to inject the reaction gas reacting with the organometallic compound of the source gas. The reason for supplying the purge gas before supplying the reaction gas is to prevent the source gas remaining inside the nozzle from reacting with the reaction gas.

Here, the source gas is a metal source such as trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), trichloride (GaCl3), which are organometallic compounds, is bubbled with hydrogen gas (carrier gas). It may include. The reaction gas includes an ammonia gas that reacts with the organometallic compound of the source gas, and the purge gas contains H2 gas or N2 gas for cleaning the source gas remaining in the nozzle.

4 is a graph showing that the source gas is sequentially sprayed through the seven nozzles.

3 and 4, the controller 420 sequentially controls the nozzles 300 for injecting the source gas by controlling the opening / closing valves 406 installed in the branch lines 404. As shown in FIG. 4, first, when the first nozzle injects the source gas A in step 1, the remaining six second to seven nozzles inject the reaction gas. In step 2, the first nozzle stops the injection of the source gas A, and the second nozzle injects the source gas A. The first nozzle sprays a purge gas C to remove the source gas A remaining therein. The remaining five nozzles (3-7 nozzles) inject the reaction gas (B). In step 3, the second nozzle stops the injection of the source gas A, and the third nozzle injects the source gas A. The second nozzle injects a purge gas C to remove the source gas A remaining therein. The remaining five nozzles (first, fourth to seventh nozzles) inject the reaction gas (B). Through this process, the raw material gas A is sequentially sprayed from the first nozzle to the seventh nozzle. Since the source gas is shortly injected while passing through the seven nozzles until the thin film deposition process is completed, the phenomenon in which the source gas is thermally decomposed inside the nozzle can be prevented.

As shown in FIG. 5, when the nozzle of the source gas is changed (change from the nozzle to another nozzle) so that the source gas injection is performed smoothly, the injection may be repeated for some time.

As such, the chemical vapor deposition apparatus can prevent the thermal decomposition of the raw material gas in the nozzle to improve the quality of the nitride film formed on the substrate and reduce the amount of the raw material gas, thereby reducing costs.

The temperature and reaction pressure of the process tube for the growth of the gallium nitride-based thin film is 850 ~ 1200 degrees and 1 ~ 300torr, respectively.

6 is a view showing another example of the nozzle.

As shown in FIG. 6, the nozzles 300 ′ may have a double pipe structure. The nozzle 300 ′ is installed so as to surround the first nozzle pipe 310 and the first nozzle pipe 310 having the first gas injection hole 312 formed thereon for injecting the raw material gas and spraying the reaction gas. The second gas injection holes 322 may include a second nozzle pipe 320 formed thereon. The first gas injection holes 312 are formed on the connection ports 314 extending from the first nozzle pipe 310 to the second nozzle pipe 320. In the case of using the nozzle having a double pipe structure, a separate purge gas supply is not required because the source gas and the reaction gas do not react in the nozzle.

In the above, the configuration and operation of the vertical substrate processing equipment according to the present invention has been shown in accordance with the above description and drawings, but this is just described, for example, and various changes and modifications can be made without departing from the spirit of the present invention. Of course.

100: process tube 200: boat
300: nozzle 400: gas supply unit

Claims (12)

delete In the chemical vapor deposition apparatus for the growth of gallium nitride based LED thin film:
A process tube in which a boat in which a plurality of substrates are accommodated is accommodated;
A heater assembly installed to surround the process tube;
Nozzles installed vertically in the process tube;
A gas supply unit connected to each of the nozzles to supply the source gas to sequentially inject the source gas mixed with the organometallic compound;
The gas supply part
Chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, characterized in that for supplying the reaction gas so that the remaining nozzles other than the nozzle for injecting the source gas to inject the reaction gas reacts with the organometallic compound of the source gas. In the chemical vapor deposition apparatus for the growth of gallium nitride based LED thin film:
A process tube in which a boat in which a plurality of substrates are accommodated is accommodated;
A heater assembly installed to surround the process tube;
Nozzles installed vertically in the process tube;
A gas supply unit connected to each of the nozzles to supply the source gas to sequentially inject the source gas mixed with the organometallic compound;
The gas supply part
Among the remaining nozzles except the nozzle for injecting the source gas, the nozzle which injected the source gas until immediately before the purge gas is supplied for a predetermined time, and then the reaction gas is supplied, and the remaining nozzles are supplied with the reaction gas. Chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film. In the chemical vapor deposition apparatus for the growth of gallium nitride based LED thin film:
A process tube in which a boat in which a plurality of substrates are accommodated is accommodated;
A heater assembly installed to surround the process tube;
Nozzles installed vertically in the process tube;
A gas supply unit connected to each of the nozzles to supply the source gas to sequentially inject the source gas mixed with the organometallic compound;
The gas supply part
A gas supply line connected to each of the nozzles;
At least two branching lines branching from the gas supply line and provided with an on / off valve;
A source gas supply source connected to any one of the at least two branch lines;
A reaction gas supply source connected to another branch line of the at least two branch lines;
Chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, characterized in that it comprises a controller for controlling the opening and closing valves installed in the at least two branch lines. 5. The method of claim 4,
The gas supply part
Chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, characterized in that it further comprises a purge gas supply source connected to another branch line of the at least two branch lines. The method of claim 5,
The source gas is formed by evaporating metal sources such as trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), and trichloride (GaCl3), which are organometallic compounds, with hydrogen gas.
The reaction gas is ammonia gas,
The purge gas is a chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, characterized in that the H2 gas and N2 gas. The method of claim 2,
Each of the nozzles
Metal sources such as trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), and trichloride (GaCl3), which are organometallic compounds, are supplied to substrates by supplying source gas bubbled with hydrogen gas A first nozzle pipe; And
Nitriding, characterized in that the organometallic compound is installed to surround the first nozzle tube to prevent the thermal decomposition in the first nozzle tube, the second nozzle tube flowing a reaction gas or cooling gas therein; Chemical vapor deposition apparatus for the growth of gallium-based LED thin film. In the chemical vapor deposition apparatus for the growth of gallium nitride based LED thin film:
A process tube in which a boat in which a plurality of substrates are accommodated is accommodated;
A heater assembly installed to surround the process tube;
Nozzles installed vertically in the process tube;
The nozzles sequentially inject a source gas mixed with an organometallic compound, and the remaining nozzles that do not inject the source gas inject a reaction gas or a purge gas. Device. In a method of growing a gallium nitride based LED thin film in a chemical vapor deposition apparatus equipped with nozzles in a process tube:
Loading a boat containing substrates into the process tube;
Supplying a source gas mixed with an organometallic compound and a reaction gas to the process tube through the nozzles to form a gallium nitride based LED thin film;
The thin film forming step
In order to prevent the inside of the nozzles from being blocked by the source gas, the nozzles sequentially spray the source gas, and the remaining nozzles that do not spray the source gas selectively spray the reaction gas and the purge gas. A gallium nitride based LED thin film growth method. 10. The method of claim 9,
The thin film forming step
When the injection of the source gas is changed from one of the nozzles to another nozzle, the nozzle that injected the source gas until immediately before the injection of the purge gas for a predetermined time, and the other nozzles to the reaction gas Gallium nitride-based LED thin film growth method characterized in that the spraying. 10. The method of claim 9,
The thin film forming step
Gallium nitride-based LED thin film growth method characterized in that the injection time of the source gas overlaps when the injection of the source gas is changed from one of the nozzles to another nozzle. The method of claim 10,
The source gas is formed by evaporating metal sources such as trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), and trichloride (GaCl3), which are organometallic compounds, with hydrogen gas.
The reaction gas is ammonia gas,
The purge gas is a gallium nitride-based LED thin film growth method, characterized in that the H2 gas and N2 gas.

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