JP2018135235A - Vapor phase growth device and vapor phase growth method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique relating to a vapor phase growth device and a vapor growth method of a GaN-layer.SOLUTION: A vapor phase growth device includes a heating container, to which first raw material gas containing organic metal including gallium and second raw material gas containing hydrogen chloride, and which can discharge third raw material gas containing a compound of gallium and chlorine by heating mixture gas of the first raw material gas and the second raw material gas and reacting it. The device includes a reaction container, to which third raw material gas discharged from the heating container and fourth raw material gas containing ammonia are supplied, and inside which a wafer is arranged.SELECTED DRAWING: Figure 1

Description

  The present specification discloses a technique related to a vapor phase growth apparatus and a vapor phase growth method for a GaN layer.

Patent Document 1 discloses a method for growing a GaN film. In the technique of Patent Document 1, a first source gas containing an organic metal containing Ga and HCl and a second source gas containing NH ₃ are supplied into a reaction tube heated from the outside. Thereby, the GaN layer can be grown on the wafer.

JP 2006-298760

When the reaction between the organic metal containing Ga and HCl is not sufficiently performed, the HCl concentration in the reaction tube becomes high.
This is a problem because the members in the reaction tube are corroded and the vapor phase growth apparatus is damaged.

  The present specification discloses a vapor phase growth apparatus. This vapor phase growth apparatus is a heating container to which a first source gas containing an organic metal containing gallium and a second source gas containing hydrogen chloride are supplied, the first source gas and the second source gas. A heating vessel capable of discharging a third raw material gas containing a compound of gallium and chlorine by reacting the mixed gas with a gas at a predetermined temperature and for a predetermined time. Further, the reaction vessel is supplied with a third source gas discharged from the heating vessel and a fourth source gas containing ammonia, and includes a reaction vessel in which a wafer is disposed. .

  When the third source gas is generated by reacting the first source gas and the second source gas, the hydrogen chloride concentration in the third source gas may increase if the reaction is not sufficiently performed. . If the hydrogen chloride concentration is high, there may be a problem such as damage to the vapor phase growth apparatus. In the technique of this specification, reaction can be accelerated | stimulated by heating 1st source gas and 2nd source gas with a heating container. By sufficiently carrying out the reaction, it is possible to suppress the concentration of hydrogen chloride contained in the third source gas.

  You may further provide the analyzer arrange | positioned on the path | route of the 1st supply line which supplies 3rd source gas to a reaction container from a heating container. The analyzer may be capable of analyzing the concentration of hydrogen chloride contained in the third source gas discharged from the heating container.

  You may further provide the valve | bulb which is arrange | positioned on a 1st supply line and can control whether 3rd source gas is supplied to a reaction container. The valve may supply the third source gas to the reaction vessel when the analyzer analyzes that hydrogen chloride contained in the third source gas has a first predetermined concentration or less.

  The heating container may be configured to be able to control the predetermined temperature according to the analysis result of the analyzer. The heating container may control the predetermined temperature so that the concentration of hydrogen chloride contained in the third source gas analyzed by the analyzer is equal to or lower than the first predetermined concentration.

  A gas supply amount control unit arranged on a second supply line for supplying the second source gas to the heating container and capable of controlling the supply amount of the second source gas may be further provided. The gas supply amount control unit may be configured to be able to control the supply amount of the second source gas in accordance with the analysis result of the analyzer. The gas supply amount control unit may control the supply amount of the second source gas so that the concentration of hydrogen chloride contained in the third source gas analyzed by the analyzer is equal to or lower than the first predetermined concentration.

  The analyzer may be configured to be able to further analyze the concentration of GaCl contained in the third source gas discharged from the heating container. The heating container may be configured to be able to control the predetermined temperature according to the analysis result of the analyzer. The heating container may control the predetermined temperature so that the concentration of GaCl contained in the third source gas analyzed by the analyzer is equal to or higher than the second predetermined concentration.

  The analyzer may be configured to be able to further analyze the concentration of GaCl contained in the third source gas discharged from the heating container. A gas supply amount control unit arranged on a second supply line for supplying the second source gas to the heating container and capable of controlling the supply amount of the second source gas may be further provided. The gas supply amount control unit may be configured to be able to control the supply amount of the second source gas in accordance with the analysis result of the analyzer. The gas supply amount control unit may control the supply amount of the second source gas so that the concentration of GaCl contained in the third source gas analyzed by the analyzer is equal to or higher than the second predetermined concentration.

  The analyzer may analyze the third source gas by mass spectrometry.

  The reaction container may include a stage capable of holding the wafer and heating the back surface of the wafer.

  The predetermined temperature may be 500 ° C. or higher.

  An analysis unit used in the vapor phase growth apparatus described in the present specification, which is disposed on a path of a first supply line for supplying a third source gas from a heating vessel to a reaction vessel, and is included in the third source gas. An analysis device capable of analyzing the concentration of hydrogen chloride, and a valve disposed on the first supply line and capable of controlling whether or not the third source gas is supplied to the reaction vessel. Also good. The valve may supply the third source gas to the reaction vessel when the analyzer analyzes that hydrogen chloride contained in the third source gas has a first predetermined concentration or less.

It is a schematic block diagram of a vapor phase growth apparatus. It is a figure which shows the relationship between heating temperature and HCl density | concentration. It is a figure which shows the relationship between heating temperature and GaCl density | concentration.

<Configuration of vapor phase growth apparatus>
FIG. 1 shows a schematic configuration diagram of a vapor phase growth apparatus 1 according to the technique of this specification. The vapor phase growth apparatus 1 is an example of an apparatus configuration for carrying out a MOHVPE (Metal Organic Hydride Vapor Phase Epitaxy) method. The vapor phase growth apparatus 1 includes a gas generation unit 10, an analysis unit 30, and a reaction vessel 60.

  The structure of the gas generation unit 10 will be described. The gas supply pipe 11 is connected to a gas inlet of an MFC (Mass Flow Controller) 13 through a valve 12. The gas supply pipe 11 is a pipe for supplying the second source gas G2 containing hydrogen chloride. In this embodiment, a case where a single gas of hydrogen chloride (HCl) is supplied as the second source gas G2 will be described. The gas outlet of the MFC 13 is connected to the vent line via the valve 14. Further, the gas outlet of the MFC 13 is connected to the connection portion 17 via the valve 15. The connection part 17 is a part where the gas supply pipe 11 is connected to the gas supply pipe 16.

A first source gas G1 containing an organic metal containing gallium is supplied to the inlet of the gas supply pipe 16. The outlet of the gas supply pipe 16 is connected to the gas inlet 22 of the heater 20. In this embodiment, a case where a mixed gas of TMG (trimethylgallium (Ga (CH ₃ ) ₃ )) and hydrogen (H ₂ ) is supplied as the first source gas G1 will be described. In the connection part 17, the first source gas G1 and the second source gas G2 are mixed to generate a mixed gas GM. The mixed gas GM is supplied to the heater 20.

  The heater 20 includes a heater 21 and an inner tube 24. The inner pipe 24 connects the gas inlet 22 and the gas outlet 23 of the heater 20. A heater 21 is disposed around the inner tube 24. The mixed gas GM moves the distance from the gas inlet 22 to the gas outlet 23 over a predetermined time. Within this predetermined time, the mixed gas GM is heated to a predetermined temperature. Thereby, the third source gas G3 containing a compound of gallium and chlorine is generated by causing a thermal reaction in the mixed gas GM. The third source gas G3 is discharged from the gas discharge port 23 of the heater 20.

  The structure of the analysis unit 30 will be described. The analysis unit 30 includes a mass spectrometer 31 and a valve unit 32. The valve unit 32 includes valves 33 and 34. The valve unit 32 is a device that can control the supply destination of the third source gas G3 to one of the flow channel 65 and the vent line. A gas supply pipe 40 is connected to the gas outlet 23 of the heater 20. The gas supply pipe 40 is connected to the inlet 66 of the flow channel 65 through the valve 33 and is connected to the vent line through the valve 34.

In the branch portion 41, a gas supply pipe 42 branches from the gas supply pipe 40. The discharge port of the gas supply pipe 42 is connected to the mass spectrometer 31. The mass spectrometer 31 is an apparatus that analyzes the composition of the third source gas G3 by mass spectrometry. In the mass spectrometer 31, for example, the concentration of HCl, GaCl, GaCl ₃ , CH ₄ , etc. in the third source gas G3 can be analyzed. An example of the mass spectrometer 31 is a quadrupole gas analyzer. From the mass spectrometer 31, the first signal SS1 to the third signal SS3 are output. The first signal SS1 to the third signal SS3 are signals for performing feedback control according to the analysis result of the mass spectrometer 31. The first signal SS1 is input to the valve unit 32. The second signal SS2 is input to the heater 21 of the heater 20. The third signal SS3 is input to the MFC 13.

The structure of the reaction vessel 60 will be described. The reaction vessel 60 includes a flow channel 65. A gas supply pipe 51 that supplies a fourth source gas G4 and a gas supply pipe 52 that supplies nitrogen (N ₂ ) gas are connected to the flow channel 65. The fourth source gas G4 is a gas containing ammonia (NH ₃ ). The gas supplied to the flow channel 65 is discharged in the direction of the arrow A1. The flow channel 65 includes a wafer 61, a susceptor 62, and a heater 63. A GaN layer is vapor-phase grown on the wafer 61. The susceptor 62 is a part that holds the wafer 61. The heater 63 is a part that heats the wafer 61 from the back surface. By providing the heater 63, it is not necessary to use a hot wall system for heating the entire flow channel 65.

<Vapor phase growth method>
The vapor phase growth apparatus 1 in FIG. 1 performs vapor phase growth of a GaN layer by the MOHVPE method. The MOHVPE method is a vapor phase growth method having the characteristics of HVPE (Hydride Vapor Phase Epitaxy) method and MOVPE (Metal-organic Vapor Phase Epitaxy) method. The HVPE method is a method for growing crystals from gaseous chloride gas at a high temperature. The HVPE method has a high growth rate, but it is difficult to grow a thin film. This is because the amount of metal chloride gas generated cannot be finely adjusted because metal chloride gas is generated from solid metal. The MOVPE method is a method of growing a crystal using an organic metal. In the MOVPE method, since it is not necessary to generate a source gas from a solid metal, a thin film can be grown. However, carbon resulting from the undecomposed organometallic raw material enters the GaN growth layer and deteriorates the characteristics of the GaN growth layer. On the other hand, the MOHVPE method is a method of growing crystals while promoting decomposition of an organic metal raw material using HCl. A thin film can be grown and the concentration of carbon can be reduced.

An example of the gas phase growth conditions is listed. The molar ratio of the supply amounts of HCl and TMG was 1: 1. The length of the inner tube 24 in the heater 20 is 50 cm, the gas flow rate in the inner tube 24 is 0.01 to 1 m / s, and the residence time of the gas in the heater 20 (that is, the heating time) is 0.5 to 50 seconds. The flow rate of the fourth source gas G4 was 1 to 10 SLM, and the N ₂ flow rate in the gas supply pipe 52 was 10 to 20 SL.

The first source gas G1 (TMG and H ₂ ) supplied from the gas supply pipe 16 and the second source gas G2 (HCl) supplied from the gas supply pipe 11 are mixed at the connection portion 17. Thereby, mixed gas GM is produced | generated. The mixed gas GM is introduced into the heater 20 from the gas inlet 22.

The heater 20 heats the mixed gas GM to a predetermined temperature to cause a thermal reaction. In the thermal reaction, TMG is decomposed by the reaction between TMG and HCl. As a result, a third source gas G3 containing a compound of gallium and chlorine, a compound of carbon and hydrogen, unreacted HCl, and the like is generated. The generated third source gas G3 is discharged from the gas discharge port 23 of the heater 20. Examples of the compound of gallium and chlorine include GaCl, GaCl ₃ , monomethylgallium chloride (MMGaCl), and the like. Examples of carbon and hydrogen compounds include CH ₄ and CH ₃ . The kind of substance contained in the third source gas G3 and the molar ratio thereof vary depending on the reaction conditions. Reaction conditions include heating temperature, heating time, molar ratio of TMG and HCl, and the like.

  The effect of the heater 20 will be described. When the first source gas G1 and the second source gas G2 are reacted to generate the third source gas G3, if the reaction between TMG and HCl is not sufficiently performed, the HCl concentration in the third source gas G3 Becomes higher. When the HCl concentration in the third source gas G3 is increased, the vapor phase growth apparatus 1 is damaged, for example, the members in the flow channel 65 are corroded, which is a problem. Thus, in the present technology, the reaction between TMG and HCl can be promoted by heating the first source gas G1 and the second source gas G2 with the heater 20. By sufficiently performing the reaction, it is possible to suppress an increase in the concentration of HCl contained in the third source gas. Damage to the vapor phase growth apparatus 1 can be suppressed.

The third source gas G3 is supplied to the flow channel 65 through the gas supply pipe 40. Further, the fourth source gas G4 (NH ₃ ) is supplied to the flow channel 65 through the gas supply pipe 51. Thereby, a GaN layer can be grown on the wafer 61 by reacting the third source gas G3 and the NH ₃ gas.

  Control of the valve unit 32 will be described. The first signal SS <b> 1 is fed back from the mass spectrometer 31 to the valve unit 32. The first signal SS1 includes information indicating the concentration of HCl contained in the third source gas G3. When the first signal SS1 indicates that the HCl contained in the third source gas G3 is equal to or lower than the predetermined concentration, the valve unit 32 opens the valve 33 and closes the valve 34. Thereby, the third source gas G3 can be supplied to the flow channel 65. On the other hand, when the first signal SS1 indicates that HCl contained in the third source gas G3 is higher than the predetermined concentration, the valve unit 32 closes the valve 33 and opens the valve 34. Thereby, the 3rd source gas G3 can be discharged to a vent line. Thereby, high-concentration HCl is not supplied to the flow channel 65. It is possible to suppress damage given to members in the flow channel 65. The predetermined concentration of HCl can be set as appropriate in consideration of the amount of damage given to the vapor phase growth apparatus 1 and the growth rate of the GaN layer.

  Control of the heater 20 will be described. A second signal SS2 is fed back from the mass spectrometer 31 to the heater 20. The second signal SS2 includes information indicating the concentration of HCl contained in the third source gas G3. The heater 21 of the heater 20 controls the heating temperature of the mixed gas GM based on the second signal SS2 so that the concentration of HCl contained in the third source gas G3 is equal to or lower than a predetermined concentration. This will be described using the simulation result of FIG. The horizontal axis is the heating temperature in the heater 20, and the vertical axis is the HCl concentration in the third source gas G3. The hatched area in FIG. 2 indicates a range of values that can be taken when the heating time is changed. As shown in FIG. 2, the HCl concentration in the third source gas G3 rapidly decreases when the heating temperature is 500 ° C. or higher, and becomes almost zero at 800 ° C. However, when the heater 20 is made of stainless steel (SUS), the heat resistance temperature of the apparatus is about 500 ° C. to 800 ° C., and thus there is an upper limit on the heating temperature. Therefore, by performing feedback control using the mass spectrometer 31, it is possible to suppress the HCl concentration in the third source gas G3 while suppressing the heating temperature within the heat resistant temperature of the heater 20. Thereby, it becomes possible to reduce both the HCl concentration and the failure of the heater 20.

  Control of the MFC 13 will be described. A third signal SS3 is fed back from the mass spectrometer 31 to the MFC 13. The third signal SS3 includes information indicating the concentration of HCl contained in the third source gas G3. When the first signal SS1 indicates that HCl contained in the third source gas G3 is equal to or higher than a predetermined concentration, the MFC 13 decreases the discharge amount of the second source gas G2 as the HCl concentration increases. Control. Thereby, it is possible to control the HCl concentration contained in the mixed gas GM to an appropriate concentration. Therefore, since the amount of HCl that has not reacted with TMG can be reduced, the HCl concentration in the third source gas can be suppressed.

<Modification>
As mentioned above, although the Example of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  Various methods can be used for temperature control of the heater 20. The second signal SS2 may include information indicating the concentration of GaCl contained in the third source gas G3. The heater 21 of the heater 20 may control the heating temperature of the mixed gas GM based on the second signal SS2 so that the concentration of GaCl contained in the third source gas G3 is equal to or higher than a predetermined concentration. . This will be described using the simulation result of FIG. The horizontal axis is the heating temperature in the heater 20, and the vertical axis is the GaCl concentration in the third source gas G3. The hatched area in FIG. 3 indicates a range of values that can be taken when the heating time is changed. As shown in FIG. 3, the GaCl concentration in the third source gas G3 increases rapidly when the heating temperature is 500 ° C. or higher, and is almost saturated at 800 ° C. GaCl is a main raw material for growing GaN on the wafer 61. Therefore, the higher the GaCl concentration, the better. However, as described above, there is an upper limit for the heat-resistant temperature of the heater 20. Therefore, by performing feedback control using the mass spectrometer 31, the GaCl concentration in the third source gas G3 can be maximized while keeping the heating temperature within the heat-resistant temperature.

Further, the heater 21 of the heater 20 is configured to heat the mixed gas GM based on the second signal SS2 so that the concentration of methane (CH ₄ ) contained in the third source gas G3 is equal to or higher than a predetermined concentration. May be controlled. The higher the CH ₄ concentration in the third source gas G3, the better. This is because CH ₄ is a stable gas and does not react even if supplied into the flow channel 65. That is, when carbon generated after decomposition of TMG is changed to CH ₄ , carbon can be prevented from being taken into the GaN layer. Therefore, by performing feedback control using the mass spectrometer 31, the CH ₄ concentration in the third source gas G3 can be maximized.

Various methods can be used to control the MFC 13. The third signal SS3 may include information indicating the concentration of GaCl or CH ₄ contained in the third source gas G3. The MFC 13 may control the discharge amount of the second source gas G2 so that the concentration of GaCl or CH ₄ contained in the third source gas G3 is equal to or higher than a predetermined concentration. As described above, the higher the GaCl concentration and the CH ₄ concentration in the third source gas G3, the better. Therefore, the composition of the third source gas G3 can be controlled to an optimum state.

The mass spectrometer 31 is not limited to mass spectrometry, and can analyze the third source gas by various methods. For example, FTIR (Fourier Transform Infrared Spectroscopy) spectroscopy may be used. HCl as a substance to be analyzed by the mass spectrometer 31, GaCl, has been illustrated and GaCl _3, CH _4, but not limited to. Various substances can be analyzed.

In the mass spectrometer 31, calibration with a calibration gas may be performed periodically for calibration of the analysis element. An example of the calibration gas is a gas in which a certain amount of CH ₄ is mixed with N ₂ .

The organometallic containing gallium is not limited to TMG. Triethylgallium (C ₂ H ₅ ) ₃ Ga) can also be used. Carrier gas supplied to the gas supply pipe 52 is not limited to N _2. H ₂ or the like can also be used.

  The analysis unit 30 may be capable of being retrofitted into the vapor phase growth apparatus 1. For example, when the vapor phase growth apparatus 1 includes the gas generation unit 10 and the reaction vessel 60, it may be possible to add the analysis unit 30 only by modifying the routing of the gas supply pipe 40 and the like. .

  Even if the length of the gas supply pipe 42 from the branch part 41 to the mass spectrometer 31 is sufficiently longer than the length of the gas supply pipe from the branch part 41 to the inlet 66 of the flow channel 65, Good. Thereby, the third source gas G3 cooled to a temperature at which analysis is possible can be supplied to the mass spectrometer 31. On the other hand, the third source gas G3 can be supplied to the flow channel 65 in a state in which the amount of temperature decrease from the temperature when discharged from the gas discharge port 23 is small. Therefore, vapor phase growth in the flow channel 65 can be performed efficiently.

  The feedback control may be performed by the mass spectrometer 31. For example, the first signal SS1 may be a signal that controls the opening and closing of the valves 33 and 33. The second signal SS2 may be a signal for controlling the temperature of the heater 21. The third signal SS3 may be a signal for controlling the opening degree of the valve in the MFC 13. Further, feedback control may not be performed.

  The heater 20 may have various configurations. For example, the structure which is equipped with the tank which can be heated and produces | generates 3rd raw material gas G3 by heating a tank may be sufficient.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

TMG and H ₂ are examples of the first source gas. HCl is an example of the second source gas. The heater 20 is an example of a heating container. The flow channel 65 is an example of a reaction vessel. The gas supply pipe 40 is an example of a first supply line. The mass spectrometer 31 is an example of an analyzer. The valve unit 32 is an example of a valve. The gas supply pipe 11 is an example of a second supply line. The MFC 13 is an example of a supply amount control unit. The susceptor 62 is an example of a stage.

  1: vapor phase growth apparatus, 13: MFC, 20: heater, 31: mass spectrometer, 32: valve unit, 61: wafer, 65: flow channel, G1: first source gas, G2: second source gas, G3: third source gas, G4: fourth source gas, GM: mixed gas

Claims (16)

A heating vessel to which a first source gas containing an organic metal containing gallium and a second source gas containing hydrogen chloride are supplied, the mixed gas of the first source gas and the second source gas being The heating container capable of discharging a third source gas containing a compound of gallium and chlorine by heating and reacting at a predetermined temperature;
A reaction vessel to which the third source gas discharged from the heating vessel and a fourth source gas containing ammonia are supplied, the reaction vessel having a wafer disposed therein;
A vapor phase growth apparatus comprising: An analyzer disposed on a path of a first supply line for supplying the third source gas from the heating container to the reaction container;
2. The vapor phase growth apparatus according to claim 1, wherein the analyzer is capable of analyzing a concentration of hydrogen chloride contained in the third source gas discharged from the heating container. A valve disposed on the first supply line and capable of controlling whether or not to supply the third source gas to the reaction vessel;
The valve supplies the third source gas to the reaction vessel when the analyzer analyzes that the hydrogen chloride contained in the third source gas has a first predetermined concentration or less. The vapor phase growth apparatus according to claim 2. The heating container is configured to be able to control the predetermined temperature according to an analysis result of the analyzer,
The said heating container controls the said predetermined temperature so that the density | concentration of the said hydrogen chloride contained in the said 3rd source gas analyzed by the said analyzer may become below a 1st predetermined density | concentration. 4. The vapor phase growth apparatus according to 2 or 3. A gas supply amount control unit arranged on a second supply line for supplying the second source gas to the heating container and capable of controlling a supply amount of the second source gas;
The gas supply amount control unit is configured to be able to control the supply amount of the second source gas according to the analysis result of the analyzer,
The gas supply amount control unit controls the supply amount of the second source gas so that the concentration of the hydrogen chloride contained in the third source gas analyzed by the analyzer is equal to or lower than a first predetermined concentration. The vapor phase growth apparatus according to any one of claims 2 to 4, wherein: The analyzer is configured to be able to further analyze the concentration of GaCl contained in the third source gas discharged from the heating container,
The heating container is configured to be able to control the predetermined temperature according to an analysis result of the analyzer,
The said heating container controls the said predetermined temperature so that the density | concentration of the said GaCl contained in the said 3rd source gas analyzed with the said analyzer may become more than a 2nd predetermined density | concentration. The vapor phase growth apparatus of any one of -5. The analyzer is configured to be able to further analyze the concentration of GaCl contained in the third source gas discharged from the heating container,
A gas supply amount control unit arranged on a second supply line for supplying the second source gas to the heating container and capable of controlling a supply amount of the second source gas;
The gas supply amount control unit is configured to be able to control the supply amount of the second source gas according to the analysis result of the analyzer,
The gas supply amount control unit controls the supply amount of the second source gas so that the concentration of GaCl contained in the third source gas analyzed by the analyzer is equal to or higher than a second predetermined concentration. The vapor phase growth apparatus according to any one of claims 2 to 6, wherein   The vapor phase growth apparatus according to claim 2, wherein the analysis apparatus analyzes the third source gas by mass spectrometry.   The vapor phase growth apparatus according to claim 1, wherein the reaction vessel includes a stage capable of holding the wafer and heating the back surface of the wafer.   The vapor phase growth apparatus according to claim 1, wherein the predetermined temperature is 500 ° C. or higher. An analysis unit used in the vapor phase growth apparatus according to claim 1,
An analyzer that is disposed on a path of a first supply line that supplies the third source gas from the heating vessel to the reaction vessel, and that can analyze the concentration of hydrogen chloride contained in the third source gas When,
A valve disposed on the first supply line and capable of controlling whether or not to supply the third source gas to the reaction vessel;
With
The valve supplies the third source gas to the reaction vessel when the analyzer analyzes that the hydrogen chloride contained in the third source gas has a first predetermined concentration or less. An analysis unit characterized by that. A mixed gas generating step for generating a mixed gas of a first source gas containing an organic metal containing gallium and a second source gas containing hydrogen chloride;
A third raw material gas generating step for generating a third raw material gas containing a compound of gallium and chlorine by reacting the mixed gas at a predetermined temperature; and
A growth step of growing a GaN layer on the wafer by supplying the third source gas and a fourth source gas containing ammonia into a reaction vessel in which the wafer is disposed;
A vapor phase growth method comprising:   The vapor phase growth method according to claim 12, further comprising an analysis step of analyzing a concentration of hydrogen chloride contained in the third source gas generated by the third source gas generation step.   The growth step supplies the third source gas to the reaction vessel when the analysis step has analyzed that the hydrogen chloride contained in the third source gas has a first predetermined concentration or less. The vapor phase growth method according to claim 13.   In the third source gas generation step, the predetermined temperature is controlled such that the concentration of the hydrogen chloride contained in the third source gas analyzed in the analysis step is equal to or lower than a first predetermined concentration. The vapor phase growth method according to claim 13 or 14.   In the mixed gas generation step, a mixing amount of the second source gas is controlled so that a concentration of the hydrogen chloride contained in the third source gas analyzed in the analysis step is equal to or lower than a first predetermined concentration. The vapor phase growth method according to any one of claims 13 to 15, wherein:

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