JPH04260692A - Cylinder container for vaporizing feeder of organometallic compound - Google Patents

Abstract

PURPOSE:To provide a cylinder container for an organometallic vaporizing feeder of small size having high safety, providing a high-quality thin film of crystal. CONSTITUTION:The top of a flat container 20 having a height dimension smaller than the maximum width dimension of the bottom is connected to a crystal growth furnace 11 by one flow channel through a valve. The flow channel at the side of the container 20 is bent and horizontally arranged in the vicinity of the joint part to the container 20. Consequently, a vaporizing feeder to be integrated into the cylinder container 20 can be miniaturized.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is directed to an organometallic vapor phase epitaxy method (
The present invention relates to a cylinder container used in an organometallic compound vaporization supply apparatus for producing an epitaxial thin film of a compound semiconductor by MOCVD (MOCVD method).

0002

BACKGROUND OF THE INVENTION In recent years, the MOCVD method using organometallic compounds has been attracting attention as a method for growing crystals of compound semiconductors. The MOCVD method is one of the crystal growth methods often used to create epitaxial thin films of compounds or mixed crystal semiconductors.The MOCVD method uses organometallic compounds such as trimethylgallium and trimethylaluminum as raw materials and utilizes their thermal decomposition reactions. This method involves growing thin film crystals.

[0003] In order to supply the organometallic compound into the crystal growth furnace, there is a method of feeding a carrier gas into a cylinder container containing the organometallic compound, vaporizing the organometallic compound, and transporting it into the crystal growth furnace. When the organometallic compound is a liquid, a carrier gas such as H2 is introduced into the compound to cause bubbling, and saturated vapor of the organometallic compound at a predetermined temperature is introduced into the crystal growth furnace.

FIG. 5 shows an example of a conventional cylinder container. The figure shows the cylinder container installed in the vaporization supply device.

In FIG. 5, 42 is a pressure reducing valve, 43 is a mass flow controller that controls the mass flow rate of carrier gas, and 45 is a cylinder container. The cylinder container 45 is filled with a liquid organometallic compound 44 . Reference numeral 46 denotes a constant temperature bath, which keeps the cylinder container 45 at a constant temperature. 47 is an inlet valve, and 48 is a dip tube for introducing carrier gas into the lower part of the cylinder container 45. 49 is an outlet valve, and 51 is a purge valve. Reference numeral 52 denotes a needle valve that maintains the gas pressure near the inlet and outlet of the cylinder container 45 at about 1 atmosphere when crystal growth is performed under reduced pressure. 53 and 54 are connection fittings. 11 is a crystal growth furnace for growing crystals; 12 is a heater; 13 is a substrate; 14 is a vacuum pump; and 15 is a valve for adjusting the degree of reduced pressure.

[0006] This device is used as follows. Connect the cylinder container 45 to a piping line. Since air or the like is mixed in the piping line from the pressure reducing valve 42 to the crystal growth furnace 11, the purge valve 51 is opened to replace the inside of the system with carrier gas. When the replacement is completed, the purge valve 51 is closed. The vapor pressure of the organometallic compound 44 is determined by accurately setting the temperature of the constant temperature bath 46. The carrier gas accurately controlled by the mass flow controller 43 is introduced into the cylinder container 45 by opening the valve 47 and bubbled therein, and the carrier gas containing the organometallic compound 44 at the desired concentration is introduced into the crystal growth furnace 11 by opening the valve 49. do. Crystal growth furnace 1
1 is depressurized by a vacuum pump 14, and group V hydride is introduced in advance from an inlet pipe 16, so that an epitaxial thin film of a compound semiconductor is formed on the substrate 13.

[0007]

However, this cylinder container 45 has the following problems regarding its structure and operation.

Since the cylinder container 45 needs to be kept at a constant temperature by placing it in a constant temperature bath 46, the valves 47 and 49 are arranged outside the constant temperature bath 46, and the distance between the valves 47 and 49 and the cylinder container 45 becomes long. . For example, in the cylinder container 45 shown in FIG. 5, the valves 47 and 49 are located just above the water surface of the constant temperature layer 46, and the operability is not good. A cylinder 45 into which the organometallic compound 44 is introduced by such bubbling.
In this case, in order to obtain a saturated gas of the organometallic compound, it is necessary to set the height dimension longer than the width dimension of the bottom part. For example, a standard cylinder of 200 ml has a vertically elongated shape with a height of 250 to 300 mm. In addition, production lines have multiple supply systems for each type of raw material in order to control productivity and film thickness. For example, to obtain a quaternary thin film, the raw material supply system alone requires 6 to 10 systems. A supply system is required, and the volume occupied by the cylinder container in the vaporization supply device becomes large. In order to increase the capacity of the cylinder container 45, the height must be further increased, which is an obstacle to downsizing the vaporization supply device.

When the cylinder container 45 is attached to a piping line or when starting or stopping raw material supply, it is necessary to supply carrier gas to purge the inside of the piping system. In this case, the valves 47 and 49 have a complicated structure and have dead space inside, making it difficult to completely purge or replace gas. The inside of the piping may become contaminated with oxidized organometallic compounds, and as a result, the quality of crystal-grown devices may deteriorate significantly.

[0010] When attaching the cylinder container 45 to the vaporization supply device, if the inlet and outlet of the carrier gas are mistakenly installed in reverse order, the organometallic compound 44 may be released to the outside of the cylinder container 45. Even if it is installed correctly, if the gas pressure on the gas inlet side becomes lower than the pressure on the gas outlet side due to gas introduction or valve operation error, the organometallic compound 44 will flow back and seriously contaminate the valve 47 and mass flow controller 43. There are things to do. It is very dangerous if such an operational error occurs when the cylinder container 45 is attached or detached.

The organometallic compound 44 is contained in the cylinder container 45.
is sufficiently filled, the space 45a above the container is narrow, so when the carrier gas bubbles introduced from the dip tube 48 burst, droplets of the organometallic compound 44 may adhere to the outlet of the cylinder container 45. Frequently, the liquid level shakes violently and the organometallic compound 44 jumps out to the outlet. If the organometallic compound 44 adheres to the piping etc. leading from the cylinder container 45 to the crystal growth furnace 11, more raw materials than the intended supply amount will be introduced into the crystal growth furnace 11, so the composition of the crystal growth will be stoichiometrically It becomes completely impossible to control.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a cylinder container for an organometallic compound vaporization supply device that is small in size, highly safe, and capable of producing a high-quality crystalline thin film. shall be.

[0013]

[Means for Solving the Problems] A cylinder container for an organometallic compound vaporization supply apparatus of the present invention, which has been made to achieve the above object, will be explained using drawings corresponding to embodiments.

As shown in FIG. 1, the cylinder container for the organometallic compound vaporization supply apparatus, which is the first invention of the present invention, has a flat container 20 whose height is shorter than the maximum width of the bottom.
A single channel 21 is provided on the top surface of the channel 21 to connect to the crystal growth furnace 11 under heating and depressurization via a valve 22, and the channel 21 on the container 20 side is bent near the connection with the container to form a horizontal It is characterized by extending in the direction.

As shown in FIG. 2, the cylinder container for the organometallic compound vaporization supply apparatus according to the second aspect of the present invention has a flat container 20 whose height is shorter than the maximum width of the bottom.
The device is characterized in that a single flow path 21 is provided on the side surface thereof, which connects via a valve 22 to a crystal growth furnace under heating and reduced pressure.

As shown in FIG. 4, a cylinder container for an organometallic compound vaporization supply apparatus according to the third aspect of the present invention has a flat container 20 whose height is shorter than the maximum width of the bottom.
A single raw material gas flow path 21 is provided which connects to the crystal growth furnace 11 under heating and reduced pressure via a raw material gas valve 25,
A carrier gas valve 35 is installed on the discharge side of the raw material gas valve 25.
a carrier gas flow path 3 connecting to a carrier gas source via
1 is connected to the block valve 32 in which the raw material gas valve 25 and the carrier gas valve 35 are integrated.

[0017]

EXAMPLES Examples of the present invention will be described in detail below. FIG. 1 shows an embodiment of a cylinder container to which the first invention of the present invention is applied. This figure shows a schematic view of the cylinder container attached to the organometallic compound vaporization supply device.

The cylinder container 20 is a flat container whose height is shorter than the maximum width of the bottom, and the interior thereof is filled with an organometallic compound 26. A single conduit 21 is provided on the upper surface of the container 20, and the container 20 side is connected to the container 2.
0 and extends horizontally, and is connected to the crystal growth furnace 11 via a valve 22 and a mass flow controller 23. A vacuum pump 14 is connected to the crystal growth furnace 11 via a valve 15 for adjusting the degree of pressure reduction. The crystal growth furnace 11 has a structure that is heated by a heater 12, and is provided with an introduction pipe 16 for introducing group V gas or the like. The cylinder container 20 and the valve 22 are housed in a constant temperature bath 24.

This device operates as follows. First, the substrate 13 is placed in the crystal growth furnace 11, heated to a predetermined temperature by the heater 12, and the pressure inside the system is reduced by the vacuum pump 14. When the temperature inside the constant temperature bath 24 is raised to a constant temperature, the vapor pressure of the organometallic compound 26 inside the cylinder container 20 increases and vaporization begins. When the valve 22 is opened in this state, the gasified organometallic compound is removed from the valve 22 of the conduit 21.
2 and is introduced into the mass flow controller 23. After the mass flow rate of the organometallic compound gas is measured and adjusted to a constant value by a mass flow controller 23, it is supplied to the crystal growth furnace 11, and an epitaxial thin film of a compound semiconductor is formed on the substrate 13. When a predetermined film thickness is obtained, the valve 22 is closed and the supply of the organometallic compound gas is stopped.

This cylinder container 20 has a flat shape and is extremely small because it is connected to the crystal growth furnace 11 through a single conduit 21 extending horizontally from its upper surface. For example, if the capacity is 200ml, the height is about 50mm, which is 1/1/2 of the conventional size (250-300mm).
Since it is 5 to 1/6, the entire vaporization supply device can be downsized. The valve 22 can be installed using the gaps between the components of the vaporization supply device, and the valve 22 has good operability. Further, even when the organometallic compound 26 is a liquid, bubbling is not performed, so droplets of the organometallic compound 44 do not adhere to the outlet of the cylinder container 45, and the organometallic compound 44 does not fly out to the outlet.

FIG. 2 shows an embodiment of a cylinder container to which the second aspect of the present invention is applied. This cylinder container 20 is shown in FIG.
The mounting position of the conduit 21 of the cylinder container 20 shown in FIG. 1 is changed to the side surface of the cylinder container 20. By attaching the conduit 21 to the side surface of the cylinder container 20 in this manner, it is possible to further downsize the entire vaporization supply device. In addition, since the valve 22 can be installed in a position that is easy to operate,
Improves work efficiency. As shown in FIG. 3, the tip of the conduit 21 may reach deep into the cylinder container 20. Figure 2
The cylinder container 20 shown in FIG. 3 is effective when the organometallic compound 26 is solid.

FIG. 4 shows an embodiment of a cylinder container to which the third aspect of the present invention is applied. In this system, a carrier gas source for conveying organometallic compound gas to the crystal growth furnace 11 is connected between the mass flow controller 23 of the cylinder container shown in FIG. 1 and the crystal growth furnace 11. A source gas valve 25 is provided between the mass flow controller 23 and the crystal growth furnace 11. A carrier gas flow path 31 connected to a carrier gas source is connected to the discharge side of the raw material gas valve 25 via a carrier gas valve 35, a heat exchanger 29, a mass flow controller 28, and a valve 30. The raw material gas valve 25 and the carrier gas valve 35 are integrated into a block valve 32. The cylinder container 20, valves 22 and 30, mass flow controllers 23 and 28, heat exchanger 29, and block valve 32 are housed in a constant temperature bath 24.

This device operates as follows. A substrate 13 is placed in a crystal growth furnace 11, heated to a predetermined temperature by a heater 12, and the pressure inside the system is reduced by a vacuum pump 14. The valve 30 and the carrier gas 35 are opened to allow a predetermined amount of carrier gas to flow, and the degree of pressure reduction adjustment valve 15 is adjusted to maintain a constant degree of pressure reduction in the crystal growth furnace 11. 11 is purged. Since the raw material gas valve 25 and the carrier gas 35 are blocked, purging can be performed quickly and reliably. When the air constant temperature bath 24 is heated to a constant temperature, the vapor pressure of the organometallic compound 26 in the cylinder container 20 increases and vaporization begins. When the valve 22 and the raw material gas valve 25 are opened, the gasified organometallic compound 26 is introduced into the mass flow controller 23 via the valve 22, and the mass flow rate is directly measured and adjusted to a constant value. 35 is integrated with a carrier gas at a constant concentration in a block valve 32, and is supplied to the crystal growth furnace 11.

[0024]

As described above in detail, the cylinder container of the present invention has a flat shape in which the height dimension is shorter than the maximum width dimension of the bottom part, and is compact. Therefore,
The vaporization supply device in which the cylinder container is incorporated can also be downsized. There is little dead space in flow paths such as valves, and purge and gas replacement can be performed quickly and reliably, and the supply amount of organometallic compounds can be adjusted accurately, so there is little compositional variation and high-quality, large-area crystalline thin films can be efficiently produced. It is possible to manufacture. Furthermore, since errors in cylinder container installation and valve operation do not occur, organometallic compounds do not flow back and contaminate the system or are released outside the system, resulting in high safety.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a vaporization supply device using a cylinder container to which a first aspect of the present invention is applied.

FIG. 2 is a schematic configuration diagram of a vaporization supply device using a cylinder container to which the second invention of the present invention is applied.

FIG. 3 is a schematic side view showing another embodiment of a cylinder container to which the second invention of the present invention is applied.

FIG. 4 is a schematic configuration diagram of a vaporization supply device using a cylinder container to which a third aspect of the present invention is applied.

FIG. 5 is a schematic configuration diagram of a vaporization supply device using a conventional cylinder container.

[Explanation of symbols]

11 is a crystal growth furnace, 12 is a heater, 13 is a substrate, 14 is a vacuum pump, 15 is a valve for adjusting the degree of reduced pressure, 20 is a cylinder container, 21 is a source gas flow path, 22 and 30 are valves, 2
3.28 is a mass flow controller, 24 is a constant temperature bath, 2
5 is a raw material gas valve, 26 is an organometallic compound, 29 is a heat exchanger, 31 is a carrier gas flow path, 32 is a block valve, and 35 is a carrier gas valve.

Claims (3)

[Claims] 1. A flow path connected to a crystal growth furnace under heating and reduced pressure via a valve is provided on the top surface of a flat container having a height dimension shorter than the maximum width dimension of the bottom part, and the flow path 1. A cylinder container for an organometallic compound vaporization supply device, characterized in that the container side is bent near a connection part with the container and extends in the horizontal direction. [Claim 2] A flow path connected to a crystal growth furnace under heating and reduced pressure via a valve is provided on the side surface of the flat container whose height dimension is shorter than the maximum width dimension of the bottom part. A cylinder container for an organometallic compound vaporization supply device. 3. A flat container having a height shorter than the maximum width at the bottom is provided with a raw material gas flow path connected to a crystal growth furnace under heating and reduced pressure via a raw material gas valve. An organometallic compound vaporization and supply device characterized in that a carrier gas flow path connected to a carrier gas source via a carrier gas valve is connected to the discharge side of the gas valve, and is a block valve in which a raw material gas valve and a carrier gas valve are integrated. cylinder container for