SEMICONDUCTOR WAFER MANUFACTURING APPARATUS

A semiconductor wafer manufacturing apparatus includes a reaction chamber, a reactant gas supply pipe and a reactant gas discharge pipe communicated with the reaction chamber, a rotating device having a cylindrical member, a lid member disposed on one end portion of the cylindrical member, a heating device disposed in a hollow chamber that is a space surrounded by the cylindrical member and the lid member, an inert gas supply pipe and an inert gas discharge pipe communicated with the hollow chamber, and a controller. The controller is configured to adjust an amount of an inert gas discharged from the inert has discharge pipe such that a pressure in the hollow chamber is higher than a pressure in the reaction chamber and equal to or lower than a pressure of a minimum closing portion of the lid member.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority from Japanese Patent Application No. 2022-112726 filed on Jul. 13, 2022. The entire disclosure of the above application is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a semiconductor wafer manufacturing apparatus.

BACKGROUND

Conventionally, there has been proposed a semiconductor wafer manufacturing apparatus for growing an epitaxial layer, which is a semiconductor layer, on a surface of a base wafer by rotating and heating the base wafer in a state where the base wafer is placed on a susceptor in a reaction chamber into which a reactant gas containing a raw material gas is introduced.

SUMMARY

The present disclosure provides a semiconductor wafer manufacturing apparatus that includes a reaction chamber forming portion forming a reaction chamber, a reactant gas supply pipe and a reactant gas discharge pipe communicated with the reaction chamber, a rotating device having a cylindrical member, a lid member disposed on one end portion of the cylindrical member, a heating device disposed in a hollow chamber surrounded by the cylindrical member and the lid member, an inert gas supply pipe and an inert gas discharge pipe communicated with the hollow chamber, and a controller. The controller is configured to adjust an amount of an inert gas discharged from the inert gas discharge pipe such that a pressure in the hollow chamber is higher than a pressure in the reaction chamber and equal to or lower than a pressure of a minimum closing portion of the lid member.

DETAILED DESCRIPTION

In a semiconductor wafer manufacturing apparatus according to a related art, a rotating device on which a base wafer is placed is disposed in a reaction chamber. The rotating device is configured to have a cylindrical member having an opening end portion at one end, and an inside of the cylindrical member is substantially closed by disposing a lid member including a susceptor at the opening end portion. When a space surrounded by the cylindrical member and the lid member is referred to as a hollow chamber, a heating device for heating the base wafer from a direction close to a rear surface of the base wafer is disposed in the hollow chamber. As the heating device, for example, a resistance heating heater made of carbon is used.

In the semiconductor wafer manufacturing apparatus described above, an inert gas is introduced into the hollow chamber in order to restrict a reactant gas from flowing from the reaction chamber into the hollow chamber and reacting with the heating device. Specifically, in the semiconductor wafer manufacturing apparatus, the inert gas is introduced into the hollow chamber to make the pressure in the hollow chamber higher than the pressure in the reaction chamber, thereby making it difficult for the reactant gas to flow from the reaction chamber into the hollow chamber.

However, when the pressure in the hollow chamber is set to be excessively higher than the pressure in the reaction chamber, there is a possibility that the lid member for closing the cylindrical member floats and is separated from the cylindrical member, and the epitaxial layer cannot be grown appropriately.

A semiconductor wafer manufacturing apparatus according to an aspect of the present disclosure includes a reaction chamber forming member, a reactant gas supply pipe, a reactant gas discharge pipe, a susceptor, a rotating device, a lid member, a heating device, an inert gas supply pipe, an inert gas discharge pipe, and a controller. The reaction chamber forming member forms a reaction chamber into which a reactant gas is to be introduced and in which an epitaxial layer is to be grown on a front surface of a base wafer. The reactant gas supply pipe is communicated with the reaction chamber and is configured to supply the reactant gas for growing the epitaxial layer to the reaction chamber. The reactant gas discharge pipe is communicated with the reaction chamber and is configured to discharge an unreacted gas from the reaction chamber. The susceptor is disposed in the reaction chamber and the base wafer is to be placed on the susceptor. The rotating device has a cylindrical member with one end portion on which the susceptor is disposed and is configured to rotate the susceptor together with the base wafer. The lid member includes the susceptor and is disposed on the one end portion of the cylindrical member. The heating device is disposed in a hollow chamber that is a space surrounded by the cylindrical member and the lid member and is configured to heat the base wafer. The inert gas supply pipe is communicated with the hollow chamber and is configured to introduce an inert gas into the hollow chamber. The inert gas discharge pipe is communicated with the hollow chamber and is configured to discharge the inert gas. The controller is configured to adjust an amount of the inert gas discharged from the inert gas discharge pipe such that a pressure in the hollow chamber is higher than a pressure in the reaction chamber and equal to or lower than a pressure of a minimum closing portion. A value obtained by dividing a mass of the lid member by an area of a portion of the lid member exposed to the hollow chamber is defined as a pressure of the lid member, and the pressure of the minimum closing portion is a pressure of a portion of the lid member at which the pressure of the lid member is minimum.

In the above configuration, the pressure in the hollow chamber is made higher than the pressure in the reaction chamber. Therefore, it is possible to restrict the reactant gas from entering the hollow chamber from the reaction chamber, and it is possible to restrict the life of the heating device from being shortened. The pressure in the hollow chamber is set to be equal to or lower than the pressure of the minimum closing portion. Thus, it is possible to restrict the floating of the portion where the pressure of the lid member becomes the smallest by increasing the pressure in the hollow chamber, and it is possible to restrict the occurrence of an issue that the epitaxial layer cannot be grown appropriately.

The following describes embodiments of the present disclosure with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals for description.

First Embodiment

A first embodiment will be described with reference to the drawings. A semiconductor wafer manufacturing apparatus according to the present embodiment is preferably applied to, for example, growing an epitaxial layer made of silicon carbide (SiC) on a surface of a base wafer to manufacture an SiC wafer. Hereinafter, a semiconductor wafer manufacturing apparatus (hereinafter, also simply referred to as a manufacturing apparatus) for manufacturing an SiC wafer will be described as an example of the semiconductor wafer manufacturing apparatus.

As shown inFIG.1, a manufacturing apparatus1includes a chamber20that forms a reaction chamber20afor growing an epitaxial layer11as a semiconductor layer on a front surface10aof a base wafer10. In the present embodiment, the chamber20corresponds to a reaction chamber forming member that forms the reaction chamber20a.

A reactant gas supply pipe30configured to supply a reactant gas for growing a crystal thin film on the front surface10aof the base wafer10is provided on an upper side of the chamber20. In the present embodiment, in order to epitaxially grow SiC, the reactant gas includes, for example, a source gas including trichlorosilane (SiHCl3) and propane (C3H8), a carrier gas including hydrogen and hydrogen chloride (HCl), and a dopant gas including nitrogen (N2).

Specifically, the reactant gas supply pipe30is disposed on the upper side of the chamber20so that a position facing the front surface10aof the base wafer10is opened. Accordingly, the reactant gas is supplied to the reaction chamber20afrom a direction intersecting the front surface10aof the base wafer10(that is, a direction substantially perpendicular to the front surface10a) toward the front surface10aof the base wafer10. Therefore, it can be said that the manufacturing apparatus1of the present embodiment has a downflow-type gas supply structure in which the reactant gas is blown down toward the front surface10aof the base wafer10.

Furthermore, a rotating device40to which the base wafer10is placed is disposed on a lower side of the reaction chamber20a. In the present embodiment, the base wafer10is placed on a susceptor50disposed on the rotating device40.

The rotating device40includes a cylindrical member41, a rotating shaft42, a driving unit43, and the like. The cylindrical member41is a member having a bottomed cylindrical shape and forms a hollow chamber41a, and the susceptor50is disposed at an opening end portion. The cylindrical member41is disposed such that the opening end portion faces the upper side of the chamber20(that is, the side of the reactant gas supply pipe30). The cylindrical member41(that is, the hollow chamber41a) is configured such that an inert gas, which will be described later, is introduced therein.

The rotating shaft42is a shaft that is rotated by an output of the driving unit43, and is connected to the cylindrical member41so as to be rotatable integrally with the cylindrical member41. The driving unit43includes a motor or the like that outputs a rotational force, and rotates the rotating shaft42. In the rotating device40configured as described above, the rotating shaft42is rotated by the output of the driving unit43, and the cylindrical member41and the susceptor50are integrally rotated.

The susceptor50has an outer shape matching the opening end portion of the cylindrical member41. The susceptor50of the present embodiment substantially closes the cylindrical member41by being disposed at the opening end portion of the cylindrical member41. As a result, the hollow chamber41aof the cylindrical member41is substantially closed.

Hereinafter, the shape of the susceptor50of the present embodiment will be described. The susceptor50of the present embodiment has an outer peripheral susceptor portion510and an inner peripheral susceptor portion520.

The outer peripheral susceptor portion510is formed in a plate shape having a first surface510aand a second surface510b, and the first surface510ahas a first recessed portion511for accommodating the base wafer10. In addition, in the outer peripheral susceptor portion510, a second recessed portion512at which the inner peripheral susceptor portion520is disposed is provided in a substantially central portion of a bottom surface of the first recessed portion511. Furthermore, in the outer peripheral susceptor portion510, a through hole513is provided in a substantially central portion of a bottom surface of the second recessed portion512. The outer peripheral susceptor portion510further has a step portion514for fitting with the opening end portion of the cylindrical member41at an outer peripheral portion of the second surface510b. The outer peripheral susceptor portion510is disposed on the cylindrical member41by fitting the step portion514into the opening end portion of the cylindrical member41.

The inner peripheral susceptor portion520is configured to have a protruding portion521and a plate portion522. The protruding portion521is disposed in a substantially central portion of the plate portion522, and is fitted in the through hole513. The plate portion522is disposed on the bottom surface of the second recessed portion512. In other words, the inner peripheral susceptor portion520has a configuration in which a recessed portion is formed at an outer peripheral portion of the plate portion522so that the protruding portion521is formed at an inner peripheral portion of the plate portion522. The protruding portion521has the same shape and the same size as the through hole513, and is configured to close the through hole513by being disposed. However, the inner peripheral susceptor portion520of the present embodiment is disposed so as to be separable from the outer peripheral susceptor portion510.

In the present embodiment, the hollow chamber41aof the cylindrical member41is substantially closed by the susceptor50. Therefore, in the present embodiment, the lid member C that closes the cylindrical member41is comprised of the susceptor50. The susceptor50disposed so as to close the cylindrical member41is disposed in a state of being exposed to the hollow chamber41a. Specifically, a portion of the second surface510bof the outer peripheral susceptor portion510that is different from the portion where the step portion514is formed and the portion where the through hole513is formed serves as an exposed surface S1that is exposed to the hollow chamber41a. The inner peripheral susceptor portion520has a tip surface in a protruding direction of the protruding portion521, and the tip surface serves an exposed surface S2that is exposed to the hollow chamber41a.

A pressure caused by the outer peripheral susceptor portion510on the exposed surface S1of the outer peripheral susceptor portion510(hereinafter, also simply referred to as a pressure of the outer peripheral susceptor portion510) is represented by (the mass of the outer peripheral susceptor portion510)/(the area of the exposed surface S1). Similarly, the pressure caused by the inner peripheral susceptor portion520on the exposed surface S2of the inner peripheral susceptor portion520(hereinafter, also simply referred to as a pressure of the inner peripheral susceptor portion520) is expressed by (the mass of the inner peripheral susceptor portion520)/(the area of the exposed surface S2). The susceptor50of the present embodiment is configured such that the pressure of the inner peripheral susceptor portion520is lower than the pressure of the outer peripheral susceptor portion510. Therefore, in the present embodiment, the pressure of the inner peripheral susceptor portion520corresponds to a pressure of a minimum closing portion.

A heater60as a heating device for heating the base wafer10from a direction close to a rear surface10bof the base wafer10is disposed in the hollow chamber41a. As the heater60, for example, a resistance heating heater made of carbon is used. Although not illustrated, the heater60is connected to a controller110and is heated to a predetermined temperature.

On the lower side of the chamber20, a reactant gas discharge pipe70for discharging a gas after reaction or an unreacted gas is provided. A portion of the reactant gas discharge pipe70located opposite to the chamber20is connected to a vacuum pump80. The reactant gas discharge pipe70is provided with a pressure detection unit71and a pressure adjustment valve72between the chamber20and the vacuum pump80. The pressure in the reaction chamber20ais adjusted to a specified pressure by adjusting an opening and closing degree of the pressure adjustment valve72based on a pressure detected by the pressure detection unit71.

In the hollow chamber41a, an inert gas supply pipe90for supplying the inert gas and an inert gas discharge pipe100for discharging the inert gas are disposed. The inert gas supply pipe90is provided with a mass flow controller91and supplies the inert gas into the hollow chamber41aat a constant flow rate. At this time, in the present embodiment, as will be described later, the pressure in the hollow chamber41ais adjusted to be higher than the pressure in the reaction chamber20a. Therefore, the reactant gas is restricted from entering the hollow chamber41athrough a gap between the lid member C (that is, the susceptor50) and the cylindrical member41.

A portion of the inert gas discharge pipe100located opposite to the hollow chamber41ais connected to the vacuum pump80. The inert gas discharge pipe100is provided with a pressure detection unit101and a pressure adjustment valve102between the hollow chamber41aand the vacuum pump80. The pressure in the hollow chamber41ais adjusted to a predetermined pressure by adjusting an opening and closing degree of the pressure adjustment valve102based on a pressure detected by the pressure detection unit101. In the present embodiment, the inert gas supply pipe90and the inert gas discharge pipe100are disposed in the cylindrical member41and communicate with the hollow chamber41a.

The reactant gas discharge pipe70and the inert gas discharge pipe100of the present embodiment are partially connected to each other at a position opposite to the vacuum pump80across the respective pressure adjustment valves72and102. The pressure detection unit101is disposed so as to detect a pressure difference at a connection portion between the reactant gas discharge pipe70and the inert gas discharge pipe100. That is, the pressure detection unit101of the present embodiment detects the pressure difference between the pressure in the reaction chamber20aand the pressure in the hollow chamber41a.

Although not particularly illustrated, a susceptor lifting device is disposed in the hollow chamber41a. The susceptor lifting device is configured to assist a transfer robot to load the susceptor50on which the base wafer10is placed into the reaction chamber20aand to unload the susceptor50from the reaction chamber20a. As the susceptor lifting and lowering device, for example, a device having a function of transferring the susceptor50to the transfer robot by raising the susceptor50and separating the susceptor50from the cylindrical member41when the susceptor50is transferred. In the present embodiment, the susceptor50is configured to have the outer peripheral susceptor portion510and the inner peripheral susceptor portion520, and the inner peripheral susceptor portion520can be separated from the outer peripheral susceptor portion510. Therefore, the transfer of the base wafer10can be facilitated. However, the manufacturing apparatus1does not have to perform loading and unloading of the susceptor50on which the base wafer10is placed, and may perform loading and unloading of only the base wafer10without moving the susceptor50.

The manufacturing apparatus1further includes the controller110. The controller110is configured by a microcomputer or the like including a central processing unit (CPU), a storage unit configured by a non-transitory tangible storage medium such as a read-only memory (ROM), a random access memory (RAM), a flash memory, or a hard disk drive (HDD), and the like.

The controller110realizes various control operations by the CPU reading and executing various data from the storage unit. Specifically, the controller110adjusts the opening and closing degree of the pressure adjustment valve72based on the pressure of the pressure detection unit71so that the pressure in the reaction chamber20abecomes a specified pressure. In addition, the controller110adjusts the opening and closing degree of the pressure regulating valve102so that the pressure in the hollow chamber41abecomes higher than the pressure in the reaction chamber20aand equal to or lower than a predetermined pressure. In the present embodiment, since the pressure detection unit101is a differential pressure gauge, the controller110adjusts the opening and closing degree of the pressure adjustment valve102based on the result of the pressure detection unit101.

Here, the predetermined pressure is a pressure at which the lid member C does not float (that is, the lid member C is not separated) due to the pressure in the hollow chamber41a. In the manufacturing apparatus1of the present embodiment, the susceptor50includes the outer peripheral susceptor portion510and the inner peripheral susceptor portion520. The pressure of the inner peripheral susceptor portion520is made smaller than the pressure of the outer peripheral susceptor portion510. Therefore, the predetermined pressure is set to a pressure at which the inner peripheral susceptor portion520does not float, and is set to be equal to or lower than the pressure of the inner peripheral susceptor portion520.

The above is the configuration of the manufacturing apparatus1according to the present embodiment. Next, a method of growing the epitaxial layer11on the front surface10aof the base wafer10using the manufacturing apparatus1will be described.

First, in the manufacturing apparatus1, the reaction chamber20ais heated to about 1600 to 1750° C. by the heater60while the susceptor50on which the base wafer10is placed is rotated at, for example, 200 rpm by the rotating device40. In the manufacturing apparatus1, the reactant gas is supplied from the reactant gas supply pipe30toward the reaction chamber20a, and the inert gas is supplied from the inert gas supply pipe90.

In the present embodiment, the pressure in the hollow chamber41ais adjusted to be higher than the pressure in the reaction chamber20a. Accordingly, it is possible to restrict the reactant gas from entering the hollow chamber41a. For example, as shown inFIG.2, when the pressure in the hollow chamber41ais equal to the pressure in the reaction chamber20a(that is, the differential pressure is 0), it is confirmed that a resistance value of the heater60steeply increases with increase in operating time. On the other hand, in the present embodiment, the pressure in the hollow chamber41ais set to be higher than the pressure in the reaction chamber20a. For example,FIG.2shows the result of setting the pressure in the hollow chamber41ato be higher than the pressure in the reaction chamber20aby 0.6 gf/cm2. Accordingly, it is possible to effectively restrict the reactant gas from entering the hollow chamber41a, and it is possible to restrict the life of the heater60from being shortened.

In the present embodiment, the pressure in the hollow chamber41ais adjusted so as to be higher than the pressure in the reaction chamber20aand equal to or lower than the pressure of the inner peripheral susceptor portion520. For example, when the mass of the inner peripheral susceptor portion520is 40 g and the area of the exposed surface S2is 50 cm2, the pressure of the inner peripheral susceptor portion520is 0.8 gf/cm2(that is, 78.4 Pa). Therefore, the pressure in the hollow chamber41ais controlled to be 0.8 gf/cm2or less. Therefore, even when the pressure in the hollow chamber41ais increased, it is possible to restrict the occurrence of issues that the inner peripheral susceptor portion520(that is, the susceptor50) floats from the cylindrical member41, the inner peripheral susceptor portion520collides with the base wafer10or the like, and the epitaxial layer11cannot be appropriately grown.

The inert gas is, for example, argon, but may be helium or the like. The flow rate of the inert gas is, for example, 6 slm, but can be changed as appropriate. However, in a case where the flow rate of the inert gas is too small, there is a possibility that the change in the discharge amount becomes small even if the opening and closing degree of the pressure adjustment valve102is changed, and there is a possibility that it becomes difficult to adjust the pressure in the hollow chamber41aby the pressure adjustment valve102. Therefore, the flow rate of the inert gas is preferably at least 1 slm.

In addition, by changing the thickness or the material of the susceptor50to increase the mass, the pressure of the susceptor50can be increased, and the pressure in the hollow chamber41acan be further increased. However, when the thickness of the susceptor50is increased, the heat capacity increases, and the time until the base wafer10is heated to the predetermined temperature increases. Therefore, the thickness of the susceptor50(for example, the inner peripheral susceptor portion520) is, for example, preferably 10 mm or less, and more preferably 5 mm or less.

In addition, when the mass of the susceptor50is increased, the pressure in the hollow chamber41acan be easily increased, but a vibration when the susceptor50is rotated by the rotating device40is easily increased, and there is a possibility that the susceptor50is easily floated by the rotation. Therefore, the susceptor50is not preferably made of a material having an excessively large mass, and is preferably made of a material containing carbon, for example, from the viewpoint of mass, processing accuracy, and heat resistance. Therefore, in the present embodiment, the susceptor50is made of, for example, SiC or a material in which a surface of isotropic graphite is coated with SiC, tantalum carbide (TaC), niobium carbide (NbC), or the like. In this case, for example, a pressure converted from a density of C having a thickness of 10 mm is preferably set to 1.8 gf/cm2(176.4 Pa) or less, and for a thickness of 5 mm, the pressure is preferably set to 0.9 gf/cm2(88.2 Pa) or less.

According to the present embodiment described above, the pressure in the hollow chamber41ais higher than the pressure in the reaction chamber20a. Therefore, it is possible to restrict the reactant gas from entering the hollow chamber41afrom the reaction chamber20a, and it is possible to restrict the life of the heater60from being shortened due to the reaction between the reactant gas and the heater60.

The pressure in the hollow chamber41ais equal to or lower than the pressure of the inner peripheral susceptor portion520(that is, the pressure of the minimum closing portion). Therefore, it is possible to restrict the occurrence of the issues that the inner peripheral susceptor portion520floats from the cylindrical member41by increasing the pressure in the hollow chamber41a, the inner peripheral susceptor portion520collides with the base wafer10or the like, and the epitaxial layer11cannot be appropriately grown. That is, in the manufacturing apparatus1of the present embodiment, the epitaxial layer11can be suitably easily grown.

In the present embodiment, the susceptor50includes the outer peripheral susceptor portion510and the inner peripheral susceptor portion520which are separable. Therefore, at the time of disposing the base wafer10or the like, only the inner peripheral susceptor portion520can be transported, and the degree of freedom of installation of the base wafer10can be improved.

Second Embodiment

The following describes a second embodiment. The present embodiment is different from the first embodiment in the shape of the susceptor50. The other configurations of the present embodiment are similar to those of the first embodiment, and therefore a description of the similar configurations will not be repeated.

In the present embodiment, as shown inFIG.3, the susceptor50is formed of a single member. The susceptor50has a recessed portion51for accommodating the base wafer10on a first surface50a. The susceptor50also has a step portion52formed on a second surface50bso as to be fitted to the opening end portion of the cylindrical member41. The susceptor50is disposed so as to close the cylindrical member41by fitting the stepped portion52into the opening end portion of the cylindrical member41. In the present embodiment, the susceptor50is formed of the single member. Therefore, the lid member C is comprised of the susceptor50.

The susceptor50is formed of the single member, and a portion of the second surface50bthat is different from the portion where the step portion52is formed serves as an exposed surface S3that is exposed to the hollow chamber41a. Therefore, in the susceptor50, the pressure caused by the susceptor50on the exposed surface S3(hereinafter, also simply referred to as a pressure of the susceptor50) is (the mass of the susceptor50)/(the area of the exposed surface S3). In the present embodiment, the pressure of the susceptor50corresponds to the pressure of the minimum closing portion.

When growing the epitaxial layer11on the front surface10aof the base wafer10, the controller110adjusts the pressure in the hollow chamber41ato be higher than the pressure in the reaction chamber20aand equal to or lower than the pressure of the susceptor50.

According to the present embodiment described above, since the pressure in the hollow chamber41ais adjusted to be higher than the pressure in the reaction chamber20aand equal to or lower than the pressure of the minimum closing portion, effects similar to those of the first embodiment can be obtained.

In the present embodiment, the lid member C is comprised of the susceptor50which is the single member. Therefore, as compared with the case where the susceptor50has the outer peripheral susceptor portion510and the inner peripheral susceptor portion520as in the first embodiment, the pressure of the minimum closing portion can be increased, and the pressure in the hollow chamber41acan be easily increased. Therefore, it is easier to restrict the reactant gas from entering the hollow chamber41afrom the reaction chamber20a, and it is possible to restrict the life of the heater60from being shortened.

Third Embodiment

The following describes a third embodiment. The present embodiment is different from the second embodiment in the shape of the susceptor50. The other configurations of the present embodiment are similar to those of the second embodiment, and therefore a description of the similar configurations will not be repeated.

In the present embodiment, as shown inFIG.4, a through hole53is formed in a bottom51aof the recessed portion51of the susceptor50. Therefore, the hollow chamber41ais closed by the susceptor50and the base wafer10. That is, in the present embodiment, the lid member C is comprised of the susceptor50and the base wafer10.

A portion of the second surface50bof the susceptor50that is different from the portion where the through hole53serves as an exposed surface S4. A portion of the rear surface10bof the base wafer10that closes the through hole53serves as an exposed surface S5.

The pressure caused by the susceptor50on the exposed surface S4of the susceptor50(hereinafter, also simply referred to as a pressure of the susceptor50) is expressed by (the mass of the susceptor50)/(the area of the exposed surface S4). Similarly, the pressure caused by the base wafer10on the exposed surface S5of the base wafer10(hereinafter, also simply referred to as a pressure of the base wafer10) is expressed by (the mass of the base wafer10)/(the area of the exposed surface S5). In the present embodiment, the pressure of the susceptor50is higher than the pressure of the base wafer10. Therefore, in the present embodiment, the pressure of the base wafer10corresponds to the pressure of the minimum closing portion.

Then, when growing the epitaxial layer11on the front surface10aof the base wafer10, the controller110adjusts the pressure in the hollow chamber41ato be higher than the pressure in the reaction chamber20aand equal to or lower than the pressure of the base wafer10.

According to the present embodiment described above, since the pressure in the hollow chamber41ais adjusted to be higher than the pressure in the reaction chamber20aand equal to or lower than the pressure of the minimum closing portion, effects similar to those of the first embodiment can be obtained.

Fourth Embodiment

The following describes a fourth embodiment. In the present embodiment, the arrangement position of the inert gas supply pipe90is adjusted as compared with the first embodiment. The other configurations of the present embodiment are similar to those of the first embodiment, and therefore a description of the similar configurations will not be repeated.

In the present embodiment, as shown inFIG.5, an opening end portion of the inert gas supply pipe90through which the inert gas is introduced is disposed closer to the center of the hollow chamber41athan an opening end portion of the inert gas discharge pipe100through which the inert gas is suctioned.

According to the present embodiment described above, since the pressure in the hollow chamber41ais adjusted to be higher than the pressure in the reaction chamber20aand equal to or lower than the pressure of the minimum closing portion, effects similar to those of the first embodiment can be obtained.

In the present embodiment, the opening end portion of the inert gas supply pipe90through which the inert gas is introduced is disposed closer to the center of the hollow chamber41athan the opening end portion of the inert gas discharge pipe100through which the inert gas is suctioned. Therefore, the hollow chamber41acan be easily filled with the inert gas.

Fifth Embodiment

The following describes a fifth embodiment. The present embodiment is different from the first embodiment in the shape of the inert gas supply pipe90. The other configurations of the present embodiment are similar to those of the first embodiment, and therefore a description of the similar configurations will not be repeated.

In the present embodiment, as shown inFIG.6, an opening end portion of the inert gas supply pipe90is bent in a direction opposite to the inert gas discharge pipe100.

According to the present embodiment described above, since the pressure in the hollow chamber41ais adjusted to be higher than the pressure in the reaction chamber20aand equal to or lower than the pressure of the minimum closing portion, effects similar to those of the first embodiment can be obtained.

Furthermore, in the present embodiment, the opening end portion of the inert gas supply pipe90is bent in the direction opposite to the inert gas discharge pipe100. Therefore, the hollow chamber41acan be easily filled with the inert gas.

Other Embodiments

Although the present disclosure has been described in accordance with the embodiments, it is understood that the present disclosure is not limited to such embodiments or structures. The present disclosure encompasses various modifications and variations within the scope of equivalents. In addition, while the various elements are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the present disclosure.

For example, in each of the above embodiments, the manufacturing apparatus1for growing the SiC epitaxial layer11has been described as an example. However, the configuration of the epitaxial layer11to be grown can be appropriately changed, and for example, the manufacturing apparatus1may grow the epitaxial layer11of gallium nitride.

In each of the above embodiments, an example has been described in which the pressure detection unit101that detects the pressure in the hollow chamber41adetects the differential pressure between the hollow chamber41aand the reaction chamber20a. However, the pressure of the hollow chamber41amay be detected by the pressure detection unit101, and the differential pressure between the reaction chamber20aand the hollow chamber41amay be derived by the controller110. However, in order to restrict the lid member C from floating or the like while restricting the reactant gas from entering behind the rear surface10bof the base wafer10, detailed pressure management is required. Therefore, it is preferable that the pressure detection unit101directly detects the differential pressure between the reaction chamber20aand the hollow chamber41a.

The embodiments described above can also be combined with each other. For example, the fourth and fifth embodiments may be appropriately combined with the first to third embodiments, and the shape of the inert gas supply pipe90may be appropriately changed.

The controller and the method thereof described in the present disclosure are implemented by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the controller and the method described in the present disclosure may be implemented by a special purpose computer configured as a processor with one or more special purpose hardware logic circuits. Alternatively, the controller and the method described in the present disclosure may be implemented by one or more special purpose computer, which is configured as a combination of a processor and a memory, which are programmed to perform one or more functions, and a processor which is configured with one or more hardware logic circuits. The computer program may be stored, as instructions to be executed by a computer, in a tangible non-transitory computer-readable medium.