Film forming apparatus and cleaning method thereof

Abstract

To provide a deposition apparatus and its manufacturing method that can ensure quality of substrates by universally cleaning the inside of a vacuum chamber.SOLUTION: A deposition apparatus 1 of the present invention has a vacuum chamber 10, an applicator section 20 for generating plasma, and a vacuum exhaust pump 50. The applicator section 20 has a gas inlet 20A for introducing cleaning gas into the vacuum chamber 10 and a gas outlet 20D for discharging plasmaized cleaning gas, and is arranged adjacent to the vacuum chamber 10 by connecting a connecting port 10A of the vacuum chamber 10 to the gas outlet 20D. A tube member 11 extending into a housing space S is connected to an inner surface side of the vacuum chamber 10 at the connecting port 10A. The cleaning gas consists of fluorine gas.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a film forming apparatus and a cleaning method thereof, and more particularly to a film forming apparatus for forming a thin film on a substrate and a cleaning method thereof. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a technique for forming a thin film (eg, silicon (Si)) on a substrate (eg, a glass substrate) by introducing a microwave plasma into a vacuum chamber. In such a vacuum chamber, when a process for forming a thin film on a substrate (hereinafter referred to as a "film formation process") is performed, film formation components (hereinafter referred to as "deposits") tend to adhere to the inner wall surfaces, etc., which tends to cause particles to be generated inside. In such cases, it is necessary to quickly remove the deposits present in the vacuum chamber, as they are one of the factors that hinder the formation of a good thin film.

[0003] In view of this, various techniques have been proposed for cleaning the inside of a vacuum chamber, such as the cleaning method described in Patent Document 1.

[0004] The cleaning method described in Patent Document 1 (Applied Materials (AMAT)) includes the steps of: (1) supplying hexafluoroethane (C 2 F 6 (1) introducing a cleaning gas consisting of a mixture of nitrogen and oxygen; and (2) removing thin films adhering to the substrate holder using the cleaning gas in plasma form. According to such a cleaning method, deposits adhering to the substrate holder and the like can be effectively removed, so that film formation processing can be carried out continuously while suppressing generation of particles. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-131752 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the cleaning method described in Patent Document 1, the cleaning gas in plasma form is mainly sprayed toward the substrate holder, making it difficult to distribute the plasma evenly inside the vacuum chamber.

[0007] In other words, the cleaning technology described in Patent Document 1 is configured in such a way that it is difficult to thoroughly clean the inside of the vacuum chamber, and therefore there is a high possibility that during the film formation process, deposits adhering to the upper inner wall surface, etc., may peel off and fall onto the substrate during film formation (mix with the thin film), which may result in a problem of reduced quality of the substrate.

[0008] In this respect, the cleaning technique described in Patent Document 1 is not sufficient in terms of ensuring the quality of the substrate, and there is still room for improvement. It is expected that such problems will become more pronounced as vacuum chambers become larger in recent years.

[0009] The present invention has been made to solve such problems, and has an object to provide a film forming apparatus and a manufacturing method thereof that can ensure the quality of substrates by thoroughly cleaning the inside of a vacuum chamber. [Means for solving the problem]

[0010] The above problem is solved by a film forming apparatus according to the present invention, which is a film forming apparatus for forming a thin film on a substrate, and which accommodates the substrate. And, General Mouth a vacuum chamber having a plasma generating means for generating plasma; Inside the vacuum chamber and an exhaust means for exhausting the air in the vacuum chamber, of Inside Departmenta gas inlet for introducing a cleaning gas for removing deposits adhering to the substrate; and a gas inlet for discharging the cleaning gas in plasma form. One a gas discharge port, and the gas discharge port is connected to an outer surface side of the vacuum chamber at the communication port, so that the gas discharge port is disposed adjacent to the vacuum chamber, and the gas discharge port is connected to an inner surface side of the vacuum chamber at the communication port. Inside the vacuum chamber a tubular member extending from the The tubular member has a plurality of through holes that extend radially through a peripheral wall of the tubular member and are spaced apart in an axial direction, The problem is solved by the cleaning gas comprising a fluorine-based gas.

[0011] In the invention relating to the film forming apparatus, it is preferable that the cleaning gas contains at least sulfur hexafluoride (SF6). In this case, the cleaning gas preferably has a sulfur hexafluoride content of 80% or more, and more preferably 100%.

[0012] In the invention relating to the film formation apparatus, it is preferable that the cleaning gas has a composition such that a cleaning speed at a position 600 mm away from the gas ejection port is 20 μm / min or more.

[0013] moreover ,before More preferably, the tubular member is configured to be rotatable about a center of rotation in the direction of extension from the communication port, and further includes a driving means capable of rotating the tubular member.

[0014] In the film forming apparatus of the present invention, it is preferable that the tubular member is made of a fluororesin.

[0015] Furthermore, in the invention relating to the film forming apparatus, it is preferable that the thin film is made of any one of silicon (Si), silicon nitride (SiN), glass, an organic material, and an oxide material.

[0016] The above problem is solved by the method for cleaning a film formation apparatus according to the present invention, which includes a cleaning gas supply step of supplying the cleaning gas that has been converted into plasma by the plasma generating means into the vacuum chamber, and a cleaning gas exhaust step of exhausting the cleaning gas that has been discharged into the vacuum chamber by the exhaust means. Effect of the Invention

[0017] As described above, the film formation apparatus and manufacturing method thereof according to the present invention have a relatively simple configuration, yet are capable of thoroughly cleaning the inside of the vacuum chamber, thereby reliably ensuring the quality of the substrate. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment of a film forming apparatus according to the present invention. [Diagram 2] FIG. 2 is a flow chart for explaining the operation process of the film forming apparatus of FIG. [Diagram 3] FIG. 3 is a schematic perspective view for explaining the internal structure of the vacuum chamber. [Figure 4] FIG. 4 is a graph showing the relationship between the gas concentration of the cleaning gas and the cleaning rate, and shows a comparison between the case where sulfur hexafluoride is used as the cleaning gas and the case where ethane hexafluoride is used as the cleaning gas. [Diagram 5] FIG. 5 is a graph showing the relationship between the content of sulfur hexafluoride and the cleaning speed, comparing measurements taken at a position 150 mm away from the gas ejection port and measurements taken at a position 600 mm away from the gas ejection port. [Figure 6] FIG. 6 is a table showing the cleaning speed when sulfur hexafluoride is discharged through a tubular member, and shows a comparison between the case where the distance from the gas discharge port to the through-hole is 100 mm and the case where the distance is 300 mm. [Figure 7] FIG. 7 is a schematic cross-sectional view showing a modified example of the film forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A preferred embodiment of a film forming apparatus and a cleaning method thereof according to the present invention will be described below with reference to the drawings. Fig. 1 is a schematic diagram showing an overview of a film forming apparatus 1 according to this embodiment, and Fig. 2 is a flow chart for explaining the operation process of the film forming apparatus 1.

[0020] <Overall configuration of film forming apparatus 1> 1, the film forming apparatus 1 according to this embodiment is an apparatus for forming a thin film on a substrate (e.g., a glass substrate, not shown), and includes a vacuum chamber 10, an applicator unit 20, a microwave generating unit 30, a cleaning gas supplying unit 40, a vacuum exhaust pump 50, and a control unit 60. The film forming apparatus 1, the vacuum chamber 10, the applicator unit 20, and the vacuum exhaust pump 50 correspond to the "film forming apparatus", "vacuum chamber", "plasma generating means", and "exhaust means" described in the claims, respectively.

[0021] (Vacuum chamber 10) The vacuum chamber 10 according to this embodiment is a CVD (Chemical Vapor Deposition) container made of a metal member such as stainless steel, and having an accommodation space S for accommodating a substrate. In the accommodation space S, a substrate holder (not shown, hereinafter referred to as an "accessory member") for holding the substrate and the like are arranged. 。 In this embodiment, the thin film is formed on the substrate by using a known CVD method (chemical vapor deposition method). As will be described in detail later, such a thin film is formed by introducing a plasma-converted film-forming gas into the accommodation space S (film-forming process).

[0022] In this embodiment, the thin film is made of any one of silicon (Si), silicon nitride (SiN), glass, an organic material, and an oxide material, and the film forming gas is a gas capable of forming such a thin film, such as silane (SiH 4 ), nitrous oxide (N2 A gas mixture consisting of 12O (O) and argon (Ar) is used.

[0023] A communication port 10A and an exhaust port 10B that communicate with the accommodation space S are formed on the upper and lower sides, respectively, of the vacuum chamber 10. The communication port 10A and the cleaning gas correspond to the "communication port" and the "cleaning gas" described in the claims, respectively.

[0024] An applicator part 20 that introduces plasmatized cleaning gas into the accommodation space S is directly connected to the outer surface of the vacuum chamber 10 through the communication port 10A, while a tube member 11 is connected to the inner surface of the applicator part 20. The tube member 11 corresponds to the "tubular member" described in the claims. The cleaning gas is a gas used to remove deposits that adhere to the inner surface of the vacuum chamber 10 that defines the storage space S and to the accessory components contained in the storage space S during the film formation process, i.e., the film formation components that make up the thin film (silicon, silicon nitride, glass, organic materials, and oxide materials). The cleaning gas according to the present embodiment is sulfur hexafluoride (SF 6 ) is used.

[0025] A plurality of through holes 11a to 11d (four in this embodiment) are formed in the tube member 11 at predetermined intervals along the extending direction (see Figs. 1 and 3). The through holes 11a to 11d correspond to the "through hole" described in the claims. In this embodiment, the cleaning gas is injected through the through holes 11a to 11d. In this respect, the through holes 11a to 11d function as injection ports for injecting the cleaning gas. In the example shown in Fig. 1 and Fig. 3, the extended end of the tube member 11 is shown as closed, but it may be open.

[0026] The tube member 11 is preferably made of a fluororesin, more preferably made of polytetrafluoroethylene (PTTE), from the viewpoints of (1) suppressing deformation due to cleaning gas, plasma, high temperature environment, etc., and (2) suppressing deactivation of plasma and ensuring ease of processing. This makes it possible to easily perform processing such as increasing the number of through holes 11a for injecting cleaning gas and shortening the length of the tube member 11 according to the shapes of the vacuum chamber 10 and the auxiliary members, the arrangement positions of the auxiliary members, etc. Note that the tube member 11 is not limited to the above-mentioned fluororesin (including polytetrafluoroethylene), and can also be made of, for example, quartz or ceramics.

[0027] The vacuum chamber 10 is connected to an equipment (hereinafter referred to as "cleaning gas supply equipment") consisting of an applicator unit 20, a microwave generation unit 30, and a cleaning gas supply unit 40, as well as an equipment (hereinafter referred to as "film formation gas supply equipment") for supplying a film formation gas to the accommodation space S. A detailed description of the cleaning gas supply equipment (applicator unit 20, microwave generation unit 30, and cleaning gas supply unit 40) will be given later. Such a deposition gas supply equipment can employ various types of equipment as long as it can form a thin film on a substrate by supplying a deposition gas to the accommodation space S. Examples of the deposition gas supply equipment include (1) a type in which the deposition gas is converted into plasma before being introduced into the accommodation space S (such as a type in the cleaning gas supply equipment according to this embodiment) and (2) a type in which the deposition gas is converted into plasma after being introduced into the accommodation space S (such as a type in the above-mentioned prior art document (JP Patent Publication No. 2001-131752)). For convenience of explanation, the following description will be given on the assumption that the former film formation gas supply equipment (see "film formation gas supply unit 45" in FIG. 1) is connected to the film formation apparatus 1. The film formation gas supply equipment (applicator unit 20, microwave generation unit 30, and film formation gas supply equipment 45) will be described in detail later.

[0028] A vacuum exhaust pump 50 is connected to the exhaust port 10B via an exhaust path 51. As a result, in this embodiment, it is possible to exhaust the film forming gas, cleaning gas, and the like in the accommodation space S to the outside, and to make the accommodation space S into a vacuum state.

[0029] (Applicator part 20) The applicator unit 20 is a device for converting into plasma the cleaning gas supplied from the cleaning gas supply unit 40 and the film formation gas supplied from the film formation gas supply unit 45. Hereinafter, unless there is no need to distinguish between the film formation gas and the cleaning gas, these will be collectively referred to as "gas." Applicator section 20 includes gas inlet 20A, microwave inlet 20B, space section 20C, and gas outlet 20D. Gas inlet 20A and gas outlet 20D correspond to the "gas inlet" and "gas outlet" in the claims, respectively.

[0030] Gas inlet 20A is connected to a gas supply path 43, which will be described later, and is an opening for introducing gas supplied via gas supply path 43 into space 20C. The microwave inlet 20B is an opening that is connected to a waveguide 34 described later and guides the microwaves supplied via the waveguide 34 to the space portion 20C. The space 20C is an area where the gas introduced through the gas inlet 20A is irradiated with microwaves supplied through the microwave inlet 20B, thereby generating a plasmatized gas (hereinafter also referred to as "microwave plasma gas") (the gas is excited into plasma). The gas discharge port 20D is directly connected to the communication port 10A of the vacuum chamber 10, and is an opening for discharging the microwave plasma gas generated in the space portion 20C.

[0031] The vacuum chamber 10 is disposed adjacent to the upper part of the vacuum chamber 10, with the communication port 10A and the gas discharge port 20D connected. In this regard, the vacuum chamber 10 according to this embodiment is configured so that the plasma gas generated in the space portion 20C can be immediately injected into the accommodation space S through the through holes 11a to 11d of the tube member 11.

[0032] 1, the gas discharge port 20D of the applicator part 20 is inserted into the communication port 10A of the vacuum chamber 10 to connect them, but the manner of connecting them is not limited to this. For example, the gas discharge port 20D may be inserted into the communication port 10A to connect them, or they may be connected via a separate tubular member.

[0033] (Microwave generating unit 30) The microwave generating unit 30 includes a magnetron 31 connected to a high voltage power supply 33 (for example, 3 to 8 kV), and a high frequency matching box 32. Since the magnetron 31 itself is now publicly known, detailed explanation of its configuration and operation will be omitted, but in this embodiment as well, it is configured to generate and output microwaves of a predetermined frequency (e.g., 2.45 GHz). The magnetron 31 according to this embodiment is connected to the microwave inlet 20B of the applicator part 20 via a waveguide 34 having a high-frequency matching box 32, and adjusts the voltage output to stabilize the microwave output based on a voltage adjustment signal output from the control device 60. This makes it possible to irradiate microwaves to the space part 20C of the applicator part 20 through which gas flows. The high-frequency matching box 32 functions to reduce the reflected microwaves from the applicator section 20 and adjust the power of the reflected microwaves (impedance matching). As such a high-frequency matching box 32, for example, a known matcher can be used.

[0034] (Cleaning gas supply unit 40) The cleaning gas supply unit 40 is a facility for supplying a cleaning gas to the applicator unit 20, and includes a cleaning gas supply source 41 and a flow rate adjustment device . The cleaning gas supply source 41 is connected to the gas inlet 20A of the applicator part 20 via a gas supply path 43, and the flow rate regulator 42 is attached to a predetermined position in the gas supply path 43. The flow rate adjustment device 42 opens and closes the valve body and adjusts the flow rate of the cleaning gas based on a flow rate adjustment signal output from the control device 60. That is, in this embodiment, the cleaning gas can be supplied to the accommodation space S via the applicator part 20 only when the accommodation space S of the vacuum chamber 10 is cleaned. Note that, for example, a mass flow controller (MFC) can be used as the flow rate adjustment device 42.

[0035] (film forming gas supply unit 45) The film forming gas supply unit 45 is a facility for supplying a film forming gas to the applicator unit 20 . The film formation gas supply unit 45 includes a film formation gas supply source 46 and a flow rate control device 42', similar to the cleaning gas supply unit 40. Note that the film formation gas supply unit 45 shown in Fig. 1 is merely one example of a film formation gas supply facility, and the above-mentioned other types of facilities can be adopted.

[0036] In the example shown in FIG. 1, a branch portion 44 is provided in gas supply path 43 on the side connecting applicator portion 20 and flow rate control device 42, and a film forming gas supply source 46 is connected to branch portion 44 via branch path 47. The flow rate control device 42' is provided at a position midway along the branch path 47, and similarly to the flow rate control device 42, opens and closes the valve body and controls the flow rate of the deposition gas based on a flow rate control signal output from the control device 60. Note that, similarly to the flow rate control device 42, a mass flow controller can be used as the flow rate control device 42'.

[0037] In the example shown in FIG. 1, since the flow rate regulators 42, 42' are configured as described above, it is possible to supply either the cleaning gas or the film forming gas to the accommodation space S by controlling the flow rate regulators 42, 42', respectively.

[0038] 1, the gas supply path 43 is provided with a branch path 47, and the cleaning gas and the film forming gas are supplied to the accommodation space S through the (common) applicator unit 20, but it is also possible to supply these gases to the accommodation space S through different applicators. Such a configuration can be realized, for example, by (1) providing a communication port different from the communication port 10A in the vacuum chamber 10, (2) connecting the different communication port to the applicator unit for the film forming gas, and (3) connecting the applicator unit for the film forming gas to the film forming gas supply path. In this case, the same microwave generating unit 30 as the applicator unit 20 may be connected to the applicator unit for the film forming gas, or a different microwave generating unit may be connected to the applicator unit for the film forming gas.

[0039] (Vacuum exhaust pump 50) The vacuum exhaust pump 50 is a device capable of reducing the pressure in the accommodation space S to a desired vacuum level based on an exhaust amount adjustment signal output from the control device 60, and is connected to the exhaust port 10B of the vacuum chamber 10 via an exhaust path 51. As the vacuum exhaust pump 50, for example, a dry pump or a turbo molecular pump can be used.

[0040] (Control device 60) The control device 60 is, for example, a known personal computer system, and has a central processing unit (CPU), a memory unit, etc. The control device 60 according to this embodiment is electrically connected to the magnetron 31, the flow rate control devices 42, 42', the vacuum exhaust pump 50, etc. The central processing unit reads various programs stored in the memory unit, executes predetermined arithmetic processing, and performs control to display a predetermined image on a display unit (not shown). In addition to this, the central processing unit performs controls such as (1) outputting a voltage adjustment signal to the magnetron 31 to adjust the voltage output to stabilize the microwave output, (2) outputting a flow rate adjustment signal to the flow rate adjustment device 42 (flow rate adjustment device 42') to adjust the flow rate of the cleaning gas (film formation gas), and (3) outputting an exhaust rate adjustment signal to the vacuum exhaust pump 50 to control starting and stopping of the motor and adjustment of the rotation speed to bring the accommodation space S into a vacuum state.

[0041] <Work process of deposition equipment 1> Next, the operation process using the film forming apparatus 1 will be described with reference to FIGS. In the following, for ease of explanation, the following will be described under the assumptions that (1) when the film formation process is performed, the substrate is automatically held by the substrate holder, and (2) after the film formation process is performed, the substrate is automatically removed from the storage space S.

[0042] 2, the working process of the film forming apparatus 1 according to this embodiment includes a film forming step S100 and a cleaning step S200. The cleaning step S200 performed by the film forming apparatus 1 corresponds to a "method for cleaning a film forming apparatus" described in the claims.

[0043] (Film forming process S100) As shown in FIGS. 1 and 2, in the film forming step S100, a process of forming a thin film on a substrate held by a substrate holder (not shown) is performed. Specifically, in the film forming step S100, a process for putting the accommodation space S into a vacuum state (hereinafter referred to as a "decompression process") is performed, and then a film forming process is performed.

[0044] The decompression process is performed by driving the vacuum exhaust pump 50 with the vacuum chamber 10 sealed, for example, with the flow rate control devices 42, 42' each closed. The vacuum exhaust pump 50 performs control such as starting and stopping the motor and adjusting the rotation speed based on a control signal (eg, an exhaust amount adjustment signal) output from the control device 60.

[0045] The film forming process S100 is started on the condition that the storage space S has reached a predetermined vacuum level and the state has stabilized. In this embodiment, the vacuum level of the storage space S is maintained by driving the vacuum exhaust pump 50 until the film forming process is completed. Specifically, in the film formation step S100, in a state where the outflow of the cleaning gas to the applicator portion 20 is stopped (the flow rate adjustment device 42 is closed), (1) the magnetron 31 is driven to supply microwaves of a predetermined frequency (e.g., 2.45 GHz) to the applicator portion 20, and (2) the flow rate adjustment device 42' is controlled to supply a film formation gas to the applicator portion 20. As described above, the driving of the magnetron 31 and the control of the flow rate adjustment device 42' are performed based on the control signal output from the control device 60. As a result, the microwave plasma gas (film formation gas) generated in the applicator portion 20 is introduced into the accommodation space S through the through holes 11a to 11d of the tube member 11, and a thin film having a predetermined thickness is formed on the substrate. As described above, the film forming gas according to the present embodiment is a gas for forming a thin film made of any one of silicon (Si), silicon nitride (SiN), glass, an organic material, and an oxide material on a substrate, such as silane (SiH 4 ), nitrous oxide (N 2 A gas mixture consisting of O and argon (Ar) is used.

[0046] When a thin film having a predetermined thickness is formed on the substrate, the film forming step S100 ends by stopping the driving of the magnetron 31 and stopping the supply of the film forming gas to the applicator unit 20. When the film forming process S100 is performed, the above-mentioned film forming components adhere not only to the substrate but also to the inner wall surface of the vacuum chamber 10 that defines the accommodation space S and to the accessory members arranged in the accommodation space S. When the film forming process S100 is performed, such adherent matter may be mixed into the thin film formed on the substrate, and in such a case, a problem occurs in that the quality of the substrate is deteriorated. Therefore, in this embodiment, in order to solve such a problem, a cleaning process S200 described later is performed after the film forming process S100 is performed.

[0047] (Cleaning process S200) In the cleaning process S200, a process is performed to remove deposits (film-forming components) that have adhered within the accommodation space S using a cleaning gas. As described above, the cleaning gas according to this embodiment is sulfur hexafluoride (SF 6 2, the film forming process S100 is followed by the cleaning process S200, but it is also possible to perform the film forming process S100 a predetermined number of times (e.g., "five times") before performing the cleaning process S200.

[0048] 2, the cleaning process S200 includes a cleaning gas supply process S201 and a cleaning gas exhaust process S202. The cleaning gas supply process S100 and the cleaning gas exhaust process S200 correspond to the "cleaning gas supply process" and the "cleaning gas exhaust process" described in the claims.

[0049] (Cleaning gas supply process S201) In the cleaning gas supply step S201, a process of supplying a cleaning gas in plasma form to the accommodation space S is performed. Specifically, in the cleaning gas supply step S201, in a state where the outflow of the film forming gas to the applicator portion 20 is stopped (the flow rate adjustment device 42' is closed), (1) the magnetron 31 is driven to supply microwaves of a predetermined frequency (e.g., 2.45 GHz) to the applicator portion 20, and (2) the flow rate adjustment device 42 is controlled to supply the cleaning gas to the applicator portion 20. The driving of the magnetron 31 and the control of the flow rate adjustment device 42 are performed based on a control signal output from the control device 60. As a result, the microwave plasma gas (cleaning gas) generated in the applicator portion 20 is introduced into the accommodation space S through the through holes 11a to 11d of the tube member 11. As will be described in detail later, when the deposits present in the accommodation space S come into contact with the cleaning gas in plasma form, they are decomposed and removed (gasified) by the sputtering effect.

[0050] (Cleaning gas exhaust process S202) In the cleaning gas exhaust process S202, a process of exhausting the cleaning gas in the accommodation space S under reduced pressure is performed. Specifically, in the cleaning gas exhaust process S202, a process of exhausting various gases present in the accommodation space S to the outside is performed by adjusting the motor rotation speed of the vacuum exhaust pump 50 based on an exhaust amount adjustment signal output from the control device 60. As a result, the deposits decomposed and removed in the cleaning gas supply process S201 are exhausted to the outside.

[0051] The cleaning process S200 according to this embodiment is configured to introduce a cleaning gas that has been converted into plasma into the accommodation space S while the accommodation space S is being evacuated and depressurized. In this respect, the present embodiment is configured to perform the cleaning gas supply step S201 after the cleaning gas exhaust step S202 has been performed. Note that the order, duration, etc. of performing the cleaning gas supply step S201 and the cleaning gas exhaust step S202 are not limited to this, and for example, the cleaning gas supply step S202 may be performed after the cleaning gas supply step S201.

[0052] To make it easier to understand how the deposits are decomposed and removed by the plasma cleaning gas, let us assume that the deposits (film-forming component) is "silicon (Si)" and the cleaning gas is "sulfur hexafluoride (SF 6 )" (content (gas concentration) 100%) will be used as an example. "Sulfur hexafluoride (SF 6 When the cleaning gas, which is made of sulfur hexafluoride (SF), is irradiated with microwaves in the space 20C of the applicator part 20, the energy of the microwaves converts the gas into sulfur hexafluoride (SF 6 The S-F bond in the hydrogen atom is dissociated to produce fluorine (F). When this gas comes into contact with the deposit (Si) present in the storage space S, the fluorine (F) changes to Si (silicon) + 4F (fluorine) → SiF 4 As the chemical reaction progresses, the deposits (film-forming components) are gradually decomposed and removed (gasified). The deposits thus decomposed and removed are sucked up by the vacuum exhaust pump 50 and discharged to the outside.

[0053] In this manner, in this embodiment, by connecting communication port 10A of vacuum chamber 10 and gas discharge port 20D of applicator part 20, applicator part 20 is disposed adjacent to vacuum chamber 10. For this reason, in this embodiment, the cleaning gas (fluorine-based gas) that has been made into plasma can be directly supplied to the accommodation space S, so that the fluorine (F) radicals generated by the applicator part 20 can be efficiently brought into contact with the deposits (film-forming components) present in the accommodation space S while remaining in an activated state. As a result, the deposits present in the accommodation space S can be efficiently decomposed and removed, so that the vacuum chamber 10 can be reliably cleaned in a short time.

[0054] In addition, in this embodiment, the cleaning gas plasmatized by the applicator portion 20 flows through the tube member 11 extending into the storage space S, and is then sprayed from the through holes 11a to 11d, thereby being supplied to the storage space S. That is, in this embodiment, the plasmatized cleaning gas can be sprayed toward a desired position and can also be efficiently diffused, so that it can be distributed evenly within the accommodation space S. As a result, even in a large vacuum chamber, the plasmatized cleaning gas can be brought into good contact with the deposits, so that the interior can be efficiently cleaned.

[0055] Furthermore, in this embodiment, the accommodation space S is configured to be evacuated by the vacuum exhaust pump 50 (cleaning gas exhaust step S202) while the cleaning gas is being introduced into the accommodation space S (cleaning gas supply step S201). That is, in this embodiment, since the decomposed and removed (gasified) deposits can be discharged to the outside as needed, the inside of the accommodation space S can be smoothly kept clean.

[0056] Furthermore, in this embodiment, since the cleaning gas is introduced into the accommodation space S while being exhausted, the cleaning gas can be suitably stirred and distributed within the accommodation space S. That is, according to the present embodiment, the cleaning gas can be brought into contact with the deposits (film-forming components) present in the accommodation space S more efficiently, so that the cleaning effect of the cleaning gas can be further improved.

[0057] <Test> In this embodiment, the cleaning gas is sulfur hexafluoride (SF 6 The fluorine-based gas used herein contains fluorine, the content of which is preferably 80% or more, and more preferably 100%. The reasons for this will be explained below based on the results of tests carried out using the film forming apparatus 1, with reference to FIG. 1 and FIGS.

[0058] In this test, two tests, "Test 1" and "Test 2," were conducted to verify the cleaning effect of the cleaning gas. "Test 1" is a test for comparing the cleaning speed (μm / min) when cleaning is performed using a cleaning gas containing sulfur hexafluoride with the cleaning speed when cleaning is performed using a cleaning gas containing ethane hexafluoride. Note that ethane hexafluoride is a gas that is widely and commonly used as a cleaning gas (see, for example, the above-mentioned "Prior Art Literature"). "Test 2" is a test to compare the cleaning speed when cleaning a position 150 mm away from the gas discharge port 20D with the cleaning speed when cleaning a position 600 mm away from the gas discharge port 20D. The above cleaning speed corresponds to the "cleaning speed" described in the claims.

[0059] In "Test 1" and "Test 2", the cleaning speed was measured using the film forming apparatus 1 under the following conditions. Cleaning gas pressure: 110Pa Cleaning gas flow rate: 1000sccm Magnetron 31 power consumption: 2000W Size of the accommodation space S of the vacuum chamber 10: width 1100 mm ("width W" in FIG. 3), depth 750 mm ("depth D" in FIG. 3), height 700 mm ("height H" in FIG. 3)

[0060] In addition, in "Test 1" and "Test 2", the cleaning speed is measured using a sample having a deposit (film-forming component) such as silicon (Si) on its outer surface, for example, a substrate equivalent to a substrate on which a thin film is formed.

[0061] (Test 1) FIG. 4 is a graph showing the measurement results of “Test 1”, which is a graph showing the comparison results between the cleaning speed when a gas containing sulfur hexafluoride was used and the cleaning speed when a gas containing ethane hexafluoride was used. In "Test 1," the cleaning speed was measured under the following test conditions. Position of sample: 150 mm away from gas outlet 20D of applicator part 20 Cleaning gas 1: Sulfur hexafluoride (SF 6 ) and oxygen (O 2 ) mixed gas (except when the content of sulfur hexafluoride is 100%) Cleaning gas 2 (comparison): ethane hexafluoride (C 2 F 6 ) and oxygen (O 2 ) mixed gas (except when the content of hexafluoroethane is 100%) Measurement of cleaning speed: for each specified content of sulfur hexafluoride and ethane hexafluoride

[0062] 4, it can be seen that when a gas containing sulfur hexafluoride is used, the cleaning speed remains at a relatively high value of 45 to 50 μm / min when the content exceeds 80%. In contrast, when a gas containing ethane hexafluoride is used, the cleaning speed remains at a relatively high value (about 5 μm / min) when the content is 50%, and generally remains at a low value (0 to 5 μm / min).

[0063] 4, it is clear from a comparison of the maximum cleaning speeds of sulfur hexafluoride and ethane hexafluoride, with the former at 50 μm / min (content 80%) and the latter at 5 μm / min (content 50%), which is 1 / 10 of the former. In this respect, according to "Test 1", it can be said that sulfur hexafluoride has a higher cleaning effect than ethane hexafluoride.

[0064] (Test 2) FIG. 5 is a graph showing the measurement results of "Test 2," which is a graph comparing the cleaning speed when using sulfur hexafluoride to clean a position 150 mm away from the gas outlet 20D and the cleaning speed when using sulfur hexafluoride to clean a position 600 mm away from the gas outlet 20D. In "Test 2," the cleaning speed was measured under the following test conditions. Positions of the sample: 150 mm and 600 mm away from the gas outlet 20D of the applicator part 20 Cleaning gas: Sulfur hexafluoride (SF 6 ) and oxygen (O 2 ) mixed gas (except when the content of sulfur hexafluoride is 100%) Measuring cleaning speed: for each sample position and for each specific sulfur hexafluoride content

[0065] 5, when the distance from the gas discharge port 20D to the sample is 150 mm, the cleaning speed remains at a relatively high value of 45 to 50 μm / min when the sulfur hexafluoride content exceeds 80%. In contrast, when the distance from the gas discharge port 20D to the sample is 600 mm, the cleaning speed remains at a relatively low value of 5 μm / min when the sulfur hexafluoride content is 80% or less, but when the content exceeds 80%, the cleaning speed increases rapidly, and when the content reaches 100%, the cleaning speed increases to 20 μm / min.

[0066] Thus, according to the graph shown in FIG. 5, the evaluation result shows that when the content of sulfur hexafluoride is 80% or more, more preferably 100%, the cleaning effect can be reliably achieved regardless of the distance from the gas discharge port 20D of the applicator part 20 to the cleaning target.

[0067] Incidentally, from the graph shown in Fig. 5, when the distance from the gas discharge port 20D of the applicator part 20 to the sample is 150 mm, it can be seen that the latter has a generally lower cleaning speed (cleaning effect) than the latter when the distance is 600 mm. In other words, even if a fluorine-based gas not containing sulfur hexafluoride is used, if a cleaning speed similar to the latter can be obtained, it can be expected to have the same cleaning effect (see Fig. 5) as a gas containing sulfur hexafluoride. In the latter test results, the cleaning speed was the fastest at 20 μm / min when the sulfur hexafluoride content was 100%. In this regard, when a fluorine-based gas not containing sulfur hexafluoride is used as the cleaning gas, it is preferable to satisfy the condition that the cleaning speed at a position 600 mm away from the gas discharge port 20D of the applicator part 20 is 20 μm / min or more.

[0068] (Test 3) As described above, in this embodiment, the cleaning gas is injected from the through holes 11a to 11d of the tube member 11 and introduced into the accommodation space S. Therefore, in order to verify the cleaning effect of the cleaning gas passing through the tube member 11, in addition to the above-mentioned "Test 1" and "Test 2", "Test 3" was performed. In "Test 3", the same film forming apparatus 1 as in "Test 1" and "Test 2" was used, for example, a vacuum chamber 10 in which the storage space S was formed with dimensions of width D: 1100 mm, depth D: 750 mm, and height H: 700 mm (see Figure 3). In "Test 3", a gas containing 100% sulfur hexafluoride was used as the cleaning gas.

[0069] In "Test 3", a tube member 11 having the following shape was used (see FIG. 3). Material: Polytetrafluoroethylene (PTTE) ·Shape / Straight pipe shape Size: Total length 400mm, outer diameter 40mm, inner diameter 23mm ·Diameter of through holes 11a~11d: 12mm Distance from the upper end to the through hole 11a (height h1), distance between the through holes 11a and 11b (height h2): 50 mm Distance between through holes 11b and 11c (height h3), distance between through holes 11c and 11d (height h4), distance from through hole 11d to the extended end (height h5): 100 mm

[0070] In "Test 3", the same samples as those in "Test 1" and "Test 2" were used (see "Samples SP1 and SP2" in FIG. 3). Sample SP1 was placed at a horizontal distance of 150 mm (see "width w1" in FIG. 3) from through-hole 11b, while sample SP2 was placed at a horizontal distance of 150 mm (see "width w2" in FIG. 3) from through-hole 11d. That is, in "Test 3", the distance (gas supply distance) from the gas discharge port 20D of the applicator part 20 (see FIG. 1) to the sample SP1 was set to 250 mm (h1+h2+w1), and the distance to the sample SP1 was set to 450 mm (h1+h2+h3+h4+w2), and the cleaning speed was measured (see FIGS. 3 and 6).

[0071] FIG. 6 is a table showing the measurement results of "Test 3." As shown in FIG. 6, the result of "Test 3" was a cleaning speed of 14.84 μm / min for sample SP1 and a cleaning speed of 12.96 μm / min for sample SP2. From these results, it was demonstrated that even when the cleaning gas is supplied to the accommodation space S through the tube member 11, a high cleaning effect can be ensured without any inferiority.

[0072] As described above, in this embodiment, by connecting communication port 10A of vacuum chamber 10 and gas discharge port 20D of applicator part 20, applicator part 20 is disposed adjacent to vacuum chamber 10. For this reason, in this embodiment, the cleaning gas (fluorine-based gas) that has been made into plasma can be directly supplied to the accommodation space S, so that the fluorine radicals generated by the applicator part 20 can be efficiently brought into contact with the deposits present in the accommodation space S while remaining in an activated state. As a result, the deposits present in the accommodation space S can be efficiently decomposed and removed, so that the vacuum chamber 10 can be reliably cleaned in a short time.

[0073] Furthermore, in this embodiment, the cleaning gas plasmatized by the applicator portion 20 flows through the tube member 11 extending into the storage space S, and is then sprayed from the through holes 11a to 11d, thereby being supplied to the storage space S. That is, in this embodiment, the plasmatized cleaning gas can be sprayed toward a desired position and can also be efficiently diffused, so that it can be distributed evenly within the accommodation space S. As a result, even in a large vacuum chamber, the plasmatized cleaning gas can be brought into good contact with the deposits, so that the interior can be efficiently cleaned.

[0074] As described above, according to this embodiment, the vacuum chamber 10 in which the film formation process is performed can be constantly kept clean, so that the quality of the substrate can be reliably ensured.

[0075] In the example shown in Figs. 1 and 3, the tube member 11 is formed into a straight tube shape, but it may be formed into other shapes, for example, an L shape, a T shape having a branch, or a curved shape. Moreover, the inner diameter does not need to be uniform, and for example, it may be gradually narrowed or enlarged toward the extended end. Furthermore, in the example shown in Figs. 1 and 3, four through holes are formed in the tube member 11, but the number may be three or less, or five or more. Furthermore, when a plurality of through holes are formed, they do not need to be formed in a line along the extension direction as shown in Figs. 1 and 3, but may be formed randomly.

[0076] Furthermore, it is preferable that the tube member 11 is configured to be detachable from the communication opening 10A of the vacuum chamber 10. With this configuration, not only can the tube member 11 be easily replaced when it is broken or damaged, but the inside of the vacuum chamber 10 can be effectively cleaned by attaching a tube member of a desired shape (for example, the above-mentioned L-shaped tube member) to the communication opening 10A.

[0077] The tube member 11 may be configured to be rotatable in the vacuum chamber 10. For example, as shown in FIG. A pipe-shaped vacuum shaft 12 is attached to the communication port 10A of the vacuum chamber 10 in an airtight manner so as to be freely rotatable. One end of the vacuum shaft 12 is attached to the gas discharge port 20D of the applicator part 20 (see FIG. 1) in an airtight and rotatable manner, and the other end is inserted and fixed into the tube member 11. A drive unit 13 (e.g., a motor) is disposed outside the vacuum chamber 10; The vacuum shaft 12 and the rotating shaft 13a of the drive unit 13 are connected by an endless belt 14 (e.g., a timing belt). This can be achieved by performing the following operations.

[0078] With this configuration, the cleaning gas can be discharged in a desired direction, and therefore the cleaning gas can be more evenly distributed in the accommodation space S, thereby effectively cleaning the inside of the vacuum chamber 10. The driving unit 13 corresponds to the "driving means" described in the claims.

[0079] Although the embodiment of the invention made by the present inventor has been described above, the present invention is not limited by the description and drawings that form part of the disclosure of the present invention according to the embodiment. In other words, it should be added that all other embodiments, examples, and operation techniques made by those skilled in the art based on the embodiment are naturally included in the scope of the present invention. [Explanation of symbols]

[0080] 1 Film deposition equipment 10 Vacuum chamber 10A communication port 10B Exhaust port 11 Tube members (tubular members) 11a~11d Through hole 11e Tsubabe 12 Vacuum Shaft 13 Drive unit 13a Rotation axis 14 Endless Belt 20 Applicator section (plasma generating means) 20A Gas inlet 20B Microwave inlet 20C Space 20D Gas outlet 30 Microwave generation unit 31 Magnetron 32 High frequency matching box 33 High Voltage Power Supply 34 Waveguide 40 Cleaning gas supply unit 41 Cleaning gas supply source 42,42´ Flow rate adjustment device 43 Gas supply line 44 Branch 45 Deposition gas supply section 46 Deposition gas supply source 47 Fork in the road 50 Vacuum exhaust pump (exhaust means) 51 Exhaust duct 60 Control device S Storage space SP1, SP2 samples W,w1,w2 Width D Depth H, h1~h5 Height

Claims

1. A film forming apparatus for forming a thin film on a substrate, a vacuum chamber that accommodates the substrate and has a communication port; A plasma generating means for generating plasma; an exhaust means for exhausting the inside of the vacuum chamber; Equipped with The plasma generating means includes: a gas inlet for introducing a cleaning gas for removing deposits adhering to the inside of the vacuum chamber; a gas outlet for discharging the cleaning gas in plasma form; having the gas discharge port is connected to an outer surface side of the vacuum chamber at the communication port, the gas discharge port being disposed adjacent to the vacuum chamber; a tubular member extending into the vacuum chamber is connected to the communication port on the inner surface side of the vacuum chamber, The tubular member has a plurality of through holes that extend radially through a peripheral wall of the tubular member and are spaced apart in an axial direction, The film forming apparatus, wherein the cleaning gas is a fluorine-based gas.

2. The cleaning gas is sulfur hexafluoride (SF ６ The film forming apparatus according to claim 1 ,

3. 3. The film forming apparatus according to claim 2, wherein the cleaning gas contains sulfur hexafluoride at a content of 80% or more.

4. 4. The film forming apparatus according to claim 3, wherein the cleaning gas contains 100% sulfur hexafluoride.

5. 2. The film forming apparatus according to claim 1, wherein the cleaning gas has a composition such that a cleaning speed at a position 600 mm away from the gas discharge port is 20 [mu]m / min or more.

6. The tubular member is configured to be rotatable about a rotation center in an extension direction extending from the communication port, The film forming apparatus according to claim 1 , further comprising a driving means capable of rotating the tubular member.

7. 7. The film forming apparatus according to claim 1, wherein the tubular member is made of a fluororesin.

8. 7. The film forming apparatus according to claim 1, wherein the thin film is made of any one of silicon (Si), silicon nitride (SiN), glass, an organic material, and an oxide material.

9. A method for cleaning a film forming apparatus according to any one of claims 1 to 6, comprising: a cleaning gas supplying step of supplying the cleaning gas converted into plasma by the plasma generating means into the vacuum chamber; a cleaning gas exhaust step of exhausting the cleaning gas discharged into the vacuum chamber by the exhaust means; A method for cleaning a film forming apparatus comprising the steps of:

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