KR101205424B1 - CVD FOR THE GROWTH OF GaN-BASED LED - Google Patents

Abstract

The present invention relates to a nozzle unit used in a chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, the nozzle unit of the present invention is an organic metal compound trimethylgallium (TMGa), trimethylgallium (TMGa), trimethylgallium from the outside (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl), trichloride (GaCl3), such as a nozzle nozzle for supplying a source gas bubbled with hydrogen gas to the substrate; A vacuum nozzle tube installed to surround the injection nozzle tube and having a vacuum surrounding a space surrounding the injection nozzle tube; And a cooling nozzle tube installed to surround the vacuum nozzle tube and having at least one injection hole through which cooling gas flows and injects cooling gas into a space surrounding the injection 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.

Of the present invention for achieving the above object

According to an embodiment of the invention,

Basically, heat is transferred in three ways: convection, conduction, and radiation. Since conduction and convection require an intermediate medium through which heat can pass, the efficiency of heat transfer drops dramatically when the intermediate medium is removed in pure vacuum.

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 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.
FIG. 2 is a perspective view of the first nozzle unit shown in FIG. 1.
3 is a plan 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.
4 is an enlarged view illustrating main parts of FIG. 3.
5 to 7 are views showing another example of the first 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.

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to FIGS. 1 to 5. 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 is a 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. FIG. 2 is a perspective view of the first nozzle unit shown in FIG. 1. 3 is a plan 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. 4 is an enlarged view illustrating main parts of FIG. 3.

1 to 4, 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 inner tube 102 of the corresponding 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 is supplied with a raw material gas from the outside and the injection nozzle pipe 310, the gas injection hole 312 is formed on one surface, and the cooling nozzle pipe 320 is installed to surround the injection nozzle pipe 310 ). The injection 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 reacting on the substrate. The amount of unnecessary gas can be reduced by improving the efficiency and optimizing the amount of gas used. The gas injection holes 312 are formed on the connection ports 314 extending from the injection nozzle pipe 310 to the cooling nozzle pipe 320.

In the cooling nozzle pipe 320, a cooling gas flows in an annular space surrounding the injection nozzle pipe 310 to prevent the organometallic compound from being pyrolyzed in the injection nozzle pipe 310. The cooling nozzle pipe 320 may be fixed to the inner wall surface of the inner tube 102 by welding or the like.

The lower end of the cooling 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 blocks the heat provided to the injection nozzle pipe while passing through the space between the injection nozzle pipe 310 and the cooling nozzle pipe 320, and is provided to the cooling nozzle pipe 320. It flows into the inner space of the inner tube 102 through the formed exhaust hole 322 and is used for cooling the inner gas.

The first nozzle unit 300 having the above-described configuration has a cooling nozzle tube 320 surrounding the injection 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. Cooling gas flowing in the) may block the heat to suppress the temperature rise of the injection nozzle pipe (310). As such, the first nozzle unit 300 suppresses the temperature rise of the injection nozzle tube 310 and thermally decomposes in the injection nozzle tube 310 before the organometallic compound injected through the injection nozzle tube 310 reaches the substrate. It is possible to reduce the cost by improving the quality of the nitride film formed on the substrate and reducing the amount of raw material gas used by preventing it from being formed.

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 injection nozzle pipe 310 for supplying the raw material gas containing the organometallic compound is not directly exposed to a high temperature, an internal temperature rise of the injection nozzle pipe 310 can be suppressed, and thus, the organic metal Pyrolysis of the compound 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.

5 to 7 are views showing another embodiment of the first 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 first nozzle unit 300 ′ shown in FIGS. 5 to 7 has a triple tube shape. The first nozzle unit 300 ′ includes an injection nozzle tube 310 for injecting a source gas mixed with an organometallic compound for forming a nitride (GaN) thin film to the substrates loaded on the boat 200, and an injection nozzle tube ( It is installed to surround 310, the space surrounding the injection nozzle tube 310 is installed to surround the vacuum nozzle tube 330 and the vacuum nozzle tube 330 in a vacuum state, and surround the vacuum nozzle tube 330 And a cooling nozzle tube 320 having at least one injection hole 322 through which the cooling gas flows and injects the cooling gas into the space.

As such, the first nozzle unit 300 ′ is provided with a vacuum nozzle tube 330 between the injection nozzle tube 310 and the cooling nozzle tube 320, thereby providing a vacuum space 332 provided by the vacuum nozzle tube 330. By dramatically lowering the heat transfer efficiency due to heat conduction and convection, the temperature rise of the injection nozzle tube 310 can be minimized. A vacuum pump 306 may be connected to the vacuum nozzle tube 330, or alternatively, the vacuum nozzle tube 330 may be manufactured by completely sealing the inside of the vacuum nozzle tube in a vacuum state. Basically, heat is transferred in three ways: convection, conduction, and radiation. Since conduction and convection require an intermediate medium through which heat can pass, the efficiency of heat transfer decreases rapidly when the intermediate medium is removed in pure vacuum. will be.

Meanwhile, the injection nozzle pipe 310 has gas injection holes 312, and the gas injection holes 312 are formed through the vacuum nozzle pipe 330 and the cooling nozzle pipe 320 in the injection nozzle pipe 310. It is formed on the connection port 314.

In the cooling nozzle tube 320, a cooling gas flows in a space surrounding the vacuum nozzle tube 330 to prevent the organometallic compound from being pyrolyzed in the injection nozzle tube 310.

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 (7)

delete 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;
A first nozzle unit installed vertically inside the process tube and supplying a raw material gas containing an organometallic compound mixed therein to form a gallium nitride-based thin film; And
A second nozzle unit installed vertically inside the process tube in parallel with the first nozzle unit and supplying a reaction gas reacting with the organometallic compound of the source gas supplied through the first nozzle unit; ;
The first nozzle unit is
An injection nozzle tube supplied with a source gas from the outside and having gas injection holes formed on one surface thereof;
A vacuum nozzle tube installed to surround the injection nozzle tube, and configured to block heat transfer from the outside in which the interior surrounding the injection nozzle tube maintains a vacuum state; And
Cooling gas flows in the annular space surrounding the vacuum nozzle tube and is installed to surround the vacuum nozzle tube and prevents the organometallic compound from thermally decomposing in the injection nozzle tube. A chemical vapor deposition apparatus for growing a gallium nitride-based LED thin film, characterized in that it comprises a cooling nozzle tube having exhaust holes for injection into the interior space. The method of claim 3,
The source gas is gallium nitride characterized in that a metal source of trimethylgallium (TMGa), dimethylgallium chloride (DMGaCl), diethylgallium chloride (DEGaCl) or trichloride (GaCl3), which is an organometallic compound, is bubbled with hydrogen gas. Chemical vapor deposition apparatus for growing LED thin film. The method of claim 3,
The cooling gas is H2 gas and N2 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. delete delete

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