JP2008166670A - Metal organic vapor supply apparatus, metal organic vapor phase growth apparatus, metal organic vapor phase growth method, gas flow rate regulator, semiconductor manufacturing apparatus, and semiconductor manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal-organic vaporizing and feeding apparatus which can be simplified, metal-organic chemical vapor deposition apparatus, gas flow rate regulator, semiconductor manufacturing apparatus, and semiconductor manufacturing method. <P>SOLUTION: The metal-organic vaporizing and feeding apparatus includes a retention vessel 1 for retaining a metal-organic material 13, a bubbling gas feeding path 3 which is connected to the retention vessel 1 and feeds bubbling gas to the metal-organic material 13, a metal-organic gas feeding path 5 which is connected to the retention vessel 1 and feeds the organic metal gas produced in the retention vessel 1 and dilution gas to a deposition chamber, a dilution gas feeding path 7 which is connected to the metal-organic gas feeding path 5 and feeds the dilution gas to the metal-organic gas feeding path 5, a flow rate regulator 9 which is provided in the bubbling gas feeding path 3 and regulates the flow rate of the bubbling gas, a pressure regulator 11 which regulates the pressure of the dilution gas, and a sonic nozzle S which is disposed in the metal-organic gas feeding path 5 on a downstream side of a connecting position between the metal-organic gas feeding path 5 and the dilution gas feeding path 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organometallic vaporization supply apparatus, an organometallic vapor phase growth apparatus, an organometallic vapor phase growth method, a gas flow rate regulator, a semiconductor manufacturing apparatus, and a semiconductor manufacturing method, and more specifically, a nitride compound semiconductor. The present invention relates to an organic metal vaporization supply apparatus, an organic metal vapor phase growth apparatus, a metal organic vapor phase growth method, a gas flow rate regulator, a semiconductor manufacturing apparatus, and a semiconductor manufacturing method.

  The metal organic chemical vapor deposition (MOCVD) method is one of the typical vapor deposition methods, vaporizing an organic metal and thermally decomposing it on the substrate surface to form a film. It is a method to do. Since this method can control the film thickness and composition and is excellent in productivity, it is widely used as a film forming technique when manufacturing a semiconductor device.

  The MOCVD apparatus used for the MOCVD method includes a chamber, a susceptor disposed in the chamber, and an organic metal vaporization supply device for gasifying and flowing an organic metal raw material to the substrate surface. In an MOCVD apparatus, a substrate is placed on a susceptor, the inside of the chamber is controlled to an appropriate pressure, the substrate is heated to an appropriate temperature, and an organometallic gas is introduced onto the substrate surface using an organometallic vaporization supply device. Thus, film formation is performed. Here, in order to make the state of the film to be formed uniform, it is required that the organometallic gas flowing on the surface of the substrate always has a constant flow rate. In the MOCVD apparatus, various organometallic vaporization supply apparatuses have been proposed in order to keep the flow rate of the organometallic gas constant.

  FIG. 12 is a diagram schematically showing a configuration of a conventional organometallic vaporizer. Referring to FIG. 12, a conventional organometallic vaporization supply apparatus includes a storage container 101, a bubbling gas supply path 103, an organometallic gas supply path 105, a dilution gas supply path 107, a thermostat 110, and a valve V101. To V106, mass flow controllers M101 and M102, and a pressure gauge P101.

  A storage container 101 is disposed in the thermostatic chamber 110, the liquid of the organometallic raw material 113 is stored in the storage container 101, and a bubbling gas supply path 103 is connected to the upstream side of the storage container 101. ing. The bubbling gas supply path 103 extends so as to reach the inside of the organometallic raw material 113. The bubbling gas supply path 103 is provided with a valve V102, a mass flow controller M102, and a valve V103 in order from the upstream side.

  An organometallic gas supply path 105 is connected to the downstream side of the storage container 101. The organometallic gas supply path 105 is connected to a position where it does not contact the liquid organometallic raw material 113. The organometallic gas supply path 105 is provided with a valve V104, a pressure gauge P101, and a valve V105 (pressure control valve) in order from the upstream side. The pressure gauge P101 and the valve V105 are electrically connected. The organometallic gas supply path 105 is connected to a film forming chamber (not shown) on the downstream side.

  A dilution gas supply path 107 is connected to the organic metal gas supply path 105. Dilution gas supply path 107 is connected to organometallic gas supply path 105 at a position where pressure gauge P101 is provided. The dilution gas supply path 107 is provided with a valve V101 and a mass flow controller M101 in order from the upstream side. Further, a valve (bypass valve) V106 is provided between the bubbling gas supply path 103 and the organometallic gas supply path 105.

  In the conventional organometallic vaporizer, the organometallic gas is supplied to the film forming chamber as follows. First, bubbling gas is supplied to the bubbling gas supply path 103 by opening the valve V102. The bubbling gas is introduced into the storage container 101 by controlling the mass flow rate by the mass flow controller M102 and closing the valve V106 and opening the valve V103. The liquid temperature of the organometallic raw material 113 is kept constant by the thermostatic chamber 110, and thereby the vapor pressure is also kept constant. When the bubbling gas is introduced into the storage container 101, an amount of the organometallic gas corresponding to the flow rate of the bubbling gas is generated from the organometallic raw material 113 by the bubbling, and the generated organometallic gas and the one by one are opened by opening the valve V104. Part of the bubbling gas is introduced into the organometallic gas supply path 105. On the other hand, the dilution gas is supplied to the dilution gas supply path 107 by opening the valve V101. The mass flow rate of the dilution gas is controlled by the mass flow controller M101, and the dilution gas is introduced into the organometallic gas supply path 105 and mixed with the organometallic gas and the bubbling gas. The total pressure of the mixed gas of the organometallic gas, the dilution gas, and the bubbling gas is measured by the pressure gauge P101, and the valve V105 is adjusted based on the value of the pressure gauge P101. As a result, the organometallic gas is supplied to the film formation chamber at an appropriate flow rate and pressure. Since the total pressure of the mixed gas is controlled by the pressure gauge P101 and the valve V105, the concentration of the organometallic gas in the mixed gas is constant.

In addition, the structure similar to the said conventional organometallic vaporization supply apparatus is disclosed by Unexamined-Japanese-Patent No. 2002-313731 (patent document 1), for example. In Patent Document 1, an organometallic raw material is stored in an organometallic raw material gas supply source, and an introduction for introducing H ₂ gas into the organometallic raw material gas supply source is provided upstream of the organometallic raw material gas supply source. The line is connected. The introduction line is provided with a valve and a mass flow controller. An introduction line for introducing the organometallic source gas into the reactor is connected to the downstream side of the organometallic source gas supply source. The introduction line is provided with a pressure gauge and a valve. The pressure gauge and the valve are electrically connected. Also in the configuration of Patent Document 1, a mass flow controller is used to control the flow rate of each of the dilution gas and the organometallic gas.
JP 2002-313731 A

  The mass flow controller calculates the flow rate of the gas in the flow path from the flow rate passing through the bypass line, and has an electric circuit for performing flow rate control based on the calculation result, a control valve for flow rate adjustment, and the like. Therefore, it has a complicated configuration. The conventional organometallic vaporization supply apparatus requires at least two mass flow controllers, namely, a mass flow controller M102 for controlling the flow rate of the organometallic gas and a mass flow controller M101 for controlling the flow rate of the bubbling gas (dilution gas). is there. For this reason, there is a problem that the conventional apparatus for vaporizing and supplying an organic metal is complicated. Further, since the apparatus is complicated, the manufacturing cost of the organometallic vaporization supply apparatus is increased, and further, the cost of film formation by the MOCVD method is increased.

  Accordingly, an object of the present invention is to provide an organic metal vaporization supply apparatus, an organic metal vapor phase growth apparatus, an organic metal vapor phase growth method, a gas flow rate regulator, a semiconductor manufacturing apparatus, and a semiconductor manufacturing method capable of simplifying the apparatus. Is to provide.

  An organometallic vaporization supply apparatus of the present invention is connected to a container for storing an organometallic raw material, a bubbling gas supply path connected to the container and supplying a bubbling gas to the organometallic raw material, and the container, and An organic metal gas supply path for supplying an organic metal gas generated in the container and a dilution gas for diluting the organic metal gas to the film forming chamber, and an organic metal gas supply path connected to the organic metal gas supply path. A dilution gas supply path for supplying to the gas, a bubbling gas supply path, a flow rate adjusting unit for adjusting the flow rate of the bubbling gas, a pressure adjusting unit for adjusting the pressure of the dilution gas, and an organic metal And a throttling portion disposed in the organometallic gas supply path downstream from the connection position between the gas supply path and the dilution gas supply path. The throttle portion can adjust the flow rate of the gas passing by the upstream gas pressure.

  According to the organometallic vaporization supply apparatus of the present invention, the gas pressure in the organometallic gas supply path is substantially adjusted by the pressure regulator, and the flow rate of the gas supplied to the film forming chamber is controlled by the gas pressure in the organometallic gas supply path. Adjusted. For this reason, the flow rate of the organometallic gas introduced into the film formation chamber can be adjusted by the flow rate adjusting unit and the pressure adjusting unit. As a result, a mass flow controller for controlling the flow rate of the dilution gas is not required, so that the apparatus can be simplified.

  Preferably, in the organometallic vaporization supply apparatus, the flow rate adjusting unit includes a bubbling gas element capable of adjusting a flow rate of the gas passing by an upstream gas pressure and a downstream gas pressure, and an upstream side of the bubbling gas element. And a bubbling gas pressure adjusting unit for adjusting the pressure of the bubbling gas supply passage.

  Accordingly, the flow rate of the bubbling gas can be controlled by adjusting the pressure by the bubbling gas pressure adjusting unit. Therefore, a mass flow controller for controlling the flow rate of the bubbling gas is not necessary, and the apparatus can be further simplified. In addition, since the bubbling gas pressure can be adjusted by the bubbling gas pressure adjusting unit, even if the bubbling gas pressure upstream of the flow rate adjusting unit fluctuates rapidly, the fluctuation affects the downstream side. Can be prevented.

  Preferably, in the organometallic vaporization supply apparatus, the organometallic gas supply path includes a first supply path and a second supply path, and the throttle section includes a first throttle section and a second throttle section provided in the first supply path. And a second throttle portion provided in the supply path. The first supply path and the second supply path are connected downstream of the connection position and downstream of the first throttle part and the second throttle part. A first switching means for switching the type of the bubbling gas between the first bubbling gas and the second bubbling gas; and a flow path for the organometallic gas and the dilution gas between the first supply path and the second supply path. And a second switching means for switching.

  Thereby, according to the kind of bubbling gas, a throttle part can be selected and used from a 1st throttle part and a 2nd throttle part. As a result, it is possible to prevent the flow rate characteristics of the gas introduced into the film formation chamber from changing as the bubbling gas used is changed.

  In the organometallic vaporization supply apparatus, preferably, the first bubbling gas is supplied to the bubbling gas supply path, and the flow path of the organometallic gas is switched to the first supply path, and upstream of the first throttle unit. When the gas pressure on the side is a predetermined value, the flow rate of the gas passing through the first restrictor, the second bubbling gas is supplied to the bubbling gas supply path, and the organometallic gas flow path is switched to the second supply path And when the gas pressure on the upstream side of the second throttle portion is the predetermined value, the flow rate of the gas passing through the second throttle portion is equalized. The part is composed.

  Thereby, even if the bubbling gas to be used is changed from the first bubbling gas to the second bubbling gas, the flow rate of the gas introduced into the film forming chamber can be made equal.

  Preferably, the organometallic vaporization supply apparatus further includes a dilution gas flow rate measurement unit that is provided in the dilution gas supply path and measures the flow rate of the dilution gas.

  Thus, when the type of the bubbling gas is switched, it can be determined from the flow rate of the dilution gas whether or not the inside of the container has been replaced with the switched bubbling gas, so that the pre-bubbling time can be shortened. .

  Preferably, in the organometallic vaporization supply apparatus, the dilution gas flow rate measurement unit includes a dilution gas element capable of adjusting a flow rate of the gas passing by an upstream gas pressure and a downstream gas pressure, and a dilution gas element. Also has a dilution gas pressure gauge for measuring the pressure on the upstream side and a thermometer for measuring the temperature of the dilution gas element.

  Accordingly, the flow rate of the gas passing through the dilution gas element can be calculated from the measurement value of the dilution gas pressure gauge.

  The MOCVD apparatus of the present invention comprises the above-described organometallic vaporization supply apparatus, a gas supply path for supplying another gas used for film formation to the film formation chamber, an organic metal gas and another gas. And a film formation chamber for film formation. Thereby, simplification of the MOCVD apparatus can be achieved. Further, film formation can be performed using a large number of source gases.

  The metal organic chemical vapor deposition method of the present invention includes a flow rate adjusting step for adjusting the flow rate of a bubbling gas to supply the bubbling gas to the organometallic raw material, a pressure adjusting step for adjusting the pressure of the dilution gas, a flow rate adjusting step and a pressure. After the adjusting step, a mixing step of mixing the organometallic gas generated from the organometallic raw material and a dilution gas to obtain a mixed gas, and after the mixing step, the mixed gas is supplied to the film forming chamber through the throttle portion to perform film formation. A film forming step. The throttle portion can adjust the flow rate of the gas passing by the upstream gas pressure.

  According to the organometallic vapor phase growth method of the present invention, the pressure of the mixed gas of the organometallic gas and the dilution gas is substantially adjusted by the pressure adjusting step, and the gas supplied to the film forming chamber is controlled by the pressure of the mixed gas. The flow rate is adjusted. For this reason, the flow rate of the organometallic gas introduced into the film formation chamber can be adjusted by the flow rate adjusting step and the pressure adjusting step. As a result, since it is not necessary to use a mass flow controller to control the flow rate of the dilution gas, the apparatus can be simplified.

  Preferably, in the metal organic vapor phase epitaxy method, the constriction section has a first constriction section and a second constriction section, and the film forming step passes a mixed gas according to the type of dilution gas or bubbling gas. A switching step of switching the aperture portion from the first aperture portion to the second aperture portion is included.

  Thereby, according to the kind of bubbling gas, a throttle part can be selected and used from a 1st throttle part and a 2nd throttle part. As a result, it is possible to prevent the flow rate characteristics of the gas introduced into the film formation chamber from changing as the bubbling gas used is changed.

  Preferably, the organometallic vapor phase growth method further includes a measurement step of measuring the flow rate of the dilution gas. In the measurement process, the film forming process is performed after the flow rate of the dilution gas converges to a constant value.

  Thus, when the type of the bubbling gas is switched, it can be determined from the flow rate of the dilution gas whether or not the inside of the container has been replaced with the switched bubbling gas, so that the pre-bubbling time can be shortened. .

Preferably, in the metal organic chemical vapor deposition method, a compound semiconductor is formed in the film forming step, and more preferably, the compound semiconductor is Al _x Ga _y In _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1). , 0 ≦ x + y ≦ 1).

Since a large number of source gases are used when forming a compound semiconductor, particularly Al _x Ga _y In _1-xy N, the metal organic vapor phase epitaxy method of the present invention is suitable.

  The gas flow controller of the present invention includes an element capable of adjusting a flow rate of a gas passing therethrough by an upstream gas pressure and a downstream gas pressure, and a first pressure for measuring a pressure downstream of the element. A second pressure gauge for measuring the pressure upstream of the element, a thermometer for measuring the temperature of the element, and a pressure adjustment for adjusting the pressure of the gas upstream of the element Department.

  According to the gas flow rate regulator of the present invention, the gas pressure upstream of the element is adjusted based on the measurement value of the first pressure gauge and the measurement value of the second pressure gauge, and thereby the gas passing through the element The flow rate of can be adjusted. As a result, a mass flow controller for controlling the gas flow rate is not necessary, and the apparatus can be simplified.

  A semiconductor manufacturing apparatus according to the present invention includes a substrate processing chamber for processing a substrate, a plurality of conduits connected to the substrate processing chamber and for supplying gas to the substrate processing chamber, and at least of the plurality of conduits The gas flow rate regulator provided in any one of the above is provided. The plurality of pipelines are connected to each other on the upstream side of the gas flow controller.

  According to the semiconductor manufacturing apparatus of the present invention, the gas pressure on the upstream side of the element is adjusted based on the measured value of the first pressure gauge and the measured value of the second pressure gauge, and thereby the gas passing through the element is adjusted. The flow rate can be adjusted. As a result, a mass flow controller for controlling the gas flow rate is not necessary, and the apparatus can be simplified.

  The semiconductor manufacturing method of the present invention is a manufacturing method using the semiconductor manufacturing apparatus, and includes a step of adjusting the pressure upstream of the element by the pressure adjusting unit.

  According to the semiconductor manufacturing method of the present invention, even if the pressure on the upstream side of the element varies, the gas flow rate adjusted by the gas flow rate regulator hardly changes.

  The manufacturing apparatus is preferably an apparatus for forming a semiconductor, more preferably a nitride compound semiconductor, on a substrate by vapor phase growth. Preferably, the vapor phase growth is a hydride vapor phase growth method or a metal organic vapor phase growth method.

  The manufacturing method preferably further includes a step of forming a semiconductor, more preferably a nitride compound semiconductor, on the substrate by vapor phase growth. Preferably, the vapor phase growth is a hydride vapor phase growth method or a metal organic vapor phase growth method.

  According to the organometallic vaporization supply apparatus, organometallic vapor phase growth apparatus, organometallic vapor phase growth method, gas flow rate regulator, semiconductor manufacturing apparatus, and semiconductor manufacturing method of the present invention, the apparatus can be simplified.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a diagram schematically showing a configuration of an organometallic vaporization supply apparatus according to Embodiment 1 of the present invention. With reference to FIG. 1, the organometallic vaporization supply apparatus in this Embodiment is the storage container 1, the bubbling gas supply path 3, the organometallic gas supply path 5, the dilution gas supply path 7, and the gas flow regulator. As a flow rate adjusting unit 9, a thermostat 10, a pressure adjusting unit 11, a sonic nozzle S as a throttle unit, valves V3 and V4, and a thermometer T2.

  A liquid of the organometallic raw material 13 is stored in the storage container 1, and a bubbling gas supply path 3 is connected to the upstream side of the storage container 1. The bubbling gas supply path 3 extends so as to reach the inside of the organometallic raw material 13. The bubbling gas supply path 3 is provided with a flow rate adjusting unit 9 for adjusting the flow rate of the bubbling gas. An organometallic gas supply path 5 is connected to the downstream side of the storage container 1. The organometallic gas supply path 5 is connected to a position where it does not contact the liquid organometallic raw material 13. Dilution gas supply path 7 is connected to organometallic gas supply path 5 at position A. The dilution gas supply path 7 is provided with a pressure adjusting unit 11 for adjusting the pressure of the dilution gas. A sonic nozzle S and a thermometer T2 are provided in order from the upstream side in the organometallic gas supply path 5 on the downstream side of the position A. The organometallic gas supply path 5 is connected to a film forming chamber (not shown) on the downstream side.

  The sonic nozzle S passes through the sonic nozzle S when the ratio PA2 / PA1 between the gas pressure PA1 upstream of the sonic nozzle S and the gas pressure PA2 downstream of the sonic nozzle S falls below a certain value (critical pressure ratio). It has the property that the flow rate of gas is equal to the speed of sound. As a result, the flow rate of the gas passing through the sonic nozzle S does not depend on the downstream gas pressure, and the flow rate of the gas passing through the sonic nozzle S can be adjusted by the upstream gas pressure and the temperature of the sonic nozzle S. Become. Specifically, the flow rate Q of the gas passing through the sonic nozzle S is expressed by the following equation (1).

Q = A × Cd × PA1 × (Mw × Cp / Cv / R / T) ^1/2 (1)
Here, A is a constant, Cd is an outflow coefficient, a coefficient that varies depending on the type of gas, Mw is the molar mass of the gas, Cp is the constant pressure specific heat, Cv is the constant volume specific heat, R is the gas constant, and T is the sonic nozzle S. Temperature. For example, when the critical pressure ratio PA2 / PA1 is 0.52 and the gas pressure PA2 on the deposition chamber side (downstream side) is atmospheric pressure, the pressure PA1 upstream of the sonic nozzle S needs to be 195 kPa or more. is there. An example of the relationship between the gas pressure PA1 upstream of the sonic nozzle S and the flow rate of the gas passing through the sonic nozzle is shown in FIG.

  2 and Table 1, it can be seen that the flow rate of the gas passing through the sonic nozzle S is substantially proportional to the gas pressure PA1 on the upstream side of the sonic nozzle S.

  The pressure adjusting unit 11 includes a valve V1 and a pressure gauge P1 in order from the upstream side. The valve V1 and the pressure gauge P1 are electrically connected to each other.

  Referring to FIG. 1, a flow rate adjustment unit 9 includes a valve V2 as a bubbling adjustment unit, a pressure gauge P2, a laminar flow element F as a bubbling gas element, a pressure gauge P3, and a thermometer in order from the upstream side. T1. The valve V2 and the pressure gauge P2 are electrically connected to each other. The laminar flow element F has, for example, a shape in which a plurality of pipes are bundled or a shape like a porous filter, and the gas pressure PB1 on the upstream side of the laminar flow element F and the downstream of the laminar flow element F. The flow rate of the gas passing through the laminar flow element F can be adjusted by the gas pressure PB2 on the side and the temperature of the laminar flow element F. Specifically, the flow rate Q of the gas passing through the laminar flow element in FIG. 1 is represented by the following formula (2) using Qm represented by the formula (3).

Q = ((B ² + 4A × Qm) ^1/2 −B) / 2A (2)
Qm = (PB1-PB2) × (PB1 + PB2 + α) × C / T (3)
Here, A, B, and C are constants, and T is the temperature of the laminar flow element F. An example of the relationship between the differential pressure between the upstream gas pressure PB1 and the downstream gas pressure PB2 of the laminar flow element F and the flow rate of the gas passing through the laminar flow element F is shown in FIG.

  Referring to FIG. 3, the flow rate of the gas passing through laminar flow element F is the same as that of gas pressure PB1 on the upstream side of laminar flow element F and the downstream side when pressure PB2 on the downstream side is 161 kPa, 201 kPa, and 241 kPa. It can be seen that the difference can be calculated with the pressure PB2 on the side.

  Referring to FIG. 1, in the organometallic vaporization supply apparatus according to the present embodiment, an organometallic gas is supplied to the deposition chamber as described below, and deposition is performed.

  First, bubbling gas is supplied to the bubbling gas supply path 3 by opening the valve V2. The flow rate of the bubbling gas is adjusted by the flow rate adjusting unit 9 and introduced into the storage container 1 through the valve V3 (flow rate adjusting step). In other words, the gas pressure (gas pressure upstream of the laminar flow element F) PB1 in the bubbling gas supply path 3 between the valve V2 and the laminar flow element F is adjusted by the valve V2 according to the value of the pressure gauge P2. . Further, the gas pressure PB2 on the downstream side of the laminar flow element F is substantially adjusted by the operation of a valve V1, which will be described later, according to the value of the pressure gauge P3. Further, the temperature of the laminar flow element F is measured by the thermometer T1. Then, the flow rate of the bubbling gas introduced into the storage container 1 is controlled by appropriately controlling the pressure PB1 and the pressure PB2 according to the temperature of the laminar flow element F. When the bubbling gas is introduced into the storage container 1 and supplied to the organometallic raw material 13, an amount of the organometallic gas corresponding to the amount of the supplied bubbling gas is generated by bubbling. Then, the generated organometallic gas and a part of the bubbling gas are introduced into the organometallic gas supply path 5 through the valve V4. On the other hand, the dilution gas is supplied to the dilution gas supply path 7 by opening the valve V1. The pressure of the dilution gas is adjusted by the pressure adjustment unit 11 (pressure adjustment step), and the dilution gas is supplied to the organometallic gas supply path 5 through the dilution gas supply path 7. In the pressure adjusting unit 11, the pressure of the dilution gas is adjusted by the valve V1 according to the value of the pressure gauge P1. The dilution gas supplied to the organometallic gas supply path 5 is mixed with the organometallic gas and the bubbling gas to form a mixed gas (mixing step). The mixed gas is supplied at an appropriate flow rate through the sonic nozzle S and is supplied to the film forming chamber to form a film (film forming process).

  Here, since the dilution gas supply path 7 is connected to the organometallic gas supply path 5, the pressure measured by the pressure gauge P1 is equal to the pressure PA1 of the organometallic gas supply path 5 on the upstream side of the sonic nozzle S. Become. The pressure PA1 is a pressure obtained by combining the organometallic gas, the bubbling gas, and the dilution gas, and the pressure PA1 can be substantially controlled by the valve V1. In the sonic nozzle S, the pressure of the gas (organic gas) flowing downstream of the sonic nozzle S is adjusted by adjusting the pressure measured by the pressure gauge P1 to an appropriate value based on the value of the thermometer T2. The flow rate is controlled. When the valve V3 and the valve V4 are open, the pressure measured by the pressure gauge P1, the pressure PA1 upstream of the sonic nozzle S, and the pressure PA2 measured by the pressure gauge P3 are substantially equal. For this reason, the gas pressure PB2 downstream of the laminar flow element F can be substantially adjusted by operating the valve V1. Strictly speaking, PA2 (= PB2) is increased by a pressure corresponding to the amount of the liquid organometallic raw material 13.

  In addition, the storage container 1 is arrange | positioned in the thermostat 10, The liquid temperature of the organometallic raw material 13 is kept constant by the thermostat 10, and, thereby, the vapor pressure is also kept constant. Thereby, the pressure of the organometallic gas in the total pressure (pressure PA1) is controlled to be constant, and an amount of organometallic gas corresponding to the partial pressure of the organometallic gas in the flow rate of the bubbling gas is supplied to the organometallic gas supply path 5. Controlled to be supplied.

  The organometallic vaporization supply apparatus in the present embodiment includes a storage container 1 for storing the organometallic raw material 13, and a bubbling gas supply path that is connected to the storage container 1 and supplies a bubbling gas to the organic metal raw material 13. 3, connected to the storage container 1 and connected to the organometallic gas supply path 5 for supplying the organic metal gas and dilution gas generated in the storage container 1 to the film forming chamber, and the organometallic gas supply path 5, Further, a dilution gas supply path 7 for supplying the dilution gas to the organometallic gas supply path 5, a flow rate adjusting unit 9 for adjusting the flow rate of the bubbling gas provided in the bubbling gas supply path 3, and the pressure of the dilution gas And a sonic nozzle S arranged in the organometallic gas supply path 5 on the downstream side of the position A. The sonic nozzle S can adjust the flow rate of the gas passing by the upstream gas pressure.

  According to the organometallic vaporization supply apparatus in the present embodiment, the gas pressure in the organometallic gas supply path 5 is substantially adjusted by the valve V1 of the pressure adjusting unit 11, and the film is formed by the gas pressure in the organometallic gas supply path 5. The flow rate of the gas supplied to the chamber is adjusted. For this reason, the flow rate of the organometallic gas introduced into the film forming chamber can be adjusted by the flow rate adjusting unit 9 and the pressure adjusting unit 11. As a result, a mass flow controller for controlling the flow rate of the dilution gas is not required, so that the apparatus can be simplified. Furthermore, with the simplification of the apparatus, the manufacturing cost of the organometallic vaporization supply apparatus can be reduced, and further, the cost of film formation by the MOCVD method can be reduced.

  Further, by adopting the sonic nozzle S as the throttle portion, the downstream pressure can be used even at atmospheric pressure, and film formation can be performed in a state where the film forming chamber is at atmospheric pressure. Thereby, a particularly good crystal of the nitride semiconductor can be obtained.

  The flow rate adjusting unit 9 is arranged on the upstream side of the laminar flow element F, the laminar flow element F capable of adjusting the flow rate of the gas passing by the upstream gas pressure and the downstream gas pressure, and is supplied with a bubbling gas. And a valve V2 for adjusting the pressure in the passage 3.

  Thereby, the flow rate of the bubbling gas can be controlled by adjusting the pressure by the valve V2. Therefore, a mass flow controller for controlling the flow rate of the bubbling gas is not necessary, and the apparatus can be further simplified. In addition, since the pressure of the bubbling gas can be adjusted by the valve V2, even if the pressure of the bubbling gas (primary side pressure) on the upstream side of the flow rate adjusting unit 9 fluctuates rapidly, the fluctuation is reduced to the downstream side. It is possible to prevent the influence. That is, the supply source for supplying the bubbling gas to the bubbling gas supply path 3 is for supplying bubbling gas (hereinafter referred to as other gas) used for bubbling other organic metal gas, or for transporting raw materials. It may also be used as a carrier gas or various purge gases. When the supply source is used to supply other gas, if the supply of other gas is started while supplying the bubbling gas to the organometallic vaporization supply device of the present embodiment, the original pressure of the other gas decreases rapidly. There are things to do. The sudden decrease in pressure of other gases leads to fluctuations in the amount of generated organometallic gas. According to the organometallic vaporizing and supplying apparatus of the present embodiment, since a rapid change in the pressure of the bubbling gas can be suppressed by the valve V2, a change in the amount of the organometallic gas can be suppressed. As a result, stability during film formation and film uniformity are improved.

  The metal organic chemical vapor deposition method in the present embodiment includes a flow rate adjusting step of adjusting the flow rate of the bubbling gas to supply the bubbling gas to the organometallic raw material 13, a pressure adjusting step of adjusting the pressure of the dilution gas, and a flow rate adjustment. After the step and the pressure adjusting step, a mixed step of mixing the organometallic gas generated from the organic metal raw material 13 and the dilution gas to obtain a mixed gas, and after the mixing step, the mixed gas is supplied to the film forming chamber through the sonic nozzle S. A film forming process for forming a film. The sonic nozzle S can adjust the flow rate of the gas passing by the upstream gas pressure.

  According to the organometallic vapor phase growth method in the present embodiment, the pressure of the mixed gas of the organometallic gas and the dilution gas is substantially adjusted by the pressure adjusting step, and is supplied to the film forming chamber by the pressure of the mixed gas. The gas flow rate is adjusted. For this reason, the flow rate of the organometallic gas introduced into the film formation chamber can be adjusted by the flow rate adjusting step and the pressure adjusting step. As a result, since it is not necessary to use a mass flow controller to control the flow rate of the dilution gas, the apparatus can be simplified.

  In the present embodiment, the case where the sonic nozzle S is used as the throttle portion has been described. However, the throttle portion of the present invention may be other than the sonic nozzle, and the gas passing by the upstream gas pressure. As long as the flow rate is adjustable.

  In the present embodiment, the case where the laminar flow element F is used as the flow rate adjusting unit has been described. However, the flow rate adjusting unit of the present invention may be other than the laminar flow element, and adjusts the flow rate of the bubbling gas. Anything to do. FIG. 4 is a diagram showing a modification of the organometallic vaporization supply apparatus according to Embodiment 1 of the present invention. In FIG. 4, a mass flow controller M <b> 1 is used as the flow rate adjusting unit 9. In addition, since structures other than the flow volume control part 9 in FIG. 4 are the same as that of the structure of FIG. 1, the description is not repeated.

  In addition, according to the flow rate adjusting unit 9 in the present embodiment, the gas pressure upstream of the laminar flow element F is adjusted based on the measured value of the pressure gauge P2 and the measured value of the pressure gauge P3, thereby forming a layer. The flow rate of the gas passing through the flow element F can be adjusted. As a result, a mass flow controller for controlling the gas flow rate is not necessary, and the apparatus can be simplified.

  Such a gas flow rate controller (flow rate control unit 9) is effective when used in another vapor phase growth apparatus such as a hydride vapor phase growth (HVPE) method, in addition to being used in an organic metal vaporization supply apparatus. is there.

  The HVPE method is one of typical manufacturing methods of nitride-based compound semiconductors other than the MOCVD method, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-12900. In particular, a gallium nitride free-standing substrate is manufactured. Suitable for Similar to the MOCVD method, the HVPE method uses a gas such as ammonia, hydrogen, and nitrogen, and further uses a hydrogen chloride gas. These flow rates are accurately controlled and introduced into the reactor. Conventionally, the flow rate is controlled by an expensive mass flow controller. On the other hand, when the gas flow rate regulator of the present invention is used, the flow rate of these gases can be controlled, so that the apparatus can be simplified.

  Further, the gas flow rate regulator according to the present invention is characterized in that the flow rate fluctuation on the secondary side with respect to the pressure fluctuation on the primary side (supply side) is smaller than that of the conventional mass flow controller.

The inventors of the present application conducted the following experiment in order to confirm the effect of the gas flow rate regulator of the present invention. Specifically, a conventional gas flow controller composed of a mass flow controller of N ₂ gas with a full scale of 1 slm and a mass flow controller of full scale of 50 slm and the gas flow controller of the present invention are prepared, and their performance is compared. did. The primary pressure of N ₂ gas having a gauge pressure of 0.2 MPa was varied using a regulator. The primary pressure of N ₂ gas was varied in the range of 10 to 70 kPa at 1 second intervals. The flow rate of N ₂ gas was set to 500 sccm and 20 slm, respectively. The flow rate change amount at this time was ± 0.4% at the full scale of 1 slm and ± 0.2% at the full scale of 50 slm in the gas flow rate regulator of the present invention. On the other hand, the amount of change in the flow rate of the conventional gas flow controller is on average about 1.5 to 4 times larger than that of the gas flow controller of the present invention.

  This result is due to the fact that, in the gas flow rate regulator of the present invention, the pressure control valve also serves as a regulator, and thus is inherently resistant to pressure fluctuations on the primary side. On the other hand, since the conventional mass flow controller has a flow rate adjusting valve downstream of the flow rate sensor, it is susceptible to fluctuations in the measured flow rate due to pressure fluctuations on the primary side. As described above, according to the gas flow controller of the present invention, it is possible to realize a simple configuration as compared with the prior art, it is inexpensive, and high accuracy can be achieved.

(Embodiment 2)
FIG. 5 schematically shows a configuration of the MOCVD apparatus in the second embodiment of the present invention. Referring to FIG. 5, the MOCVD apparatus in the present embodiment includes an organometallic vaporization supply apparatus 20, a gas supply path 19, and a film formation chamber 17. The organometallic vaporization supply device 20 and the gas supply path 19 are both connected to the film forming chamber 17 and supply different gases to the film forming chamber 17.

The organometallic vaporization supply apparatus 20 in the present embodiment can use H ₂ or N ₂ as the bubbling gas and the dilution gas, and can switch the sonic nozzle according to the type of the bubbling gas and the dilution gas. This is different from the organometallic vaporization supply apparatus of the first embodiment. Hereinafter, the configuration of the organometallic vaporizer 20 will be described.

In the organic metal vaporization supply device 20, a connection path 15 is provided for connecting the bubbling gas supply path 3 upstream of the valve V2 and the dilution gas supply path 7 upstream of the valve V1. Further, a valve V6 is provided in the bubbling gas supply path 3 further upstream than the connection position of the connection path 15, and a valve V5 is provided in the dilution gas supply path 7 further upstream of the connection position of the connection path 15. Is provided. The valve V5, the valve V6, and the connection path 15 are switching means for switching the type of the bubbling gas supplied to the bubbling gas supply path 3 and the dilution gas supplied to the dilution gas supply path 7 between H ₂ and N _2. (First switching means).

  The organometallic gas supply path 5 has a first supply path 5a, a second supply path 5b, a film formation chamber supply path 5c, and an exhaust path 5d. On the downstream side of the position A, the organometallic gas supply path 5 is branched into a first supply path 5a and a second supply path 5b, and the first supply path 5a and the second supply are downstream of the branch position. The path 5b is connected again. On the further downstream side than the connection position between the first supply path 5a and the second supply path 5b, the organometallic gas supply path 5 is branched into a film formation chamber supply path 5c and an exhaust path 5d. The film forming chamber supply path 5c is connected to the film forming chamber 17, and the exhaust path 5d is connected to the exhaust port. The first supply path 5a is provided with a valve V7 and a sonic nozzle S1 as a first throttle part in order from the upstream side, and the second supply path 5b is provided with a sonic speed as a valve V8 and a second throttle part in order from the upstream side. A nozzle S2 is provided. The valves V7 and V8 are switching means (second switching means) for switching the flow path of the organometallic gas and the dilution gas between the first supply path 5a and the second supply path 5b.

  In the organometallic gas supply path 5 downstream of the connection position of the first supply path 5a and the second supply path 5b and upstream of the branch position of the film formation chamber supply path 5c and the exhaust path 5d, A thermometer T2 and a valve V9 are provided. A valve V10 is provided in the film forming chamber supply path 5c, and a valve V11 is provided in the exhaust path 5d. A valve V12 is provided in the bubbling gas supply path 3 downstream of the connection position of the connection path 15 and upstream of the valve V2, and a bubbling gas supply path 3 downstream of the laminar flow element F is provided. A valve V13 is provided so as to connect the organometallic gas supply path 5 upstream from the position A.

  In FIG. 5, the flow rate Q of the gas passing through the laminar flow element is expressed by the above equation (2). In FIG. 5, the flow rate Q of the gas passing through the sonic nozzles S1 and S2 is expressed by the above equation (1).

  In addition, since the structure of the organometallic vaporization supply apparatus 20 other than this is the same as that of the organometallic vaporization supply apparatus in Embodiment 1 shown in FIG. 1, the same code | symbol is attached | subjected to the same member, The The explanation will not be repeated.

  In the organometallic vaporization supply apparatus 20 in the present embodiment, the organometallic gas is supplied to the deposition chamber as described below, and deposition is performed.

First, by switching the valve V5 and the valve V6 with the valve V12 opened, either one of H ₂ and N ₂ is supplied to the bubbling gas supply path 3 as a bubbling gas. That is, when H ₂ gas is used as the bubbling gas, the valve V5 is opened and the valve V6 is closed, and when N ₂ gas is used as the bubbling gas, the valve V5 is closed and the valve V6 is opened. The flow rate of the bubbling gas is adjusted by the flow rate adjusting unit 9 and is introduced into the storage container 1 through the valve V3. At this time, the valve V13 is closed. Then, the organometallic gas generated from the organometallic raw material 13 and a part of the bubbling gas are introduced into the organometallic gas supply path 5 through the valve V4.

  Here, until the flow rate of the bubbling gas is stabilized, the valve V10 may be closed and the valve V11 may be opened to cause the bubbling gas to flow into the exhaust path 5d. In this case, when the flow rate of the bubbling gas is stabilized, the valve V11 is closed, the valve V10 is opened, and the mixed gas is supplied to the film forming chamber 17 through the film forming chamber supply path 5c.

  On the other hand, the same kind of dilution gas as the bubbling gas is supplied to the dilution gas supply path 7 by opening the valve V1. The pressure of the dilution gas is adjusted by the pressure adjusting unit 11 and is supplied to the organometallic gas supply path 5 through the dilution gas supply path 7. The dilution gas supplied to the organometallic gas supply path 5 is mixed with the organometallic gas and the bubbling gas to form a mixed gas.

The sonic nozzle through which the mixed gas passes is switched according to the type of dilution gas and bubbling gas (switching step). For example, when H ₂ gas is used as the dilution gas and the bubbling gas, the valve V7 is opened and the valve V8 is closed. Thereby, the mixed gas passes through the first supply path 5a and the sonic nozzle S1. When N ₂ gas is used as the dilution gas and bubbling gas, the valve V7 is closed and the valve V8 is opened. Thereby, the mixed gas passes through the second supply path 5b and the sonic nozzle S2. The mixed gas that has passed through the sonic nozzle S1 or S2 has an appropriate flow rate, and is supplied to the film formation chamber through the organometallic gas supply path 5, the valve V9, the film formation chamber supply path 5c, and the valve V10. Then, for example, a compound semiconductor is formed using the organometallic gas and another gas supplied from the gas supply path 19. In the case where Al _x Ga _y In _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1) is formed as a compound semiconductor, for example, trimethylaluminum (TMA) is used as the organometallic raw material 13. For example, trimethylgallium (TMG) and trimethylindium (TMI) and ammonia (NH ₃ ) as a group V raw material are supplied from the gas supply path 19.

  According to the organometallic vaporization supply apparatus 20 in the present embodiment, the following effects can be obtained in addition to the same effects as those of the organometallic vaporization supply apparatus of the first embodiment.

The organometallic gas supply path 5 has a first supply path 5a and a second supply path 5b, and the sonic nozzle is provided in the sonic nozzle S1 and the second supply path 5b provided in the first supply path 5a. The sonic nozzle S2 is provided, and the first supply path 5a and the second supply path 5b are connected downstream of the position A and downstream of the sonic nozzles S1 and S2. The organometallic vaporization supply device 20 includes a valve V5, a valve V6, a connection path 15, and a first supply path 5a for switching the type of bubbling gas supplied to the bubbling gas supply path 3 between H ₂ and N _2. Valves V7 and V8 for switching the flow path of the mixed gas with the second supply path 5b are further provided.

  In the metal organic chemical vapor deposition method according to the present embodiment, the sonic nozzle has the sonic nozzle S1 and the sonic nozzle S2, and the film forming process passes the mixed gas according to the type of the dilution gas or the bubbling gas. A switching step of switching the sonic nozzle from the sonic nozzle S1 to S2 is included.

  Thereby, according to the kind of bubbling gas, a sonic nozzle can be selected and used from the sonic nozzle S1 and the sonic nozzle S2. As a result, it is possible to prevent the flow rate characteristics of the gas introduced into the film formation chamber from changing as the bubbling gas used is changed.

Note that the gas pressure on the upstream side of the sonic nozzle S1 is a predetermined value when H ₂ is supplied to the bubbling gas supply path 3 and the flow path of the organometallic gas is switched to the first supply path 5a. In this case, the flow rate of the gas passing through the sonic nozzle S1, the case where N ₂ is supplied to the bubbling gas supply path 3, and the flow path of the organometallic gas is switched to the second supply path 5b, and the sonic nozzle S2 The sonic nozzles S1 and S2 may be configured so that the flow rate of the gas passing through the sonic nozzle S2 when the upstream gas pressure is the predetermined value is equal. When the gas type is different, the conductance for the sonic nozzle is different. Therefore, when the gas type is changed and the sonic nozzle having the same diameter is used, the flow rate of the passing gas may be greatly different. Therefore, by configuring the sonic nozzle as described above, the flow rate of the gas introduced into the film forming chamber can be made equal even if the bubbling gas used is changed from H ₂ to N ₂ .

(Embodiment 3)
FIG. 6 is a diagram schematically showing the configuration of the MOCVD apparatus in the third embodiment of the present invention. Referring to FIG. 6, organometallic vaporization supply apparatus 20 in the present embodiment is different from the organometallic vaporization supply apparatus of the second embodiment shown in FIG. 5 in that it has a dilution gas flow rate measurement unit 16. ing. Hereinafter, the configuration of the organometallic vaporizer 20 will be described.

  A dilution gas flow rate measurement unit 16 is provided between the valve V1 and the pressure gauge P1 in the dilution gas supply path 7. The dilution gas flow measuring unit 16 includes a pressure gauge P4 as a dilution gas pressure gauge, a laminar flow element F2 as a dilution gas element, and a thermometer T3 in order from the upstream side. The bubbling gas supply path 3 includes a first bubbling gas supply path 3a and a second bubbling gas supply path 3b. The first bubbling gas supply path 3a and the second bubbling gas supply path 3b are branched downstream from the connection position with the connection path 15, and a pressure gauge P3 is provided downstream from the branch position. The first bubbling gas supply path 3a and the second bubbling gas supply path 3b are connected again on the upstream side of the position.

  In the first bubbling gas supply path 3a, a valve V12A, a valve V2A, a pressure gauge P2A, and a laminar flow element F1A are installed in this order from the upstream side. The valve V2A and the pressure gauge P2A are electrically connected to each other. The valve V2A, the pressure gauge P2A, the laminar flow element F1A, the pressure gauge P3, and the thermometer T1 constitute a flow rate adjusting unit 9A for adjusting the flow rate of the gas flowing through the first bubbling gas supply path 3a. That is, the gas pressure upstream of the laminar flow element F1A measured by the pressure gauge P2A, the gas pressure downstream of the laminar flow element F1A measured by the pressure gauge P3, and the laminar flow element measured by the thermometer T3 The flow rate of the gas passing through the first bubbling gas supply path 3a is calculated according to the temperature of F1A, the valve V2A is controlled based on the flow rate of this gas, and the flow rate of the gas passing through the first bubbling gas supply path 3a is Adjusted.

  Similarly, a valve V12B, a valve V2B, a pressure gauge P2B, and a laminar flow element F1B are installed in order from the upstream side in the second bubbling gas supply path 3b. The valve V2B and the pressure gauge P2B are electrically connected to each other. The valve V2B, the pressure gauge P2B, the laminar flow element F1B, the pressure gauge P3, and the thermometer T1 constitute a flow rate adjusting unit 9B for adjusting the flow rate of the gas flowing through the second bubbling gas supply path 3b.

  The laminar flow elements F1A and F1B have different gas flow rates when the upstream and downstream differential pressures are the same. For example, when the pressure difference between the upstream gas pressure and the downstream gas pressure is a certain value, the laminar flow element F1A is designed to pass 300 sccm of gas, and the laminar flow element F1B is 20 sccm. Designed to let gas through.

  In addition, since the structure of the organic metal vaporization supply apparatus 20 other than this is the same as the structure of the organic metal vaporization supply apparatus in Embodiment 2 shown in FIG. 5, the same code | symbol is attached | subjected to the same member, The The explanation will not be repeated.

  According to the organometallic vaporization supply apparatus 20 in the present embodiment, the flow rate of the bubbling gas can be changed. That is, when flowing a large amount of bubbling gas into the bubbling gas supply path 3, the valve V12A is opened and the valve V12B is closed while the valve V5 or V6 is opened, and the bubbling gas is bubbled into the first bubbling gas supply path 3a. Gas is flowed. When a small amount of bubbling gas is allowed to flow into the bubbling gas supply path 3, the valve V12B is opened and the valve V12A is closed with the valve V5 or V6 being opened, and the bubbling gas is supplied to the second bubbling gas supply path 3b. Will be washed away.

In addition, the types of bubbling gas and dilution gas can be changed. That is, when switching the dilution gas and the bubbling gas from N ₂ gas to H ₂ gas, the valve V6 is closed and the valve V5 is opened as in the second embodiment. At this time, the valve V8 is closed and the valve V7 is opened, and the sonic nozzle used is switched from the sonic nozzle S2 to the sonic nozzle S1.

Here, immediately after the dilution gas and the bubbling gas are switched, N ₂ gas remains in the storage container 1, so that the gas passing through the sonic nozzle S 1 includes not only H ₂ gas but also N ₂ gas. Yes. Since the conductance of N ₂ gas is smaller than the conductance of H ₂ gas, the flow rate of gas passing through the sonic nozzle S1 is smaller in the case of H ₂ gas containing N ₂ gas than in the case of pure H ₂ gas. The film formation becomes unstable. Moreover, since the flow rate fluctuates, it becomes impossible to control at a constant gas flow rate. In addition, depending on the type of film to be formed, there may be a fatal effect on characteristics. For example, in the case of forming a ternary mixed crystal film represented by In _x Ga _1-x N, if hydrogen is contained in the gas, it becomes difficult for In to be taken in, and the In composition extremely decreases. Therefore, the type of gas including bubbling gas is limited to N ₂ gas (including ammonia). That is, when switching from bubbling with H ₂ gas to bubbling with N ₂ gas, sufficient pre-bubbling must be performed and the gas in the storage container must be replaced with N ₂ gas. Therefore, when the dilution gas and the bubbling gas are switched, pre-bubbling is performed in order to discharge the remaining gas.

  When the flow rate of the gas passing through the sonic nozzle S1 decreases, the pressure on the upstream side of the sonic nozzle S1 increases and the measured value of the pressure gauge P1 increases. Since the valve V1 is controlled so that the value of the pressure gauge P1 becomes constant, the valve V1 is closed when the measured value of the pressure gauge P1 rises, and the flow rate of the dilution gas in the dilution gas supply path 7 decreases. On the other hand, when pre-bubbling is performed for a certain time after switching, new dilution gas and bubbling gas are filled into the storage container 1, and the flow rate of the dilution gas increases again and converges to a constant value. According to the organometallic vaporization supply apparatus 20 of the present embodiment, the change in the flow rate of the dilution gas is measured (measurement step), and the film is formed after the flow rate of the dilution gas converges to a constant value. As a result, useless pre-bubbling can be omitted and the pre-bubbling time can be shortened.

  Specifically, the flow rate of the dilution gas is measured by the following method. The gas pressure PB1 upstream of the laminar flow element F2 is measured by the pressure gauge P4, the gas pressure PB2 downstream of the laminar flow element F2 is measured by the pressure gauge P1, and the temperature of the laminar flow element F2 is measured by the thermometer T3. T is measured. Then, the flow rate Q of the gas passing through the laminar flow element F2 is calculated using the above equations (2) and (3).

  In the present embodiment, the case where the dilution gas flow rate measuring unit 16 is configured by the pressure gauge P4, the laminar flow element F2, and the thermometer T3 has been described. The gas flow rate measurement unit may be configured by a mass flow meter.

In the second and third embodiments, the case where H ₂ or N ₂ is used as the bubbling gas and the dilution gas has been described. However, a gas other than H ₂ and N ₂ may be used, for example, Ar or He gas. Can also be used. In the present embodiment, the case where the same kind of gas is used as the bubbling gas and the dilution gas has been described. However, different gases may be used as the bubbling gas and the dilution gas.

(Embodiment 4)
FIG. 7A is a diagram schematically showing a configuration of a semiconductor manufacturing apparatus according to the fourth embodiment of the present invention. Referring to FIG. 7A, the semiconductor manufacturing apparatus in the present embodiment includes a substrate processing chamber 31, gas supply paths 33a to 33e as a plurality of pipes, and a flow rate adjusting unit 9 (gas flow rate controller). And. Each of the gas supply paths 33a to 33e is connected to the substrate processing chamber 31, and each of the gas supply paths 33a to 33e is provided with each of the flow rate adjusting units 9. Further, the gas supply paths 33a to 33e are connected to each other at a position B upstream of the flow rate adjusting unit 9, and a pressure reducing valve V31 is provided in the gas supply path 33 upstream of the position B as necessary. Yes.

  FIG.7 (b) is a figure which shows schematically the structure of the flow volume adjustment part in Embodiment 4 of this invention. Referring to FIGS. 7A and 7B, the flow rate adjusting unit 9 is for adjusting the flow rate of the gas passing through each of the gas supply paths 33a to 33e. The flow rate adjusting unit 9 shown in FIG. It has the same composition as. That is, the flow rate adjusting unit 9 includes a valve V2 (pressure adjusting unit), a pressure gauge P2 (second pressure gauge), a laminar flow element F, and a pressure gauge P3 (first pressure gauge) in order from the upstream side. And a thermometer T1. The valve V2 and the pressure gauge P2 are electrically connected to each other. The pressure gauge P2 is for measuring the pressure upstream of the laminar flow element F, the pressure gauge P3 is for measuring the pressure downstream of the laminar flow element F, and the thermometer T1 is This is for measuring the temperature of the laminar flow element F. The laminar flow element F has a gas flow rate passing through the laminar flow element F based on the gas pressure PB1 upstream of the laminar flow element F, the gas pressure PB2 downstream of the laminar flow element F, and the temperature of the laminar flow element F. Is adjustable.

  In the semiconductor manufacturing apparatus of the present embodiment, a semiconductor device is manufactured by the following method. First, a substrate to be processed is placed in the substrate processing chamber 31. Next, the pressure of the gas introduced into the gas supply path 33 is appropriately adjusted using the pressure reducing valve V31. Subsequently, in each of the gas supply paths 33a to 33e, the gas pressure PB1 upstream of the laminar flow element F is adjusted by the valve V2 according to the value of the pressure gauge P2. As a result, the gas passing through the laminar flow element F has a desired flow rate and is supplied to the substrate processing chamber 31 through each of the gas supply paths 33a to 33e. In the substrate processing chamber 31, a semiconductor such as a nitride-based semiconductor is formed on the substrate using a vapor phase growth method such as HVPE method or MOCVD method. Thereafter, the exhaust gas is discharged from the substrate processing chamber 31 through the exhaust gas pipe 37 to the outside.

  The flow rate adjusting unit 9 in the present embodiment includes a laminar flow element F that can adjust the flow rate of the gas passing by the upstream gas pressure PB1 and the downstream gas pressure PB2, and a pressure gauge for measuring the pressure PB2. P3, a pressure gauge P2 for measuring the pressure PB1, a thermometer T1 for measuring the temperature of the laminar flow element F, and a valve V2 for adjusting the gas pressure PB1.

  Further, the semiconductor manufacturing apparatus in the present embodiment has a substrate processing chamber 31 for processing a substrate, and a plurality of gas supply paths 33a connected to the substrate processing chamber 31 and for supplying gas to the substrate processing chamber 31. To 33e and a flow rate adjusting unit 9 provided in each of the plurality of gas supply paths 33a to 33e. Each of the gas supply paths 33a to 33e is connected to each other at the position B.

  Furthermore, the semiconductor manufacturing method according to the present embodiment is a manufacturing method using the semiconductor manufacturing apparatus of FIG. 7, and includes a step of adjusting the pressure PB1 with the valve V2.

  According to the flow rate adjusting unit 9, the semiconductor manufacturing apparatus, and the semiconductor manufacturing method in the present embodiment, the gas pressure PB1 is adjusted based on the measured value of the pressure gauge P2 and the measured value of the pressure gauge P3, thereby providing a laminar flow element. The flow rate of the gas passing through F can be adjusted. As a result, a mass flow controller for controlling the gas flow rate is not necessary, and the apparatus can be simplified. In addition, the gas flow rate change and pressure change on the upstream side of the flow rate adjusting unit 9 are less affected, and the gas flow rate can be controlled with higher accuracy than the mass flow controller.

  In particular, in the semiconductor manufacturing apparatus shown in FIG. 7, a large number of gas supply paths 33a to 33e are connected in parallel. Each of the gas supply paths 33a to 33e is assigned a gas flow path according to the purpose, such as a raw material supply gas, a purge gas, or a dilution gas. Conventionally, a mass flow controller is provided in each of the gas supply paths 33a to 33e. Some mass flow controllers have various full scales (maximum flow rate with adjustable flow rate) from several sccm to several hundred slm.

  In the semiconductor manufacturing apparatus shown in FIG. 7, when the flow rate of the gas flowing through one gas supply path is changed, the upstream pressure (in the gas supply path 33) also changes. When a mass flow controller having a large full scale is provided in each of the gas supply passages 33a to 33e as the flow rate control unit 9, the flow rate of the gas whose pressure fluctuations upstream of the flow rate control unit 9 flows through the other gas supply channels Greatly affects. As a result, the conventional semiconductor manufacturing apparatus cannot control the gas flow rate with high accuracy.

  Here, in order to reduce the effect of upstream pressure fluctuations on the flow rate of the gas flowing through other gas supply paths, a pressure reducing valve is individually installed on the upstream side of each mass flow controller, or automatic pressure reducing is performed inside the mass flow controller. It is conceivable to provide a valve. However, these methods require a new configuration such as a pressure reducing valve and an automatic pressure reducing valve, resulting in an increase in cost.

On the other hand, in the present embodiment, since the laminar flow element F is used as the flow rate adjusting unit 9, the influence of the upstream pressure fluctuation on the gas flow rate can be reduced, and the increase in cost can be suppressed. Can do. In addition, a wide range of flow rates can be controlled. Particularly in a semiconductor manufacturing apparatus, the same gas (for example, H ₂ gas, N ₂ gas, NH ₃ gas, or hydrogen chloride (HCl) gas) is supplied to a substrate processing chamber through a gas supply line connected in parallel. In this respect, the present invention is useful.

  In the present embodiment, the case where the flow rate adjusting unit of FIG. 7B is used as the flow rate adjusting unit 9 provided in each of the gas supply paths 33a to 33e has been described, but in the semiconductor manufacturing apparatus of the present invention. The flow rate adjusting unit shown in FIG. 7B may be provided as the flow rate adjusting unit 9 in at least one of the gas supply channels 33a to 33e. In this case, a mass flow controller may be used as some of the flow rate adjusting units 9.

  FIG. 7A shows only one set of gas supply paths 33a to 33e for supplying one type of gas, but a plurality of sets of gas supply paths are provided according to the type of gas to be used. May be. That is, as shown in FIG. 8, in addition to the set of gas supply paths 33 a to 33 e branched from the gas supply path 33, the set of gas supply paths 34 a to 34 e branched from the gas supply path 34 and branched from the gas supply path 35. The gas supply paths 35 a to 35 e may be provided, a gas flow rate controller may be provided in each gas supply path, and each gas supply path may be connected to the substrate processing chamber 31. Thereby, it is possible to realize a semiconductor manufacturing apparatus capable of controlling the flow rates of various kinds of gases with high accuracy and at low cost.

Trimethylgallium (TMGa) was bubbled using the organometallic vaporization supply apparatus shown in FIG. 6, and the flow rate of the dilution gas during the bubbling was measured. Specifically, first, the valves V5 and V12B were closed, the valves V6 and V12A were opened, and N ₂ gas having a flow rate of 50 sccm was introduced into the storage container 1. At this time, the valve V7 was closed, the valve V8 was opened, and the flow rate of the organometallic gas was adjusted using the sonic nozzle S2. Then, after a lapse of a certain time, the valves V6 and V12A were closed, the valves V5 and V12B were opened, and H ₂ gas having a flow rate of 20 sccm was introduced into the storage container 1 for a certain time. At this time, the valve V8 was closed, the valve V7 was opened, and the flow rate of the organometallic gas was adjusted using the sonic nozzle S1. Further, after a certain period of time, the valve V5 was closed and the valve V6 was opened, and N ₂ gas having a flow rate of 20 sccm was introduced into the storage container 1. At this time, the valve V7 was closed, the valve V8 was opened, and the flow rate of the organometallic gas was adjusted using the sonic nozzle S2. During bubbling, the temperature of the storage container was kept at 20 ° C., and the pressure of the bubbler was kept at 250 kPa by controlling the valve V1. The flow rate of the dilution gas was measured by the dilution gas flow rate measurement unit 16.

FIG. 9A is a diagram showing a change in the flow rate of the bubbling gas flowing through the flow rate control units 9A and 9B in the first embodiment of the present invention, and FIG. 9B shows the dilution gas supply path 7 in the first embodiment of the present invention. It is a figure which shows the flow volume change of the dilution gas which passes. Referring to FIG. 9 (a) and 9 (b), immediately after switching the bubbling gas and dilution gas from 1600 seconds around at 50sccm of the flow rate of N ₂ gas to the flow rate of H ₂ gas of 20 sccm, a diluent gas H ₂ The gas flow rate once decreases to about 800 sccm, then increases again and converges to about 900 sccm. Meanwhile, immediately after switching the bubbling gas and dilution gas from 20sccm of the flow rate of H ₂ gas in the vicinity of 4200 seconds N ₂ gas at a flow rate of 20sccm, the flow rate of N ₂ gas is dilution gas, about with little decrease 960sccm Remains. From these results, it can be seen that it is possible to determine whether or not the replacement of the bubbling gas inside the storage container 1 is completed by providing the dilution gas flow rate measurement unit 16. It has also been found that pre-bubbling takes a longer time when switching from N ₂ gas to H ₂ gas than when switching from H ₂ gas to N ₂ gas.

  In this example, the response of the actual flow rate to the set value of the flow rate controller was examined. FIG. 10 is a diagram schematically showing the configuration of the experimental apparatus in Example 2 of the present invention. Referring to FIG. 10, the experimental apparatus of the present embodiment includes a pressure reducing valve V41 and a valve V42, a flow rate adjusting unit 41, a pressure gauge P41, and a laminar flow element F41. The gas supply pipe 43 is provided with a pressure reducing valve V41, a flow rate adjusting unit 41, a pressure gauge P41, and a laminar flow element F41 in order from the upstream side. Further, the gas supply pipe 43 a is branched from the gas supply pipe 43 between the pressure reducing valve V 41 and the flow rate adjusting unit 41. A valve V42 is provided in the gas supply pipe 43a. The gas supply pipe 43 communicates with the atmosphere on the downstream side, and the gas supply pipe 43a communicates with the exhaust port on the downstream side.

  In this experimental apparatus, the flow rate adjusting unit 9 shown in FIG. A solenoid valve was used as the valve V2 of the flow rate adjusting unit 9 in the present invention. The solenoid valve is a valve that controls a valve by a magnetic field generated by passing a current through a coil.

  In addition, a mass flow controller having a piezo valve arranged as the flow rate adjustment unit 41 was used as Comparative Example 1. A piezo valve compresses and expands a piezo element according to the presence or absence of an electric current, thereby controlling the valve.

  Further, Comparative Example 2 is a mass flow controller having a thermal valve arranged as the flow rate adjustment unit 41. The thermal type valve is one in which a current is passed through a resistor to generate heat in the resistor and the valve is controlled by this heat.

Using this experimental apparatus, an experiment was conducted by the following method. The flow rate setting value of the flow rate adjustment unit 41 was rapidly increased from 0 (a state in which no flow occurred) to 10%, 50%, and 100% of the full scale (100 sccm) of the flow rate adjustment unit 41. And the gas flow rate which flows through the laminar flow element F41 from the value of the pressure gauge P41 and atmospheric pressure was calculated, and the downstream gas flow rate was measured. Then, the time until the downstream gas flow rate converges within 0.5% of the set value of the flow rate control unit was measured. N ₂ and H ₂ were used as the gas.

  The response speed of the pressure gauge P41 was 10 msec or less, and the delay of the measurement system due to gas compression, volume, etc. was negligible. Further, the pressure on the upstream side of the flow rate adjusting unit 41 was adjusted to 0.3 MPa by the pressure reducing valve V41. The results of this example are shown in Table 2.

Referring to Table 2, the same results were obtained when either N ₂ or H ₂ gas was used. That is, when the gas flow rate was increased to 10% and increased to 50%, the convergence time of the example of the present invention was shorter than the convergence time of Comparative Examples 1 and 2. In addition, when the gas flow rate was increased to 100%, the convergence time of the example of the present invention was the same as that of Comparative Example 1 and was shorter than the convergence time of Comparative Example 2. From the above results, it was found that the gas flow rate regulator of the present invention exhibits a sufficiently fast response.

In this example, the influence of the upstream pressure change on the downstream gas flow rate was examined. Specifically, the experiment was performed by the following method using the experimental apparatus of FIG. By opening and closing the valve V42, the pressure on the upstream side of the flow rate adjusting unit 41 was rapidly changed with a fluctuation range of 0.05 MPa in the case of N ₂ and 0.03 MPa in the case of H ₂ . And the gas flow rate which flows through the laminar flow element F41 from the value of the pressure gauge P41 and atmospheric pressure was calculated, and the downstream gas flow rate was measured. The set value of the gas flow controller was 50 sccm. And the time until the change of the downstream gas flow rate converges within 0.5% of the full scale and the maximum value of the change amount of the downstream gas flow rate were measured.

  The other experimental conditions were the same as in Example 2. The result of the convergence time of the downstream gas flow rate is shown in Table 3, and the result of the maximum value of the change amount of the downstream gas flow rate is shown in Table 4. In Table 4, a plus sign means that the downstream gas flow rate has increased, and a minus sign means that the downstream gas flow rate has decreased.

  With reference to Table 3 and Table 4, the convergence time of the present invention example was equivalent to the convergence time of Comparative Example 1, and was significantly shorter than the convergence time of Comparative Example 2. Further, the amount of change in the inventive example was significantly smaller than the amount of change in Comparative Examples 1 and 2. This result is presumed to be due to the structure of the mass flow controller. That is, the mass flow controller has a structure in which the pressure is measured in a branch path branched from the gas supply path, and the pressure flowing through the gas supply pipe is controlled based on this pressure. For this reason, when the pressure on the upstream side fluctuates rapidly, the pressure in the branch passage cannot follow the pressure in the gas supply pipe due to the influence of gas accumulation in the gas supply pipe. As a result, the gas density in the gas supply pipe and the gas density in the branch path are different from each other, so that an accurate flow rate cannot be measured, and the downstream gas flow rate is adversely affected. On the other hand, in the present invention example, since the upstream pressure is controlled by the valve V2, the influence of the upstream pressure fluctuation on the downstream gas flow rate is small.

  From the above results, it was found that according to the gas flow rate regulator and the semiconductor manufacturing apparatus of the present invention, the influence of the upstream pressure change on the downstream gas flow rate is small.

  In this example, the influence of the temperature change on the flow rate adjusting unit was examined. FIG. 11 is a diagram schematically showing the configuration of an experimental apparatus in Example 4 of the present invention. Referring to FIG. 11, the experimental apparatus of the present embodiment includes a pressure reducing valve V41, a mass flow controller M41, a flow rate adjusting unit 41, and a thermostatic chamber 45. The gas supply pipe 43 is provided with a pressure reducing valve V41, a mass flow controller M41, and a flow rate adjusting unit 41 in order from the upstream side. Further, the flow rate adjusting unit 41 is disposed in the constant temperature bath 45. The flow rate adjustment unit 41 outputs the flow rate of the gas flowing through the flow rate adjustment unit 41.

  In this experimental apparatus, the flow rate adjusting unit 9 shown in FIG. In addition, a mass flow controller having a piezo valve arranged as the flow rate adjustment unit 41 was used as Comparative Example 1. Further, Comparative Example 2 is a mass flow controller having a thermal valve arranged as the flow rate adjustment unit 41.

Using this experimental apparatus, an experiment was conducted by the following method. The pressure was adjusted by the pressure reducing valve V41, the gas flow rate was adjusted by the mass flow controller M41, and 50 sccm of N ₂ gas was continuously supplied to the flow rate adjustment unit 41. Without adjusting the gas flow rate by the flow rate adjusting unit 41, the valve of the flow rate adjusting unit 41 was fully opened. In this state, by changing the temperature of the thermostatic chamber 45, the temperature of the flow rate adjusting unit 41 was rapidly changed in the range of 10 ° C to 40 ° C. And the flow volume of the gas which flows through the flow volume adjustment part 41 was measured, and the maximum value of the variation | change_quantity of gas flow volume was measured.

  The other experimental conditions were the same as in Example 2. The results of this example are shown in Table 5. The maximum value of the change amount of the gas flow rate in Table 5 is shown as a ratio (percentage) to the full scale of the flow rate adjustment unit 41.

  Referring to Table 5, in spite of the fact that a constant flow rate of gas is flowing, a change occurs in the measurement values of all flow rate regulators. However, regardless of how the temperature of the flow rate adjusting unit 41 was changed, the amount of change in the measured value of the example of the present invention was significantly smaller than the amount of change in the measured value of Comparative Examples 1 and 2. This result is presumed to be due to the structure of the mass flow controller. That is, since the mass flow controller measures the flow rate with a thermal sensor in the branch path, the measurement value is greatly affected by the temperature fluctuation of the mass flow controller. On the other hand, in the example of the present invention, the measured flow rate value is corrected based on the temperature of the laminar flow element F measured by the thermometer T1, and thus the measured value is hardly affected by the temperature.

  From the above results, it was found that according to the gas flow controller and the semiconductor manufacturing apparatus of the present invention, the influence of the temperature change on the flow controller is small.

  The embodiments and examples disclosed above are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments and examples but by the scope of claims, and is intended to include all modifications and variations within the meaning and scope equivalent to the scope of claims. .

  The present invention is particularly suitable for forming a nitride compound semiconductor.

It is a figure which shows schematically the structure of the organometallic vaporization supply apparatus in Embodiment 1 of this invention. It is a figure which shows an example of the relationship between gas pressure PA1 of the upstream of the sonic nozzle S, and the flow volume of the gas which passes a sonic nozzle. 4 is a diagram illustrating an example of a relationship between a differential pressure between an upstream gas pressure PB1 and a downstream gas pressure PB2 of a laminar flow element F and a flow rate of gas passing through the laminar flow element F. FIG. It is a figure which shows the modification of the organometallic vaporization supply apparatus in Embodiment 1 of this invention. It is a figure which shows schematically the structure of the MOCVD apparatus in Embodiment 2 of this invention. It is a figure which shows schematically the structure of the MOCVD apparatus in Embodiment 3 of this invention. (A) is a figure which shows roughly the structure of the semiconductor manufacturing apparatus in Embodiment 4 of this invention. (B) is a figure which shows roughly the structure of the flow volume adjustment part in Embodiment 4 of this invention. It is a figure which shows schematically the structure of the modification of the semiconductor manufacturing apparatus in Embodiment 4 of this invention. (A) is a figure which shows the flow volume change of the bubbling gas which flows through the flow volume adjustment parts 9A and 9B in Example 1 of this invention, (b) is the dilution which passes through the dilution gas supply path 7 in Example 1 of this invention. It is a figure which shows the flow volume change of gas. It is a figure which shows roughly the structure of the experimental apparatus in Example 2 of this invention. It is a figure which shows roughly the structure of the experimental apparatus in Example 4 of this invention. It is a figure which shows schematically the structure of the conventional organometallic vaporization supply apparatus.

Explanation of symbols

  1, 101 storage container, 3, 3a, 3b, 103 bubbling gas supply path, 5,105 organometallic gas supply path, 5a first supply path, 5b second supply path, 5c film formation chamber supply path, 5d exhaust path, 7, 107 Diluting gas supply path, 9, 9A, 9B, 41 Flow rate adjusting unit, 10, 45, 110 Thermostatic bath, 11 Pressure adjusting unit, 13, 113 Organometallic raw material, 15 connection path, 16 Diluting gas flow rate measuring unit, Reference Signs List 17 Deposition chamber, 19 Gas supply path, 20 Organometallic vaporization supply device, 31 Substrate processing chamber, 33, 33a to 33e Gas supply path, 37 Exhaust gas pipe, 43, 43a Gas supply pipe, A, B position, F, F1A, F1B, F2, F41 Laminar flow element, M1, M41, M101, M102 Mass flow controller, P1-P4, P2A, P2B, P41, P101 Pressure gauge, PA1, P 2, PB1, PB2 gas pressure, S, S1, S2 sonic nozzle, T1 to T3 thermometer, V1~V13, V2A, V2B, V12A, V12B, V42, V101~V106 valve, V31, V41 reducing valve.

Claims (23)

A container for storing organometallic raw materials;
A bubbling gas supply path connected to the vessel and for supplying bubbling gas to the organometallic raw material;
An organometallic gas supply path connected to the container and configured to supply an organometallic gas generated in the container and a dilution gas for diluting the organometallic gas to the film forming chamber;
A dilution gas supply path connected to the organometallic gas supply path and for supplying the dilution gas to the organometallic gas supply path;
A flow rate adjusting unit provided in the bubbling gas supply path and for adjusting the flow rate of the bubbling gas;
A pressure adjusting unit for adjusting the pressure of the dilution gas;
A throttle portion disposed in the organometallic gas supply path downstream from the connection position of the organometallic gas supply path and the dilution gas supply path;
The throttling portion is an organometallic vaporization supply device capable of adjusting a flow rate of a gas passing therethrough by an upstream gas pressure.   The flow rate adjusting unit is disposed on the upstream side of the bubbling gas element, the bubbling gas element capable of adjusting the flow rate of the gas passing by the upstream gas pressure and the downstream gas pressure, and the bubbling The organometallic vaporization supply device according to claim 1, further comprising a bubbling gas pressure adjustment unit for adjusting a pressure of the gas supply path. The organometallic gas supply path has a first supply path and a second supply path, and the throttle section is provided in a first throttle section provided in the first supply path and a second supply path provided in the second supply path. The first supply path and the second supply path are connected downstream of the connection position and downstream of the first throttle part and the second throttle part,
First switching means for switching the type of the bubbling gas between a first bubbling gas and a second bubbling gas;
3. The organometallic vaporization according to claim 1, further comprising a second switching unit configured to switch a flow path of the organometallic gas and the dilution gas between the first supply path and the second supply path. Feeding device.   The first bubbling gas is supplied to the bubbling gas supply path, and the flow path of the organometallic gas is switched to the first supply path, and the gas pressure upstream of the first throttle portion is The flow rate of the gas passing through the first restrictor when the value is a predetermined value, the second bubbling gas is supplied to the bubbling gas supply path, and the organometallic gas flow path is switched to the second supply path. And when the gas pressure upstream of the second restrictor is the predetermined value, the first restrictor and the flow rate of the gas passing through the second restrictor are equal. The organometallic vaporization supply apparatus of Claim 3 with which the said 2nd aperture | diaphragm | squeeze part is comprised.   The metal-organic vaporization supply apparatus according to any one of claims 1 to 4, further comprising a dilution gas flow rate measurement unit that is provided in the dilution gas supply path and measures the flow rate of the dilution gas.   The dilution gas flow rate measuring unit measures the dilution gas element capable of adjusting the flow rate of the gas passing through the upstream gas pressure and the downstream gas pressure, and the pressure upstream of the dilution gas element. The metal-organic vaporization supply apparatus of Claim 5 which has a pressure gauge for dilution gas for this, and a thermometer for measuring the temperature of the said element for dilution gas. The organometallic vaporization supply device according to any one of claims 1 to 6,
A gas supply path for supplying another gas used for film formation to the film formation chamber;
An organometallic vapor phase growth apparatus comprising: the deposition chamber for performing deposition using the organometallic gas and the other gas. Adjusting the flow rate of the bubbling gas and supplying the bubbling gas to the organometallic raw material; and
A pressure adjusting step for adjusting the pressure of the dilution gas;
After the flow rate adjusting step and the pressure adjusting step, a mixing step of obtaining a mixed gas by mixing the organometallic gas generated from the organometallic raw material and the dilution gas;
A film forming process for forming a film by supplying the mixed gas to the film forming chamber through the throttle after the mixing process;
The metal-organic vapor phase epitaxy method, wherein the throttle unit is capable of adjusting a flow rate of a gas passing therethrough according to an upstream gas pressure. The diaphragm has a first diaphragm and a second diaphragm,
The film forming step includes a switching step of switching a throttle portion through which the mixed gas is passed from the first throttle portion to the second throttle portion according to the type of the dilution gas or the bubbling gas. The organometallic vapor phase growth method described.   10. The organometallic vapor phase according to claim 8, further comprising a measurement step of measuring a flow rate of the dilution gas, wherein the film formation step is performed after the flow rate of the dilution gas converges to a constant value in the measurement step. Growth method.   The metal organic chemical vapor deposition method according to claim 8, wherein a compound semiconductor is formed in the film forming step. The organometallic vapor phase growth method according to claim 11, wherein the compound semiconductor is made of Al _x Ga _y In _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). An element capable of adjusting the flow rate of gas passing by the upstream gas pressure and the downstream gas pressure;
A first pressure gauge for measuring the pressure downstream of the element;
A second pressure gauge for measuring the pressure upstream of the element;
A thermometer for measuring the temperature of the element;
A gas flow rate regulator comprising: a pressure regulator for regulating the gas pressure upstream of the element. A substrate processing chamber for processing the substrate;
A plurality of conduits connected to the substrate processing chamber and for supplying gas to the substrate processing chamber;
The gas flow rate regulator according to claim 13 provided in at least one of the plurality of pipelines,
The semiconductor manufacturing apparatus, wherein the plurality of pipe lines are connected to each other upstream of the gas flow controller.   The semiconductor manufacturing apparatus according to claim 14, which is an apparatus for forming a semiconductor on the substrate by vapor deposition.   The semiconductor manufacturing apparatus according to claim 15, which is an apparatus for forming a nitride-based compound semiconductor on the substrate by vapor deposition.   The semiconductor manufacturing apparatus according to claim 15, wherein the vapor phase growth is a hydride vapor phase growth method.   The semiconductor manufacturing apparatus according to claim 15, wherein the vapor phase growth is a metal organic vapor phase growth method. A manufacturing method using the semiconductor manufacturing apparatus according to claim 14,
A semiconductor manufacturing method comprising a step of adjusting the pressure upstream of the element by the pressure adjusting unit.   The semiconductor manufacturing method according to claim 19, further comprising a step of forming a semiconductor on the substrate by vapor deposition.   21. The semiconductor manufacturing method according to claim 20, further comprising a step of forming a nitride-based compound semiconductor on the substrate by vapor deposition.   The semiconductor manufacturing apparatus according to claim 20 or 21, wherein the vapor phase growth is a hydride vapor phase growth method.   The semiconductor manufacturing apparatus according to claim 20 or 21, wherein the vapor phase growth is an organic metal vapor phase growth method.

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