Semiconductor Wafer Manufacturing Equipment

Abstract

To provide manufacturing equipment of semiconductor wafers capable of suppressing getting inability to properly grow the epitaxial layer.SOLUTION: The manufacturing equipment of semiconductor wafers includes: a heating unit 60 that is provided in a hollow chamber 41a which is a space surrounded by a cylinder 41 and a lid C; an inert gas supply pipe 90 for guiding inert gas to the hollow chamber 41a; and an inert gas exhaust pipe 100 for exhausting the inert gas. Defining the value that is obtained by dividing the mass of the lid C by the area S2, S3, and S5 of the part of the lid C exposed to hollow chamber 41a as the pressure of the lid C, and defining the smallest part of the pressure of the lid C as the pressure at the minimum occlusion, the hollow chamber 41a is configured so as to adjust the amount of the inert gas exhausted from the inert gas exhaust pipe 100 so that the pressure is higher than the pressure in the reaction chamber 20a and the pressure is below the pressure at the minimum occlusion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a manufacturing apparatus for semiconductor wafers.

Background Art

[0002] Conventionally, there has been proposed a manufacturing apparatus for semiconductor wafers in which, in a reaction chamber into which a reaction gas containing a raw material gas is introduced, a base wafer is placed on a susceptor and rotated while being heated to grow an epitaxial layer, which is a semiconductor layer, on the surface of the base wafer (see, for example, Patent Document 1).

[0003] Specifically, in this manufacturing apparatus for semiconductor wafers, a rotating device on which a base wafer is disposed is disposed in the reaction chamber. The rotating device has a configuration having a cylindrical portion with an open end on one end side, and a lid portion including a susceptor is disposed at the open end so that the inside is substantially closed. Then, when the space surrounded by the cylindrical portion and the lid portion is a hollow chamber, a heating device for heating the base wafer from the back side is disposed in the hollow chamber. Note that, for example, a carbon resistance heater is used as such a heating device.

[0004] Further, in this manufacturing apparatus for semiconductor wafers, in order to suppress the reaction gas flowing from the reaction chamber into the hollow chamber and reacting with the heating device, an inert gas is introduced into the hollow chamber. Specifically, in this manufacturing apparatus for semiconductor wafers, an inert gas is introduced into the hollow chamber to make the pressure in the hollow chamber higher than the pressure in the reaction chamber, so that it becomes difficult for the reaction gas to flow from the reaction chamber into the hollow chamber.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, if the pressure in the hollow chamber is made too high compared to the pressure in the reaction chamber, the lid for closing the cylindrical portion may float and come off from the cylindrical portion, and it may become impossible to appropriately grow the epitaxial layer.

[0007] In view of the above points, an object of the present invention is to provide a semiconductor wafer manufacturing apparatus capable of suppressing the inability to appropriately grow an epitaxial layer.

Means for Solving the Problems

[0008] Claim 1 for achieving the above object is a semiconductor wafer manufacturing apparatus, comprising: a reaction chamber forming portion (20) that forms a reaction chamber (20a) into which a reaction gas is introduced and on the surface (10a) side of a base wafer (10), an epitaxial layer (11) is grown; a reaction gas supply pipe (30) provided in the reaction chamber for supplying a reaction gas for growing an epitaxial layer in the reaction chamber; a reaction gas exhaust pipe (70) provided in the reaction chamber for exhausting unreacted gas from the reaction chamber; a susceptor (50) disposed in the reaction chamber on which the base wafer is disposed; a rotating device (40) having a cylindrical portion (41) on one end side of which the susceptor is disposed and rotating the susceptor together with the base wafer; a lid portion (C) including the susceptor disposed on one end side of the cylindrical portion; a heating device (60) provided in the hollow chamber defined by the cylindrical portion and the lid portion for heating the base wafer; an inert gas supply pipe (90) provided in the hollow chamber for introducing an inert gas into the hollow chamber; and an inert gas exhaust pipe (100) provided in the hollow chamber for exhausting the inert gas. When the value obtained by dividing the mass of the lid portion by the area (S2, S3, S5) of the portion of the lid portion exposed to the hollow chamber is defined as the pressure of the lid portion, and the smallest portion of the pressure of the lid portion is defined as the pressure of the minimum closing portion, the amount of the inert gas exhausted from the inert gas exhaust pipe is adjusted so that the pressure in the hollow chamber is higher than the pressure in the reaction chamber and equal to or lower than the pressure of the minimum closing portion.

[0009] According to this, the pressure in the hollow chamber is made higher than the pressure in the reaction chamber. Therefore, it is possible to suppress the reaction gas from entering the hollow chamber from the reaction chamber, and it is possible to suppress a decrease in the life of the heating device. Further, the pressure in the hollow chamber is set to be equal to or lower than the pressure at the minimum blockage portion. Therefore, it is possible to suppress the smallest part of the pressure of the lid portion from rising due to increasing the pressure in the hollow chamber, and it is possible to suppress the occurrence of a problem that an epitaxial layer cannot be appropriately grown.

[0010] Note that the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence relationship between the component etc. and the specific components etc. described in the embodiments described later.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are denoted by the same reference numerals and will be described.

[0013] (First Embodiment) The first embodiment will be described with reference to the drawings. Note that the semiconductor wafer manufacturing apparatus of the present embodiment is preferably applicable to manufacturing a SiC wafer by growing an epitaxial layer made of silicon carbide (hereinafter also simply referred to as SiC) on the surface of a base wafer. Hereinafter, as a semiconductor wafer manufacturing apparatus, a semiconductor wafer manufacturing apparatus for manufacturing a SiC wafer (hereinafter also simply referred to as a manufacturing apparatus) will be described as an example.

[0014] As shown in FIG. 1, the manufacturing apparatus 1 has a chamber 20 that constitutes a reaction chamber 20a for growing an epitaxial layer 11 as a semiconductor layer on the surface 10a side of the base wafer 10. In the present embodiment, the chamber 20 corresponds to a reaction chamber forming portion that forms the reaction chamber 20a.

[0015] On the upper side of the chamber 20, a reaction gas supply pipe 30 for supplying a reaction gas for growing a crystal thin film on the surface 10a side of the base wafer 10 is provided. In the present embodiment, in order to epitaxially grow SiC, the reaction gas includes, for example, a source gas composed of trichlorosilane (SiHCl3) and propane (C3H8), a carrier gas composed of hydrogen and hydrogen chloride (HCl), and a dopant gas composed of nitrogen (N2).

[0016] Specifically, the reaction gas supply pipe 30 is arranged on the upper side of the chamber 20 so that the position facing the surface 10a of the base wafer 10 is open. Thereby, the reaction gas is supplied to the reaction chamber 20a from a direction intersecting the surface 10a of the base wafer 10 (that is, a direction substantially orthogonal to the surface 10a) toward the surface 10a of the base wafer 10. Therefore, it can be said that the manufacturing apparatus 1 of the present embodiment has a downflow type gas supply structure that blows down the reaction gas toward the surface 10a of the base wafer 10.

[0017] In addition, a rotating device 40 on which the base wafer 10 is arranged is arranged on the lower side of the reaction chamber 20a. In the present embodiment, the base wafer 10 is arranged on a susceptor 50 arranged on the rotating device 40.

[0018] The rotating device 40 is configured to include a cylindrical portion 41, a rotating shaft 42, a driving portion 43, etc. The cylindrical portion 41 is a bottomed cylindrical member that forms a hollow chamber 41a, and a susceptor 50 is arranged at an end portion on the opening end side. And the cylindrical portion 41 is arranged such that the opening end side faces upward of the chamber 20 (that is, the reaction gas supply pipe 30 side). Note that, although specifically described later, an inert gas described later is introduced into the cylindrical portion 41 (that is, the hollow chamber 41a).

[0019] The rotating shaft 42 is a shaft that rotates by the output of the driving portion 43, and is connected to the cylindrical portion 41 so as to be rotatable integrally with the cylindrical portion 41. The driving portion 43 is composed of a motor or the like that outputs a rotational force, and rotates the rotating shaft 42. And in the rotating device 40 configured in this way, the rotating shaft 42 rotates by the output of the driving portion 43, and the cylindrical portion 41 and the susceptor 50 rotate integrally.

[0020] The susceptor 50 has an outer shape that matches the opening end portion of the cylindrical portion 41. And the susceptor 50 of the present embodiment substantially closes the cylindrical portion 41 by being arranged at the opening end portion of the cylindrical portion 41. Thereby, the hollow chamber 41a of the cylindrical portion 41 is substantially closed.

[0021] Hereinafter, the shape of the susceptor 50 of the present embodiment will be described. The susceptor 50 of the present embodiment has a shape having an outer edge susceptor portion 510 and an inner edge susceptor portion 520.

[0022] The outer-edge susceptor part 510 is plate-shaped with one surface 510a and the other surface 510b, and a first recess 511 for accommodating the base wafer 10 is formed on the one surface 510a side. Further, the outer-edge susceptor part 510 has a second recess 512 for arranging the inner-edge susceptor part 520 formed at a substantially central part of the bottom surface of the first recess 511. Furthermore, the outer-edge susceptor part 510 has a through-hole 513 formed at a substantially central part of the bottom surface of the second recess 512. Also, the outer-edge susceptor part 510 has a step part 514 for fitting with the open-end part of the cylindrical part 41 formed at the outer-edge part on the other surface 510b side. And the outer-edge susceptor part 510 is arranged in the cylindrical part 41 when the step part 514 is fitted with the open-end part of the cylindrical part 41.

[0023] The inner-edge susceptor part 520 is configured to have a convex part 521 arranged in the through-hole 513 and a plate part 522 arranged at the bottom surface of the second recess 512 with the convex part 521 arranged at a substantially central part. In other words, the inner-edge susceptor part 520 is configured such that a recessed part is formed on the outer-edge side of the plate part 522 and a convex part 521 is formed on the inner-edge side. Note that the convex part 521 has the same shape and the same size as the through-hole 513 and is configured to close the through-hole 513 when arranged. However, the inner-edge susceptor part 520 of the present embodiment is arranged in a state separable from the outer-edge susceptor part 510.

[0024] And in the present embodiment, the hollow chamber 41a of the cylindrical part 41 is substantially closed by the susceptor 50. For this reason, in the present embodiment, the susceptor 50 constitutes a lid part C for closing the cylindrical part 41. Also, the susceptor 50 arranged to close the cylindrical part 41 is arranged in a state exposed to the hollow chamber 41a. Specifically, the part of the other surface 510b of the outer-edge susceptor part 510 different from the part where the step part 514 is formed and the part where the through-hole 513 is formed becomes an exposed surface S1 exposed to the hollow chamber 41a. The front end surface of the inner-edge susceptor part 520 in the protruding direction of the convex part 521 becomes an exposed surface S2 exposed to the hollow chamber 41a.

[0025] Here, the pressure caused by the outer edge susceptor portion 510 on the exposed surface S1 of the outer edge susceptor portion 510 (hereinafter, also simply referred to as the pressure of the outer edge susceptor portion 510) is (the mass of the outer edge susceptor portion 510) / (the area of the exposed surface S 1 ). Similarly, the pressure caused by the inner edge susceptor portion 520 on the exposed surface S2 of the inner edge susceptor portion 520 (hereinafter, also simply referred to as the pressure of the inner edge susceptor portion 520) is (the mass of the inner edge susceptor portion 520) / (the area of the exposed surface S2). And the susceptor 50 of the present embodiment is configured such that the pressure of the inner edge susceptor portion 520 is smaller than the pressure of the outer edge susceptor portion 510. For this reason, in the present embodiment, the pressure of the inner edge susceptor portion 520 corresponds to the pressure of the minimum closing portion.

[0026] In the hollow chamber 41a, a heater 60 as a heating device for heating the base wafer 10 from the back surface 10b side is disposed. The heater 60 is, for example, a carbon resistance heater, and although not shown, it is connected to the control unit 110 and heated to a predetermined temperature.

[0027] The chamber 20 is provided with an exhaust pipe 70 for reaction gas for exhausting the reacted gas and unreacted gas downward. The exhaust pipe 70 for reaction gas has a portion on the side opposite to the chamber 20 side connected to a vacuum pump 80. Further, the exhaust pipe 70 for reaction gas is provided with a pressure detection unit 71 and a pressure adjustment valve 72 between the chamber 20 and the vacuum pump 80. And the opening / closing ratio of the pressure adjustment valve 72 is adjusted based on the pressure of the pressure detection unit 71 in the reaction chamber 20a, and adjusted to a predetermined pressure (i.e., a specific pressure) .

[0028] In the hollow chamber 41a, an inert gas supply pipe 90 for supplying an inert gas and an inert gas exhaust pipe 100 for exhausting the inert gas are arranged. The inert gas supply pipe 90 is provided with a mass flow controller 91 and supplies the inert gas into the hollow chamber 41a at a constant flow rate. At this time, in the present embodiment, as will be described later, the pressure in the hollow chamber 41a is adjusted to be higher than the pressure in the reaction chamber 20a. Therefore, the entry of the reaction gas into the hollow chamber 41a from the gap between the lid portion C (that is, the susceptor 50) and the cylindrical portion 41 is suppressed.

[0029] The portion of the inert gas exhaust pipe 100 on the side opposite to the hollow chamber 41a is connected to a vacuum pump 80. Further, the inert gas exhaust pipe 100 is provided with a pressure detection unit 101 and a pressure regulating valve 102 between the hollow chamber 41a and the vacuum pump 80. Then, the pressure in the hollow chamber 41a is adjusted to a predetermined pressure by adjusting the opening / closing ratio of the pressure regulating valve 102 based on the pressure detected by the pressure detection unit 101. In the present embodiment, the inert gas supply pipe 90 and the inert gas exhaust pipe 100 are arranged in the cylindrical portion 41 and communicate with the hollow chamber 41a.

[0030] Here, the reaction gas exhaust pipe 70 and the inert gas exhaust pipe 100 of the present embodiment are partially connected at a position on the side opposite to the vacuum pump 80 with the respective pressure regulating valves 72, 102 interposed therebetween. The pressure detection unit 101 is arranged to detect the pressure difference at the connection portion between the reaction gas exhaust pipe 70 and the inert gas exhaust pipe 100. That is, the pressure detection unit 101 of the present embodiment detects the differential pressure between the pressure in the reaction chamber 20a and the pressure in the hollow chamber 41a.

[0031] Although not particularly shown, in the hollow chamber 41a, there is arranged susceptor lifting equipment for assisting the loading of the susceptor 50 on which the base wafer 10 is placed into the reaction chamber 20a by the transfer robot and the unloading of the susceptor 50 from the reaction chamber 20a. This susceptor lifting equipment has, for example, a function of lifting the susceptor 50 when unloading the susceptor 50 to separate it from the cylindrical portion 41 and delivering the susceptor 50 to the transfer robot. At this time, in the present embodiment, the susceptor 50 has a configuration including an outer edge susceptor portion 510 and an inner edge susceptor portion 520, and the inner edge susceptor portion 520 can be separated from the outer edge susceptor portion 510. For this reason, it is possible to facilitate the delivery of the base wafer 10. However, the manufacturing apparatus 1 may be one that performs the loading and unloading of only the base wafer 10 without moving the susceptor 50, instead of performing the loading and unloading of the susceptor 50 on which the base wafer 10 is placed.

[0032] Furthermore, the manufacturing apparatus 1 includes a control unit 110. The control unit 110 is composed of a microcomputer or the like including a storage unit and the like composed of non-transitory physical storage media such as a CPU, ROM, RAM, flash memory, and HDD (not shown). The CPU is the abbreviation of Central Processing Unit, the ROM is the abbreviation of Read Only Memory, the RAM is the abbreviation of Random Access Memory, and the HDD is the abbreviation of Hard Disk Drive.

[0033] Then, the control unit 110 realizes various control operations by the CPU reading various data from the storage unit and executing them. Specifically, the control unit 110 adjusts the opening / closing rate of the pressure regulating valve 72 so that the pressure in the reaction chamber 20a becomes a predetermined pressure based on the pressure detected by the pressure detection unit 71. Also, the control unit 110 adjusts the opening degree of the pressure regulating valve 102 so that the pressure in the hollow chamber 41a is higher than the pressure in the reaction chamber 20a and the pressure in the hollow chamber 41a is not more than a predetermined pressure, with respect to the pressure in the reaction chamber 20a and the pressure in the hollow chamber 41a. In the present embodiment, since the pressure detection unit 101 is a differential pressure gauge, the control unit 110 adjusts the opening / closing rate of the pressure regulating valve 102 based on the result of the pressure detection unit 101.

[0034] Here, the predetermined pressure is the pressure at which the lid portion C does not float (i.e., the lid portion C does not separate) due to the pressure in the hollow chamber 41a. In the manufacturing apparatus 1 of the present embodiment, the susceptor 50 has an outer edge susceptor portion 510 and an inner edge susceptor portion 520. And, the pressure of the inner edge susceptor portion 520 is made lower than the pressure of the outer edge susceptor portion 510. For this reason, the predetermined pressure is set to the pressure at which the inner edge susceptor portion 520 does not float, and is set to be equal to or lower than the pressure of the inner edge susceptor portion 520.

[0035] The above is the configuration of the manufacturing apparatus 1 in the present embodiment. Next, a method for growing the epitaxial layer 11 on the surface 10a of the base wafer 10 using the above manufacturing apparatus 1 will be described.

[0036] First, in the manufacturing apparatus 1 as described above, while rotating the susceptor 50 on which the base wafer 10 is placed by the rotating device 40 at, for example, 200 rpm, the reaction chamber 20a is heated by the heater 60 until it reaches about 1600 to 1750°C. And, in the manufacturing apparatus 1, a reaction gas is supplied from the reaction gas supply pipe 30 toward the reaction chamber 20a, and an inert gas is supplied from the inert gas supply pipe 90.

[0037] In this case, in the present embodiment, the pressure in the hollow chamber 41a is adjusted to be higher than the pressure in the reaction chamber 20a. Thereby, it is possible to suppress the reaction gas from entering the hollow chamber 41a. For example, as shown in FIG. 2, when the pressure in the hollow chamber 41a is equal to the pressure in the reaction chamber 20a (i.e., the differential pressure is 0), it is confirmed that the resistance value of the heater 60 increases steeply as the usage time becomes longer. On the other hand, in the present embodiment, the pressure in the hollow chamber 41a is made higher than the pressure in the reaction chamber 20a. For example, FIG. 2 shows the result of making the pressure in the hollow chamber 41a 0.6 gf / cm 2 higher than the pressure in the reaction chamber 20a. Thereby, it is possible to effectively suppress the reaction gas from entering the hollow chamber 41a, and it is possible to suppress the shortening of the life of the heater 60.

[0038] In addition, in the present embodiment, the pressure in the hollow chamber 41a is adjusted to be higher than the pressure in the reaction chamber 20a and equal to or lower than the pressure in the inner edge susceptor portion 520. For example, when the mass of the inner edge susceptor portion 520 is 40 g and the area of the exposed surface S2 is 50 cm 2 , the pressure in the inner edge susceptor portion 520 is 0.8 gf / cm 2 (i.e., 78.4 Pa). Therefore, the hollow chamber 41a is controlled so that the pressure is 0.8 gf / cm 2 or less. Accordingly, even if the pressure in the hollow chamber 41a is increased, it is possible to suppress the problem that the inner edge susceptor portion 520 (i.e., the susceptor 50) floats from the cylindrical portion 41 and the inner edge susceptor portion 520 collides with the base wafer 10 or the like, and the epitaxial layer 11 cannot be appropriately grown.

[0039] The inert gas is, for example, argon, but may be helium or the like. Further, the inert gas has, for example, a flow rate of 6 slm, but can be appropriately changed. However, when the flow rate of the inert gas is too small, even if the opening / closing rate of the pressure regulating valve 102 is changed, the change in the exhaust amount may be small, and it may be difficult to adjust the pressure in the hollow chamber 41a with the pressure regulating valve 102. Therefore, the flow rate of the inert gas is preferably at least 1 slm.

[0040] In addition, by changing the thickness and material of the susceptor 50 to increase the mass, the pressure of the susceptor 50 can be increased, and the pressure in the hollow chamber 41a can be further increased. However, when the thickness of the susceptor 50 is increased, the heat capacity increases, and the time until the base wafer 10 is heated to a predetermined temperature becomes longer. Therefore, the thickness of the susceptor 50 (for example, the inner edge susceptor portion 520) is preferably, for example, 10 mm or less, and more preferably 5 mm or less.

[0041] On the other hand, when the mass of the susceptor 50 is increased, it becomes easier to increase the pressure in the hollow chamber 41a. However, when the susceptor 50 is rotated by the rotating device 40, vibrations are likely to increase, and the susceptor 50 may easily float due to rotation. For this reason, it is not preferable for the susceptor 50 to be made of a material with too large a mass. For example, from the viewpoints of mass, processing accuracy, and heat resistance, it is preferably a material containing carbon. Therefore, in the present embodiment, for example, it is made of a material in which SiC or the like, and SiC, tantalum carbide (TaC), niobium carbide (NbC), or the like is coated on the surface of isotropic graphite. In this case, for example, the pressure converted from the density of C with a thickness of 10 mm is preferably 2 1.8 gf / cm 2 (176.4 Pa) or less, and if the thickness is 5 mm, it is preferably 0.9 gf / cm

[0042] According to the present embodiment described above, the pressure in the hollow chamber 41a is higher than the pressure in the reaction chamber 20a. Therefore, it is possible to suppress the reaction gas from entering the hollow chamber 41a from the reaction chamber 20a, and it is possible to suppress the reaction between the reaction gas and the heater 60 and the reduction in the life of the heater 60.

[0043] Also, the pressure in the hollow chamber 41a is equal to or lower than the pressure in the inner-edge susceptor portion 520 (that is, the pressure at the minimum blocking portion). Therefore, by increasing the pressure in the hollow chamber 41a, it is possible to suppress the inner-edge susceptor portion 520 from floating from the cylindrical portion 41 and the occurrence of a problem that the inner-edge susceptor portion 520 collides with the base wafer 10 or the like and the epitaxial layer 11 cannot be grown appropriately. That is, in the manufacturing apparatus 1 of the present embodiment, the epitaxial layer 11 can be easily grown preferably.

[0044] (1) In the present embodiment, the susceptor 50 has an outer-edge susceptor portion 510 and an inner-edge susceptor portion 520 and is separable. Therefore, when placing the base wafer 10 or the like, it is possible to transport only the inner-edge susceptor portion 520, and the degree of freedom in installing the base wafer 10 can be improved.

[0045] (Second Embodiment) The second embodiment will be described. This embodiment is the same as the first embodiment except that the shape of the susceptor 50 is changed. Since other aspects are the same as those of the first embodiment, the description thereof will be omitted here.

[0046] In this embodiment, as shown in FIG. 3, the susceptor 50 is composed of a single member. And, the susceptor 50 has a recess 51 formed on one surface 50a side for accommodating the base wafer 10. Further, the susceptor 50 has a stepped portion 52 formed on the other surface 50b side for fitting with the open end portion of the cylindrical portion 41. And, by fitting the stepped portion 52 to the open end portion of the cylindrical portion 41, the susceptor 50 is arranged so as to close the cylindrical portion 41. Note that, in this embodiment, the susceptor 50 is composed of a single member. Therefore, the susceptor 50 constitutes the lid portion C.

[0047] Also, this susceptor 50 is composed of a single member, and a portion different from the portion where the stepped portion 52 is formed on the other surface 50b becomes the exposed surface S3 exposed to the hollow chamber 41a. Therefore, in this susceptor 50, the pressure caused by the susceptor 50 on the exposed surface S3 (hereinafter, also simply referred to as the pressure of the susceptor 50) is (the mass of the susceptor 50) / (the area of the exposed surface S3). And, in this embodiment, the pressure of the susceptor 50 corresponds to the pressure of the minimum closing portion.

[0048] When growing the epitaxial layer 11 on the surface 10a of the base wafer 10, the control unit 110 adjusts the pressure in the hollow chamber 41a to be higher than that in the reaction chamber 20a and equal to or lower than the pressure of the susceptor 50.

[0049] According to the present embodiment described above, since the pressure in the hollow chamber 41a is adjusted to be higher than the pressure in the reaction chamber 20a and equal to or lower than the pressure of the minimum closing portion, the same effects as those of the first embodiment can be obtained.

[0050] (1) In this embodiment, the lid portion C is constituted by a susceptor 50 of a member. Therefore, compared with the case where the susceptor 50 is constituted by the outer edge susceptor portion 510 and the inner edge susceptor portion 520 as in the first embodiment, the pressure of the minimum closing portion can be increased, and the pressure of the hollow chamber 41a can be easily increased. Therefore, further, it becomes easy to suppress the reaction gas from entering the hollow chamber 41a from the reaction chamber 20a, and it is possible to suppress the reduction of the life of the heater 60.

[0051] (Third Embodiment) The third embodiment will be described. In this embodiment, the shape of the susceptor 50 is changed with respect to the second embodiment. Since the other aspects are the same as those of the second embodiment, the description is omitted here.

[0052] In this embodiment, as shown in FIG. 4, a through hole 53 is formed in the bottom portion 51a of the recess 51 of the susceptor 50. Therefore, the hollow chamber 41a is closed by the susceptor 50 and the base wafer 10. That is, in this embodiment, the susceptor 50 and the base wafer 10 constitute the lid portion C.

[0053] Further, a portion of the other surface 50b of the susceptor 50 different from the portion where the through hole 53 is formed becomes the exposed surface S4. A portion of the back surface 10b of the base wafer 10 that closes the through hole 53 becomes the exposed surface S5.

[0054] The pressure caused by the susceptor 50 on the exposed surface S 4 of the susceptor 50 (hereinafter, also simply referred to as the pressure of the susceptor 50) is represented by (mass of the susceptor 50) / (area of the exposed surface S4). Similarly, the pressure caused by the base wafer 10 on the exposed surface S5 of the base wafer 10 (hereinafter, also simply referred to as the pressure of the base wafer 10) is represented by (mass of the base wafer 10) / (area of the exposed surface S5). And in this embodiment, the pressure of the susceptor 50 is made higher than the pressure of the base wafer 10. Therefore, in this embodiment, the pressure of the base wafer 10 corresponds to the pressure of the minimum closing portion.

[0055] When the control unit 110 grows the epitaxial layer 11 on the surface 10a of the base wafer 10, it adjusts the pressure in the hollow chamber 41a to be higher than that in the reaction chamber 20a and not higher than the pressure of the base wafer 10.

[0056] According to the present embodiment described above, since the pressure in the hollow chamber 41a is adjusted to be higher than the pressure in the reaction chamber 20a and not higher than the pressure of the minimum blocking portion, the same effects as those of the first embodiment can be obtained.

[0057] (Fourth Embodiment) The fourth embodiment will be described. In this embodiment, the arrangement position of the supply pipe 90 for the inert gas is adjusted with respect to the first embodiment. Since other aspects are the same as those of the first embodiment, the description thereof is omitted here.

[0058] In this embodiment, as shown in FIG. 5, the opening end from which the inert gas is discharged in the supply pipe 90 for the inert gas is arranged closer to the center of the hollow chamber 41a than the opening end that sucks the inert gas in the exhaust pipe 100 for the inert gas.

[0059] According to the present embodiment described above, since the pressure in the hollow chamber 41a is adjusted to be higher than the pressure in the reaction chamber 20a and not higher than the pressure of the minimum blocking portion, the same effects as those of the first embodiment can be obtained.

[0060] (1) In this embodiment, the opening end from which the inert gas is discharged in the supply pipe 90 for the inert gas is arranged closer to the center of the hollow chamber 41a than the opening end that sucks the inert gas in the exhaust pipe 100 for the inert gas. Therefore, it is easier to fill the hollow chamber 41a with the inert gas.

[0061] (Fifth Embodiment) The fifth embodiment will be described. In this embodiment, the shape of the supply pipe 90 for the inert gas is changed with respect to the first embodiment. Since other aspects are the same as those of the first embodiment, the description thereof is omitted here.

[0062] In this embodiment, as shown in FIG. 6, the opening end side of the supply pipe 90 for the inert gas is bent to the side opposite to the exhaust pipe 100 for the inert gas.

[0063] According to the present embodiment described above, since the pressure in the hollow chamber 41a is adjusted to be higher than the pressure in the reaction chamber 20a and not higher than the pressure at the minimum blockage portion, the same effects as those of the first embodiment can be obtained.

[0064] (1) In this embodiment, the opening end side of the supply pipe 90 for the inert gas is bent to the side opposite to the exhaust pipe 100 for the inert gas. Therefore, it is easy to fill the inert gas into the hollow chamber 41a.

[0065] (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 the embodiments and structures. The present disclosure includes various modifications and modifications within an equivalent range. In addition, various combinations and forms, and further other combinations and forms including only one element, more, or less thereof, are within the scope and spirit of the present disclosure.

[0066] For example, in each of the above embodiments, the manufacturing apparatus 1 for growing the epitaxial layer 11 of SiC has been described as an example. However, the configuration of the epitaxial layer 11 to be grown can be appropriately changed. For example, the manufacturing apparatus 1 for growing the epitaxial layer 11 of gallium nitride may be used.

[0067] In each of the above embodiments, an example has been described in which the pressure detection unit 101 that detects the pressure in the hollow chamber 41a detects the differential pressure between the hollow chamber 41a and the reaction chamber 20a. However, the pressure in the hollow chamber 41a may be detected by the pressure detection unit 101, and the differential pressure between the reaction chamber 20a and the hollow chamber 41a may be derived by the control unit 110. However, in order to suppress the reaction gas from leaking around the back surface 10b side of the base wafer 10 and prevent the lid portion C from floating, etc., detailed pressure management is required. For this reason, it is preferable that the pressure detection unit 101 directly detects the differential pressure between the reaction chamber 20a and the hollow chamber 41a.

[0068] Moreover, the above embodiments can be combined. For example, the fourth and fifth embodiments may be appropriately combined with the first to third embodiments, and the shape of the supply pipe 90 for the inert gas may be appropriately changed.

[0069] The control unit and its method described in the present disclosure may be realized 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 control unit and its method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Or, the control unit and its method described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured by one or more hardware logic circuits. Further, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by a computer.

Explanation of Reference Numerals

[0070] 10 Base wafer 10a Surface 11 Epitaxial layer 20 Chamber (reaction chamber forming portion) 20a Reaction chamber 40 Rotating device 41 Cylindrical part 41a Hollow chamber 40 Rotating device 50 Susceptor 60 Heating device 90 Supply pipe for inert gas 100 Exhaust pipe for inert gas C Lid part

Claims

1. A semiconductor wafer manufacturing apparatus, comprising: a reaction chamber forming section (20) that forms a reaction chamber (20a) into which a reaction gas is introduced and on the surface (10a) side of a base wafer (10), an epitaxial layer (11) is grown; a reaction gas supply pipe (30) provided in the reaction chamber for supplying a reaction gas for growing the epitaxial layer in the reaction chamber; a reaction gas exhaust pipe (70) provided in the reaction chamber for exhausting unreacted gas from the reaction chamber; a susceptor (50) disposed in the reaction chamber on which the base wafer is placed; a rotating device (40) having a cylindrical portion (41) on one end side of which the susceptor is disposed, for rotating the susceptor together with the base wafer; a lid portion (C) including the susceptor disposed on one end side of the cylindrical portion; a heating device (60) provided in the hollow chamber defined by the cylindrical portion and the lid portion as a hollow chamber (41a) for heating the base wafer; an inert gas supply pipe (90) provided in the hollow chamber for introducing an inert gas into the hollow chamber; an inert gas exhaust pipe (100) provided in the hollow chamber for exhausting the inert gas, and comprising: The pressure of the lid portion is defined as the value obtained by dividing the mass of the lid portion by the area (S2, S3, S5) of the portion of the lid portion exposed to the hollow chamber. When the smallest portion of the pressure of the lid portion is defined as the pressure of the minimum blockage portion, the amount of the inert gas exhausted from the inert gas exhaust pipe is adjusted such that the pressure in the hollow chamber is higher than the pressure in the reaction chamber and is equal to or lower than the pressure of the minimum blockage portion. A semiconductor wafer manufacturing apparatus having a control unit (110) for controlling the amount of the inert gas.

2. The susceptor is supported on one end side of the cylindrical portion and includes an outer edge susceptor portion (510) in which a through hole (513) is formed, and a portion disposed in the through hole, and an inner edge susceptor portion (520) supported by the outer edge susceptor portion and separable from the outer edge susceptor portion. The lid portion is composed of the susceptor. The semiconductor wafer manufacturing apparatus according to claim 1, wherein the pressure of the minimum blockage portion is defined as the value obtained by dividing the mass of the inner edge susceptor portion by the area (S2) of the portion of the inner edge susceptor portion exposed to the hollow chamber.

3. The susceptor is composed of a member disposed at the open end of the cylindrical portion. The manufacturing apparatus for a semiconductor wafer according to claim 1, wherein the pressure of the minimum blocking portion is a value obtained by dividing the mass of the susceptor by the area (S3) of the portion of the susceptor exposed to the hollow chamber.

4. The susceptor has a through hole (53) formed therein, The base wafer is disposed in a state of closing the through hole, The lid portion is composed of the susceptor and the base wafer, The manufacturing apparatus for a semiconductor wafer according to claim 1, wherein the pressure of the minimum blocking portion is a value obtained by dividing the mass of the base wafer by the area (S5) of the portion of the base wafer exposed to the hollow chamber.

5. The manufacturing apparatus for a semiconductor wafer according to any one of claims 1 to 4, wherein an opening end portion that discharges the inert gas of the inert gas supply pipe is closer to the center in the hollow chamber than an opening end portion that sucks the inert gas of the inert gas exhaust pipe.

6. The manufacturing apparatus for a semiconductor wafer according to any one of claims 1 to 4, wherein a side of the opening end portion that discharges the inert gas of the inert gas supply pipe is bent to the side opposite to a side of the opening end portion that sucks the inert gas of the inert gas exhaust pipe.

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