Vacuum treatment device

Abstract

The present invention provides a vacuum processing device capable of removing particles brought in as much as possible while maintaining a vacuum atmosphere. The device comprises vacuum chambers (1, 2) provided with processing units (4), a vacuum pump (15) connected to the vacuum chambers, and a stage (3) installed in the vacuum chambers. The device comprises a swing mechanism, wherein the stage is in a first posture when a substrate (Sw) is facing the processing unit and is processed, and in a second posture when the stage is not in the processing state, and the swing mechanism swings the stage between the first and second postures. The device also comprises an injection mechanism (5) for injecting an inert gas toward the stage in the vacuum chamber, the injection mechanism being configured to switch between a first flow rate and a second flow rate, wherein the first flow rate can eject particles attached to at least one of the stage and the substrate while maintaining a vacuum atmosphere of a predetermined pressure in the vacuum chamber, and the second flow rate can transfer particles diffused in the vacuum chamber due to the ejection to the vacuum pump.

Description

Technical Field

[0001] The present invention relates to a vacuum processing apparatus, and more particularly to an apparatus for performing a predetermined process on a substrate to be processed in a vacuum atmosphere. Background Art

[0002] This type of vacuum processing device is used to perform various vacuum processes such as sputtering, vacuum evaporation or CVD film forming, dry etching, ion implantation or heat treatment on a substrate to be processed in a vacuum atmosphere. For example, a sputtering device that performs film forming on a large-area glass substrate by sputtering in the manufacturing process of a flat panel display panel includes a vacuum chamber, a vacuum pump for vacuum exhausting the interior of the vacuum chamber is connected to the vacuum chamber, and a stage on which the substrate to be processed is mounted is provided in the vacuum chamber. A rotating shaft is provided on the stage, and the stage can swing freely around the rotating axis between a horizontal posture (first posture) in which the main surface of the stage on which the substrate to be processed is provided faces upward in the vertical direction and an upright posture (second posture) in which the main surface of the stage on which the substrate to be processed is provided faces horizontally. In addition, a sputtering cathode unit as a processing unit is arranged on the wall of the vacuum chamber opposite to the main surface of the stage in the upright posture (for example, refer to Patent Document 1).

[0003] However, the various vacuum processing devices mentioned above are regularly maintained by the operator manually, such as replenishing film-forming materials, replacing target materials, and replacing anti-adhesion plates to prevent film-forming materials from adhering to the inner wall of the vacuum chamber. In this case, even if the vacuum chamber is set in a clean room with a specified air cleanliness, particles floating in the clean room may be brought into the vacuum chamber and adhere to the main surface of the stage, etc. Such particles may hinder good vacuum processing, so it is desirable to remove the brought-in particles after the maintenance is completed (for example, in the vacuum processing devices used in the manufacturing process of flat panel display panels, with the recent high precision and high functionality, it is required to minimize the number of particles below a specified size).

[0004] As one of the methods for removing particles, it is generally known to repeat the so-called periodic ventilation in which the vacuum chamber is alternately alternated between atmospheric atmosphere and vacuum atmosphere of a specified pressure. Thus, when a ventilation gas such as nitrogen or argon is introduced into the vacuum chamber of the vacuum atmosphere, particles attached to the main surface of the stage, etc., fly up, and then, when the vacuum chamber is evacuated by a vacuum pump, the particles can be removed as much as possible by transferring the flying particles to the vacuum pump. Such periodic ventilation is effective for vacuum processing devices, such as those used in the manufacturing process of semiconductor devices, where the volume of the vacuum chamber does not need to be too large due to the small size of the substrate to be processed (silicon wafer). However, in the case of vacuum processing devices used in the manufacturing process of flat panel display panels, where the volume of the vacuum chamber has to be increased due to the large size of the substrate to be processed, particles cannot be effectively removed. Moreover, if the volume of the vacuum chamber is large, a lot of time is required for the exhaust process to return the vacuum chamber to the atmospheric atmosphere and the exhaust process to form a vacuum atmosphere of a specified pressure, thereby causing a problem of impairing production efficiency.

[0005] Prior art literature

[0006] Patent Literature

[0007] [Patent Document 1] International Patent Publication WO2019 / 082868 Summary of the Invention

[0008] Technical problem to be solved by the invention

[0009] In view of the above problems, the technical problem of the present invention is to provide a vacuum processing device that can remove the brought-in particles as much as possible while maintaining a vacuum atmosphere.

[0010] Means of solving technical problems

[0011] In order to solve the above technical problems, the vacuum processing device of the present invention has a vacuum chamber, which is provided with a processing unit for performing a prescribed treatment on a processed substrate in a vacuum atmosphere, a vacuum pump for vacuum exhausting the interior of the vacuum chamber is connected to the vacuum chamber, and a stage on which the processed substrate is installed is installed in the vacuum chamber; it is provided with a swing mechanism, the posture of the stage when the processed substrate arranged on the stage and the processing unit are opposite to each other and the prescribed treatment is performed is a first posture, and the posture of the stage other than when the prescribed treatment is performed is a second posture, the swing mechanism swings the stage around the rotation axis between the first posture and the second posture; it is characterized in that it also has an injection mechanism for injecting inert gas onto the stage in the vacuum chamber, the injection mechanism is configured to switch the flow rate between a first flow rate and a second flow rate, the first flow rate can spray away particles attached to at least one of the stage and the processed substrate in a state where the vacuum atmosphere is at a prescribed pressure in the vacuum chamber, and the second flow rate can transfer particles diffused in the vacuum chamber due to the spraying to the vacuum pump.

[0012] According to the present invention, after the operator has performed maintenance such as replenishing the film-forming material, replacing the target material, and replacing the anti-adhesion plate to prevent the film-forming material from adhering to the inner wall of the vacuum chamber, the vacuum chamber is evacuated to a specified pressure range in the viscous flow region (for example, a range of 5Pa to 1000Pa) using a vacuum pump. When the vacuum is exhausted to the specified pressure range, with the stage set to the second posture, an inert gas such as nitrogen and argon is sprayed to the stage at a first flow rate through the injection mechanism. The first flow rate is set to, for example, a range of 1SLM to 100SLM, preferably a flow rate of 10SLM or more. At this time, the effective exhaust speed of the vacuum pump is appropriately set to maintain the vacuum chamber within the above-mentioned pressure range. The injection time of the inert gas at the first flow rate can be experimentally obtained in advance, for example, or calculated by simulation. In addition, the injection of the inert gas to the stage at the first flow rate can be performed after the vacuum chamber is evacuated to a high vacuum (for example, 10SLM) by using a vacuum pump. -5 Furthermore, in order to perform vacuum treatment on the substrate to be processed, the process can also be performed with the substrate to be processed placed on the stage. In this way, particles attached to the stage or the substrate to be processed are blown away and spread in the vacuum chamber (particle flying step).

[0013] Next, when the flying of the particles attached to the stage or the processed substrate ends, the injection mechanism switches from the first flow rate to the second flow rate, and the inert gas is introduced into the vacuum chamber. The second flow rate is set to a flow rate in the range of 300 sccm to 1000 sccm according to the size of the flying particles, for example. At this time, as described above, the effective exhaust speed of the vacuum pump is appropriately set to maintain the pressure in the vacuum chamber within the above-mentioned range. Thus, the particles diffused into the vacuum chamber are guided to the exhaust port of the vacuum chamber connected to the vacuum pump and transferred to the vacuum pump (particle transfer process). The injection time of the inert gas at the second flow rate is the same as described above, for example, it can be experimentally obtained in advance, or calculated by simulation. In addition, the flying process and the transfer process can be repeated multiple times in sequence.

[0014] Thus, in the present invention, after the vacuum chamber is set to a vacuum atmosphere, a relatively large amount (first flow rate) of inert gas is injected to cause particles attached to the stage, etc. to fly. A smaller amount (second flow rate) of inert gas is introduced and directed to the exhaust port, so that the flying particles do not further adhere to the stage, etc., thereby maintaining the vacuum atmosphere in the vacuum chamber and removing as many particles as possible. Moreover, since repeated ventilation and exhaust processes to return the vacuum chamber to the atmospheric atmosphere are not required, the time required to remove particles can be reduced, which is advantageous when the vacuum chamber has a large volume. Furthermore, since an inert gas is used, when the substrate to be processed is placed on the stage in the second posture and the stage is swung to the first posture in this state, and vacuum processing is performed, particles can be removed before vacuum processing.

[0015] In the present invention, the spray mechanism may include a spray nozzle disposed above the stage within the vacuum chamber and parallel to the rotation axis, and having a length equal to or greater than the width of the stage along the rotation axis. The spray nozzle sprays a first flow rate of inert gas in a linear pattern while the stage oscillates between the first and second postures. In this manner, the inert gas can be sprayed across the entire main surface of the stage, where the substrate being processed is located, by utilizing the oscillation of the stage, thereby reliably dislodging particles adhering to the stage and the like.

[0016] Furthermore, in the present invention, the spray mechanism may include a spray nozzle disposed above the stage within the vacuum chamber and parallel to the rotation axis, having a length equal to or greater than the width of the stage along the rotation axis; and a drive source configured to swing the nozzle hole of the spray nozzle about another rotation axis parallel to the rotation axis. This allows, for example, spraying inert gas over the entire main surface of the stage on which the substrate being processed is placed, even without swinging the stage. Furthermore, when spraying inert gas at the second flow rate, swinging the nozzle hole of the spray nozzle advantageously allows more reliable guidance of flying particles to an exhaust port. Furthermore, if the exhaust port of the vacuum chamber, to which the exhaust pipe from the vacuum pump is connected, is located below the stage, gravity can be added to more reliably guide flying particles to the exhaust port. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic cross-sectional view of the vacuum processing apparatus (sputtering apparatus) according to this embodiment.

[0018] Figure 2 It is a front view explaining the injection nozzle. DETAILED DESCRIPTION

[0019] Hereinafter, with reference to the accompanying drawings, an embodiment of the vacuum processing apparatus of the present invention will be described, taking as an example a case where a film forming process using a sputtering method is performed in a vacuum atmosphere, a sputtering cathode is used as a processing unit, and a glass substrate (hereinafter referred to as "substrate Sw") is used as a substrate to be processed, and a predetermined thin film is formed on one surface of the substrate Sw within a vacuum chamber in a vacuum atmosphere. Hereinafter, the terms indicating the up and down directions refer to the installation posture of the vacuum processing apparatus. Figure 1 As a benchmark.

[0020] Reference Figure 1 The vacuum processing device (sputtering device) VM has a main chamber 1 that is roughly box-shaped. The upper wall of the main chamber 1 located in the vertical direction has a curved shape corresponding to the swing of the gantry in order to allow the swing of the gantry mentioned later and to minimize the volume of the main chamber. In addition, a side wall of the main chamber 1 ( Figure 1 The auxiliary chamber 2 is connected to the left side wall of the main chamber 1 and can be connected to each other through an opening 11 provided on one side wall of the main chamber 1. Figure 1 An opening 13 for substrate transport, freely opened and closed by a baffle 12, is provided on the right side wall of the main chamber 1. Substrates Sw can freely enter and exit the main chamber 1 through this opening. Furthermore, an exhaust port 14 is formed on the bottom wall of the main chamber 1, located vertically downward. An exhaust pipe 15a from a vacuum pump 15 is connected to the exhaust port 14, enabling the main chamber 1 to be evacuated from atmospheric pressure to a high vacuum region. In this embodiment, the exhaust port 14 is located below the injection nozzle described later. Furthermore, a pilot valve 15b is provided on the exhaust pipe 15a, which adjusts the effective exhaust speed of the vacuum pump 15.

[0021] A stand 3 that can swing freely while holding the substrate Sw is provided in the main chamber 1. The stand 3 has a support plate portion 31, which has an area slightly larger than the substrate Sw and has a functional component for holding the substrate Sw. Although not specifically illustrated, known components such as claws or mechanical clamps provided on the outer periphery of the upper surface of the support plate portion 31 can be used as functional components. An arm portion 32 extending obliquely downward is installed at one end of the lower surface of the support plate portion 31 located on the auxiliary chamber 2 side, and the lower end of the arm portion 32 is connected to a rotating shaft portion 33 that is axially supported in the main chamber 1 in a manner extending in the horizontal direction. One end of the rotating shaft portion 33 ( Figure 1 The stage 3 is connected to the output shaft of the motor 34 serving as a driving mechanism (in the depth direction of the substrate 1). As a result, the stage 3 can freely swing between a second posture in which the main surface (the surface holding the substrate Sw) of the support plate portion 31 of the stage 3 holding the substrate Sw faces vertically upward, and a first posture in which the outer peripheral edge of the support plate portion 31 abuts against the inner surface of a side wall portion of the main chamber 1 located at the outer peripheral edge of the opening 11.

[0022] A sputtering cathode 4, serving as a processing unit, is installed in the auxiliary chamber 2. The sputtering cathode 4 includes a target 41 positioned facing the stage 3 in the first posture, and is installed in the auxiliary chamber 2 via a backing plate 42 bonded to one surface of the target 41. Although not specifically illustrated, the auxiliary chamber 2 is also connected to a vacuum pump. Furthermore, it can also introduce noble gases such as argon to form plasma in the vacuum chamber 1, as well as reactive gases during reactive sputtering. Depending on the type of target, a predetermined negative potential or AC power is applied to the target 41 from a sputtering power supply (not shown), forming a plasma in the auxiliary chamber 2. The target 41 is sputtered, thereby forming a predetermined thin film on the surface of the substrate Sw.

[0023] However, the vacuum processing apparatus VM described above requires periodic maintenance, such as replacement of the target 41 or an anti-adhesion plate (not shown), performed manually by the operator. Even if the main chamber 1 is located within a clean room with a specified air cleanliness level, particles floating within the clean room may be drawn into the main chamber 1 and adhere to the support plate 31 of the stage 3, etc. Because such particles can adversely affect film formation on the substrate Sw, it is necessary to minimize the number of particles smaller than a specified size before film formation. In this embodiment, an injection mechanism 5 is provided to inject an inert gas into the stage 3.

[0024] Also refer to Figure 2 The injection mechanism 5 includes an injection nozzle 51 provided on the inner surface of the upper wall of the main chamber 1. The injection nozzle 51 is formed by a nozzle having a width ( Figure 1 The main chamber 1 is a cylindrical body made of metal with a length of 1 / 2 (width in the depth direction). On its outer peripheral surface, a plurality of nozzle holes 51a are arranged at intervals in one direction, and an inert gas can be ejected linearly from each nozzle hole 51a. In addition, an air pipe 52 that passes through the upper wall of the main chamber 1 and protrudes into the interior is connected to the injection nozzle 51. In this case, although not specifically illustrated, a diffusion plate can be arranged in the injection nozzle 51 to diffuse the inert gas supplied through the air pipe 52 and eject the inert gas roughly evenly from each nozzle hole 51a. Moreover, the air pipe 52 is connected to a gas source outside the figure via a flow control valve 53. A rare gas such as nitrogen or argon is used as the inert gas. In addition, the flow control valve 53 switches the supply of inert gas to the injection nozzle 51 by switching between a first flow rate and a second flow rate. The first flow rate can eject particles attached to the stage 3 and the substrate Sw, and the second flow rate can diffuse the flying particles in the main chamber 1 and send them to the exhaust port 14. The spray nozzle 51 is also connected to the rotating shaft of a motor 54, which serves as a driving source. This driving source rotates about its axis (rotation axis). By reciprocating the spray nozzle 51 within a predetermined angular range, each nozzle hole 51a can be reciprocated about the axis within a predetermined angular range. The following describes the procedure for removing particles after maintenance.

[0025] After maintenance is performed, when the stage 3 is in the second posture, the main chamber 1 and the auxiliary chamber 2 are evacuated to a prescribed pressure range in the viscous flow region (for example, a range of 5Pa to 1000Pa) by using the vacuum pump 15. When the vacuum is exhausted to the prescribed pressure range, the flow control valve 53 is controlled to supply the inert gas to the injection nozzle 51 at a first flow rate, and the inert gas is ejected linearly from each nozzle hole 51a at the first flow rate. The first flow rate is set to, for example, a range of 1SLM to 100SLM, preferably a flow rate of 10SLM or more, and the opening of the guide valve 15b is appropriately adjusted to maintain the pressure in the main chamber 1 within the above-mentioned range. At the same time, the motor 54 is used to reciprocate the injection nozzle 51 within a prescribed angle range, and the stage 3 is swung until it reaches the first posture. The injection time of the inert gas at the first flow rate can be experimentally obtained in advance, or calculated by simulation, and the swing speed of the stage 3 is set accordingly. In addition, the main chamber 1 and the auxiliary chamber 2 can be evacuated to a high vacuum (for example, 10 -5 After the inert gas is injected at the first flow rate toward the stage 3, the inert gas may be injected while the substrate Sw is placed on the stage 3 to form a film on the substrate Sw. Thus, a linear inert gas is injected onto the stage 3, including the entire main surface of the support plate 31. Particles adhering to the stage 3 or the substrate Sw are ejected and dispersed within the main chamber 1 (particle injection step).

[0026] Next, when stage 3 assumes the first posture and the flying of particles attached to stage 3 or substrate Sw ceases, stage 3 maintains its first posture (i.e., the main chamber 1 and auxiliary chamber 2 remain isolated from each other). While the injection nozzle 51 continues to rotate, the flow control valve 53 is controlled to supply inert gas to the injection nozzle 51 at a second flow rate, causing the inert gas to be linearly ejected from each nozzle orifice 51a at the second flow rate. The second flow rate is set to a range of, for example, 300 sccm to 1000 sccm, depending on the size of the flying particles. At this time, the opening of the pilot valve 15b is appropriately adjusted, as described above, to maintain the pressure within the main chamber 1 within the aforementioned range. Consequently, combined with gravity, the particles dispersed within the main chamber 1 are guided to the exhaust port 14 and transferred to the vacuum pump 15 (particle transfer process). The injection time of the inert gas at the second flow rate is similar to that described above and can be determined experimentally or calculated through simulation. Furthermore, such a flying step and a transfer step may be repeated in sequence a plurality of times. In the particle flying step, the inert gas may be sprayed at the first flow rate when the stage 3 is swung from the first posture to the second posture.

[0027] According to the above embodiment, a relatively large amount (first flow rate) of inert gas is injected to cause particles attached to the stage 3 and the like to fly. In order to prevent the flying particles from further adhering to the stage 3 and the like, a relatively small amount (second flow rate) of inert gas is introduced to the exhaust port 14, thereby exhausting as many particles as possible while maintaining the vacuum atmosphere in the main chamber 1. Furthermore, since there is no need to repeatedly perform ventilation and exhaust processes to return the main chamber 1 to the atmospheric atmosphere, the time required to remove particles is reduced, which is advantageous when the volume of the main chamber 1 is large. Furthermore, since an inert gas is used, it is also possible to place the substrate Sw on the stage 3 in the second posture, and to swing the stage 3 to the first posture in this state. When film formation is performed, particles can be removed before this.

[0028] The embodiments of the present invention have been described above, but various modifications are possible without departing from the scope of the technical concept of the present invention. In the above embodiment, the injection mechanism 5 is described by taking the case where the injection nozzle 51 is provided on the inner side of the upper wall of the main chamber 1 as an example, but its form and configuration are not limited to this, as long as the first flow rate of inert gas is injected onto at least the entire main surface of the support plate portion 31 that is most likely to have an impact during vacuum processing. For example, if the stage 3 is swung as in the present embodiment, there is no need to rotate the injection nozzle 51. Furthermore, in the above embodiment, the exhaust port 14 is described by taking the case where the exhaust port 14 is provided on the bottom wall of the main chamber 1 as an example, but it is not limited to this, as long as it is a position to which particles diffused in the main chamber 1 are guided. Furthermore, in the above embodiment, the sputtering device is described as an example, but if it is a device using a swinging stage, the present invention can also be applied to other vacuum processing devices such as film forming processing devices using vacuum evaporation or CVD methods, dry etching processing devices, or ion implantation processing devices.

[0029] Description of Reference Numerals

[0030] VM. Vacuum processing device, Sw. Substrate (substrate to be processed), 1. Main chamber (vacuum chamber), 2. Auxiliary chamber (vacuum chamber), 3. Stage, 4. Sputtering cathode (processing unit), 5. Injection device, 51. Injection nozzle, 14. Exhaust port, 15. Vacuum pump, 15a. Exhaust pipe, 54. Motor (driving source).

Claims

1. A vacuum processing apparatus comprising a vacuum chamber, wherein the vacuum chamber is provided with a processing unit for performing a predetermined process on a substrate to be processed in a vacuum atmosphere, a vacuum pump for evacuating the interior of the vacuum chamber is connected to the vacuum chamber, and a stage on which the substrate to be processed is mounted is installed within the vacuum chamber, the vacuum processing apparatus comprising a swing mechanism for swinging the stage between the first and second postures, with the stage positioned so that the substrate to be processed, mounted on the stage, faces the processing unit and is subjected to the predetermined process, as a first posture, and with the stage positioned so that the substrate to be processed, mounted on the stage, faces the processing unit and is subjected to the predetermined process, as a second posture, when the stage is not subjected to the predetermined process; The vacuum processing device is characterized in that: The apparatus further comprises an injection mechanism for injecting an inert gas toward the stage within the vacuum chamber, the injection mechanism being configured to switch between a first flow rate for injecting particles attached to at least one of the stage and the substrate being processed while maintaining a vacuum atmosphere at a predetermined pressure within the vacuum chamber, and a second flow rate for transferring particles diffused within the vacuum chamber by the injection toward a vacuum pump. The injection mechanism includes an injection nozzle, which is arranged above the stage in the vacuum chamber and parallel to the rotation axis and has a length equal to or greater than the width of the stage along the rotation axis. When the stage swings between the first posture and the second posture, a first flow rate of inert gas is injected linearly from the injection nozzle.

2. A vacuum processing apparatus comprising a vacuum chamber, wherein the vacuum chamber is provided with a processing unit for performing a predetermined process on a substrate to be processed in a vacuum atmosphere, a vacuum pump connected to the vacuum chamber for evacuating the interior of the vacuum chamber, and a stage on which the substrate to be processed is mounted is installed within the vacuum chamber, the vacuum processing apparatus comprising a swing mechanism for swinging the stage between the first and second postures, wherein the stage is positioned such that the substrate to be processed, mounted on the stage, faces the processing unit and is subjected to the predetermined process, and the stage is positioned such that the stage is not subjected to the predetermined process. The vacuum processing device is characterized in that: The apparatus further comprises an injection mechanism for injecting an inert gas toward the stage within the vacuum chamber, the injection mechanism being configured to switch between a first flow rate for injecting particles attached to at least one of the stage and the substrate being processed while maintaining a vacuum atmosphere at a predetermined pressure within the vacuum chamber, and a second flow rate for transferring particles diffused within the vacuum chamber by the injection toward a vacuum pump. The injection mechanism includes an injection nozzle, which is arranged above the stage in parallel with the rotation axis in the vacuum chamber and has a length equal to or greater than the width of the stage along the rotation axis; the vacuum processing device has a driving source, which causes the nozzle hole of the injection nozzle to swing around another rotation axis parallel to the rotation axis.

3. The vacuum processing device according to claim 1 or 2, characterized in that: An exhaust port of the vacuum chamber, to which an exhaust pipe from the vacuum pump is connected, is opened below the stage.

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