Vapor growth device and vapor growth method

Abstract

To provide a vapor growth device and method capable of suppressing deposition of by-products.SOLUTION: A vapor growth device 100 includes: a reaction chamber 10; a holder 15 on which a substrate W can be placed and which is rotatable; a gas introduction unit 11 capable of supplying a first process gas SG1 containing a material gas and a second process gas SG2 not containing the material gas into the reaction chamber; and a control unit 14 that controls supply of the first process gas and the second process gas into the reaction chamber and controls rotation of the holder. The control unit performs control so as to supply the second process gas into the reaction chamber during a first period before forming a film on the substrate, and supply the first process gas and the second process gas into the reaction chamber during a second period in which a film is formed on the substrate after the first period. The control unit also performs control such that a first rotational speed of the holder during the first period is greater than a second rotational speed of the holder during the second period.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vapor phase growth apparatus and a vapor phase growth method for forming a film by supplying a gas to a substrate. [Background technology]

[0002] One method for forming high-quality semiconductor films is epitaxial growth, which involves forming a single-crystal film on the surface of a substrate by vapor phase growth. In a vapor phase growth apparatus using epitaxial growth, the substrate is placed on a holder in a reaction chamber maintained at normal or reduced pressure.

[0003] Then, while the substrate is heated, a process gas containing the source gas for the film is supplied to the reaction chamber through a gas inlet at the top of the reaction chamber, where a thermal reaction of the process gas occurs on the surface of the substrate, forming an epitaxial film on the surface of the substrate.

[0004] During the formation of an epitaxial film, by-products may deposit on components in a reaction chamber. The by-products originate from the source gas. If the by-products fall onto the surface of the substrate before or during the formation of the epitaxial film, the by-products are incorporated into the epitaxial film. The by-products incorporated into the epitaxial film form defects in the epitaxial film. The defects formed in the epitaxial film may cause, for example, defects in semiconductor devices manufactured using the epitaxial film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-46855 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a vapor phase growth apparatus and a vapor phase growth method that are capable of suppressing the deposition of by-products. [Means for solving the problem]

[0007] A vapor phase growth apparatus according to one embodiment of the present invention comprises a reaction chamber, a rotatable holder disposed within the reaction chamber and capable of placing a substrate thereon, a gas inlet disposed above the reaction chamber and capable of supplying a first process gas containing a raw material gas and a second process gas not containing the raw material gas to the reaction chamber, and a control unit that controls the supply of the first process gas and the second process gas to the reaction chamber and the rotation of the holder, wherein the control unit controls the supply of the second process gas to the reaction chamber during a first period before a film is formed on the substrate, and controls the supply of the first process gas and the second process gas to the reaction chamber during a second period after the first period during which the film is formed on the substrate, and the control unit controls the first rotation speed of the holder during the first period to be greater than the second rotation speed of the holder during the second period.

[0008] In the vapor phase growth apparatus of the above aspect, it is preferable that the control unit controls the first rotation speed to be 300 rpm or more and the second rotation speed to be less than 300 rpm.

[0009] In the vapor phase growth apparatus of the above aspect, it is preferable that the control unit controls the first rotation speed to be at least twice as fast as the second rotation speed.

[0010] In the vapor phase growth apparatus of the above aspect, it is preferable that the control unit controls the flow rate of the second process gas supplied to the reaction chamber during the first period to be greater than the sum of the flow rate of the first process gas supplied to the reaction chamber during the second period and the flow rate of the second process gas during the second period.

[0011] In the vapor phase growth apparatus of the above aspect, it is preferable that the second process gas contains hydrogen gas, and the control unit controls the flow rate of the hydrogen gas supplied to the reaction chamber during the first period to be greater than the flow rate of the hydrogen gas supplied to the reaction chamber during the second period.

[0012] In the vapor phase growth apparatus of the above aspect, it is preferable that the second process gas contains chlorine gas, and the control unit controls the flow rate of chlorine gas supplied to the reaction chamber during the first period to be greater than the flow rate of chlorine gas supplied to the reaction chamber during the second period.

[0013] In the vapor phase growth apparatus of the above aspect, it is preferable that the control unit controls the pressure in the reaction chamber so that a first pressure in the reaction chamber during the first period is greater than a second pressure in the reaction chamber during the second period.

[0014] In the vapor phase growth apparatus of the above aspect, a first heater provided below the holder; a sidewall provided in a region of the reaction chamber between the holder and the gas inlet and extending along a wall surface of the reaction chamber; a second heater provided between the wall surface and the side wall, It is preferable that, during the first period, the control unit controls the first heater and the second heater so that the shape of the substrate becomes upwardly convex.

[0015] One embodiment of the vapor phase growth method of the present invention is a vapor phase growth method for forming a film on a substrate placed on a holder installed in a reaction chamber, wherein a second process gas not containing a raw material gas is supplied into the reaction chamber during a first period before the film is formed on the substrate, and the holder is rotated at a first rotational speed during the first period, and a first process gas containing the raw material gas is supplied into the reaction chamber during a second period after the first period during which the film is formed on the substrate, and the holder is rotated at a second rotational speed lower than the first rotational speed during the second period.

[0016] In the vapor phase growth method of the above aspect, it is preferable that the first rotation speed is 300 rpm or more, and the second rotation speed is less than 300 rpm. [Effects of the Invention]

[0017] According to the present invention, it is possible to realize a vapor phase growth apparatus and a vapor phase growth method that are capable of suppressing the deposition of by-products. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic cross-sectional view of a vapor phase growth apparatus according to a first embodiment. [Figure 2] FIG. 2 is an explanatory diagram of control by a control circuit in the vapor phase growth apparatus of the first embodiment. [Figure 3] FIG. 2 is an explanatory diagram of a problem with the vapor phase growth apparatus of the first embodiment. [Figure 4] FIG. 2 is an explanatory diagram of the operation and effect of the vapor phase growth apparatus of the first embodiment. [Figure 5] FIG. 2 is an explanatory diagram of the operation and effect of the vapor phase growth apparatus of the first embodiment. [Figure 6] FIG. 4 is an explanatory diagram of control by a control circuit in a vapor phase growth apparatus according to a modified example of the first embodiment. [Figure 7] FIG. 6 is an explanatory diagram of control by a control circuit in a vapor phase growth apparatus according to a second embodiment. [Figure 8] FIG. 10 is an explanatory diagram of control by a control circuit in a vapor phase growth apparatus according to a first modified example of the second embodiment. [Figure 9] FIG. 10 is an explanatory diagram of control by a control circuit in a vapor phase growth apparatus according to a third embodiment. [Figure 10] FIG. 10 is an explanatory diagram of control by a control circuit in a vapor phase growth apparatus according to a fourth embodiment. [Figure 11] FIG. 10 is a schematic cross-sectional view of a vapor phase growth apparatus according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] In this specification, the same or similar components may be denoted by the same reference numerals.

[0021] In this specification, the direction of gravity when the vapor deposition apparatus is set up so that a film can be formed is defined as "down," and the opposite direction is defined as "up." Therefore, "lower" means a position in the direction of gravity relative to a reference, and "lower" means the direction of gravity relative to a reference. "Upper" means a position in the opposite direction to the direction of gravity relative to a reference, and "upper" means the opposite direction to the direction of gravity relative to a reference. Furthermore, "vertical direction" means the direction of gravity.

[0022] In addition, in this specification, the term "process gas" is a general term for gases used to form a film, and is a concept that includes, for example, source gas, assist gas, dopant gas, carrier gas, purge gas, and mixtures thereof.

[0023] (First embodiment) A vapor phase growth apparatus according to a first embodiment includes a reaction chamber, a rotatable holder disposed within the reaction chamber and capable of supporting a substrate, a gas inlet disposed above the reaction chamber and capable of supplying a first process gas containing a source gas and a second process gas not containing the source gas to the reaction chamber, and a controller configured to control the supply of the first and second process gases to the reaction chamber and to control the rotation of the holder. The controller controls the supply of the second process gas to the reaction chamber during a first period before a film is formed on the substrate, and the supply of the first and second process gases to the reaction chamber during a second period after the first period during which a film is formed on the substrate. The controller controls the first rotation speed of the holder during the first period to be greater than the second rotation speed of the holder during the second period.

[0024] 1 is a schematic cross-sectional view of a vapor phase growth apparatus according to a first embodiment. The vapor phase growth apparatus 100 according to the first embodiment is, for example, a single-wafer type epitaxial growth apparatus that epitaxially grows a single-crystal SiC film (silicon carbide film) on a single-crystal SiC substrate (silicon carbide substrate). The vapor phase growth apparatus 100 according to the first embodiment is a vertical type vapor phase growth apparatus in which a process gas is supplied vertically to the surface of the SiC substrate.

[0025] The vapor phase growth apparatus 100 of the first embodiment includes a reaction chamber 10, a gas introduction unit 11, a vacuum pump 12, and a control circuit 14 (control unit). The reaction chamber 10 includes a susceptor 15 (holder), a rotor 16, a rotation shaft 18, a rotation drive mechanism 20, a first heater 22, a reflector 28, a support column 30, a fixed base 32, a fixed shaft 34, a hood 40 (side wall), a second heater 42, and a gas exhaust port 44. The first heater 22 includes a lower heater 22a and an upper heater 22b.

[0026] The vapor phase growth apparatus 100 of the first embodiment includes a first source gas supply pipe 81, a second source gas supply pipe 82, a purge gas supply pipe 83, and a gas exhaust pipe 84.

[0027] The reaction chamber 10 is made of, for example, stainless steel. The reaction chamber 10 has a cylindrical wall 10a. In the reaction chamber 10, a SiC film 13 is formed on a wafer W. The wafer W is an example of a substrate. The SiC film 13 is an example of a film.

[0028] The susceptor 15 is provided in the reaction chamber 10. A wafer W can be placed on the susceptor 15. The susceptor 15 may have an opening in the center. The susceptor 15 is an example of a holder.

[0029] The susceptor 15 is made of a highly heat-resistant material such as SiC, carbon, or carbon coated with SiC or TaC.

[0030] The susceptor 15 is fixed to the upper part of a rotor 16. The rotor 16 is fixed to a rotation shaft 18. The susceptor 15 is indirectly fixed to the rotation shaft 18.

[0031] The rotation shaft 18 can be rotated by a rotation drive mechanism 20. The rotation drive mechanism 20 rotates the rotation shaft 18, thereby rotating the susceptor 15. By rotating the susceptor 15, the wafer W placed on the susceptor 15 can be rotated.

[0032] The rotation drive mechanism 20 can rotate the susceptor 15 at a rotation speed of, for example, 300 rpm or more and 1000 rpm or less. The rotation drive mechanism 20 can rotate the wafer W at a rotation speed of, for example, 300 rpm or more and 1000 rpm or less. The rotation drive mechanism 20 is composed of, for example, a motor and a bearing.

[0033] The first heater 22 is provided below the susceptor 15. The first heater 22 is provided inside the rotating body 16. The first heater 22 heats the wafer W held on the susceptor 15 from below. The first heater 22 is, for example, a resistance heater.

[0034] The first heater 22 includes, for example, a lower heater 22a and an upper heater 22b. The lower heater 22a is, for example, disk-shaped and mainly heats the inner portion of the wafer W. The upper heater 22b is, for example, annular and mainly heats the outer periphery of the wafer W.

[0035] The reflector 28 is provided below the first heater 22. The first heater 22 is provided between the reflector 28 and the susceptor 15.

[0036] The reflector 28 reflects heat radiated downward from the first heater 22, thereby improving the heating efficiency of the wafer W. The reflector 28 also prevents members below the reflector 28 from being heated. The reflector 28 has, for example, a disk shape. The reflector 28 is formed of a highly heat-resistant material, for example, carbon coated with SiC.

[0037] The reflector 28 is fixed to a fixed base 32 by, for example, a plurality of support columns 30. The fixed base 32 is supported by, for example, a fixed shaft 34.

[0038] A push-up pin (not shown) is provided inside the rotor 16 in order to detach the susceptor 15 from the rotor 16. The push-up pin penetrates, for example, the reflector 28 and the first heater 22.

[0039] The hood 40 is provided in the region between the susceptor 15 and the gas inlet 11 of the reaction chamber 10. The hood 40 is provided along the wall surface of the wall 10a of the reaction chamber 10. The hood 40 is an example of a side wall. The hood 40 may also be referred to as a liner.

[0040] The hood 40 has, for example, a cylindrical shape. The hood 40 has a function of preventing the process gas from coming into contact with the second heater 42. The hood 40 is formed of a highly heat-resistant material, for example, carbon coated with SiC.

[0041] The second heater 42 is provided between the hood 40 and the wall surface of the wall 10a of the reaction chamber 10. The second heater 42 heats the wafer W held on the susceptor 15 from above.

[0042] By heating the wafer W with the second heater 42 in addition to the first heater 22, it is possible to heat the wafer W to a temperature required for growing a SiC film, for example, a temperature of 1500° C. or higher. The second heater 42 is, for example, a resistance heater.

[0043] The gas exhaust port 44 is provided at the bottom of the reaction chamber 10. The gas exhaust port 44 exhausts excess reaction products produced after the source gas reacts on the surface of the wafer W and excess process gas to the outside of the reaction chamber 10.

[0044] Furthermore, a wafer inlet / outlet and a gate valve (not shown) are provided in the reaction chamber 10. The wafer inlet / outlet and the gate valve allow the wafer W to be loaded into the reaction chamber 10 and the wafer W to be unloaded from the reaction chamber 10.

[0045] The gas inlet 11 is provided above the reaction chamber 10. The gas inlet 11 supplies a first source gas SG1, a second source gas SG2, and a purge gas PG to the reaction chamber 10.

[0046] The first source gas SG1 and the second source gas SG2 are examples of a first process gas, and the purge gas PG is an example of a second process gas.

[0047] The first source gas supply pipe 81 supplies the first source gas SG1 to the gas inlet 11. The first source gas SG1 is supplied from the gas inlet 11 to the reaction chamber .

[0048] The second source gas supply pipe 82 supplies the second source gas SG2 to the gas inlet 11. The second source gas SG2 is supplied from the gas inlet 11 to the reaction chamber .

[0049] The purge gas supply pipe 83 supplies the purge gas PG to the gas inlet 11. The purge gas PG is supplied from the gas inlet 11 to the reaction chamber .

[0050] The first source gas SG1, the second source gas SG2, and the purge gas PG are supplied from the gas inlet 11 to the reaction chamber 10 in a separated state.

[0051] The first source gas SG1 includes a raw material gas (source gas). The first source gas SG1 is, for example, a source gas of silicon (Si). The first source gas SG1 includes, for example, silicon (Si) and chlorine (Cl). The first source gas SG1 is, for example, silane (SiH4) or silane chloride (SiH 4-n Cl n(n=1 to 4). The first source gas SG1 includes, for example, hydrogen chloride (HCl). The first source gas SG1 includes, for example, hydrogen gas (H). The first source gas SG1 is, for example, a mixed gas of silane (SiH), hydrogen chloride (HCl), and hydrogen gas (H).

[0052] Hydrogen chloride (HCl) is an assist gas that suppresses clustering of silicon and also has the function of etching by-products containing silicon that accumulate in the flow path of the first source gas SG1.

[0053] Hydrogen gas (H2) is a carrier gas. Argon gas (Ar), for example, can also be used as the carrier gas.

[0054] The second source gas SG2 includes a raw material gas (source gas). The second source gas SG2 is, for example, a carbon (C) source gas. The second source gas SG2 includes carbon (C). The second source gas SG2 includes, for example, a hydrocarbon. The second source gas SG2 is, for example, a mixed gas of propane (C3H8) and hydrogen gas (H2).

[0055] The second source gas SG2 includes, for example, an n-type impurity dopant gas, such as nitrogen gas.

[0056] The purge gas PG does not contain a raw material gas (source gas). The purge gas PG has a function of stabilizing the flows of the first source gas SG1 and the second source gas SG2, for example, during the formation of the SiC film 13. The purge gas PG also has a function of removing by-products adhering to the inner surface of the hood 40 before the formation of the SiC film 13.

[0057] The purge gas PG includes, for example, hydrogen (H). The purge gas PG includes, for example, hydrogen gas (H2). The purge gas PG is, for example, hydrogen gas (H2).

[0058] Instead of hydrogen gas (H2), for example, argon gas (Ar) can be used as the purge gas PG.

[0059] The purge gas PG includes, for example, chlorine (Cl). The purge gas PG includes, for example, hydrogen chloride (HCl). The purge gas PG is, for example, a mixed gas of hydrogen gas (H 2 ) and hydrogen chloride (HCl).

[0060] The gas exhaust pipe 84 is connected to the gas exhaust port 44 of the reaction chamber 10. Excess reaction products generated after the source gas reacts on the surface of the wafer W and excess process gas are exhausted to the outside of the reaction chamber 10 through the gas exhaust pipe 84.

[0061] The vacuum pump 12 is connected to the gas exhaust pipe 84. The vacuum pump 12 has a function of controlling the pressure inside the reaction chamber 10.

[0062] The control circuit 14 is, for example, an electronic circuit. The control circuit 14 includes, for example, hardware and software. The control circuit 14 is an example of a control unit.

[0063] The control circuit 14 includes, for example, a central processing unit (CPU). The control circuit 14 includes, for example, a storage device. The storage device included in the control circuit 14 is, for example, a semiconductor memory, a solid state device (SSD), or a hard disk.

[0064] The storage device of the control circuit 14 stores, for example, a computer program for realizing the operation of the control circuit 14.

[0065] The control circuit 14 has a function of controlling, for example, the supply of a first source gas SG1, a second source gas SG2, and a purge gas PG into the reaction chamber 10. For example, a mass flow controller (not shown) is provided in each of the first source gas supply pipe 81, the second source gas supply pipe 82, and the purge gas supply pipe 83. The control circuit 14 controls the supply of the first source gas SG1, the second source gas SG2, and the purge gas PG into the reaction chamber 10 by controlling, for example, the mass flow controllers provided in each of the first source gas supply pipe 81, the second source gas supply pipe 82, and the purge gas supply pipe 83.

[0066] The control circuit 14 has a function of controlling, for example, the rotation of the susceptor 15. The control circuit 14 controls the rotation of the susceptor 15, for example, by controlling the rotation drive mechanism 20. The control circuit 14 can change the rotation speed of the susceptor 15, for example, by controlling the rotation drive mechanism 20.

[0067] The control circuit 14 has a function of controlling, for example, the power supply to the first heater 22 and the second heater 42. The control circuit 14 controls the temperature of the wafer W by controlling, for example, the power supply to the first heater 22 and the second heater 42.

[0068] The control circuit 14 has a function of controlling, for example, the pressure inside the reaction chamber 10. The control circuit 14 controls the pressure inside the reaction chamber 10 by controlling, for example, the vacuum pump 12.

[0069] 2 is an explanatory diagram of control by the control circuit of the vapor phase growth apparatus of the first embodiment. Starting from the bottom, Fig. 2 shows the time change in the gas flow rate of the process gas supplied to the reaction chamber 10 of the vapor phase growth apparatus 100, the time change in the rotation speed of the susceptor 15, the time change in the power input to the second heater 42, and the time change in the pressure of the reaction chamber 10. The flow rate of the process gas supplied to the reaction chamber 10, the rotation speed of the susceptor 15, the power input to the second heater 42, and the pressure of the reaction chamber 10 are controlled by the control circuit 14.

[0070] When forming the SiC film 13 on the wafer W, a first period, a second period, and a third period are provided consecutively in this order. The first period is a period before the SiC film 13 is formed on the wafer W. The second period is a period during which the SiC film 13 is formed on the wafer W. During the second period, a first source gas SG1 and a second source gas SG2 are supplied into the reaction chamber 10, and the SiC film 13 grows on the wafer W. The third period is a period after the SiC film 13 is formed on the wafer W.

[0071] The control circuit 14 controls the supply of the first source gas SG1 and the second source gas SG2 to the reaction chamber 10 to start at time t1, which is the start time of the second period. The control circuit 14 controls the supply of the first source gas SG1 and the second source gas SG2 to the reaction chamber 10 to end at time t2, which is the end time of the second period.

[0072] The supply of the first source gas SG1 and the second source gas SG2 into the reaction chamber 10 does not necessarily have to start simultaneously. For example, the supply of either the first source gas SG1 or the second source gas SG2 into the reaction chamber 10 may start before time t1, which is the start time of the second period. Time t1, which is the start time of the second period, is the time when the supply of both the first source gas SG1 and the second source gas SG2 starts.

[0073] The control circuit 14 controls the supply of the purge gas PG to the reaction chamber 10 at time t0, which is the start time of the first period. The purge gas PG is, for example, argon gas.

[0074] The control circuit 14 controls the flow rate of the purge gas PG to increase during the first period, for example, and also controls the purge gas PG to switch from argon gas to hydrogen gas during the first period, for example.

[0075] The control circuit 14 controls the flow rate of the purge gas PG to be constant during the second period.

[0076] The control circuit 14 controls the flow rate of the purge gas PG to decrease during the third period, for example, and also controls the purge gas PG to switch from hydrogen gas to argon gas during the third period, for example.

[0077] The control circuit 14 controls the susceptor 15 so that it does not rotate at time t0, which is the start time of the first period. In other words, the control circuit 14 controls the rotation speed of the susceptor 15 so that it is 0 rpm at time t0, which is the start time of the first period.

[0078] The control circuit 14 controls the susceptor 15 to rotate at a first rotation speed R1 during the first period, and at time t1, which is the start time of the second period, the control circuit 14 controls the susceptor 15 to rotate at a second rotation speed R2.

[0079] The first rotation speed R1 is greater than the second rotation speed R2, and is, for example, between two and twenty times the second rotation speed R2.

[0080] The first rotation speed R1 is, for example, 300 rpm or more and 1000 rpm or less, and the second rotation speed R2 is, for example, 50 rpm or more and less than 300 rpm.

[0081] For example, the control circuit 14 controls the rotation speed of the susceptor 15 to be constant during the second period. For example, the control circuit 14 controls the susceptor 15 to stop rotating midway through the third period.

[0082] The control circuit 14 controls the power supplied to the second heater 42 to be the first power Po1 at time t0, which is the start time of the first period. The control circuit 14 controls the power supplied to the second heater 42 to be the second power Po2 midway through the first period.

[0083] The second power Po2 is greater than the first power Po1. As the power input to the second heater 42 increases, the temperature of the wafer W increases.

[0084] The control circuit 14 controls the power supplied to the second heater 42 to be constant during the second period.

[0085] The control circuit 14 reduces the power supplied to the second heater 42 at time t2, which is the end time of the second period, and controls the power supplied to the second heater 42 to, for example, the first power Po1.

[0086] The control circuit 14 controls the pressure in the reaction chamber 10 to be constant throughout the first period, the second period, and the third period. The control circuit 14 controls the pressure in the reaction chamber 10 to be maintained at pressure Pr0 throughout the first period, the second period, and the third period.

[0087] Next, an example of the vapor phase growth method according to the first embodiment will be described.

[0088] The vapor phase growth method of the first embodiment is a vapor phase growth method for forming a silicon carbide film on a substrate placed on a holder provided in a reaction chamber, in which a second process gas not containing a raw material gas is supplied into the reaction chamber during a first period before forming the silicon carbide film on the substrate, and the holder is rotated at a first rotational speed during the first period, and a first process gas containing the raw material gas is supplied into the reaction chamber during a second period after the first period for forming the silicon carbide film on the substrate, and the holder is rotated at a second rotational speed lower than the first rotational speed during the second period.

[0089] The vapor phase growth method of the first embodiment uses a vapor phase growth apparatus 100 shown in Fig. 1. Hereinafter, an example will be described in which a single crystal SiC film 13 (silicon carbide film) is formed on the surface of a wafer W of single crystal SiC.

[0090] The first source gas SG1 and the second source gas SG2 include raw material gases for the SiC film 13. The first source gas SG1 and the second source gas SG2 are an example of a first process gas.

[0091] The purge gas PG does not contain a source gas for the SiC film 13. The purge gas PG is an example of a second process gas.

[0092] The following description will be given taking as an example a case where the first source gas SG1 is a mixed gas of silane (SiH4), hydrogen chloride (HCl), and hydrogen gas (H2), the second source gas SG2 is a mixed gas of propane (C3H8) and hydrogen gas (H2), and the purge gas PG is hydrogen gas (H2) or argon gas (Ar).

[0093] The vapor phase growth method of the first embodiment will be described below with reference to FIG.

[0094] First, at time t0, which is the start time of the first period, the susceptor 15 on which the wafer W is placed is carried into the reaction chamber 10. The wafer W is made of single-crystal SiC.

[0095] At time t0, argon gas is supplied into the reaction chamber 10 as a purge gas PG.

[0096] At time t0, the power supplied to the second heater 42 is set to first power Po1. Also at time t0, power is supplied to the first heater 22. The wafer W is heated by the first heater 22 and the second heater 42.

[0097] At time t0, the pressure in the reaction chamber is pressure Pr0. During a first period, the pressure in the reaction chamber is maintained at a constant pressure. During the first period, the pressure in the reaction chamber is maintained at, for example, pressure Pr0.

[0098] Next, the wafer W is rotated at a first rotation speed R1 by the rotation drive mechanism 20. The first rotation speed R1 is, for example, not less than 300 rpm and not more than 1000 rpm.

[0099] Next, the purge gas PG is switched from argon gas to hydrogen gas, and the flow rate of the purge gas PG is increased. During the first period, for example, only the purge gas PG is supplied into the reaction chamber 10.

[0100] Next, the power input to the second heater 42 is increased from the first power Po1 to the second power Po2. The increase in the power input to the second heater 42 increases the temperature of the wafer W. Furthermore, the increase in the power input to the second heater 42 also increases the temperature of the hood 40.

[0101] Next, at time t1, which is the start time of the second period, the first source gas SG1 and the second source gas SG2 start to be supplied into the reaction chamber 10. The first source gas SG1 and the second source gas SG2 are supplied into the reaction chamber 10 until time t2, which is the end time of the second period.

[0102] During the second period, the first source gas SG1 and the second source gas SG2 are supplied, so that the SiC film 13 grows on the wafer W.

[0103] During the second period, the flow rates of the first source gas SG1 and the second source gas SG2 are, for example, kept constant. Also, during the second period, the flow rate of the purge gas PG is kept constant.

[0104] The supply of the first source gas SG1 and the second source gas SG2 into the reaction chamber 10 does not necessarily have to start simultaneously. For example, the supply of either the first source gas SG1 or the second source gas SG2 into the reaction chamber 10 may start before time t1, which is the start time of the second period. Time t1, which is the start time of the second period, is the time when the supply of both the first source gas SG1 and the second source gas SG2 starts.

[0105] At time t1, the rotation speed of the susceptor 15 is reduced so that the susceptor 15 rotates at a second rotation speed R2. The second rotation speed R2 is lower than the first rotation speed R1. In other words, the first rotation speed R1 is higher than the second rotation speed R2.

[0106] The first rotation speed R1 is, for example, not less than 2 times and not more than 20 times the second rotation speed R2. The second rotation speed R2 is, for example, not less than 50 rpm and less than 300 rpm.

[0107] The rotation speed of the susceptor 15 is maintained at a constant rotation speed for the second period, for example. The rotation speed of the susceptor 15 is maintained at a second rotation speed R2 for the second period, for example.

[0108] During the second period, for example, the input power to the first heater 22 and the input power to the second heater 42 are kept constant. During the second period, for example, the input power to the second heater 42 is kept at the second power Po2. During the second period, for example, the temperature of the wafer W is kept at a constant temperature.

[0109] During the second period, the pressure inside the reaction chamber 10 is maintained at a constant pressure. During the second period, the pressure inside the reaction chamber 10 is maintained at, for example, pressure Pr0.

[0110] At time t2, which is the end time of the second period, the supply of the first source gas SG1 and the second source gas SG2 into the reaction chamber 10 is stopped. By stopping the supply of the first source gas SG1 and the second source gas SG2, the growth of the SiC film 13 on the wafer W is stopped.

[0111] At time t2, which is the end time of the second period, the power input to the second heater 42 is reduced so that the power input to the second heater 42 becomes, for example, the first power Po1. By reducing the power input to the second heater 42, the temperature of the wafer W decreases.

[0112] Next, in the middle of the third period, the purge gas PG is switched from hydrogen gas to argon gas, and the flow rate of the purge gas PG is reduced in the middle of the third period.

[0113] In the middle of the third period, the rotation speed of the susceptor 15 is changed from the second rotation speed R2 to zero rotation.

[0114] During the third period, the pressure inside the reaction chamber 10 is maintained at a constant pressure. During the third period, the pressure inside the reaction chamber 10 is maintained at, for example, pressure Pr0.

[0115] At time t3, which is the end time of the third period, the wafer W is unloaded from the reaction chamber 10 together with the susceptor 15.

[0116] The SiC film 13 is formed on the wafer W by the above vapor phase growth method.

[0117] Next, the operation and effects of the vapor phase growth apparatus and vapor phase growth method of the first embodiment will be described.

[0118] When forming a SiC film 13 on the surface of a wafer W using the vapor phase growth apparatus 100, the temperature of the wafer W needs to be high, at 1500° C. or higher. In order to raise the temperature of the wafer W to a high temperature, a second heater 42 is provided in the vapor phase growth apparatus 100. The provision of the second heater 42 makes it possible to heat the wafer W from its upper surface side.

[0119] As the temperature of second heater 42 rises, hood 40, which is provided inside second heater 42, is heated. As hood 40 is heated, the temperature of the inner surface of hood 40 rises. As the temperature of the inner surface of hood 40 rises, by-products resulting from the source gas are deposited on the inner surface of hood 40 during the formation of SiC film 13. The by-products are substances whose main component is SiC.

[0120] The by-products deposited on the inner surface of the hood 40 may fall onto the surface of the wafer W before or during the formation of the SiC film 13. The fallen by-products may be taken into the SiC film 13 and form defects in the SiC film 13. The defects formed in the SiC film 13 may cause defects in a semiconductor device manufactured using the SiC film 13, for example.

[0121] For example, by-products deposited on the inner surface of hood 40 can be removed by opening reaction chamber 10 to the atmosphere and cleaning hood 40. Therefore, by cleaning hood 40 so that the thickness of by-products deposited on the inner surface of hood 40 does not exceed a predetermined thickness at which the frequency of by-products falling increases, the occurrence of defects in SiC film 13 can be suppressed. However, if the frequency of cleaning hood 40 increases, the throughput of forming SiC film 13 decreases and the manufacturing cost of SiC film 13 increases. Therefore, it is desirable to suppress the deposition of by-products, which cause defects, on the inner surface of hood 40.

[0122] Fig. 3 is an explanatory diagram of the problem with the vapor phase growth apparatus of the first embodiment, and corresponds to Fig. 1 of the first embodiment.

[0123] The vapor phase growth apparatus 100 of the first embodiment rotates the wafer W by rotating the susceptor 15 during the formation of the SiC film 13, i.e., during the second period in FIG. 2 . Rotating the wafer W increases, for example, the growth rate of the SiC film 13 formed on the wafer W. Increasing the growth rate of the SiC film 13 improves, for example, the throughput of the formation of the SiC film 13. It is known that the growth rate of the SiC film 13 increases as the rotation speed of the susceptor 15 increases.

[0124] The inventors' investigations have revealed that if the rotation speed of the susceptor 15 during the formation of the SiC film 13 becomes too high, turbulence of the process gas occurs at the outer periphery of the wafer W, as shown in Fig. 3. It has also become clear that the turbulence of the process gas increases the deposition rate of by-products 90 on the inner surface of the hood 40.

[0125] 4 is an explanatory diagram of the operation and effect of the vapor phase growth apparatus of the first embodiment. In the first embodiment, as shown in FIG. 2, the first rotation speed R1 of the susceptor 15 in the first period is higher than the second rotation speed R2 of the susceptor 15 in the second period. In other words, the second rotation speed R2 of the susceptor 15 in the second period is lower than the first rotation speed R1 of the susceptor 15 in the first period.

[0126] 4, by reducing the second rotation speed R2 of the susceptor 15 during the formation of the SiC film 13, it is possible to suppress the generation of turbulence in the process gas at the outer periphery of the wafer W. Therefore, it is possible to reduce the deposition rate of the by-products 90 on the inner surface of the hood 40. In other words, it is possible to suppress the deposition of the by-products 90 on the inner surface of the hood 40.

[0127] Furthermore, in the first embodiment, the formation of defects in the SiC film 13 is suppressed by increasing the first rotation speed R1 of the susceptor 15 in the first period.

[0128] 2, the power input to the second heater 42 increases from a first power Po1 to a second power Po2. The increase in the power input to the second heater 42 increases the temperature of the second heater 42. The increase in the temperature of the second heater 42 increases the temperature of the hood 40.

[0129] When the temperature of the hood 40 rises, thermal stress is applied to the by-products 90 deposited on the inner surface of the hood 40. The thermal stress applied to the by-products 90 makes the by-products 90 more likely to fall onto the surface of the wafer W. The by-products 90 that have fallen onto the surface of the wafer W in the first period are incorporated into the SiC film 13 in the subsequent second period, forming defects.

[0130] In the first embodiment, the first rotation speed R1 of the susceptor 15 is increased during the first period, so that the by-products 90 that have fallen onto and adhered to the surface of the wafer W are removed from the surface by centrifugal force. Therefore, the amount of by-products 90 on the surface of the wafer W is reduced when the second period begins. Therefore, the formation of defects in the SiC film 13 is suppressed.

[0131] 5 is an explanatory diagram of the operation and effect of the vapor phase growth apparatus of the first embodiment. Starting from the bottom, the graphs in FIG. 5 show the correlation between the deposition rate of by-products 90 on the inner surface of hood 40 and the rotation speed of susceptor 15, the correlation between the growth rate of SiC film 13 and the rotation speed of susceptor 15, and the correlation between the removal efficiency of by-products 90 adhering to the surface of wafer W and the rotation speed of susceptor 15.

[0132] The correlation between the deposition rate of the by-products 90 on the inner surface of the hood 40 and the rotation speed of the susceptor 15 indicates a relative value when the deposition rate when the rotation speed is 600 rpm is used as a reference. The correlation between the growth rate of the SiC film 13 and the rotation speed of the susceptor 15 indicates a relative value when the growth rate when the rotation speed is 600 rpm is used as a reference. The correlation between the removal efficiency of the by-products 90 attached to the surface of the wafer W and the rotation speed of the susceptor 15 indicates a relative value when the removal efficiency when the rotation speed is 600 rpm is used as a reference. The removal efficiency of the by-products 90 attached to the surface of the wafer W is, for example, the ratio of the number of by-products 90 removed by the rotation of the wafer W to the total number of by-products 90 attached to the surface of the wafer W.

[0133] 5, the deposition rate of by-products 90 begins to increase when the rotation speed reaches 300 rpm or higher. This is thought to be because turbulence in the process gas begins to occur when the rotation speed reaches 300 rpm or higher. Therefore, from the viewpoint of suppressing deposition of by-products 90 on the inner surface of hood 40, second rotation speed R2 in the second period is preferably less than 300 rpm, more preferably 250 rpm or less, and even more preferably 200 rpm or less.

[0134] 5, the growth rate of SiC film 13 tends to saturate when the rotation speed is 50 rpm or higher. Therefore, from the viewpoint of increasing the growth rate of SiC film 13, the second rotation speed R2 in the second period is preferably 50 rpm or higher, and more preferably 100 rpm or higher.

[0135] 5, the removal efficiency of the by-products 90 starts to increase when the rotation speed becomes 300 rpm or higher. Therefore, from the viewpoint of removing the by-products 90 attached to the surface of the wafer W in the first period, the first rotation speed R1 is preferably 300 rpm or higher, more preferably 500 rpm or higher, and even more preferably 700 rpm or higher.

[0136] From the viewpoint of achieving both the removal of by-products 90 in the first period and the suppression of the deposition of by-products 90 on the inner surface of hood 40 in the second period, it is preferable that the first rotation speed R1 be at least twice the second rotation speed R2, more preferably at least three times, and even more preferably at least five times.

[0137] The vapor phase growth apparatus and vapor phase growth method of the first embodiment can suppress the deposition of by-products 90 on the inner surface of the hood 40. Furthermore, the vapor phase growth apparatus and vapor phase growth method of the first embodiment can suppress the formation of defects in the SiC film 13 formed on the wafer W.

[0138] (Variation) The vapor phase growth apparatus of the modified example of the first embodiment differs from the vapor phase growth apparatus of the first embodiment in that the control unit controls the third rotation speed of the holder during the third period after the silicon carbide film is formed after the second period so that the third rotation speed of the holder during the third period is greater than the second rotation speed of the holder during the second period.

[0139] Fig. 6 is an explanatory diagram of control by a control circuit in a vapor phase growth apparatus according to a modified example of the first embodiment. Starting from the bottom, Fig. 6 shows the time change in the gas flow rate of the process gas supplied to the reaction chamber 10 of the vapor phase growth apparatus 100, the time change in the rotation speed of the susceptor 15, the time change in the power input to the second heater 42, and the time change in the pressure in the reaction chamber 10. Fig. 6 corresponds to Fig. 2 of the first embodiment.

[0140] 6, the control circuit 14 starts increasing the rotation speed of the susceptor 15 at time t2, which is the end time of the second period and the start time of the third period, and controls the susceptor 15 to rotate at a third rotation speed R3 during the third period. The control circuit 14 controls the susceptor 15 to rotate at a second rotation speed R2 at time t1, which is the start time of the second period.

[0141] The third rotation speed R3 is greater than the second rotation speed R2. The third rotation speed R3 is, for example, between two and twenty times the second rotation speed R2. The third rotation speed R3 is, for example, equal to the first rotation speed R1.

[0142] The third rotation speed R3 is, for example, not less than 300 rpm and not more than 1000 rpm.

[0143] For example, the control circuit 14 controls the rotation speed of the susceptor 15 to decrease from the third rotation speed R3 in the middle of the third period so that the susceptor 15 does not rotate.

[0144] In the modification of the first embodiment, the third rotation speed R3 of the susceptor 15 during the third period is increased, so that the by-products 90 that have fallen onto and adhered to the surface of the wafer W are removed from the surface by centrifugal force. Therefore, for example, in a process after the wafer W is unloaded from the vapor phase growth apparatus 100, adverse effects caused by the by-products 90 that have adhered to the surface of the wafer W can be prevented.

[0145] As described above, according to the first embodiment and the modified examples, it is possible to realize a vapor phase growth apparatus and a vapor phase growth method that are capable of suppressing the deposition of by-products.

[0146] (Second embodiment) The vapor phase growth apparatus and vapor phase growth method of the second embodiment differ from the vapor phase growth apparatus and vapor phase growth method of the first embodiment in that the control unit controls the flow rate of the second process gas supplied to the reaction chamber during the first period to be greater than the sum of the flow rate of the first process gas supplied to the reaction chamber during the second period and the flow rate of the second process gas during the second period. Hereinafter, some of the description overlapping with the first embodiment may be omitted.

[0147] Fig. 7 is an explanatory diagram of control by the control circuit of the vapor phase growth apparatus of the second embodiment. From the bottom up, Fig. 7 shows the time change in the gas flow rate of the process gas supplied to the reaction chamber 10 of the vapor phase growth apparatus 100, the time change in the rotation speed of the susceptor 15, the time change in the power input to the second heater 42, and the time change in the pressure in the reaction chamber 10. Fig. 7 corresponds to Fig. 2 of the first embodiment.

[0148] As shown in FIG. 7, the control circuit 14 controls the flow rate of the purge gas PG to decrease from the first period to time t1, which is the start time of the second period.

[0149] The control circuit 14 controls the flow rate of the purge gas PG supplied to the reaction chamber 10 during the first period so that it is greater than the sum of the flow rates of the first source gas SG1, the second source gas SG2, and the purge gas PG supplied to the reaction chamber 10 during the second period. The flow rate of the purge gas PG supplied to the reaction chamber 10 during the first period is, for example, two to five times the sum of the flow rates of the first source gas SG1, the second source gas SG2, and the purge gas PG supplied to the reaction chamber 10 during the second period.

[0150] During the first period, the purge gas PG supplied to the reaction chamber 10 promotes the falling of the by-products 90 deposited on the inner surface of the hood 40. For example, the purge gas PG flowing along the inner surface of the hood 40 cools the by-products 90 deposited on the inner surface of the hood 40. As the by-products 90 are cooled, the thermal stress applied to the by-products 90 increases, promoting the falling of the by-products 90. In addition, for example, the impact of molecules and atoms in the purge gas PG flowing along the inner surface of the hood 40 is applied to the by-products 90 deposited on the inner surface of the hood 40. The impact of molecules and atoms on the by-products 90 promotes the falling of the by-products 90.

[0151] The flow rate of hydrogen gas supplied to the reaction chamber 10 during the first period is greater than the flow rate of hydrogen gas supplied to the reaction chamber 10 during the second period. The flow rate of hydrogen gas supplied to the reaction chamber 10 during the first period is, for example, two to five times the flow rate of hydrogen gas supplied to the reaction chamber 10 during the second period.

[0152] Hydrogen gas has a high specific heat and thermal conductivity. Therefore, the cooling efficiency of the by-products 90 by hydrogen gas is high. The specific heat and thermal conductivity of hydrogen gas are higher than those of, for example, argon gas. Therefore, the cooling efficiency of the by-products 90 by hydrogen gas is higher than that of, for example, argon gas.

[0153] According to the vapor phase growth apparatus and vapor phase growth method of the second embodiment, the falling of by-products 90 accumulated on the inner surface of hood 40 is promoted during the first period, which results in suppressing the accumulation of by-products 90 on the inner surface of hood 40. Therefore, according to the vapor phase growth apparatus and vapor phase growth method of the second embodiment, it is possible to further suppress the accumulation of by-products 90 on the inner surface of hood 40 compared to the first embodiment. Furthermore, according to the vapor phase growth apparatus and vapor phase growth method of the second embodiment, it is possible to suppress the formation of defects in SiC film 13 formed on wafer W, similar to the first embodiment.

[0154] (First Modification) The vapor phase growth apparatus of the first modified example of the second embodiment differs from the vapor phase growth apparatus of the second embodiment in that the second process gas contains chlorine gas, and the control unit controls the flow rate of chlorine gas supplied to the reaction chamber during the first period to be greater than the flow rate of chlorine gas supplied to the reaction chamber during the second period.

[0155] Fig. 8 is an explanatory diagram of control by a control circuit in a vapor phase growth apparatus according to a first modified example of the second embodiment. Starting from the bottom, Fig. 8 shows the time change in the gas flow rate of the process gas supplied to the reaction chamber 10 of the vapor phase growth apparatus 100, the time change in the rotation speed of the susceptor 15, the time change in the power input to the second heater 42, and the time change in the pressure in the reaction chamber 10. Fig. 8 corresponds to Fig. 7 of the second embodiment.

[0156] 8, the purge gas PG contains chlorine gas (HCl). The purge gas PG is, for example, a mixed gas of hydrogen gas (H 2 ) and chlorine gas (HCl).

[0157] As in the second embodiment, the control circuit 14 controls the flow rate of the purge gas PG supplied to the reaction chamber 10 during the first period so that it is greater than the sum of the flow rates of the first source gas SG1, the second source gas SG2, and the purge gas PG supplied to the reaction chamber 10 during the second period. The flow rate of the purge gas PG supplied to the reaction chamber 10 during the first period is, for example, two to five times the sum of the flow rates of the first source gas SG1, the second source gas SG2, and the purge gas PG supplied to the reaction chamber 10 during the second period.

[0158] The flow rate of chlorine gas supplied to the reaction chamber 10 during the first period is greater than the flow rate of chlorine gas supplied to the reaction chamber 10 during the second period. The flow rate of chlorine gas supplied to the reaction chamber 10 during the first period is, for example, two to five times the flow rate of chlorine gas supplied to the reaction chamber 10 during the second period.

[0159] According to the vapor phase growth apparatus and vapor phase growth method of the first modification of the second embodiment, during the first period, the by-products 90 deposited on the inner surface of the hood 40 are etched by the chlorine gas contained in the purge gas PG. As a result, compared to the second embodiment, it is possible to further suppress the deposition of the by-products 90 on the inner surface of the hood 40.

[0160] (Second Modification) The vapor phase growth apparatus of the second variant of the second embodiment differs from the second embodiment in that, in the second process gas supplied to the reaction chamber during the first period, the flow rate of the second process gas flowing along the inner surface of the side wall is greater than the flow rate of the second process gas flowing in the center of the reaction chamber.

[0161] For example, the flow rate of the purge gas PG supplied to the reaction chamber 10 during the first period and flowing along the inner surface of the hood 40 is greater than the flow rate of the purge gas PG supplied to the reaction chamber 10 during the first period and flowing in the center of the reaction chamber 10. The flow rate of the purge gas PG flowing along the inner surface of the hood 40 is, for example, two to five times the flow rate of the purge gas PG flowing in the center of the reaction chamber 10.

[0162] The flow rate of the purge gas PG flowing along the inner surface of the hood 40 is represented, for example, by the flow rate of the purge gas PG supplied to the reaction chamber 10 from one gas supply port provided in the outer periphery of the gas introduction part 11. The flow rate of the purge gas PG flowing in the center of the reaction chamber 10 is represented, for example, by the flow rate of the purge gas PG supplied to the reaction chamber 10 from one gas supply port provided in the center of the gas introduction part 11.

[0163] For example, a partition wall is provided in the purge gas PG storage chamber in the gas inlet 11, and a central purge gas storage chamber and an outer peripheral purge gas storage chamber are provided. Purge gas supply pipes that can independently control the gas supply amount are connected to the central purge gas storage chamber and the outer peripheral purge gas storage chamber. By adopting the above configuration, it becomes possible to independently control the flow rate of the purge gas PG flowing along the inner surface of the hood 40 and the flow rate of the purge gas PG flowing in the central portion of the reaction chamber 10.

[0164] According to the vapor phase growth apparatus and vapor phase growth method of the second modification of the second embodiment, the flow rate of the purge gas PG flowing along the inner surface of the hood 40 increases during the first period, facilitating the dropping of the by-products 90 deposited on the inner surface of the hood 40. Therefore, compared to the second embodiment, it is possible to further suppress the deposition of the by-products 90 on the inner surface of the hood 40.

[0165] As described above, according to the second embodiment and the modified example, it is possible to realize a vapor phase growth apparatus and a vapor phase growth method that are capable of suppressing the deposition of by-products.

[0166] (Third embodiment) The vapor phase growth apparatus and vapor phase growth method of the third embodiment differ from the vapor phase growth apparatus and vapor phase growth method of the first embodiment in that the control unit controls the first pressure in the reaction chamber during the first period to be higher than the second pressure in the reaction chamber during the second period. Hereinafter, some of the content that overlaps with the first embodiment may be omitted.

[0167] Fig. 9 is an explanatory diagram of control by a control circuit of a vapor phase growth apparatus of the third embodiment. From the bottom up, Fig. 9 shows the time change in the gas flow rate of the process gas supplied to the reaction chamber 10 of the vapor phase growth apparatus 100, the time change in the rotation speed of the susceptor 15, the time change in the power input to the second heater 42, and the time change in the pressure in the reaction chamber 10. Fig. 9 corresponds to Fig. 2 of the first embodiment.

[0168] The control circuit 14 controls the pressure inside the reaction chamber 10 to be a pressure Pr0 at time t0, which is the start time of the first period. The control circuit 14 controls the pressure inside the reaction chamber 10 by controlling the vacuum pump 12.

[0169] The control circuit 14 controls the pressure in the reaction chamber 10 to become a first pressure Pr1 in the middle of the first period. The first pressure Pr1 is greater than the pressure Pr0.

[0170] The control circuit 14 controls the pressure in the reaction chamber 10 to be a second pressure Pr2 at time t1, which is the start time of the second period. The second pressure Pr2 is equal to the pressure Pr0, for example.

[0171] The first pressure Pr1 is greater than the second pressure Pr2, and is, for example, two times to five times the second pressure Pr2.

[0172] The first pressure Pr1 is, for example, 4×10 4 Pa or more 1×10 5 The second pressure Pr2 is, for example, 2×10 4 Pa or more 5×10 4 Pa or less.

[0173] The control circuit 14 controls the pressure in the reaction chamber 10 to be constant, for example, during the second period and the third period. For example, the control circuit 14 controls the pressure in the reaction chamber 10 to be a second pressure Pr2 during the second period and the third period.

[0174] During the first period, the pressure inside the reaction chamber 10 is increased to promote the falling of the by-products 90 deposited on the inner surface of the hood 40. For example, the increased pressure inside the reaction chamber 10 increases the probability that molecules and atoms in the purge gas PG will impact the by-products 90 deposited on the inner surface of the hood 40. Therefore, the falling of the by-products 90 is promoted.

[0175] According to the vapor phase growth apparatus and vapor phase growth method of the third embodiment, the by-products 90 accumulated on the inner surface of the hood 40 are promoted to fall during the first period, which results in suppressing the accumulation of the by-products 90 on the inner surface of the hood 40. Therefore, according to the vapor phase growth apparatus and vapor phase growth method of the third embodiment, it is possible to further suppress the accumulation of the by-products 90 on the inner surface of the hood 40 compared to the first embodiment. Furthermore, according to the vapor phase growth apparatus and vapor phase growth method of the third embodiment, it is possible to suppress the formation of defects in the SiC film 13 formed on the wafer W, similar to the first embodiment.

[0176] As described above, according to the third embodiment, it is possible to realize a vapor phase growth apparatus and a vapor phase growth method that are capable of suppressing the deposition of by-products.

[0177] (Fourth embodiment) The vapor phase growth apparatus and vapor phase growth method of the fourth embodiment differ from the vapor phase growth apparatus and vapor phase growth method of the first embodiment in that the control unit controls the first heater and the second heater so that the shape of the substrate becomes convex upward during the first period. Hereinafter, some of the description that overlaps with the first embodiment may be omitted.

[0178] 10(a), 10(b), and 10(c) are explanatory diagrams of control by the control circuit of the vapor phase growth apparatus of the fourth embodiment. 10(a), 10(b), and 10(c) are diagrams showing the shape of the wafer W placed on the susceptor 15.

[0179] Fig. 10(a) is a diagram showing a case where the shape of the wafer W is flat, Fig. 10(b) is a diagram showing a case where the shape of the wafer W is upwardly convex, and Fig. 10(c) is a diagram showing a case where the shape of the wafer W is downwardly convex.

[0180] By controlling the power supplied to the first heater 22 and the power supplied to the second heater 42 using the control circuit 14, the shape of Figure 10(a), the shape of Figure 10(b), or the shape of Figure 10(c) can be realized.

[0181] For example, the input power of the first heater 22 and the input power of the second heater 42 are adjusted to make the temperature of the upper surface of the wafer W higher than the temperature of the lower surface of the wafer W. By increasing the temperature of the upper surface of the wafer W, the thermal expansion of the upper surface of the wafer W becomes larger than the thermal expansion of the lower surface of the wafer W, and an upwardly convex shape as shown in FIG. 10(b) can be realized.

[0182] In the first period, the control circuit 14 controls the power supplied to the first heater 22 and the power supplied to the second heater 42 so that the shape of the wafer W becomes upwardly convex.

[0183] In the second period, the control circuit 14 controls the power supplied to the first heater 22 and the power supplied to the second heater 42 so that the shape of the wafer W becomes a desired shape suitable for forming the SiC film 13.

[0184] During the second period, the control circuit 14 controls the power input to the first heater 22 and the power input to the second heater 42, for example, so that the shape of the wafer W becomes flat. Also, during the second period, the control circuit 14 controls the power input to the first heater 22 and the power input to the second heater 42, for example, so that the shape of the wafer W becomes convex upward. Also, during the second period, the control circuit 14 controls the power input to the first heater 22 and the power input to the second heater 42, for example, so that the shape of the wafer W becomes convex downward.

[0185] During the first period, the wafer W has an upward convex shape, which improves the efficiency of removing the by-products 90 adhering to the surface of the wafer W. This is thought to be because the wafer W has an upward convex shape, which makes it less likely that the movement of the by-products 90 toward the outer periphery of the wafer W is hindered by centrifugal force.

[0186] According to the vapor phase growth apparatus and vapor phase growth method of the fourth embodiment, as in the first embodiment, it is possible to suppress deposition of by-products 90 on the inner surface of hood 40. Furthermore, according to the vapor phase growth apparatus and vapor phase growth method of the fourth embodiment, the efficiency of removing by-products 90 adhering to the surface of wafer W during the first period is improved. Therefore, it is possible to further suppress the formation of defects in SiC film 13 formed on wafer W.

[0187] As described above, according to the fourth embodiment, it is possible to realize a vapor phase growth apparatus and a vapor phase growth method that are capable of suppressing the deposition of by-products.

[0188] (Fifth embodiment) The vapor phase growth apparatus and vapor phase growth method of the fifth embodiment differ from those of the first embodiment in that the first process gas containing raw material gas is a mixed gas of a silicon source gas and a carbon source gas. Hereinafter, some of the description overlapping with the first embodiment may be omitted.

[0189] 11 is a schematic cross-sectional view of a vapor phase growth apparatus according to a fifth embodiment. The vapor phase growth apparatus 200 according to the fifth embodiment is, for example, a single-wafer type epitaxial growth apparatus that epitaxially grows a single-crystal SiC film (silicon carbide film) on a single-crystal SiC substrate (silicon carbide substrate). The vapor phase growth apparatus 200 according to the fifth embodiment is a vertical type vapor phase growth apparatus in which a process gas is supplied vertically to the surface of the SiC substrate.

[0190] A vapor phase growth apparatus 200 of the fifth embodiment includes a reaction chamber 10, a gas introduction unit 11, a vacuum pump 12, and a control circuit 14 (control unit). The reaction chamber 10 includes a susceptor 15 (holder), a rotor 16, a rotation shaft 18, a rotation drive mechanism 20, a first heater 22, a reflector 28, a support column 30, a fixed base 32, a fixed shaft 34, a hood 40 (side wall), a second heater 42, and a gas exhaust port 44. The first heater 22 includes a lower heater 22a and an upper heater 22b.

[0191] The vapor phase growth apparatus 200 of the fifth embodiment includes a mixed source gas supply pipe 80, a purge gas supply pipe 83, and a gas exhaust pipe .

[0192] The gas inlet 11 is provided above the reaction chamber 10. The gas inlet 11 supplies the reaction chamber 10 with a mixed source gas SGx and a purge gas PG.

[0193] The source gas mixture SGx is an example of a first process gas, and the purge gas PG is an example of a second process gas.

[0194] The mixed source gas supply pipe 80 supplies the mixed source gas SGx to the gas inlet 11. The mixed source gas SGx is supplied from the gas inlet 11 to the reaction chamber .

[0195] The purge gas supply pipe 83 supplies the purge gas PG to the gas inlet 11. The purge gas PG is supplied from the gas inlet 11 to the reaction chamber .

[0196] The mixed source gas SGx is a source gas of silicon (Si) and carbon (C). The mixed source gas SGx includes, for example, silicon (Si), carbon (C), and chlorine (Cl). The mixed source gas SGx includes, for example, silane (SiH4) or chlorosilane (SiH4-nCln: n=1 to 4). The mixed source gas SGx includes, for example, hydrocarbon. The mixed source gas SGx includes, for example, hydrogen chloride (HCl). The mixed source gas SGx includes, for example, hydrogen gas (H2). The mixed source gas SGx is, for example, a mixed gas of silane (SiH4), propane (C3H8), hydrogen chloride (HCl), and hydrogen gas (H2).

[0197] The mixed source gas SGx includes, for example, an n-type impurity dopant gas, such as nitrogen gas.

[0198] The purge gas PG does not contain a raw material gas (source gas). The purge gas PG has a function of stabilizing the flows of the first source gas SG1 and the second source gas SG2, for example, during the formation of the SiC film 13. The purge gas PG also has a function of removing by-products adhering to the inner surface of the hood 40 before the formation of the SiC film 13.

[0199] The purge gas PG includes, for example, hydrogen (H). The purge gas PG includes, for example, hydrogen gas (H2). The purge gas PG is, for example, hydrogen gas (H2).

[0200] Instead of hydrogen gas (H2), for example, argon gas (Ar) can be used as the purge gas PG.

[0201] The purge gas PG includes, for example, chlorine (Cl). The purge gas PG includes, for example, hydrogen chloride (HCl). The purge gas PG is, for example, a mixed gas of hydrogen gas (H 2 ) and hydrogen chloride (HCl).

[0202] According to the vapor phase growth apparatus and vapor phase growth method of the fifth embodiment, as in the first embodiment, it is possible to suppress deposition of by-products 90 on the inner surface of the hood 40. Furthermore, according to the vapor phase growth apparatus and vapor phase growth method of the fifth embodiment, as in the first embodiment, it is possible to suppress formation of defects in the SiC film 13 formed on the wafer W.

[0203] As described above, according to the fifth embodiment, it is possible to realize a vapor phase growth apparatus and a vapor phase growth method that are capable of suppressing the deposition of by-products.

[0204] The embodiments of the present invention have been described above with reference to specific examples. The above-described embodiments are merely examples and do not limit the present invention. Furthermore, the components of each embodiment may be combined as appropriate.

[0205] In the first to fifth embodiments, the case of forming a single-crystal SiC film has been described as an example, but the present invention can also be applied to the formation of a polycrystalline or amorphous SiC film. Furthermore, the present invention can also be applied to the formation of films other than SiC films.

[0206] Furthermore, in the first to fifth embodiments, a single crystal SiC wafer has been described as an example of the substrate, but the substrate is not limited to a single crystal SiC wafer.

[0207] In the first to fifth embodiments, nitrogen is used as an n-type impurity, but it is also possible to use, for example, phosphorus (P) as the n-type impurity.It is also possible to use a p-type impurity as the impurity.

[0208] In the first to fifth embodiments, descriptions of the apparatus configuration, manufacturing method, and other aspects not directly necessary for explaining the present invention have been omitted, but the required apparatus configuration, manufacturing method, and the like can be appropriately selected and used. In addition, all vapor phase growth apparatuses and vapor phase growth methods that incorporate the elements of the present invention and that can be appropriately modified by those skilled in the art are encompassed within the scope of the present invention. The scope of the present invention is defined by the claims and their equivalents. [Explanation of symbols]

[0209] 10 Reaction chamber 11 Gas inlet 13 SiC film (membrane) 14 Control circuit (control section) 15 Susceptor (holder) 22 First heater 40 Hood (side wall) 42 Second heater 100 Vapor phase growth equipment 200 Vapor phase growth equipment Pr1 First pressure Pr2 Second pressure R1 First rotation speed R2 Second rotation speed SG1 First source gas (first process gas) SG2 Second source gas (first process gas) SGx Source Gas Mixture (First Process Gas) PG Purge gas (second process gas) W wafer (substrate)

Claims

1. A reaction chamber; a rotatable holder that is provided in the reaction chamber and that can hold a substrate; a gas inlet portion provided above the reaction chamber and capable of supplying a first process gas containing a source gas and a second process gas not containing the source gas into the reaction chamber; a control unit that controls the supply of the first process gas and the second process gas to the reaction chamber and controls the rotation of the holder, the control unit controls to supply the second process gas to the reaction chamber during a first period before a film is formed on the substrate, and to supply the first process gas and the second process gas to the reaction chamber during a second period after the first period during which the film is formed on the substrate; The control unit controls the first rotation speed of the holder during the first period to be greater than the second rotation speed of the holder during the second period.

2. 2. The vapor phase growth apparatus according to claim 1, wherein the control unit controls the first rotation speed to be equal to or greater than 300 rpm and the second rotation speed to be less than 300 rpm.

3. 2. The vapor phase growth apparatus according to claim 1, wherein the control unit controls the first rotation speed to be at least twice as fast as the second rotation speed.

4. 2. The vapor phase growth apparatus according to claim 1, wherein the control unit controls the flow rate of the second process gas supplied to the reaction chamber during the first period to be greater than the sum of the flow rate of the first process gas supplied to the reaction chamber during the second period and the flow rate of the second process gas during the second period.

5. 2. The vapor phase growth apparatus according to claim 1, wherein the second process gas contains hydrogen gas, and the control unit controls the flow rate of the hydrogen gas supplied to the reaction chamber during the first period to be greater than the flow rate of the hydrogen gas supplied to the reaction chamber during the second period.

6. 2. The vapor phase growth apparatus according to claim 1, wherein the second process gas contains chlorine gas, and the control unit controls the flow rate of the chlorine gas supplied to the reaction chamber during the first period to be greater than the flow rate of the chlorine gas supplied to the reaction chamber during the second period.

7. 2. The vapor phase growth apparatus of claim 1, wherein the control unit controls the pressure in the reaction chamber so that a first pressure in the reaction chamber during the first period is greater than a second pressure in the reaction chamber during the second period.

8. a first heater provided below the holder; a sidewall provided in a region of the reaction chamber between the holder and the gas inlet and extending along a wall surface of the reaction chamber; a second heater provided between the wall surface and the side wall, 2. The vapor phase growth apparatus according to claim 1, wherein the control unit controls the first heater and the second heater so that the shape of the substrate becomes upwardly convex during the first period.

9. 1. A vapor deposition method for forming a film on a substrate placed on a holder provided in a reaction chamber, comprising: supplying a second process gas, which does not include a source gas, into the reaction chamber for a first period of time prior to forming the film on the substrate; rotating the holder at a first rotational speed for the first period of time; supplying a first process gas containing the source gas into the reaction chamber during a second period for forming the film on the substrate after the first period; The vapor deposition method further comprises rotating the holder at a second rotation speed that is lower than the first rotation speed during the second period.

10. 10. The vapor deposition method according to claim 9, wherein the first rotation speed is equal to or greater than 300 rpm, and the second rotation speed is less than 300 rpm.

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