JPH10223541A - Chemical vapor deposition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid turbulence in the flow of a feed gas when switching the feed gas by controlling the amount of supply of a carrier gas for a feed pipe from a carrier gas supply source, and setting a pressure difference between a gas supply pipe and a feed pipe to a given pressure difference. SOLUTION: A carrier gas is allowed to flow to a gas supply pipe 10, so that a feed gas rapidly reaches a reaction pipe 13 and a non-used gas is guided to a feed pipe 20 by closing valves v2 , v4 , or v6 or opening a valve v1 , v3 , or v5 . The detection signal of the pressure difference between the gas supply pipe 10 and the feed pipe 20 by a detection means 20 for detecting the pressure difference between the gas supply pipe 10 and the feed pipe 20. Then, by the detection signal, a control means 50 for controlling the amount of supply of a carrier gas for the feed pipe 20 from a carrier gas supply source 33 is controlled. Then, by the control means 50, a carrier gas that is controlled to a specific amount is allowed to flow to the feed pipe 20, thus setting a pressure difference between the gas supply pipe 10 and the feed pipe 20 to a given value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a vapor phase growth apparatus (C
VD device).

[0002]

2. Description of the Related Art For example, an LED (Light Emitting Diod)
e), HEMT (High Electron Mobility Transistor)
For example, metal organic chemical vapor deposition (MOCVD) or the like, which can accurately and reproducibly control the supply of raw materials, is suitable for compound semiconductor film formation, for example, epitaxial growth in various semiconductor device apparatuses. . Further, these methods are characterized by crystal growth in a non-equilibrium state, and can obtain a mixed crystal of a multi-component compound semiconductor which is difficult by a liquid phase growth method (LED).

FIG. 3 is a schematic diagram of a metalorganic vapor phase epitaxy apparatus (hereinafter referred to as MOCVD apparatus) as a conventional general vapor phase epitaxy apparatus.

For example, the epitaxy of a GaAs-based, GaInP-based, or other compound semiconductor layer by MOCVD is described as follows.
Group II raw materials include trimethylgallium (TMG
a), an organic metal source gas supply source 34 for obtaining an organic metal source gas such as trimethyl indium (TMIn) is provided, and as a group V source, for example, a first source gas supply source 31 for obtaining arsine (AsH ₃ ); And phosphine (P
A second source gas supply source 32 for obtaining H ₃ ) is provided.

Here, the organic metal source gas supply source 34, the first source gas supply source 31, and the second source gas supply source 32 are collectively referred to as a portion surrounded by a broken line in FIG.
It is referred to as a source gas supply unit 30.

In FIG. 3, one organic metal source gas supply source 34 and two source gas supply sources 31 and 32 are provided.
However, in practice, it is assumed that an organic metal source gas supply source and a source gas supply source are arranged for each source.

The organometallic raw material gas supply source 34 contains the above-mentioned organometallic raw materials, and the carrier gas from the carrier gas supply source 33 which is highly purified by a purifying device (not shown). Is blown out from the carrier gas supply pipe 53 by controlling the flow rate through the mass flow controller 43, and is taken out by bubbling, and guided to the gas supply pipe 10 connected to the reaction pipe 13 in which the substrate 16 on which the vapor phase growth is to be performed is arranged. To the intended reaction tube 13.

At this time, in the gas supply pipe 10, the flow rate of the carrier gas is controlled by the mass flow controller 45 from the carrier gas sub-line 55 so that the organometallic raw material gas reaches the reaction tube 13 quickly. It has been done.

Further, since a relatively small amount of carrier gas is used for bubbling the organic metal raw material, the organic metal raw material gas from the organic metal raw material gas supply source 34 is introduced to the gas supply pipe 10 quickly. The mass flow controller 44 controls the flow rate of the carrier gas to flow through the carrier gas pushing line 54.

Similarly, first and second source gas supply sources 3
1 and 32 are also filled with the above-mentioned source gas.
Then, in accordance with a target film to be vapor-phase grown in the reaction tube 13, a required amount is taken out by controlling the flow rate by the mass flow controllers 41 and 42, respectively, and the substrate 16 on which the vapor-phase growth is performed is disposed. The reaction tube 1 is led to the gas supply tube 10 connected to the reaction tube 13 and finally the target reaction tube 1
Lead to 3.

The respective source gases thus sent into the reaction tube 13 are sent to a substrate 16 on a susceptor 15 maintained at a constant temperature by heating means 14 such as a high-frequency coil, where thermal decomposition occurs. The target compound semiconductor layer is epitaxially grown on the substrate 16.

Then, each necessary source gas is supplied to the reaction tube 13.
However, as for the raw material gas which is not used, for example, valves v ₂ , v ₄ ,
Alternatively Close v _6, valve v _1, v ₃ or v ₅
Is opened and guided to the delivery pipe 20.

[0013]

Here, FIG. 3 described above is used.
In the vapor phase growth apparatus shown in FIG.
6, a GaInP-based compound semiconductor layer is formed.
A case where a GaAs-based compound semiconductor layer is formed on an aInP-based compound semiconductor layer will be described.

An organic metal raw material gas supply source 34 in FIG. 3 includes a group III raw material trimethylgallium (TMGa),
It is assumed that trimethylindium (TMIn) is housed therein, and a cylinder (cylinder) of a group V source material, arsine (AsH ₃ ), is used as the first source gas supply source 31, and a second source gas supply source 32 , A cylinder of phosphine (PH ₃ ) is used.

In this vapor phase growth apparatus, GaInP
When a GaAs-based compound semiconductor layer is formed on the base compound semiconductor layer, depending on the composition of each semiconductor layer,
A necessary gas and an unnecessary gas are separately supplied to the gas supply pipe 10 and the delivery pipe 20.

That is, first, when forming a GaInP-based compound semiconductor layer, trimethyl gallium (TMGa) and trimethyl indium (TM
In), the valve v _{2 of the} switching means vs.
Is opened, the valve v ₁ is closed, and the gas supply pipe 10 is guided.
On the other hand, at this time, since the phosphine (PH ₃ ) of the second source gas supply source 32 is used for the group V source, the valve v ₆ of the switching means vs is opened, the valve v ₅ is closed, and the gas supply pipe 10 is closed. Since the arsine (AsH ₃ ) of the first source gas supply source 31 is not used, the valve v ₃ of the switching means vs is opened, v ₄ is closed, and the gas is led to the delivery pipe 20.

Thus, in this vapor phase growth apparatus, a GaInP-based compound semiconductor layer is formed on the substrate 16.

Next, when a GaAs-based compound semiconductor layer is formed on this GaInP-based compound semiconductor layer,
To use trimethylgallium (TMGa) as a II group material, opening the valve v ₂ switching means vs, kept closing the valve v _1. On the other hand, at this time, as for the group V raw material, arsine (AsH) of the first raw material gas supply source 31 was used.
To use _3), closing the valve v ₃ switching means vs, v ₄ by opening leading to the gas supply pipe 10, the second phosphine source gas supply source 32 (PH ₃₎ is not used, the switching means opening the valve v ₅ of vs, close the v _6, once led to a delivery tube 20, then, stop the phosphine (PH ₃₎ closes the valve 32v, and instead of this, from the carrier gas supply unit 33, The flow rate is controlled by the MFC 46 so that the carrier gas having the same flow rate as the phosphine (PH ₃ ) flows through the delivery pipe 20.

Thus, in this vapor phase growth apparatus, a GaAs compound semiconductor layer is formed on the GaInP compound semiconductor layer.

However, the arsine (AsH ₃ )
Since the viscosity of the gas is greatly different between the source gas such as methane and phosphine (PH ₃ ) and the carrier gas, the carrier gas having the same flow rate is simply used instead of the source gas.
, The pressure in the delivery pipe 20 drops and the delivery pipe 2
0 and a pressure difference between the gas supply pipe 10.

As described above, the delivery pipe 20 and the gas supply pipe 10
When a pressure difference is generated between the gas supply pipe 10 and the gas supply pipe 10 and the delivery pipe 20, the flow of the source gas is disturbed when the source gas is switched again to perform the vapor phase growth.

That is, for example, arsine (AsH ₃ ) flowing in the gas supply pipe 10 is switched to the delivery pipe 20,
When flowing phosphine (PH ₃ ) through the gas supply pipe 10,
As described above, when the pressure of the gas supply pipe 10 is higher than that of the delivery pipe 20, the phosphine (PH ₃ )
Is difficult to flow into the gas supply pipe 10 because of the pressure difference. On the contrary, for some reason,
When the pressure of the delivery pipe 20 is higher than that of the gas supply pipe 10, arsine (AsH ₃ ) flows into the delivery pipe 20 rapidly due to the pressure difference.

As described above, the gas supply pipe 10 and the delivery pipe 20 make it difficult for the raw material gas to flow in, or flow rapidly, so that the flow of the raw material gas is disturbed when the raw material gas is switched. When a semiconductor film having a multilayer structure is formed, the sharpness of the hetero interface of each layer is reduced.

The fluctuation of the pressure between the gas supply pipe 10 and the delivery pipe 20 at the time of the switching of the source gas is,
It has been found that there is a problem with the supply or delivery of the group source gas.

In the present invention, the pressure between the gas supply pipe 10 and the delivery pipe 20 is set to a predetermined pressure difference, for example, by making these pressures equal, so that the flow of the source gas is disturbed when the source gas is switched. Provided is a vapor phase growth apparatus capable of avoiding occurrence.

[0026]

According to the present invention, there is provided a vapor phase growth apparatus comprising: a reaction tube for performing vapor phase growth; a source gas supply section including a plurality of source gas supply sources; a carrier gas supply section; Gas supply pipe that supplies the raw material gas from the gas supply section and the carrier gas from the carrier gas supply section to the reaction tube, and sends the raw material gas from the raw material gas supply section and the carrier gas from the carrier gas supply section to the outside of the reaction tube A supply pipe for supplying the source gas from the source gas supply unit to the gas supply pipe and the delivery pipe, and switching means for supplying the source gas from at least one source gas supply source and a carrier gas. Gas exchange means for sending out to the outside of the gas supply unit, detection means for detecting a pressure difference between the gas supply pipe and the delivery pipe, and transmission from the carrier gas supply source based on a pressure difference detection signal obtained by the detection means. The pressure difference between the delivery tube and the gas supply pipe to control the supply amount of the carrier gas to the pipe and has a control means for setting a predetermined pressure difference.

According to the vapor phase growth apparatus of the present invention, when one source gas from the source gas supply source is switched to another source gas, the pressure difference between the gas supply pipe and the delivery pipe is reduced to a predetermined pressure difference. In order to supply the carrier gas, the amount of the carrier gas is switched to the source gas, and a detecting means for detecting a pressure difference between the gas supply pipe and the delivery pipe is provided. Since the supply amount of the carrier gas from the carrier gas supply source to the delivery pipe is controlled by the detection signal of the pressure difference, it is possible to prevent the flow of the source gas from being disturbed when the source gas is switched. In addition, the steepness of the hetero interface of each layer of the semiconductor film can be secured, and deterioration of the film quality can be avoided.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a metal organic chemical vapor deposition apparatus (MOCVD apparatus) will be described as an embodiment of the vapor phase growth apparatus of the present invention.

FIG. 1 shows a schematic diagram of a vapor phase growth apparatus of the present invention. The vapor phase growth apparatus of the present invention provides a reaction tube 1 for performing vapor phase growth.
3 and a source gas supply unit 3 including a plurality of source gas supply sources
0, the carrier gas supply unit 33, and the source gas supply unit 30
A gas supply pipe 10 for supplying the raw material gas from the reactor and the carrier gas from the carrier gas supply unit 33 to the reaction tube 13;
A delivery pipe 20 for sending the source gas from the source gas supply unit 30 and a carrier gas from the carrier gas supply unit 33 to the outside of the reaction tube 13, and a source gas from the source gas supply unit 30 and the delivery pipe 20. A gas exchange means 101, 102 for switching between and supplying a source gas from at least one source gas supply source and a carrier gas to feed the source gas outside the source gas supply unit; Detecting means 7 for detecting a pressure difference with the delivery pipe 20
0, and the supply amount of the carrier gas from the carrier gas supply source 33 to the delivery pipe 20 is controlled by the detection signal of the pressure difference obtained from the detection means to control the gas supply pipe 10 and the delivery pipe 2.
Control means 50 for setting a pressure difference from zero to a predetermined pressure difference.

For example, the epitaxy of a GaAs-based or GaInP-based compound semiconductor layer by the MOCVD method is as follows.
Group II raw materials include trimethylgallium (TMG
a), an organic metal source gas supply source 34 for obtaining an organic metal source gas such as trimethylindium (TMIn) is provided, and a first source for obtaining arsine (AsH ₃ ) and phosphine (PH ₃ ) as a group V source A gas supply source 31 and a second source gas supply source 32 are provided.

The first and second source gas supply sources 31 and 32 are switched between a source gas therefrom and a carrier gas from a carrier gas supply source 33, and
Gas exchange means 101 and 102 for sending out gas are provided.

Here, the portion surrounded by the broken line in FIG. 1 is generally referred to as the organic metal source gas supply source 34, the first source gas supply source 31, and the second source gas supply source 32.
It is referred to as a source gas supply unit 30.

In FIG. 1, one organic metal source gas supply source 34, two source gas supply sources 31 and 32
However, in practice, it is assumed that an organic metal source gas supply source and a source gas supply source are arranged for each source.

The organic metal raw material gas supply source 34 contains an organic metal raw material, and a carrier gas from the carrier gas supply source 33 which has been purified by a purifying device (not shown). By controlling the flow rate through the mass flow controller 43, the gas is blown from the carrier gas supply pipe 53, taken out by bubbling, and guided to the gas supply pipe 10 connected to the reaction pipe 13 in which the substrate 16 on which the vapor phase growth is to be performed is arranged. It is led to the target reaction tube 13.

At this time, in the gas supply pipe 10, the flow rate is controlled by the mass flow controller 45 from the carrier gas sub-line 55 so that the organometallic raw material gas quickly reaches the reaction pipe 13 so that the carrier gas flows. Has been made.

Since the amount of the carrier gas used for bubbling the organometallic raw material is relatively small, the carrier gas is supplied from the organometallic raw material gas supply source 34 to the gas supply pipe 10 quickly. The mass flow controller 44 controls the flow rate of the carrier gas to flow through the gas pushing line 54.

Similarly, the first and second source gas supply sources 3
1 and 32 are also filled with the above-mentioned source gas.
Then, in accordance with a target film to be vapor-phase grown in the reaction tube 13, a required amount is taken out by controlling the flow rate by the mass flow controllers 41 and 42, respectively, and the substrate 16 on which the vapor-phase growth is performed is disposed. The reaction tube 1 is led to the gas supply tube 10 connected to the reaction tube 13 and finally the target reaction tube 1
Lead to 3.

Each raw material gas thus sent into the reaction tube 13 is sent to the substrate 16 on the susceptor 15 maintained at a constant temperature by heating means 14 such as a high-frequency coil, where thermal decomposition occurs. The target compound semiconductor layer is epitaxially grown on the substrate 16.

Depending on the type of the compound semiconductor layer to be formed, necessary source gases are led to the reaction tube 13 through the gas supply pipe 10, but unused source gases are switched by the switching means vs. Valve v ₂ ,
The valve v ₄ or v ₆ is closed, and the valve v ₁ , v ₃ or v ₅ is opened to lead to the delivery pipe 20.

The gas phase growth apparatus shown in FIG. 1 is provided between the gas supply pipe 10 and the delivery pipe 20 with detection means 70 for detecting a pressure difference between the gas supply pipe 10 and the delivery pipe 20. The detection means 70 provides a pressure difference detection signal.

A control means 50 for controlling the supply amount of the carrier gas from the carrier gas supply source 33 to the delivery pipe 20 based on the pressure difference detection signal obtained by the detection means 70 is provided. By 50, the pressure difference between the gas supply pipe 10 and the delivery pipe 20 is maintained at a predetermined value.

Next, in the above-described vapor phase growth apparatus shown in FIG. 1, a GaInP-based compound semiconductor layer is formed on the substrate 16 in the reaction tube 13 and a GaAs-based compound semiconductor layer is formed on the GaInP-based compound semiconductor layer. A case where a compound semiconductor layer is formed will be described.

Here, the organometallic raw material gas supply source 34 includes a group III raw material trimethylgallium (TMGa),
It is assumed that trimethylindium (TMIn) is contained therein, a first source gas supply source 31 includes a group V source material, arsine (AsH ₃ ), and a second source gas supply source 32 includes:
It is assumed that phosphine (PH ₃ ) is filled.

[0044] First, the case of forming a GaInP-based compound semiconductor layer, in order to use the trimethyl gallium (TMGa), trimethylindium (TMIn) as a group III raw material, opening the valve v ₂ switching means vs, valve v ₁ is closed and led to the gas supply pipe 10. At this time,
Since phosphine (PH ₃ ) of the second source gas supply source 32 is used as the group V source, the valve 32v ₂ of the gas exchange means 102 is opened, the valve 32v ₁ is closed, and the valve v ₆ of the switching means vs is opened. open, leading to the gas supply pipe 10 by closing the valve v _5.

At this time, since arsine (AsH ₃ ) of the first source gas supply source 31 is not used, the gas exchange means 1
01 to close the valve 31v _2, open the valve 31v _1,
A carrier gas having a pressure equal to that of the source gas, for example, a carrier gas having a flow rate eight times that of the source gas is flow-controlled by the MFC 41 and guided to the delivery pipe 20.

On the other hand, at this time, a detection signal of the pressure difference between the gas supply pipe 10 and the delivery pipe 20 is obtained by the detection means 70 for detecting the pressure difference between the gas supply pipe 10 and the delivery pipe 20.
Based on this detection signal, control means 50 for controlling the supply amount of the carrier gas from the carrier gas supply source 33 to the delivery pipe 20, for example, the MFC, is controlled.
As a result, the carrier gas controlled to a predetermined amount is supplied to the delivery pipe 2.
0, so that the pressure difference between the gas supply pipe 10 and the delivery pipe 20 is maintained at a predetermined value, for example, evenly.

Thus, in this vapor phase growth apparatus, a GaInP-based compound semiconductor layer is formed on the substrate 16.

Next, when a GaAs-based compound semiconductor layer is formed on this GaInP-based compound semiconductor layer,
To use trimethylgallium (TMGa) as a II group material, opening the valve v ₂ switching means vs, by closing the valve v _1, it guides the material gas to the gas supply pipe 10.
At this time, as the group V source material, the first source gas supply source 3
To use one of arsine (AsH _3), opening the valve 31v ₂ gas exchange means 101, closing the valve 31v _1, opening the valve v ₄ switching means vs, valve v ₃
Is closed and guided to the gas supply pipe 10.

At this time, since the phosphine (PH ₃ ) of the second source gas supply source 32 is not used, the gas exchange means 1
Closed 02 of the valve 32v _2, in place of this, opening the valve 32v _1, the raw material gas and the same carrier gas at a pressure, for example eight times the raw material gas flow rate carrier gas MF
C42 The flow and flow rate control, opening the valve v ₅ switching means vs, close the v _6, leading to delivery tube 20.

As described above, the gas supply pipe 10
The detection means 70 for detecting the pressure difference between the delivery pipe 20 and the gas supply pipe 10 provides a detection signal of the pressure difference between the delivery pipe 20, and the carrier gas supply source 33 supplies the carrier gas to the delivery pipe 20. Control means 50 for controlling the amount;
For example, the MFC is controlled, and the carrier gas controlled to a predetermined amount is caused to flow through the delivery pipe 20 by the control means 50,
The pressure difference between the gas supply pipe 10 and the delivery pipe 20 is maintained at a predetermined value, for example, evenly.

As described above, in the vapor phase growth apparatus shown in FIG. 1, when the source gas from the source gas supply source is switched to the source gas from another source gas supply source, the gas supply pipe 10 and the delivery pipe are connected. An amount of carrier gas necessary to balance the pressure of the pipe 20 is switched to the source gas and supplied to the delivery pipe 20, and the carrier gas is supplied between the gas supply pipe 10 and the delivery pipe 20. Detection means 70 for detecting the pressure difference between the carrier gas supply source 33 and the delivery pipe 2 from the carrier gas supply source 33 according to the pressure difference detection signal obtained by the detection means 70.
Control means 5 for controlling the supply amount of carrier gas with respect to 0
0, for example, controlling the MFC to supply the carrier gas to the delivery pipe 20 from the carrier gas supply source 33 to supply the gas to the gas supply pipe 1.
Since the pressure difference between 0 and the delivery pipe 20 is set to a predetermined pressure difference, it is possible to prevent the flow of the raw material gas from being disturbed when switching the raw material gas, and it is possible to prevent the flow of the raw material gas from being disturbed. Steepness can be ensured, and deterioration in film quality can be avoided.

Next, another example of the vapor phase growth apparatus of the present invention will be described.
This will be described with reference to FIG. In FIG. 2, the portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 2, the vapor phase growth apparatus of this example employs one of a first source gas supply source 31 and a second source gas supply source 32 constituting a source gas supply unit 30. Alternatively, an auxiliary control means 60 for controlling the supply amount of the carrier gas from the carrier gas supply unit 33 to the delivery pipe 20 by turning on and off both the source gas supply sources 31 and 32 is provided. .

Here, ON / OFF of the source gas supply means that the source gas is supplied or stopped by switching the gas exchange means 101 and 102.

Also in FIG. 2, one organic metal source gas supply source 34 and two source gas supply sources 31 and 32 are provided.
However, in practice, it is assumed that an organic metal source gas supply source and a source gas supply source are arranged for each source.

In the vapor phase growth apparatus shown in FIG. 2, a case where a large amount of source gas is supplied from the first source gas supply source 31 or the second source gas supply source 32 constituting the source gas supply unit 30. Then, a large amount of carrier gas is supplied to the delivery pipe 20 by the auxiliary control means 60 for controlling the supply rate of the carrier gas from the carrier gas supply unit 33 to the delivery pipe 20 according to the supply quantity of the source gas.

That is, in the semiconductor vapor deposition, for example, when the source gas of the first source gas supply source 31 is used and the source gas of the second source gas supply source 32 is not used, the gas exchange means 101 Valve of valve 31v ₂
Open the, close the valve 31v _1, a raw material gas MFC41
The gas exchange means 102
Closing the valve 32v _2, Alternatively, the valve 32
v Open _1, carrier gas of the source gas equivalent to the pressure of the first material gas supply source 31, for example eight times the flow rate carrier gas of the source gas by MFC42 flow by flow control.
In this case, when the source gas of the first source gas supply source 31 has a large capacity, the capacity of the MFC 42 is often not sufficient to control the flow rate of the carrier gas having the same pressure. In the case, the first source gas supply source 31
Auxiliary control means 60 is controlled in accordance with the supply amount of the raw material gas from
And a carrier gas sufficient to maintain the pressure difference between the feed pipe 20 and the feed pipe 20 at a predetermined value.

Contrary to the case described above, in the semiconductor vapor deposition, the source gas of the second source gas supply source 32 is used,
Even when the source gas of the first source gas supply source 31 is not used, the pressure difference between the gas supply pipe 10 and the delivery pipe 20 can be maintained at a predetermined value by the same operation.

As described above, the vapor phase growth apparatus shown in FIG.
When the source gas from the source gas supply source is large in volume and the source gas from one source gas supply source is switched and supplied with the source gas from another source gas supply source, the gas exchange means 101, Even when the pressure difference between the gas supply pipe 10 and the delivery pipe 20 cannot be maintained at a predetermined value by the supply amount of the carrier gas alone, the supply amount of the source gas from the source gas supply source depends on the supply amount of the source gas. Thus, by providing the auxiliary control means 60 capable of controlling the supply amount of the carrier gas, the same effects as those of the vapor phase growth apparatus shown in FIG. 1 can be obtained. That is, the gas supply pipe 1
The vapor pressure growth can be performed while maintaining the pressure difference between 0 and the delivery pipe 20 at a predetermined value, for example, at a uniform pressure.

In the above-described embodiment, a case has been described where the present invention is applied to a metal organic chemical vapor deposition apparatus (MOCVD apparatus) as a vapor phase growth apparatus. However, the present invention is not limited to this example. The present invention can be applied to any vapor phase growth apparatus that has a configuration in which a source gas from a gas supply unit is fed into a reaction tube to grow a target compound.

Further, in the above embodiment, the case where the gas exchange means 101 and 102 are provided in the cylinder (cylinder) of the source gas supply source for supplying the group V source material has been described, but the present invention is limited to this example. It is not
The same applies to an organometallic raw material supply source that supplies a group II raw material.

Further, the vapor phase growth apparatus of the present invention has a III-
The present invention is not limited to the case of performing group V semiconductor vapor deposition, but can be applied to the case of performing II-VI group semiconductor vapor deposition.

[0063]

According to the present invention, when switching one source gas from a source gas supply source to a source gas from another source gas supply source, it is possible to avoid occurrence of disturbance in the flow of the source gas. Was completed. For this reason, the steepness of the interface between the respective layers of the target semiconductor film can be ensured, and deterioration of the film quality can be avoided.

Further, by providing the auxiliary control means, even when a large volume of source gas flows, the pressure of the delivery pipe and the gas supply pipe can be maintained at the same level.
Vapor-phase growth can be performed, and even when a large-capacity source gas is used, the steepness of the interface between the layers of the target semiconductor film can be secured, and deterioration of the film quality can be avoided.

[Brief description of the drawings]

FIG. 1 shows a schematic diagram of a vapor phase growth apparatus of the present invention.

FIG. 2 is a schematic view of a vapor phase growth apparatus according to another example of the present invention.

FIG. 3 shows a schematic view of a conventional vapor phase growth apparatus.

[Explanation of symbols]

10 gas supply pipe, 13 reaction tube, 14 heating means, 1
Reference Signs List 5 susceptor, 16 substrates, 20 delivery pipe, 30 source gas supply unit, 31 first source gas supply source, 31 v ₁ , 3
_{1v 2, 32v 1, 32v 2} , 32v valve, 32
2nd source gas supply source, 33 carrier gas supply unit, 3
4 Organic metal raw material gas supply source, 41, 42, 43, 4
4, 45, 46 mass flow controller, 50 control means, 53 carrier gas supply pipe, 54 carrier gas extrusion line, 55 carrier gas sub-line, 5
6 carrier gas delivery line, 60 auxiliary control means, 7
0 detecting unit, 101, 102 the gas exchange means, v _1, v
_{2, v 3, v 4,} v 5, v 6 valves, vs switching means

Claims (2)

[Claims] 1. A reaction tube for performing vapor phase growth, a source gas supply unit including a plurality of source gas supply sources, a carrier gas supply unit, a source gas from the source gas supply unit, and a source gas from the carrier gas supply unit. A gas supply pipe for supplying the carrier gas to the reaction tube; a delivery pipe for delivering the source gas from the source gas supply unit and the carrier gas from the carrier gas supply unit to the outside of the reaction tube; Switching means for switching and supplying the source gas from the gas supply unit to the gas supply pipe and the delivery pipe; and switching the source gas from at least one source gas supply source and the carrier gas to the outside of the source gas supply unit. Gas detecting means for detecting a pressure difference between the gas supply pipe and the delivery pipe; and a carrier gas supply means based on a detection signal of the pressure difference from the detecting means. Control means for controlling a supply amount of a carrier gas from a source to the delivery pipe to set a pressure difference between the gas supply pipe and the delivery pipe to a predetermined pressure difference. . 2. A supply amount of a carrier gas to the delivery pipe is controlled by turning on / off one or more source gas supply sources among a plurality of source gas supply sources constituting the source gas supply unit. The vapor phase growth apparatus according to claim 1, further comprising an auxiliary control unit.