Plasma processing apparatus

Abstract

The present invention provides a plasma processing apparatus capable of reducing the possibility of particles moving in a vacuum container adhering to a dielectric cover. A magnetic field introduction window (3) provided to a wall surface of a vacuum container (2) includes a metal plate (31) formed with a plurality of slits (311), a dielectric cover (32) covering the plurality of slits (311), a gasket (33) provided between the dielectric cover (32) and the metal plate (31), and an anti-adhesion plate (34) provided to the metal plate (31) in a manner of covering at least a portion of the plurality of slits (311).

Description

Technical Field

[0001] This invention relates to a plasma processing apparatus that uses plasma to process the object being processed. Background Technology

[0002] Plasma processing apparatuses are known to generate plasma by flowing a high-frequency current through an antenna, thereby using the plasma to process substrates and other materials. For example, the plasma processing apparatus described in Patent Document 1 includes: a vacuum container having an opening; a metal plate configured to block the opening and having a plurality of slits extending in the thickness direction; a plate-shaped dielectric cover contacting and supported with the metal plate, blocking the plurality of slits from the outside of the vacuum container; and an antenna disposed outside the vacuum container facing the metal plate. By flowing a high-frequency current through the antenna, a high-frequency electric field and a high-frequency magnetic field are generated, and the high-frequency magnetic field is transmitted into the vacuum container through the dielectric cover and the slits of the metal plate. This allows for the generation of inductively coupled plasma within the vacuum container.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-198282 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] When performing various processes using a plasma processing apparatus with the aforementioned structure, particles within the vacuum container sometimes migrate and adhere to and accumulate on the inner side of the vacuum container, the metal plate, and the dielectric cover. For example, when the plasma processing apparatus is used as a sputtering apparatus, sputtered particles adhere to and accumulate on the dielectric cover, etc. If the accumulation of sputtered particles is a conductive metal film, the metal film accumulated on the dielectric cover may become conductive with the metal plate at the slit. In this case, if a high-frequency current flows through the antenna, the metal film and the metal plate are inductively heated, and the dielectric cover is also heated. Since the dielectric cover serves to maintain the vacuum within the vacuum container, heating the dielectric cover is undesirable. Therefore, frequent cleaning of the dielectric cover is necessary.

[0008] An embodiment of the present invention aims to realize a plasma processing apparatus, etc., that can reduce the possibility of particles such as sputtered particles moving in a vacuum container attaching to the dielectric cover.

[0009] Technical means to solve the problem

[0010] To address the aforementioned problem, a plasma processing apparatus according to an embodiment of the present invention includes: a vacuum container housing a workpiece to be processed; an antenna disposed outside the vacuum container and generating a high-frequency magnetic field; and a magnetic field guiding window disposed on the wall of the vacuum container and guiding the high-frequency magnetic field into the interior of the vacuum container in order to generate plasma inside the vacuum container. The magnetic field guiding window includes: a metal plate having a plurality of slits; a dielectric cover covering the plurality of slits; a gasket disposed between the dielectric cover and the metal plate; and an anti-adhesion plate disposed on the metal plate to cover at least a portion of the plurality of slits.

[0011] The effects of the invention

[0012] According to one embodiment of the present invention, the possibility of particles moving within a vacuum container adhering to the dielectric shield can be reduced. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view showing a schematic structure of a plasma processing apparatus according to an embodiment of the present invention.

[0014] Figure 2 This is a top view showing the schematic structure of the magnetic field introduction window in the plasma processing device.

[0015] Figure 3 yes Figure 2 A cross-sectional view at line AA.

[0016] Figure 4 yes Figure 2 A cross-sectional view at the BB line.

[0017] Figure 5 This is a cross-sectional view showing a schematic structure of a plasma processing apparatus according to another embodiment of the present invention.

[0018] Figure 6 yes Figure 5 A cross-sectional view at the CC line.

[0019] Explanation of symbols

[0020] 1: Plasma processing device

[0021] 2: Vacuum container

[0022] 3: Magnetic field introduction window

[0023] 7: Antenna

[0024] 9: Maintaining section

[0025] 21: Processing Room

[0026] 22: Wall

[0027] 23: Opening

[0028] 31: Metal plate

[0029] 32: Dielectric shield

[0030] 33: Washer

[0031] 34: Anti-adhesion plate

[0032] 311: Slit

[0033] 312: concave part Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described in detail. Furthermore, for ease of explanation, components having the same function as those shown in each embodiment will be labeled with the same symbols, and their descriptions will be omitted as appropriate.

[0035] [Implementation Method 1]

[0036] Reference Figures 1-4 An embodiment of the present invention will be described.

[0037] <Structure of Plasma Processing Device 1>

[0038] Figure 1 This is a cross-sectional view showing the schematic structure of the plasma processing apparatus 1 according to this embodiment. Figure 1 In this context, the direction in which the antenna 7 extends is defined as the X-axis direction, the direction from the vacuum container 2 toward the antenna 7 is defined as the Z-axis direction, and the direction orthogonal to both the X-axis and Z-axis directions is defined as the Y-axis direction.

[0039] like Figure 1 As shown, the plasma processing apparatus 1 is an apparatus that performs plasma processing on a substrate or other workpiece W1 using inductively coupled plasma P1. Here, the substrate is, for example, a substrate for a flat panel display (FPD) such as a liquid crystal display or an organic electroluminescence (EL) display, or a flexible substrate for a flexible display. Furthermore, the workpiece W1 can be a semiconductor substrate used for various applications. Moreover, the workpiece W1 is not limited to a substrate-like form, such as a tool. The processing performed on the workpiece W1 includes, for example, film formation using plasma chemical vapor deposition (CVD) or sputtering, etching using plasma, ashing, and removal of coated films.

[0040] The plasma processing apparatus 1 includes a vacuum container 2, a magnetic field introduction window 3, an antenna 7, and a holding part 9. A processing chamber 21, which is evacuated and supplied with gas, is formed inside the vacuum container 2. The vacuum container 2 is, for example, a metal container. On the wall 22 of the vacuum container 2 (in... Figure 1 In the example, the upper surface has an opening 23 that extends through the thickness direction. The vacuum container 2 is electrically grounded.

[0041] The gas introduced into the processing chamber 21 can correspond to the processing performed on the workpiece W1 contained in the processing chamber 21. For example, when forming a film on the workpiece W1 by plasma CVD (Chemical Vapor Deposition), the gas is either a raw material gas or a gas diluted with a diluent such as H2. To give a more specific example, when the raw material gas is SiH4, a Si film can be formed on the workpiece W1; when the raw material gas is SiH4+NH3, a SiN film can be formed on the workpiece W1; when the raw material gas is SiH4+O2, a SiO2 film can be formed on the workpiece W1; and when the raw material gas is SiF4+N2, a SiN:F film (silicon fluoride nitride film) can be formed on the workpiece W1.

[0042] <Structure of Magnetic Field Introduction Window 3>

[0043] Figure 2 This is a top view showing the general structure of the magnetic field introduction window 3. Figure 3 yes Figure 2 A cross-sectional view at line AA. Figure 4 yes Figure 2 A cross-sectional view at the BB line. Furthermore, in Figures 2-4 Antenna 7 is omitted. Furthermore, in Figure 2 The dielectric cover 32, which will be described later, is omitted. The omitted component is indicated by a dashed line.

[0044] The magnetic field introduction window 3 includes a metal plate 31 and a dielectric cover 32. The magnetic field introduction window 3 introduces a high-frequency magnetic field generated by the antenna 7 into the processing chamber 21 to generate plasma. The metal plate 31 and the dielectric cover 32 are arranged sequentially in the Z-axis direction.

[0045] A metal plate 31 is disposed on the wall 22 of the vacuum container 2 in a manner that blocks the opening 23. A plurality of slits 311 are formed in the metal plate 31, extending through the metal plate 31 in the Z-axis direction. The plurality of slits 311 extend in the Y-axis direction and are arranged in the X-axis direction. The metal plate 31 is configured substantially parallel to the surface of the object being processed, W1.

[0046] The dielectric cover 32 is disposed on the outside of the vacuum container 2 in such a way that it covers a plurality of slits 311. The dielectric cover 32 is entirely composed of a dielectric material and is flat. The material constituting the dielectric cover 32 may be an inorganic material such as alumina, silicon carbide or silicon nitride ceramics, quartz glass, alkali-free glass, or a resin material such as Teflon (registered trademark).

[0047] In this embodiment, the magnetic field introduction window 3 also includes a gasket 33 and an anti-adhesion plate 34. The gasket 33 is disposed between the metal plate 31 and the dielectric cover 32. The gasket 33 may also be an O-ring, and the material of the gasket 33 may include fluorinated rubber (viton). The vacuum inside the processing chamber 21 is maintained by the metal plate 31 blocking the opening 23, the dielectric cover 32 covering the multiple slits 311, and the gasket 33.

[0048] Anti-adhesion plate 34 is disposed on metal plate 31 in such a way that it covers at least a portion of the plurality of slits 311. Anti-adhesion plate 34 may be made of the same material as dielectric shield 32, or may be thinner than dielectric shield 32.

[0049] According to the structure described, the metal plate 31 and the dielectric cover 32 are separated by a gasket 33. Therefore, even if the metal plate 31 undergoes induction heating, the heat transferred from the metal plate 31 to the dielectric cover 32 can be reduced. Furthermore, even if particles moving within the vacuum container 2 pass through the multiple slits 311 in the metal plate 31, the possibility of particles adhering to the dielectric cover 32 is reduced because some of the particles adhere to the anti-adhesion plate 34. As a result, the possibility of the dielectric cover 32 being heated due to particles adhering to and accumulating on it is reduced.

[0050] In addition, such as Figure 1 , Figure 2 As shown, ideally, a plurality of anti-adhesion plates 34 are provided on the metal plate 31 to cover a plurality of slits 311, and gaskets 33 are provided around the plurality of anti-adhesion plates 34. In this case, since gaskets 33 are also provided between adjacent anti-adhesion plates 34, the distance between the metal plate 31 and the dielectric cover 32 can be maintained more reliably.

[0051] In addition, such as Figure 1 , Figure 2 As shown, ideally, each of the plurality of anti-adhesion plates 34 does not block the slits 311. That is, a portion of the plurality of slits 311 is exposed from the anti-adhesion plates 34. Thus, the space formed by the metal plate 31, the dielectric cover 32, and the gasket 33 communicates with the internal space of the vacuum container 2, allowing gas in the space to be drawn through the internal space using a vacuum pump (not shown). As a result, a pressure difference is prevented between the space and the internal space.

[0052] The high-frequency magnetic field generated by the antenna 7 is supplied to the processing chamber 21 through the dielectric cover 32, the anti-adhesion plate 34, and multiple slits 311. As a result, inductively coupled plasma P1 is generated in the processing chamber 21.

[0053] (Additional Notes)

[0054] Furthermore, if a vacuum is drawn inside the vacuum container 2, due to the pressure difference between the inside and outside of the vacuum container 2, pressure is applied to the dielectric cover 32 towards the metal plate 31. As a result, the gasket 33 is compressed and the dielectric cover 32 moves towards the metal plate 31. In addition, the portion of the dielectric cover 32 not supported by the gasket 33 bends towards the metal plate 31.

[0055] At this time, if the dielectric cover 32 comes into contact with the anti-adhesion plate 34, pressure is applied from the dielectric cover 32 to the anti-adhesion plate 34. Therefore, the anti-adhesion plate 34 not only reduces the possibility of particles moving inside the vacuum container 2 adhering to the dielectric cover 32, but also maintains the pressure difference between the inside and outside of the vacuum container 2. However, in this case, it is considered that the anti-adhesion plate 34 may be damaged due to the pressure applied from the dielectric cover 32 to the anti-adhesion plate 34.

[0056] Therefore, ideally, the dielectric cover 32 has a specified strength so that even if the vacuum container 2 is evacuated, the dielectric cover 32 will not come into contact with the anti-adhesion plate 34. Additionally, the gasket 33 is ideally as follows: Figure 2 The diagram shows a structure in which a dielectric cover 32 is supported around an anti-adhesion plate 34. In this case, the structure that reduces the possibility of particles adhering to the dielectric cover 32 and the structure that maintains the pressure difference between the inside and outside of the vacuum container 2 are respectively separated into the anti-adhesion plate 34 and the dielectric cover 32.

[0057] [Implementation Method 2]

[0058] Reference Figure 5 , Figure 6 Another embodiment of the present invention will be described.

[0059] Figure 5 This is a cross-sectional view showing the schematic structure of the plasma processing apparatus 1 of this embodiment. Figure 6 yes Figure 5 A cross-sectional view at the CC line. The plasma processing apparatus 1 of this embodiment and... Figures 1-4 Compared to the plasma processing device 1 shown, the metal plate 31 has a different shape, but the other structures are the same.

[0060] like Figure 5 , Figure 6 As shown, the metal plate 31 in this embodiment and Figures 1-4Compared to the metal plate 31 shown, the difference is that the area between the slits 311 and the anti-adhesion plate 34 is a recess 312, while the other structures are the same.

[0061] According to the structure described, the anti-adhesion plate 34 is separated from the metal plate 31 at the portion facing the recess 312. Therefore, even if particles adhere to the anti-adhesion plate 34 at the portion facing the slit 311 and form a conductive film, the conductive film is unlikely to come into contact with the recess 312 and conduct electricity. Thus, in the event of a high-frequency current flowing in the antenna 7, induced current can be prevented from being generated in the metal plate 31. As a result, the strength of the magnetic field generated by the antenna 7 can be prevented from decreasing due to induced current.

[0062] Furthermore, considering that the film deposition rate of the sputtering apparatus used on a mass production line is approximately 200 nm / min, the depth of the recess 312 is ideally greater than 2 mm. In this case, it would take more than 150 hours before the conductive film becomes conductive with the recess 312. Therefore, even if the sputtering apparatus is operated continuously, the maintenance of the magnetic field introduction window 3 only needs to be performed about once a week. In addition, the upper limit of the depth of the recess 312 is determined by various conditions such as the thickness and strength of the metal plate 31.

[0063] (Additional Notes)

[0064] Furthermore, in the described embodiment, the anti-adhesion plate 34 is disposed on the upper surface of the metal plate 31, but it may also be disposed on the lower surface of the metal plate 31. However, in this case, it is necessary to use an adhesive or the like to fix the anti-adhesion plate 34 to the metal plate 31. In addition, in the described embodiment, the dielectric cover 32 is plate-shaped, but it is not limited to this; for example, it may also be a box-shaped structure with one open side.

[0065] 〔Summarize〕

[0066] The plasma processing apparatus of Embodiment 1 of the present invention has the following structure: a vacuum container housing the object to be processed; an antenna disposed outside the vacuum container and generating a high-frequency magnetic field; and a magnetic field guiding window disposed on the wall of the vacuum container and guiding the high-frequency magnetic field into the interior of the vacuum container in order to generate plasma inside the vacuum container. The magnetic field guiding window includes: a metal plate having a plurality of slits; a dielectric cover covering the plurality of slits; a gasket disposed between the dielectric cover and the metal plate; and an anti-adhesion plate disposed on the metal plate to cover at least a portion of the plurality of slits.

[0067] According to the structure, the dielectric shield is separated from the metal plate by a gasket. Furthermore, an anti-adhesion plate covers at least a portion of the plurality of slits in the metal plate. Thus, if particles moving within the vacuum container are to pass through the plurality of slits in the metal plate, they adhere to the anti-adhesion plate, thereby reducing the likelihood of adhesion to the dielectric shield. Consequently, the possibility of the dielectric shield being heated due to particle adhesion and accumulation is reduced.

[0068] According to Embodiment 1, the plasma processing apparatus of Embodiment 2 of the present invention may include a plurality of anti-adhesion plates covering a plurality of the plurality of slits, with gaskets disposed around each of the plurality of anti-adhesion plates. In this case, since the gaskets are also disposed between adjacent anti-adhesion plates, the distance between the metal plate and the dielectric cover can be maintained more reliably.

[0069] The plasma processing apparatus of Embodiment 3 of the present invention, based on Embodiments 1 and 2, preferably includes a space between the dielectric cover and the anti-adhesion plate that is in communication with the internal space of the vacuum container. In this case, a vacuum pump can be used to evacuate the gas in the space via the internal space of the vacuum container. As a result, a pressure difference can be prevented between the space and the interior of the vacuum container.

[0070] According to Embodiment 4 of the present invention, the plasma processing apparatus is based on Embodiments 1 to 3, wherein the portion of the metal plate between the slits facing and adjacent to the anti-adhesion plate is a recess.

[0071] In this case, the anti-adhesion plate separates from the metal plate at the portion facing the recess. Therefore, even if particles adhere to the anti-adhesion plate and form a conductive film at the portion facing the slit, the conductive film is unlikely to contact the recess and conduct electricity. Thus, induced current can be prevented from being generated in the metal plate when a high-frequency current flows through the antenna. As a result, the strength of the magnetic field generated by the antenna is prevented from decreasing due to induced current.

[0072] According to Embodiment 4, the plasma processing apparatus of Embodiment 5 of the present invention preferably has a depth of 2 mm or more in the recess. In this case, even if the plasma processing apparatus is operated continuously, the maintenance of the magnetic field introduction window only needs to be performed about once a week.

[0073] This invention is not limited to the various embodiments described. Various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of this invention.

Claims

1. A plasma processing apparatus, comprising: A vacuum container that holds the object being processed inside; An antenna is disposed outside the vacuum container and generates a high-frequency magnetic field; as well as A magnetic field introduction window is disposed on the wall of the vacuum container, and the high-frequency magnetic field is introduced into the interior of the vacuum container in order to generate plasma inside the vacuum container. The magnetic field import window includes: A metal plate with multiple slits; A dielectric shield covering the plurality of slits; A gasket is disposed between the dielectric cover and the metal plate; and An anti-adhesion plate is disposed on the metal plate in such a way that it covers at least a portion of the plurality of slits. The metal plate is separated from the dielectric cover by the gasket.

2. The plasma processing apparatus according to claim 1, wherein the magnetic field induction window comprises a plurality of anti-adhesion plates covering a plurality of the plurality of slits. The gaskets are disposed around each of the plurality of anti-adhesion plates.

3. The plasma processing apparatus according to claim 1 or 2, wherein the space between the dielectric cover and the anti-adhesion plate is in communication with the internal space of the vacuum container.

4. The plasma processing apparatus according to claim 1 or 2, wherein the portion of the metal plate between the slits facing and adjacent to the anti-adhesion plate is a recess.

5. The plasma processing apparatus according to claim 4, wherein the depth of the recess is 2 mm or more.

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