JP2002367911A - Device and method for manufacturing vapor growth semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the fluctuation in the quantity of supplied material gas caused by the pressure variation at the initial stage of supplying in the case where the material gas is supplied from a bubbler to a reactor. SOLUTION: A vapor growth semiconductor manufacturing device 50 is so arranged as to grow a thin film crystal layer in vapor phase, by switching it to be supplied to either a material supply line 56 or a material vent line 58 to supply the material gas from the bubblers 70, 80, and 90 into the reactor 53. The first pressure controller 11 for regulating the pressure within the material supply line 56 and the second pressure controller 120 for regulating the pressure within the material vent line 58 are provided. The pressure is regulated so that the pressure within the material supply line 56 and the pressure within the material vent line 58 may be equal, thereby suppressing fluctuation from occurring in the quantity of supply into the reactor of material gas at switching of material gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for producing a vapor-growth semiconductor, in which a thin film vapor-phase growth layer can be formed on a substrate by switching source gases.

[0002]

2. Description of the Related Art In order to manufacture a thin-film crystal wafer by sequentially growing a semiconductor thin-film crystal layer on a semiconductor substrate in a vapor phase, a raw material for a single-crystal thin film is introduced into a high-temperature furnace as a gas phase, and its chemical reaction or 2. Description of the Related Art A vapor growth semiconductor manufacturing apparatus has been used in which a semiconductor thin film is crystal-grown on a predetermined semiconductor substrate provided beforehand in the high-temperature furnace by thermal decomposition.

[0003] As shown in FIG. 2, this kind of conventional vapor-phase grown semiconductor manufacturing apparatus has an inlet port 3 of a reactor 3 in which a semiconductor substrate 2 placed on a susceptor 1 is accommodated.
A is connected to a raw material supply line 4 for introducing the raw material as a gas phase into the reactor 3.
Is supplied as a carrier gas from a hydrogen supply source (not shown) at a constant pressure to a source material 4 for vapor-phase growth on the semiconductor substrate 2. Bubblers 10, 20, 30 for enabling supply are connected to the raw material supply line 4.

The temperature of the bubbler 10 is controlled by a thermostat 11, and a hydrogen gas whose flow rate is controlled by a mass flow controller 13 is fed into a raw material 12 contained in the bubbler 10 through a pipe 14. The material is foamed, so that the raw material can be turned into a vapor. The bubbler 10 and the raw material supply line 4 are connected by a pipe 17 in which an on-off valve 15 and a flow control valve 16 are provided in series. A mixed gas of the raw material and a hydrogen gas as a carrier gas is flow-regulated into the raw material supply line 4, sent as a raw material gas, and supplied into the reactor 3 via the raw material supply line 4.

The reactor 3 is provided with a coil 5 for high-frequency induction heating of the semiconductor susceptor 1, whereby the raw material gas sent into the reactor 3 is thermally decomposed near the semiconductor substrate 2, 2 can be grown with an epitaxial crystal. The gas after the reaction is discharged from the outlet port 3B of the reactor 3 and sent to the exhaust gas line 6.

When the on-off valve 15 is closed, the source gas from the flow control valve 16 is allowed to escape into the exhaust gas line 6 to which nitrogen gas is supplied at a predetermined pressure. The connection point with the regulating valve 16 and the exhaust gas line 6 are connected by a discharge pipe 19 provided with another on-off valve 18. On-off valve 15,
18 is controlled to open and close by a process control unit (not shown) so that when one is closed, the other is opened, so that the raw material gas from the flow control valve 16 is supplied to the raw material supply line 4 at a predetermined timing for a predetermined time. It can be sent out.

Since the other bubblers 20 and 30 have exactly the same configuration, the portions corresponding to the portions of the bubbler 10 among the portions of the bubblers 20 and 30 are denoted by the corresponding reference numerals of the 20s and 30s. A description thereof will be omitted.

Each raw material gas produced as described above in the bubblers 10, 20, 30 is taken out after being adjusted to a predetermined pressure state by a corresponding flow control valve, and the open / close valve 1 is provided.
5, 18, 25, 28, 35, and 38 are controlled to open and control the corresponding on-off valves 15, 25, and 35 to react at a required timing the amount of source gas required for forming each thin film layer. It can be sent to the container 3.

[0009]

Since the conventional apparatus for manufacturing a vapor phase growth semiconductor is constructed as described above, the open / close state of each on-off valve is changed in order to switch the source gas supplied to the source supply line 4. If the pressure in the raw material supply line is not the same as the pressure in the reactor when the raw gas is supplied from the bubbler to the reactor, the supply amount of the raw gas changes. However, this causes a problem that the supply amount of the raw material gas to the reactor does not reach the expected amount, and the crystal growth rate does not become constant with the lapse of time in a required vapor phase growth period.

In the case where a plurality of raw materials are simultaneously supplied to a raw material supply line to form a thin film crystal layer on a semiconductor substrate by mixed crystal growth, the above-described pressure fluctuation occurs at the start of the supply of the raw material gas. In addition, there arises a problem that a composition shift occurs in the initial stage of the crystal growth start, and a crystal having a predetermined composition cannot be grown. In addition, when impurity doping is performed, a carrier concentration shift occurs at the beginning of the growth, which affects the electrical characteristics of the finished product, resulting in a decrease in quality and a decrease in yield.

In order to solve the above-mentioned problem at the time of starting the supply of the raw material, conventionally, the opening control of the flow control valve for adjusting the flow rate of the raw material gas supplied from the bubbler is performed by using a pressure sensor and a microcomputer. The pressure in the raw material supply line and the pressure in the reactor are kept at the same pressure.

However, in order to perform the above-described pressure adjustment, an expensive valve device for adjusting the flow rate must be provided for each bubbler, and a complicated electronic control device is required for controlling the valve opening. Therefore, there is a problem in that the vapor growth semiconductor manufacturing apparatus becomes complicated and expensive, which increases the semiconductor manufacturing cost.

An object of the present invention is to provide an apparatus and a method for manufacturing a vapor phase grown semiconductor which can solve the above-mentioned problems in the prior art.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a pressure control means for each of a raw material supply line for supplying a raw material gas to a reactor and a raw material vent line for releasing the raw material gas. The pressure in each source line is controlled by adjusting the type and flow rate of the gas supplied from the upstream to make the pressure in the raw material supply line equal to the pressure in the raw material vent line. This suppresses the occurrence of fluctuations in the supply amount of the raw material gas supplied into the reactor.

According to the first aspect of the present invention, a reactor accommodating a semiconductor substrate, a bubbler or a cylinder for supplying a source gas, and an inlet of the reactor for supplying the source gas into the reactor A source supply line connected to a port, wherein the bubbler or cylinder is configured to selectively supply source gas from the bubbler or cylinder to the source supply line and discharge non-supply source gas to a source vent line. To control the pressure in the source supply line in a vapor growth semiconductor manufacturing apparatus in which a required thin film crystal layer is formed by vapor deposition on the semiconductor substrate by switching and supplying the source gas from the semiconductor substrate. A first pressure control device, and a second pressure control device for controlling the pressure in the raw material vent line, wherein the first and second pressure control devices are provided. Therefore, the pressure is controlled so as to eliminate the pressure difference between the pressure of the raw material supply line and the pressure of the raw material vent line, and the supply amount of the raw material gas supplied into the reactor at the time of switching the raw gas changes. There is proposed a vapor phase growth semiconductor manufacturing apparatus characterized by suppressing the above.

According to a second aspect of the present invention, in the first aspect of the present invention, the first pressure control device is provided in the raw material supply line upstream of a raw gas supply point from the bubbler or the cylinder. First pressure monitoring means for monitoring the pressure in the raw material supply line provided, and the pressure in the raw material supply line provided downstream of the supply point in response to the first pressure monitoring means. First to adjust
A vapor phase growth semiconductor manufacturing apparatus including a pressure regulator is proposed.

According to a third aspect of the present invention, in the first aspect of the invention, the second pressure control device includes a differential pressure monitoring means for monitoring a differential pressure between the raw material supply line and the raw material vent line. A second pressure regulator provided downstream of the discharge point to regulate the pressure in the raw material vent line in response to the differential pressure monitoring means. Is done.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the second pressure control device is provided in the raw material vent line upstream of a discharge point of the raw material gas from the bubbler or the cylinder. A second pressure monitoring means provided to monitor the pressure in the raw material vent line; and a pressure provided in the raw material vent line provided downstream of the discharge point in response to the second pressure monitoring means. And a second pressure regulator for performing the above process.

According to the fifth aspect of the present invention, the first, second,
In the invention according to the third or fourth aspect, the same gas as the carrier gas of the bubbler or the cylinder is supplied from the upstream of the raw material supply line, and the nitrogen gas is supplied from the upstream of the raw material vent line. An apparatus is proposed.

According to the sixth aspect of the present invention, the reactor is switched so as to supply the source gas from the bubbler or the cylinder to either the source supply line or the source vent line, and the source gas is stored in the reactor. For selectively controlling the pressure in the raw material supply line in a vapor-growth semiconductor manufacturing apparatus for selectively supplying the thin-film crystal layer on the semiconductor substrate by vapor-phase growth. A pressure control device, and a second pressure control device for controlling the pressure in the raw material vent line, wherein the first and second pressure control devices control the pressure in the raw material supply line and the raw material vent line. Pressure control is performed to suppress the occurrence of fluctuations in the supply amount of the source gas into the reactor when the source gas is switched. Phase growth semiconductor manufacturing apparatus is proposed.

According to the seventh aspect of the present invention, the source gas supplied from the bubbler or the cylinder is switched to be supplied to either the source supply line or the source vent line, and the source gas is accommodated in the reactor. In a vapor-phase growth semiconductor manufacturing method for selectively forming a required thin film crystal layer on the semiconductor substrate by vapor-deposition, the flow rate of nitrogen flowing through a vent line and the setting of a pressure regulator are selected. The pressure in the raw material supply pipe and the pressure in the vent line are adjusted to be equal at the raw material gas supply point by changing the pressure, and the raw material gas is switched by the pressure control in the raw material supply line and the pressure control in the raw material vent line. A method for producing a vapor-phase grown semiconductor, characterized in that a variation in the supply amount of the source gas into the reactor is sometimes suppressed. It is.

According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the apparatus for producing a vapor phase grown semiconductor according to the first, second, third, fourth or sixth aspect is used, and A vapor growth semiconductor manufacturing method has been proposed in which vapor pressure growth is performed by suppressing the pressure fluctuation in the supply line to 2.5 KPa or less.

According to the above configuration, the source gas is obtained from the bubbler or the cylinder by the carrier gas such as hydrogen gas, and the source gas is switched so as to be supplied to either the source supply line or the source vent line. The switching of the source gas can be performed by switching the connection so that the bubbler or the cylinder is connected to either the source supply line or the source vent line.

When the raw material supply line is pressure-controlled by the first pressure control device and the raw material vent line is pressure-controlled by the second pressure control device, the bubbler or cylinder is switched between the raw material supply line and the raw material vent line. Therefore, the supply amount of the source gas per unit time does not fluctuate because the pressure of the source gas supplied from the bubbler or the cylinder to the source supply line deviates from a required value.

As a result, even if the source gas is switched from the bubbler or the cylinder, it is possible to effectively suppress the fluctuation in the supply amount of the source gas supplied from the bubbler or the cylinder into the reactor.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an example of an embodiment of a vapor growth semiconductor manufacturing apparatus according to the present invention. The vapor growth semiconductor manufacturing apparatus 50 is a semiconductor manufacturing apparatus capable of forming a required thin film vapor growth layer on a substrate by switching a source gas, and a susceptor 51 made of a material such as graphite. There is provided a reactor 53 in which the semiconductor substrate 52 placed thereon is accommodated. A coil 55 for high-frequency induction heating is provided on the outer periphery of the main body 54 of the reactor 53, and a high-frequency current flows through the coil 55 to heat the susceptor 51 and bring the semiconductor substrate 52 to a required temperature. It has a known configuration that can be used.

One end of a raw material supply line 56 for introducing a gaseous raw material into the reactor 53 is connected to the inlet port 53A of the reactor 53. A hydrogen gas supply source 57 is connected to the other end of the raw material supply line 56 so that hydrogen as a carrier gas is supplied at a constant pressure to the raw material supply line 56.
It is configured to be sent inside.

A bubbler 70 is used to supply a raw material for vapor phase growth on the semiconductor substrate 52 to the raw material supply line 56 from the middle of the raw material supply line 56 in a gaseous state.
80 and 90 are provided.

In this embodiment, three bubblers are provided so as to be able to supply three types of source gases. However, the number of bubblers can be set to a number corresponding to the number of source gases to be supplied. It is not limited to three. Further, a configuration in which the raw material gas is supplied from an appropriate cylinder instead of the bubbler may be adopted.

The temperature of the bubbler 70 is controlled by a thermostat 71, and hydrogen gas, which is a carrier gas whose flow rate is controlled by a mass flow controller 73, is fed into a raw material 72 contained in the bubbler 70 through a pipe 74. By feeding the raw material 72, the raw material 72 is foamed, so that the raw material 72 can be converted into steam. The bubbler 70 and the raw material supply line 56 are connected by a pipe 76 provided with an on-off valve 75, and are a raw material and a carrier gas which are in a saturated gas phase state by the bubbler 70 by opening the on-off valve 75. A raw material gas, which is a mixed gas with hydrogen gas, is fed into a raw material supply line 56 and supplied into the reactor 3 via the raw material supply line 56.

In the reactor 53, the susceptor 51 has a coil 55
The raw material gas sent into the reactor 53 is thermally decomposed in the vicinity of the semiconductor substrate 52, and an epitaxial crystal can be grown on the semiconductor substrate 52. The gas after the reaction is discharged from the outlet port 53B of the reactor 53.

In order to allow the raw material gas from the bubbler 70 to escape to the raw material vent line 58 when the open / close valve 75 is closed, an open / close valve 77 is provided between the pipe 76 and the raw material vent line 58. It is connected by another pipe 78. A nitrogen gas supply source 59 is connected to the upstream end of the raw material vent line 58, and nitrogen gas is supplied from the nitrogen gas supply source 59 to the raw material vent line 58 at a predetermined constant pressure. At the downstream end of the raw material vent line 58, a vent device 60 is provided, and the raw material gas released from the bubbler 10 into the raw material vent line 58 is sent to the vent device 60 together with the nitrogen gas.

The pair of on-off valves 75 and 77 are controlled by the process control device 61 so that when one is closed, the other is opened, so that the source gas from the bubbler 70 is supplied at a predetermined timing. It is configured such that it can be selectively sent to the raw material supply line 56 for a predetermined time. In order to stabilize the raw material supply amount at the time of valve switching, it is preferable to minimize gas accumulation,
It is preferable to use the on-off valves 75 and 77 and a block valve incorporated in one unit.

Since the other bubblers 80 and 90 have exactly the same structure, parts corresponding to the parts of the bubbler 70 among the parts of the bubblers 80 and 90 are denoted by the corresponding reference numerals of the 80s and 90s. The same description will not be repeated for them.

At a predetermined timing, a required amount of a raw material gas is supplied through a raw material supply line 56 to the reactor 53 via a raw material supply line 56.
Since the opening / closing time control of three sets of on-off valves 75 and 77, 85 and 87, and 95 and 97 provided for each bubbler for feeding into the air is known per se, detailed description on this point is omitted. I do.

Each source gas supplied from the bubblers 70, 80, and 90 is in a gaseous state and a saturated state by bubbling the source material with hydrogen gas. By feeding the raw material gas thus configured to the raw material supply line 56 at a predetermined constant pressure, the desired raw material gas can be supplied at a desired timing simply by controlling the opening time of the on-off valves 75, 85, and 95. A desired amount can be fed into the reactor 53.

As described above, the opening / closing control of the opening / closing valves 75, 85, 95 by the process control device 61 is controlled by the raw material supply line 5.
Since it is assumed that the internal pressure at 6 is maintained at a predetermined value, the pressure in the raw material supply line 56 and the supply pressure of the raw material gas from each bubbler may not be in the same state for some reason. And the amount of the raw material gas fed into the reactor 53 fluctuates, and the composition and thickness of the thin film crystal layer to be vapor-phase grown on the semiconductor substrate 52 deviate from design values.
There is a possibility that a product as specified cannot be manufactured.

When the switching for supplying the source gas from each bubbler into the source supply line 56 is performed, the pressure of the source gas supplied to the source supply line 56 becomes equal to the pressure of the source supply line 56. In order to prevent the above-mentioned problems from occurring,
At 0, a pressure control system 100 is provided. The pressure control system 100 includes a first pressure control device 110 for maintaining the internal pressure of the raw material supply line 56 at a predetermined constant value.
And a second pressure control device 120 for maintaining the pressure in the raw material vent line 58 at the same pressure as the predetermined constant value.

The first pressure control device 110 is a material supply line 56, and the bubbler 7 in the material supply line 56
A first pressure gauge 111 which is a pressure monitoring means provided upstream of each of the raw material supply points S1, S2, and S3 from 0, 80, and 90 and a raw material supply point S1, S2, and S3. A first pressure regulating valve 112 provided on the downstream side, and the first pressure regulating valve 112
Feed line 5 based on pressure detection signal U1 from
6 is controlled by the first control unit 113 so that the pressure in 6 becomes a predetermined pressure value P.

Similarly, the second pressure control device 120 is a raw material vent line 58, and each raw material discharge point V1, from the bubblers 70, 80, 90 in the raw material vent line 58,
A second pressure gauge 121 which is pressure monitoring means provided upstream of any of V2 and V3;
2, and a second pressure regulating valve 122 provided downstream of S3. The second pressure regulating valve 122 includes:
Based on the pressure detection signal U2 from the second pressure gauge 121, the second control unit 123 controls the pressure in the raw material vent line 58 to a predetermined pressure value P.

Since the vapor phase growth semiconductor manufacturing apparatus 50 is configured as described above, the open / close valves 75, 77, 85, 87, 95, and 97 are controlled to open and close under the control of the process control unit 61. , 90 from the source gas supply line 56, disturbances caused by the opening and closing operations of these on-off valves, pressure fluctuations of the source gas generated in the bubblers 70, 80, 90, or the hydrogen gas source 57. Alternatively, even if the pressure in the raw material supply line 56 and the raw material vent line 58 fluctuates due to the fluctuation of the pressure of the gas fed from the nitrogen gas supply source 59, the pressure in the raw material supply line 56 is increased by the first pressure control device 110. Since the pressure in the raw material vent line 58 is also controlled to the predetermined constant value P by the second pressure control device 120 and the second predetermined pressure P, Always substantially equal to the internal pressure of the inner pressure and the raw material vent line 58 of the supply line 56, it can be maintained both in uniform pressure conditions.

Further, when the source gas is switched from the vent line to the source supply line, the pressure fluctuation can be reduced by switching the hydrogen gas having the same weight as the source gas from the source supply line to the vent line. Raw material line 56
In this case, a pressure loss occurs depending on the flow rate of the carrier gas and the pipe diameter. Therefore, there is a difference in internal pressure at each of the raw material supply points S1, S2, and S3. However, by adjusting the gas flow rate flowing into the vent line and the pressure set value of the vent line, the raw material supply point S1 and the raw material discharge point V1, the raw material supply point S2 and the raw material discharge point V2, and the raw material supply point S3 and the raw material discharge point V3 can be adjusted. The internal pressure values can be equalized.

Therefore, for example, when the on-off valve 77 is open and the on-off valve 75 is closed,
The open / close state of 7 and 75 is reversed so that the bubbler 70
When the source gas is switched so that the source gas which has been released from the source gas to the source vent line 58 is supplied to the source supply line 56, the internal pressures of the source supply line 56 and the source vent line 58 are both equal to P. Therefore, the supply of the raw material gas from the bubbler 70 to the raw material supply line 56 is performed at a predetermined constant pressure as scheduled, and the supply amount of the raw material gas fed into the reactor 53 per unit time is changed over time. It does not change with. The same applies to the other bubblers 80 and 90.

As a result, the supply amount of the raw material gas from each bubbler to the reactor 53 becomes the expected amount, and the crystal growth rate can be kept constant with the lapse of time in the required vapor phase growth period. Thus, the quality of each thin film layer formed by vapor phase growth can be improved. Also, when a raw material gas is simultaneously supplied from a plurality of bubblers to the raw material supply line 56 to form a thin-film crystal layer on the semiconductor substrate 52 by mixed crystal growth, the raw material supply line 56 is started when the raw gas supply is started. Since the fluctuation of the internal pressure is satisfactorily suppressed, there is no problem that a composition deviation occurs at the beginning of the growth of the crystal and a crystal having a predetermined composition cannot be grown. In the case where impurity doping is performed, the problem of carrier concentration deviation at the beginning of growth can be solved. Therefore, a thin film can be formed on the semiconductor substrate 52 as specified, and the quality of the electrical characteristics of the finished product can be improved and the yield can be improved.

According to the semiconductor device 50 for vapor phase growth, the pressure control for achieving the above-mentioned effect can be achieved by providing one pressure control device for each of the raw material supply line 56 and the raw material vent line 58. It is not necessary to provide pressure adjusting means and control means for each time. As a result, the number of expensive and complicated pressure adjustment mechanisms and control units for pressure control can be reduced, and an inexpensive and high-performance vapor-growth semiconductor manufacturing apparatus can be realized.

In general, the absolute pressure of the pressure control device may fluctuate, and requires periodic calibration. When a pressure control device is attached to each raw material line, there is a problem that time and man-hours required for calibration are required. However, in the vapor growth semiconductor manufacturing apparatus 50 according to the present invention, the number of components to be calibrated is very small and the above problem is caused. Is effective in solving the problem.

In the embodiment shown in FIG. 1, the second pressure control device 120 operates according to the pressure detection signal U 2 of the second pressure gauge 121 for detecting the internal pressure of the raw material vent line 58. Opening and closing of the second control unit 1
The case where the pressure difference between the raw material supply line 56 and the raw material vent line 58 is controlled under the control of the control unit 23 to eliminate the pressure difference has been described. However, instead of this configuration, a differential pressure gauge 124 for detecting the pressure difference between the raw material supply line 56 and the raw material vent line 58 is provided near the output ends of the hydrogen gas supply source 57 and the nitrogen gas supply source 59. 1, a differential pressure detection signal U3 from the differential pressure gauge 124 is provided.
Is input to the second control unit 123, and the second control unit 123 controls the second pressure regulating valve 12 so that the pressure difference between the raw material supply line 56 and the raw material vent line 58 is eliminated.
2 may be configured to control opening and closing.

[0048]

EXAMPLE In a state where hydrogen and arsine, which are carrier gases, were supplied to a raw material supply line, trimethyl gallium and carbon trichloride bromide were supplied for a certain period of time by switching valves of a raw material supply line and an exhaust gas line, and carbon doping was performed. GaAs
The s layer was grown. 0.7 differential pressure fluctuation when switching valves
When adjusted to Torr, the sheet resistance of the grown layer is 29.
2Ωcm ^-2 , which was as designed.

(Comparative Example) The same crystal growth is caused by a difference in pressure difference.
The sheet resistance of the grown layer when the test was performed at 2.6 kPa was 281 Ωcm ⁻² , which was lower than the design.

[0050]

According to the present invention, as described above, the fluctuation of the supply amount to the reactor at the initial stage of the supply of the source gas can be suppressed only by providing one pressure control device for each of the source supply line and the source vent line. Therefore, it is not necessary to provide pressure adjusting means and control means for each bubbler. As a result, the number of expensive and complicated pressure adjusting mechanisms and control units for pressure control can be reduced, and a low-cost and high-performance vapor-growth semiconductor manufacturing apparatus and method can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an example of a conventional vapor growth semiconductor manufacturing apparatus.

[Explanation of symbols]

 Reference Signs List 50 vapor-growth semiconductor manufacturing apparatus 51 susceptor 52 substrate 53 reactor 53A inlet port 53B outlet port 56 raw material supply line 55 coil 58 raw material vent line 70, 80, 90 bubbler 71 constant temperature bath 72 raw material 73 mass flow controller 74 pipe 75, 77 , 85, 87, 95, 97 On-off valve 76 Flow control valve 17 Pipe 100 Pressure control system 110 First pressure control device 111 First pressure gauge 112 First pressure control valve 113 First control unit 120 Second pressure control device 121 First 2 pressure gauge 122 second pressure regulating valve 123 second control unit 124 differential pressure gauge U1, U2 pressure detection signal U3 differential pressure detection signal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K030 AA18 CA04 CA12 EA01 EA03 HA15 JA05 JA09 5F045 AB10 AC08 AC15 BB08 BB16 EE03 EE04 EE05 EG06

Claims (8)

[Claims] 1. A reactor accommodating a semiconductor substrate, a bubbler or a cylinder for supplying a source gas, and a source supply connected to an inlet port of the reactor for supplying the source gas into the reactor. A supply line for selectively supplying source gas from the bubbler or the cylinder to the source supply line and switching supply of the source gas from the bubbler or the cylinder so as to discharge a non-supply source gas to the source vent line. Performing a vapor deposition on the semiconductor substrate to form a required thin film crystal layer by vapor phase growth, a first pressure control device for controlling a pressure in the raw material supply line; A second pressure control device for controlling the pressure in the raw material vent line, and the raw material supply line is controlled by the first and second pressure control devices. Pressure so as to eliminate the pressure difference between the pressure of the source gas and the pressure of the raw material vent line, so as to suppress a fluctuation in the supply amount of the raw material gas supplied into the reactor when the raw material gas is switched. An apparatus for producing a vapor-phase grown semiconductor, comprising: 2. The pressure control device according to claim 1, wherein the first pressure control device monitors a pressure in the raw material supply line provided in the raw material supply line and provided upstream of a raw gas supply point from the bubbler or the cylinder. And a first pressure regulator provided downstream of the supply point to adjust the pressure in the raw material supply line in response to the first pressure monitoring means. The apparatus of claim 1. 3. The pressure control device according to claim 2, wherein the second pressure control device is provided with a differential pressure monitoring means for monitoring a differential pressure between the raw material supply line and the raw material vent line, and the differential pressure monitoring device is provided downstream of the discharge point. 2. The apparatus according to claim 1, further comprising a second pressure regulator for adjusting a pressure in the raw material vent line in response to monitoring means. 4. The pressure control device according to claim 2, wherein the second pressure control device is provided upstream of a discharge point of the raw material gas from the bubbler or the cylinder in the raw material vent line and monitors a pressure in the raw material vent line. And a second pressure regulator provided downstream of the discharge point for adjusting the pressure in the raw material vent line in response to the second pressure monitoring means. Item 4. A vapor growth semiconductor manufacturing apparatus according to Item 1. 5. The apparatus according to claim 1, wherein the same gas as the carrier gas of the bubbler or the cylinder is supplied from upstream of the raw material supply line, and nitrogen gas is supplied from upstream of the raw material vent line. Or the vapor growth semiconductor manufacturing apparatus according to 4. 6. A source gas from a bubbler or a cylinder is switched to be supplied to either a source supply line or a source vent line, and the source gas is selectively supplied to a reactor accommodating a semiconductor substrate. A vapor pressure growth semiconductor manufacturing apparatus for laminating and forming a required thin film crystal layer on the semiconductor substrate by vapor phase growth, comprising: a first pressure control device for controlling a pressure in the raw material supply line; A second pressure control device for controlling the pressure in the vent line, and the first and second pressure control devices perform pressure control in the raw material supply line and pressure control in the raw material vent line, Vapor growth semiconductor manufacturing apparatus characterized in that fluctuations in the supply amount of the source gas into the reactor at the time of switching of the source gas are suppressed. 7. A source gas from a bubbler or a cylinder is switched so as to be supplied to either a source supply line or a source vent line, and the source gas is selectively supplied to a reactor accommodating a semiconductor substrate. In the method for manufacturing a vapor-growth semiconductor for laminating a required thin film crystal layer on the semiconductor substrate by vapor-phase growth, the flow rate of nitrogen flowing through a vent line and the setting of a pressure regulator are changed to supply raw material. The internal pressure and the pressure in the vent line are adjusted to be equal at the source gas supply point, and the reaction of the source gas during switching of the source gas is performed by controlling the pressure in the source supply line and the pressure control in the source vent line. A method for manufacturing a vapor-phase grown semiconductor, characterized in that fluctuations in the supply amount into the vessel are suppressed. 8. The gas phase growth semiconductor manufacturing apparatus according to claim 1, wherein a pressure fluctuation in the supply line at the time of switching the source gas is reduced to 2.5 KPa.
8. The method of manufacturing a semiconductor according to claim 7, wherein the vapor phase growth is performed while suppressing the temperature to below.