KR101205425B1 - 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 present invention is a process tube having an inner tube and a outer tube is installed to surround the inner tube receiving the boat containing the substrate; A heater assembly installed to surround the process tube; A first nozzle unit installed vertically inside the inner tube and supplying a raw material gas in which an organometallic compound is mixed to form a gallium nitride-based thin film; The first nozzle unit comprises: a first nozzle pipe receiving raw material gas from the outside and having gas injection holes formed on one surface thereof; And a second nozzle tube installed to surround the nozzle tube and having a cooling gas flowing in a space surrounding the first nozzle tube to prevent the organometallic compound from being thermally decomposed in the first nozzle tube.

Description

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 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.

SUMMARY OF THE INVENTION An object of the present invention is to provide a chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film that can minimize the thermal decomposition of the organometallic compound used in the nitride thin film deposition in 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 growing a gallium nitride-based LED thin film of the present invention for achieving the above object is a process tube having an inner tube and a outer tube is installed to surround the inner tube containing a plurality of substrates are accommodated ; A heater assembly installed to surround the process tube; A first nozzle unit installed vertically inside the inner tube and supplying a raw material gas in which an organometallic compound is mixed to form a gallium nitride-based thin film; The first nozzle unit comprises: a first nozzle pipe receiving raw material gas from the outside and having gas injection holes formed on one surface thereof; And a second nozzle tube installed to surround the nozzle tube and having a cooling gas flowing in a space surrounding the first nozzle tube to prevent the organometallic compound from being thermally decomposed in the first nozzle tube.

According to an embodiment of the present invention, the first nozzle unit is installed to surround the second nozzle tube, gas injection holes are formed on one surface facing the boat, and react with the organometallic compound of the source gas. It further comprises a reaction gas third nozzle pipe for supplying a gas.

According to an embodiment of the present invention, the second nozzle pipe has an exhaust hole formed at an upper end thereof so that the cooling gas exits to the exhaust space of the space between the inner tube and the outer tube.

According to an embodiment of the present invention, the second nozzle tube is fixed to the inner surface of the inner tube by welding.

According to an embodiment of the present invention, the inner tube further includes a second nozzle unit installed vertically and supplying a reaction gas reacting with the organometallic compound of the source gas supplied through the first nozzle unit. do.

According to an embodiment of the present invention, the source gas is trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), trichloride (GaCl3), trimethylaluminum (TMAI), trimethylindium (TMIn) And a metal source such as diethyl zinc (DEZn), biscyclopentadienyl magnesium (Cp2Mg), NH3, SiH4, etc. are bubbled with hydrogen gas.

The reaction gas is ammonia gas that reacts with the source gas.

According to an embodiment of the present invention, the cooling gas is H2 gas and N2 gas.

The nozzle unit for producing a gallium nitride-based LED thin film for achieving the above object is an organometallic compound of trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), trichloride (GaCl3) It is supplied with a source gas in which metal sources such as trimethyl aluminum (TMAI), trimethyl indium (TMIn), diethyl zinc (DEZn), and vice cyclopentadienyl magnesium (Cp2Mg), NH3 and SiH4 are bubbled with hydrogen gas. And a first nozzle tube having gas injection holes formed on one surface thereof. 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 cooling gas flowing therein.

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 FIG. 2.
4 and 5 are views showing another example of a nozzle unit in a chemical vapor deposition apparatus for growing a gallium nitride based LED thin film according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to FIGS. 1 to 3. 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 unit capable of minimizing thermal decomposition inside the nozzle due to the temperature rise of the nozzle.

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 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. The first nozzle unit 300 and the second nozzle unit 400 supply gas to the process tube 100 to contribute to thin film deposition on the substrate surface.

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, first and second nozzle units 300 and 400 are provided for supplying 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.

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.

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.

First nozzle unit, second nozzle unit

The first and second nozzle units 300 and 400 are substrates loaded on the boat 200 with a source gas in which an organometallic compound is mixed to form a nitride (GaN) thin film, and a reaction gas reacting with the organometallic compound of the source gas. Spray.

The first nozzle unit 300 receives the source gas through an external source gas supply unit 302. 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 first nozzle unit 300 has a double pipe structure. The first nozzle unit 300 receives the source gas from the outside and is provided with a first nozzle tube 310 having gas injection holes 312 formed on one surface thereof, and a second nozzle installed to surround the first nozzle tube 310. Tube 320. The first nozzle tube 310 has 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 forming a substrate on the substrate. By improving the reactivity and optimizing the amount of gas used, unnecessary gas consumption can be reduced. The 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 second nozzle tube 320, a cooling gas flows in a space surrounding the first nozzle tube 310 to prevent the organometallic compound from being thermally decomposed in the first nozzle tube 310. The second nozzle pipe 320 is fixed to the inner wall surface of the inner tube 102 by welding or the like.

The lower end of the second nozzle tube 320 extends out of the process tube, and receives H2 gas or N2 gas through an external cooling gas supply unit 304. The cooling gas provided from the cooling gas supply unit 304 passes through a space between the first nozzle tube 310 and the second nozzle tube 320 to form an exhaust hole 322 formed at an upper end of the second nozzle tube 320. It exits through the exhaust space 106 of the space between the inner tube 102 and the outer tube 104 through.

The first nozzle unit 300 having the above-described configuration has a second nozzle tube surrounding the first nozzle tube 310 even when the temperature inside the process tube 100 due to the radiant heat provided from the heater assembly 110 becomes high. The cooling gas flowing through the 320 rapidly releases heat to the outside to suppress the temperature rise of the first nozzle pipe 310. As such, the first nozzle unit 300 suppresses an increase in the temperature of the first nozzle tube 310 and before the organometallic compound injected through the first nozzle tube 310 reaches the substrate, the first nozzle tube 310. By preventing pyrolysis from the inside, the quality of the nitride film formed on the substrate may be improved, and the amount of raw gas used may be reduced to reduce costs.

The second nozzle unit 400 receives a reaction gas (ammonia gas) that reacts with the organometallic compound of the source gas through an external reaction gas supply unit 402, and the second nozzle unit 400 faces one side (the boat). The gas injection holes 412 are formed in the surface).

According to the present invention, since the first nozzle pipe 310 for supplying the raw material gas containing the organometallic compound is not directly exposed to a high temperature, an increase in the internal temperature of the first nozzle pipe 310 can be suppressed. Pyrolysis of organometallic compounds can be minimized.

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

4 and 5 are views showing another embodiment of the nozzle unit in the chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film according to an embodiment of the present invention.

The nozzle unit 300 ′ shown in FIGS. 4 and 5 has a triple tube shape in which the first nozzle unit 300 and the second nozzle unit 400 of the first embodiment are combined into one. That is, the nozzle unit 300 ′ sprays a source gas in which an organometallic compound is mixed to form a nitride (GaN) thin film, and a reaction gas reacting with the organometallic compound of the source gas to the substrates loaded on the boat 200. do.

The nozzle unit 300 'has a triple tube structure. The nozzle unit 300 ′ is installed to surround the first nozzle pipe 310 and the first nozzle pipe 310 in which the raw material gas is injected and the gas injection holes 312 are formed at one surface thereof, and a cooling gas flows through the second nozzle unit 300 ′. The nozzle tube 320 and the second nozzle tube 320 are provided therein, and include a third nozzle tube 330 for injecting a reaction gas reacting with the organometallic compound of the source gas. The first nozzle pipe 310 has gas injection holes 312, and the gas injection holes 312 penetrate the second nozzle pipe 320 and the third nozzle pipe 330 from the first nozzle pipe 310. Formed on the connection ports 314.

In the second nozzle tube 320, a cooling gas flows in a space surrounding the first nozzle tube 310 to prevent the organometallic compound from being thermally decomposed in the first nozzle tube 310.

The third nozzle pipe 330 receives the reaction gas reacting with the organometallic compound of the source gas through the reaction gas supply unit 402, and gas injection holes 332 are formed to spray the substrate. The third nozzle tube 330 has a function of suppressing the temperature rise of the first nozzle tube 310, and has a function of preheating (activating) the reaction gas since the external nozzle directly receives the external heat.

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: first nozzle unit
400: second nozzle unit

Claims (9)

delete In the chemical vapor deposition apparatus for the growth of gallium nitride based LED thin film:
A process tube having an inner tube accommodating a boat containing a plurality of substrates and an outer tube installed to surround the inner tube;
A heater assembly installed to surround the process tube;
A first nozzle unit installed vertically inside the inner tube and supplying a raw material gas in which an organometallic compound is mixed to form a gallium nitride-based thin film;
The first nozzle unit is
A first nozzle pipe receiving a source gas from the outside and having gas injection holes formed on one surface thereof;
A second nozzle tube installed to surround the first nozzle tube and having a cooling gas flowing in a space surrounding the first nozzle tube to prevent the organometallic compound from being thermally decomposed in the first nozzle tube; And
It is installed to surround the second nozzle tube, the gas injection hole is formed on one surface facing the boat, and comprises a reaction gas third nozzle tube for supplying a reaction gas to react with the organometallic compound of the source gas Chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, characterized in that. delete delete delete The method of claim 2,
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 a chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, characterized in that the ammonia gas. The method according to claim 6,
The cooling 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. delete delete

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