Cleaning method and film forming apparatus

Abstract

To provide a technique capable of suppressing etching of a rotary table in the case of cleaning.SOLUTION: The present invention relates to a method for cleaning the inside of a processing container in a deposition device comprising: a rotary table in which a plurality of mounting areas in each of which a substrate is mounted is provided in a circumferential direction, the rotary table provided rotatably inside of the processing container; and a gas injector which is provided while penetrating a sidewall of the processing container. The method includes: a step (a) of discharging a cleaning gas together with a carrier gas, which is adjusted to a first flow rate, from the gas injector into the processing container while rotating the rotary table; a step (b) of discharging the cleaning gas together with the carrier gas, which is adjusted to a second flow rate smaller than the first flow rate; and a step (c) of performing switching from the step (a) to the step (b) and switching from the step (b) to the step (a) the same times as the number of mounting areas while the rotary table is rotated once.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a cleaning method and a film forming apparatus. [Background technology]

[0002] There is known an apparatus for forming films on a plurality of substrates by placing the substrates along the rotation direction of a turntable and supplying a process gas from nozzles provided along the diameter of the turntable while the turntable is rotating (see, for example, Patent Document 1). In the apparatus of Patent Document 1, a film also accumulates on the turntable. As the amount of deposited film increases, particles are generated. For this reason, in the above apparatus, cleaning is periodically performed by supplying a cleaning gas to the turntable to remove the film deposited on the turntable. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-153805 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can prevent the turntable from being etched during cleaning. [Means for solving the problem]

[0005] A cleaning method according to one aspect of the present disclosure is a method for cleaning an inside of a processing vessel in a film formation apparatus including: a rotary table rotatably provided within a processing vessel, the rotary table having a plurality of mounting areas on which substrates are placed along a circumferential direction; and a gas injector provided to penetrate a sidewall of the processing vessel, the method comprising: The cleaning gas and the carrier gas are discharged from the gas injector into the processing chamber while rotating the turntable, and when the placement area is not located on a first line segment connecting the gas injector and the center of the turntable in a plan view, the flow rate of the carrier gas is adjusted to a first flow rate, when the placement area begins to be located on the first line segment in a plan view, the flow rate of the carrier gas is changed from the first flow rate to a second flow rate that is smaller than the first flow rate, and when the placement area is no longer located on the first line segment in a plan view, the flow rate of the carrier gas is changed from the second flow rate to the first flow rate. . [Effects of the Invention]

[0006] According to the present disclosure, etching of the turntable during cleaning can be suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic vertical cross-sectional view showing an example of a film forming apparatus according to an embodiment; [Figure 2] Schematic plan view of the film forming apparatus of FIG. [Figure 3] 2 is a bottom view of a gas supply / exhaust unit provided in the film forming apparatus of FIG. 1. [Figure 4] Another cross-sectional view of the film forming apparatus of FIG. [Figure 5] FIG. 1 shows a cleaning method according to an embodiment. [Figure 6] FIG. 2 shows a cleaning method according to an embodiment. [Figure 7] FIG. 3 shows a cleaning method according to an embodiment. [Figure 8] Graph showing the relationship between the flow rate of Ar gas and the etching rate distribution DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] [Film forming equipment] 1 to 4, an example of a film forming apparatus according to an embodiment will be described. The film forming apparatus 1 is an apparatus for forming a silicon nitride (SiN) film on a surface of a substrate by atomic layer deposition (ALD) or molecular layer deposition (MLD). The substrate is, for example, a semiconductor wafer (hereinafter referred to as "wafer W").

[0010] The film forming apparatus 1 includes a vacuum vessel 11 as a processing vessel. The vacuum vessel 11 has a generally circular planar shape. The vacuum vessel 11 includes a main body 11A and a top plate 11B. The main body 11A forms the side walls and bottom. The top plate 11B is attached to the main body 11A via a sealing member such as an O-ring. This allows the vacuum vessel 11 to be airtightly sealed. The main body 11A and the top plate 11B can be made of, for example, aluminum (Al).

[0011] A rotary table 12 is provided inside the vacuum vessel 11. The rotary table 12 has a disk shape and can be made of, for example, quartz. The rotary table 12 is supported at the center of its back surface by a support portion 12A and is provided horizontally.

[0012] Six recesses 14 are provided on the upper surface of the turntable 12 along the circumferential direction (rotation direction) of the turntable 12. The recesses 14 are an example of a mounting area. Each recess 14 has a circular shape in a plan view, and has a shape recessed relative to the upper surface of the turntable 12. A wafer W is mounted in each recess 14.

[0013] A rotation mechanism 13 is connected to the underside of the support portion 12A. During a film formation process, the rotation mechanism 13 rotates the turntable 12 via the support portion 12A clockwise in a plan view around the axis X in the circumferential direction of the turntable 12. The rotation mechanism 13 includes an encoder 13A that detects the rotation angle of the turntable 12 (support portion 12A), and transmits the rotation angle of the turntable 12 detected by the encoder 13A to the control portion 10. The control portion 10 identifies the position of each recessed portion 14 on the turntable 12 based on the rotation speed of the turntable 12 transmitted from the rotation mechanism 13.

[0014] A plurality of heaters 15 are provided at the bottom of the main body 11A. The heaters 15 are arranged, for example, concentrically. The heaters 15 heat the wafer W placed on the turntable 12.

[0015] A transfer port 16 is provided in a side wall of the main body 11A. The transfer port 16 is an opening for transferring the wafer W. The transfer port 16 is configured to be airtightly opened and closed by a gate valve (not shown). A transfer arm (not shown) is provided outside the vacuum chamber 11, and the wafer W is transferred into the vacuum chamber 11 by the transfer arm.

[0016] On the turntable 12, a gas supply and exhaust unit 2, a second processing region R2, a third processing region R3, and a fourth processing region R4 are arranged in this order along the rotation direction of the turntable 12, facing downstream of the rotation direction of the turntable 12.

[0017] The gas supply and exhaust unit 2 has a gas discharge port and an exhaust port for supplying a silicon (Si)-containing gas. The gas supply and exhaust unit 2 will be described below with reference to Fig. 3. In a plan view, the gas supply and exhaust unit 2 is formed in a fan shape that widens in the circumferential direction of the turntable 12 from the center toward the periphery of the turntable 12. The lower surface of the gas supply and exhaust unit 2 is close to and faces the upper surface of the turntable 12.

[0018] The lower surface of the gas supply and exhaust unit 2 is provided with gas discharge ports 21, exhaust ports 22, and purge gas discharge ports 23. A large number of gas discharge ports 21 are arranged in a fan-shaped region 24 located inside the periphery of the lower surface of the gas supply and exhaust unit 2. During film formation processing, the gas discharge ports 21 discharge a Si-containing gas downward in a shower-like manner while the turntable 12 is rotating, and supply the Si-containing gas to the entire surface of the wafer W. The silicon-containing gas is, for example, dichlorosilane (DCS) gas.

[0019] In the sector-shaped region 24, three zones 24A, 24B, and 24C are defined from the center toward the periphery of the turntable 12. The gas supply and exhaust unit 2 is provided with gas flow paths (not shown) that are separated from one another so that the Si-containing gas can be independently supplied to the gas discharge ports 21 provided in the zones 24A, 24B, and 24C. The upstream sides of the separated gas flow paths are connected to a supply source (not shown) of the Si-containing gas via piping equipped with gas supply equipment including a valve and a mass flow controller.

[0020] The exhaust port 22 and the purge gas outlet port 23 are annularly opened on the periphery of the lower surface of the gas supply and exhaust unit 2 so as to surround the fan-shaped region 24 and face the upper surface of the turntable 12. The purge gas outlet port 23 is located outside the exhaust port 22. The region on the turntable 12 inside the exhaust port 22 forms a first processing region R1 in which adsorption of the Si-containing gas onto the surface of the wafer W is performed. An exhaust device (not shown) is connected to the exhaust port 22, and a purge gas supply source is connected to the purge gas outlet port 23. The purge gas is, for example, argon (Ar) gas.

[0021] During the film formation process, the Si-containing gas is discharged from the gas discharge port 21, exhausted from the exhaust port 22, and purge gas is discharged from the purge gas discharge port 23. As a result, the Si-containing gas and purge gas discharged toward the turntable 12 travel along the upper surface of the turntable 12 toward the exhaust port 22 and are exhausted from the exhaust port 22. By discharging and exhausting the purge gas in this manner, the atmosphere in the first processing region R1 is separated from the external atmosphere, and the Si-containing gas can be supplied exclusively to the first processing region R1. In other words, mixing of the Si-containing gas supplied to the first processing region R1 with the gases and activated species of the gases supplied to the outside of the first processing region R1 by the plasma generation units 3A to 3C (described later) can be suppressed.

[0022] The second to fourth processing regions R2 to R4 are provided with plasma generation units 3A to 3C for activating (exciting) the gas supplied to each region. The plasma generation units 3A to 3C are each configured similarly. The following describes the plasma generation unit 3C shown in Figure 1 as a representative example.

[0023] The plasma generation unit 3C supplies a plasma generation gas onto the turntable 12 and also supplies microwaves to the plasma generation gas to generate plasma on the turntable 12. The plasma generation unit 3C includes an antenna 31 for supplying the microwaves.

[0024] The antenna 31 includes a dielectric plate 32 and a metallic waveguide 33. The dielectric plate 32 is formed in a generally fan-like shape that widens from the center of the turntable 12 toward the periphery in a plan view. A generally fan-shaped through-hole is provided in the top plate 11B to correspond to the shape of the dielectric plate 32, and the inner peripheral surface of the lower end of the through-hole protrudes slightly toward the center of the through-hole to form a support portion 34. The dielectric plate 32 closes the through-hole from above and is provided facing the turntable 12, with the periphery of the dielectric plate 32 supported by the support portion 34. The waveguide 33 is provided on the dielectric plate 32. The waveguide 33 has an internal space 35 extending above the top plate 11B. A slot plate 36 is provided on the upper surface of the dielectric plate 32 so as to be in contact with the dielectric plate 32. The slot plate 36 forms the lower portion of the waveguide 33. The slot plate 36 has multiple slot holes 36A. The end of the waveguide 33 on the central side of the turntable 12 is closed, and a microwave generator 37 is connected to the end on the peripheral side of the turntable 12. The microwave generator 37 supplies microwaves of, for example, 2.45 GHz to the waveguide 33.

[0025] A gas injector 41 is provided at the downstream end of the second processing region R2. The gas injector 41 is connected to a hydrogen (H2) gas supply source 41a and an argon (Ar) gas supply source 41b via a pipe 41p. The gas injector 41 discharges H2 gas and Ar gas toward the upstream side. The gas injector 41 may be connected to another gas supply source.

[0026] A gas injector 42 is provided at the upstream end of the third processing region R3. The gas injector 42 is connected to an H gas supply source 42a and an Ar gas supply source 42b via a pipe 42p. The gas injector 42 discharges H gas and Ar gas downstream. The gas injector 42 may be connected to another gas supply source.

[0027] A gas injector 43 is provided at the downstream end of the fourth processing region R4. The gas injector 43 is connected to an H2 gas supply source 43a, an ammonia (NH3) gas supply source 43b, and an Ar gas supply source 43c via a pipe 43p. The gas injector 43 discharges H2 gas, NH3 gas, and Ar gas toward the upstream side. The gas injector 43 may be connected to another gas supply source.

[0028] 1 and 2, the gas injectors 41 to 43 are each formed of a long, thin tubular body with a closed tip. The gas injectors 41 to 43 are each provided on the side wall of the vacuum vessel 11 so as to extend horizontally from the side wall toward the central region of the vacuum vessel 11, and are each disposed so as to intersect with the region through which the wafer W on the turntable 12 passes. The gas injectors 41 to 43 each have a gas discharge port 40 formed along their length. For example, the gas discharge port 40 is formed in the gas injectors 41 to 43 in a region that covers the region through which the wafer W on the turntable 12 passes.

[0029] In the second to fourth processing regions R2 to R4, the microwaves supplied to the waveguide 33 pass through the slot holes 36A of the slot plate 36 to reach the dielectric plate 32, and are supplied to the gases, such as H2 gas, NH3 gas, and Ar gas, discharged below the dielectric plate 32. As a result, plasma is formed limitedly in the second to fourth processing regions R2 to R4 below the dielectric plate 32.

[0030] 2, a gas injector 45 is provided between the second processing region R2 and the third processing region R3. The gas injector 45 is configured as a long, thin tubular body with an open tip. The gas injector 45 penetrates the side wall of the vacuum vessel 11 so as to extend horizontally from the side wall of the main body 11A toward the central region. The gas injector 45 discharges nitrogen trifluoride (NF3) gas and Ar gas from the opening at the tip toward the center of the vacuum vessel 11.

[0031] The gas injector 45 is connected to an NF3 gas supply source 45a and an Ar gas supply source 45b via a pipe 45p. A remote plasma source 46 is provided in the pipe 45p. The remote plasma source 46 activates, by plasma, the NF3 gas and Ar gas introduced into the gas injector 45 from the respective supply sources via the pipe 45p. As a result, the gas injector 45 discharges the activated NF3 gas and Ar gas into the vacuum chamber 11. The NF3 gas is an example of a cleaning gas, and the Ar gas is an example of a carrier gas.

[0032] The tip of gas injector 45 is preferably located closer to the center than the outer periphery of turntable 12 in plan view. This prevents NF3 gas and Ar gas from flowing around to the underside of turntable 12, and allows NF3 gas and Ar gas to be efficiently supplied to the upper surface of turntable 12. The tip of gas injector 45 is preferably located closer to the sidewall of main body 11A than the outer periphery of the rotational orbit of recess 14 in plan view. This allows NF3 gas and Ar gas to be supplied over a wide range from the center to the periphery of turntable 12.

[0033] As shown in FIG. 2, a separation region D is provided between the third processing region R3 and the fourth processing region R4. The ceiling surface of the separation region D is set lower than the ceiling surfaces of the third and fourth processing regions R3 and R4. In a plan view, the separation region D is formed in a fan shape that widens in the circumferential direction of the turntable 12 as it moves from the center to the periphery of the turntable 12, and its lower surface is close to and faces the upper surface of the turntable 12. The distance between the lower surface of the separation region D and the upper surface of the turntable 12 is set to, for example, 3 mm to prevent gas from entering below the separation region D. The lower surface of the separation region D may also be set at the same height as the lower surface of the top plate 11B.

[0034] A first exhaust port 51, a second exhaust port 52, and a third exhaust port 53 are opened at positions outside the turntable 12 facing the upstream end of the second processing region R2, the downstream end of the third processing region R3, and the upstream end of the fourth processing region R4, respectively. The first to third exhaust ports 51 to 53 exhaust gases from the second to fourth processing regions R2 to R4, respectively.

[0035] As shown in FIG. 1, the third exhaust port 53 is formed in an area of ​​the main body 11A outside the turntable 12 so as to open upward. The opening of the third exhaust port 53 is located below the turntable 12. The third exhaust port 53 is connected to an exhaust device 54 via an exhaust flow path 531. The first and second exhaust ports 51 and 52 are also configured similarly to the third exhaust port 53 and are connected to a common exhaust device 54, for example, via exhaust flow paths 511 and 521. Each exhaust flow path 511, 521, and 531 is provided with an exhaust amount adjustment unit (not shown), and the exhaust amounts from the first to third exhaust ports 51 to 53 by the exhaust device 54 can be adjusted individually, for example. The exhaust amounts from the first to third exhaust ports 51 to 53 may be adjusted by a common exhaust amount adjustment unit. In this way, in the second to fourth processing regions R2 to R4, the gases discharged from the gas injectors 41 to 43 are exhausted from the first to third exhaust ports 51 to 53, and a vacuum atmosphere of a pressure corresponding to the amount of exhaust is formed in the vacuum vessel 11.

[0036] As shown in FIG. 1 , the film forming apparatus 1 is provided with a control unit 10. The control unit 10 is, for example, a computer. A program is stored in the control unit 10. The program is configured to send control signals to each component of the film forming apparatus 1 to control their operation and execute a cleaning method, which will be described later. Specifically, the program controls the rotation speed of the turntable 12 by the rotation mechanism 13, the flow rate and supply / stop of each gas by each gas supply device, the exhaust amount by the exhaust device 54, the supply / stop of microwaves from the microwave generator 37 to the antenna 31, and the power supply to the heater 15. Control of the power supply to the heater 15 controls the temperature of the wafer W, and control of the exhaust amount by the exhaust device 54 controls the pressure inside the vacuum chamber 11. The program is installed in the control unit 10 from a storage medium such as a hard disk, a compact disk, a magneto-optical disk, or a memory card.

[0037] [Cleaning method] 5 to 7, a cleaning method according to the embodiment will be described. The cleaning method according to the embodiment is performed when removing a film that accumulates on the turntable 12 due to repeated film formation processes. The film is, for example, a SiN film. The cleaning method according to the embodiment is performed in a state where no wafer W is placed in the recess 14.

[0038] First, the vacuum chamber 11 is depressurized to a predetermined pressure, and the turntable 12 is rotated at a predetermined rotation speed V1. The predetermined rotation speed V1 may be, for example, 10 rpm or less. NF3 gas and Ar gas are then discharged from the gas injector 45 into the vacuum chamber 11. The NF3 gas and Ar gas are activated and discharged by the remote plasma source 46. The NF3 gas discharged into the vacuum chamber 11 etches and removes the film deposited on the turntable 12. The output power P1 of the remote plasma source 46 may be 2000 W to 4000 W, and is, for example, 3000 W.

[0039] At this time, the control unit 10 identifies the position of each recess 14 on the turntable 12 based on the rotation speed of the turntable 12 transmitted from the rotation mechanism 13. Furthermore, the control unit 10 adjusts the flow rate of the Ar gas discharged from the gas injector 45 into the vacuum chamber 11 based on the identified position of each recess 14.

[0040] Specifically, when the rotation of the turntable 12 causes the recesses 14 not to be positioned on a line segment (hereinafter referred to as the "first line segment L1") connecting the gas injector 45 and the center O of the turntable 12 in a plan view (see FIG. 5), the control unit 10 adjusts the flow rate of the Ar gas to a first flow rate F1 (step S1). The first flow rate F1 is preferably a flow rate that allows the NF3 gas and Ar gas to reach the center of the turntable 12. The first flow rate F1 may be 500 sccm to 1000 sccm, for example, 770 sccm. This allows the NF3 gas to reach a wide area from the center to the periphery of the turntable 12, thereby removing the film deposited on the turntable 12 approximately uniformly in the radial direction of the turntable 12. In FIG. 5, the region where the recesses 14 are not positioned on the first line segment L1 is indicated by region A1, and the region where the recesses 14 are positioned on the first line segment L1 is indicated by region A2. The same applies to FIGS. 6 and 7.

[0041] Next, when the recess 14 begins to be positioned on the first line segment L1 in a plan view due to the rotation of the turntable 12 (see FIG. 6), the control unit 10 changes the flow rate of the Ar gas from the first flow rate F1 to the second flow rate F2 (step S2). The second flow rate F2 is preferably smaller than the first flow rate F1 and is a flow rate at which more NF3 gas and Ar gas are supplied to the peripheral side of the turntable 12 than to the central side. The second flow rate F2 may be 100 sccm to 300 sccm, for example, 170 sccm. This makes it difficult for the NF3 gas to reach the central side of the turntable 12, thereby reducing the etching rate of the film deposited on the central side of the turntable 12. Furthermore, the control unit 10 adjusts the flow rate of the NF3 gas to the same flow rate F3 in steps S1 and S2. The flow rate F3 of the NF3 gas may be 100 sccm to 500 sccm, for example, 250 sccm.

[0042] When the film formation process is repeated, a SiN film is deposited on the turntable 12. Because the film formation process is performed with a wafer W placed in each recess 14, the thickness of the SiN film deposited on each recess 14 is smaller than the thickness of the SiN film deposited on the region of the turntable 12 other than the recess 14. Therefore, when the same amount of NF3 gas is supplied to all regions on the turntable 12, the film deposited on the recess 14 is removed before the film deposited on the region other than the recess 14, exposing the surface of the recess 14. When the exposed surface of the recess 14 is exposed to NF3 gas, the surface of the recess 14 is etched, which may change the shape of the recess 14.

[0043] Therefore, in this embodiment, in step S2, when the recess 14 begins to be positioned on the first line segment L1 in plan view (see FIG. 6), the control unit 10 reduces the flow rate of the Ar gas discharged from the gas injector 45 into the vacuum chamber 11 from the first flow rate F1 to the second flow rate F2. This makes the etching rate of the film deposited on the recess 14 lower than the etching rate of the film deposited on the peripheral edge of the turntable 12. This makes it possible to prevent the surface of the recess 14 from being exposed before the film deposited on the region of the turntable 12 other than the recess 14 is removed. As a result, it is possible to prevent the shape of the recess 14 from being changed.

[0044] Next, when the rotation of the turntable 12 causes the recess 14 to no longer be positioned on the first line segment L1 in a planar view, the control unit 10 changes the flow rate of the Ar gas ejected from the gas injector 45 into the vacuum vessel 11 from the second flow rate F2 to the first flow rate F1 (step S1).

[0045] In this way, while rotating the turntable 12, the control unit 10 switches the flow rate of the Ar gas discharged from the gas injector 45 into the vacuum chamber 11 between the first flow rate F1 and the second flow rate F2 based on whether the recesses 14 are located on the first line segment L1 in a plan view (see FIG. 7). In the film forming apparatus 1 of the embodiment, six recesses 14 are formed on the turntable 12, so the control unit 10 switches from step S1 to step S2 and from step S2 to step S1 six times during one rotation of the turntable 12, the number of times being the same as the number of recesses 14.

[0046] In steps S1 and S2, Ar gas may be discharged from the purge gas outlet 23 and the gas injectors 41 to 43. This prevents NF gas discharged from the gas injector 45 from entering the gas outlet 21 and the gas injectors 41 to 43 when cleaning the inside of the vacuum chamber 11.

[0047] Furthermore, the control unit 10 may control the rotation mechanism 13 so that the rotation speed of the turntable 12 in step S2 is higher than the rotation speed of the turntable 12 in step S1. This shortens the time that the recesses 14 are exposed to the NF3 gas, thereby preventing the surfaces of the recesses 14 from being exposed.

[0048] Furthermore, the control unit 10 may set the flow rate of the NF3 gas in step S2 to be smaller than the flow rate of the NF3 gas in step S1. This reduces the amount of NF3 gas supplied onto the recesses 14, thereby preventing the surfaces of the recesses 14 from being exposed.

[0049] Furthermore, the control unit 10 may adjust the flow rate of Ar gas discharged from the gas injector 45 into the vacuum chamber 11 to a first flow rate when the length occupied by the recess 14 on the first line segment L1 in a plan view is shorter than the length occupied by the portion other than the recess 14. Furthermore, the control unit 10 may adjust the flow rate of Ar gas discharged from the gas injector 45 into the vacuum chamber 11 to a second flow rate when the length occupied by the recess 14 on the first line segment L1 in a plan view is longer than the length occupied by the portion other than the recess 14.

[0050] [Example] 8, an example in which the relationship between the flow rate of Ar gas and the etching rate distribution was evaluated will be described. In the example, in the film formation apparatus 1, the flow rate of NF3 gas discharged from the gas injector 45 into the vacuum chamber 11 was fixed at 250 sccm, and the etching rate of the SiN film in the radial direction of the turntable 12 was measured while the flow rate of Ar gas was changed. The Ar gas flow rates were set under five conditions: 170 sccm, 270 sccm, 370 sccm, 570 sccm, and 770 sccm.

[0051] 8 is a diagram showing the relationship between the flow rate of Ar gas and the etching rate distribution, in which the horizontal axis represents the radial position of the turntable 12, and the vertical axis represents the etching rate [nm / min] of the SiN film.

[0052] 8, it can be seen that increasing the flow rate of Ar gas results in a high etching rate over a wide range from the periphery to the center of the turntable 12. This is thought to be because increasing the flow rate of Ar gas increases the flow rate of the NF3 gas discharged together with the Ar gas, allowing a large amount of NF3 plasma or NF3 radicals to reach the center of the turntable 12.

[0053] On the other hand, when the flow rate of Ar gas is reduced, a high etching rate is obtained on the periphery of the turntable 12, but the etching rate is low and the SiN film is hardly etched on the center of the turntable 12. This is thought to be because when the flow rate of Ar gas is reduced, the flow rate of the NF3 gas discharged together with the Ar gas decreases, and most of the discharged NF3 gas is consumed on the periphery of the turntable 12 and does not reach the center of the turntable 12.

[0054] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0055] In the above embodiment, the film forming apparatus has been described as having three plasma generation units, but the present disclosure is not limited thereto. For example, the film forming apparatus may have one, two, or four or more plasma generation units. Also, the film forming apparatus may not have any plasma generation units.

[0056] In the above embodiment, the plasma generation unit is a unit that generates microwave plasma, but the present disclosure is not limited to this. The plasma generation unit may include a unit that generates inductively coupled plasma, capacitively coupled plasma, etc.

[0057] In the above embodiment, the cleaning gas is NF3 gas, but the present disclosure is not limited to this. For example, the cleaning gas may be chlorine trifluoride (ClF3).

[0058] In the above embodiment, the carrier gas is Ar gas, but the present disclosure is not limited to this. For example, the carrier gas may be an inert gas such as nitrogen (N) gas. [Explanation of symbols]

[0059] 1 Film deposition equipment 11 Vacuum container 12 Rotating table 14 Recess 45 Gas Injector W wafer

Claims

1. 1. A method for cleaning an inside of a processing vessel in a film formation apparatus including: a rotary table rotatably installed within a processing vessel, the rotary table having a plurality of mounting areas on which substrates are placed along a circumferential direction; and a gas injector installed to penetrate a sidewall of the processing vessel, the method comprising: discharging a cleaning gas and a carrier gas from the gas injector into the processing chamber while rotating the turntable; When the placement area is not located on a first line segment connecting the gas injector and the center of the rotary table in a plan view, the flow rate of the carrier gas is adjusted to a first flow rate; When the placement area begins to be positioned on the first line segment in a plan view, the flow rate of the carrier gas is changed from the first flow rate to a second flow rate that is smaller than the first flow rate; When the placement area is no longer located on the first line segment in a plan view, the flow rate of the carrier gas is changed from the second flow rate to the first flow rate. Cleaning method:

2. The first flow rate is changed to the second flow rate and the second flow rate is changed to the first flow rate based on the rotation angle of the rotary table. The cleaning method according to claim 1 .

3. During one rotation of the rotary table, the change from the first flow rate to the second flow rate and the change from the second flow rate to the first flow rate are performed the same number of times as the number of the placement areas. The cleaning method according to claim 1 or 2.

4. a flow rate of the cleaning gas discharged from the gas injector into the processing vessel when the placement area is located on the first line segment in a plan view is equal to a flow rate of the cleaning gas discharged from the gas injector into the processing vessel when the placement area is not located on the first line segment in a plan view. The cleaning method according to any one of claims 1 to 3.

5. a rotation speed of the turntable when the placement area is located on the first line segment in a plan view is higher than a rotation speed of the turntable when the placement area is not located on the first line segment in a plan view; The cleaning method according to any one of claims 1 to 4.

6. The cleaning gas is nitrogen trifluoride, and is activated by remote plasma and discharged. The cleaning method according to any one of claims 1 to 5.

7. The mounting area is a recessed portion recessed from the upper surface of the rotary table. The cleaning method according to any one of claims 1 to 6.

8. A processing vessel; a rotary table rotatably provided within the processing chamber, the rotary table having a plurality of placement areas on which substrates are placed along a circumferential direction; a gas injector provided through a sidewall of the processing vessel; A control unit; Equipped with The control unit a cleaning gas and a carrier gas are discharged from the gas injector into the processing vessel while rotating the rotary table; The control unit When the placement area is not located on a first line segment connecting the gas injector and the center of the rotary table in a plan view, the flow rate of the carrier gas is adjusted to a first flow rate; When the placement area begins to be positioned on the first line segment in a plan view, the flow rate of the carrier gas is changed from the first flow rate to a second flow rate that is smaller than the first flow rate; When the placement area is no longer located on the first line segment in a plan view, the flow rate of the carrier gas is changed from the second flow rate to the first flow rate. Film deposition equipment.

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