KR102786708B1 - Fastening structure and fastening method and plasma processing apparatus - Google Patents

Abstract

The object of the present invention is to provide a fastening structure, a fastening method, and a plasma processing device capable of suppressing deposition on the head of a fastening screw in a structure in which a metal member and a cover member are fastened via a fastening screw placed inside a processing vessel that generates plasma.
The present invention comprises: a plurality of metal members arranged inside a processing vessel, each metal member having an exposed surface and screw holes that are exposed to plasma generated inside the processing vessel; a cover member arranged across the exposed surfaces of the plurality of metal members, the cover member having insulating properties and a through hole; a metal fastening screw having a screw head portion and fastening the cover member to the metal member by screwing the screw hole through the through hole; and a screw cover covering the screw head portion; wherein the screw cover comprises a first base portion made of metal that comes into contact with the screw head portion, and a first protective film that is a ceramic sprayed film that covers at least a portion of a surface of the first base portion.

Description

{FASTENING STRUCTURE AND FASTENING METHOD AND PLASMA PROCESSING APPARATUS}

The present disclosure relates to a fastening structure, a fastening method, and a plasma processing device.

Patent Document 1 discloses a plasma processing device that performs plasma processing on a substrate to be processed within a processing space. The plasma processing device has a metal window formed by a plurality of conductive partial windows, and the metal window blocks an opening on the upper surface side of a processing container to form a processing space. A resin-made insulating member is provided between adjacent partial windows. A ceramic-made insulating member cover covers a surface of the insulating member on the processing space side, and a plasma antenna for converting a processing gas into plasma by inductive coupling is provided on the upper side of the metal window. According to the plasma processing device disclosed in Patent Document 1, by using the ceramic-made insulating member cover to protect the resin-made insulating member from plasma, the function of the metal window necessary for converting a processing gas supplied within the processing space into plasma can be maintained while reducing the weight of the metal window.

Patent Document 1: Japanese Patent Publication No. 2017-27775

The present disclosure provides a fastening structure and a fastening method, and a plasma treatment device, which are advantageous in suppressing attachment of a deposition to a head of a fastening screw for fastening a metal member and a cover member placed inside a treatment container.

A fastening structure according to one aspect of the present disclosure is:

A plurality of metal members, which are arranged inside a processing vessel and have an exposed surface and screw holes that are exposed to plasma generated inside the processing vessel,

A cover member arranged across the exposed surface of the plurality of above metal members, having insulating properties and having a through hole,

A metal fastening screw having a screw head and fastening the cover member to the metal member by passing through the through hole and screwing into the screw hole, and

Screw cover covering the above screw head

With,

The above screw cover has a first metal base portion that comes into contact with the screw head portion, and a first protective film that is a ceramic coating that covers at least a portion of a surface of the first base portion.

According to the present disclosure, it is possible to suppress attachment of a deposition to a head of a fastening screw that fastens a metal member and a cover member placed inside a processing container.

Fig. 1 is a cross-sectional view showing an example of a plasma processing device according to an embodiment.
Figure 2 is a plan view of an example of a metal window as seen from the processing room side.
Figure 3 is an enlarged view of section III of Figure 2, showing the intersection area of multiple cover members.
FIG. 4 is a cross-sectional view of an example of a fastening structure according to the first embodiment, as viewed in the direction of arrow IV-IV of FIG. 3.
Fig. 5 is a cross-sectional view of an example of a fastening structure according to the second embodiment.
Fig. 6 is a cross-sectional view of an example of a fastening structure according to the third embodiment.
Fig. 7 is a longitudinal cross-sectional view of an example of a fastening structure according to the fourth embodiment.
Fig. 8 is a longitudinal cross-sectional view of an example of a fastening structure according to the fifth embodiment.

Hereinafter, a fastening structure, a fastening method, and a plasma processing device according to an embodiment of the present disclosure will be described with reference to the attached drawings. In addition, in this specification and drawings, there are cases where substantially identical components are given the same reference numerals to omit redundant descriptions.

[Plasma processing device according to implementation type]

First, an example of a plasma processing device according to an embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a cross-sectional view showing an example of a plasma processing device according to an embodiment, and FIG. 2 is a plan view of an example of a metal window as seen from the processing room side.

The plasma processing device (100) shown in Fig. 1 is an inductively coupled plasma (ICP) processing device that performs various substrate processing methods on a rectangular substrate (G) (hereinafter simply referred to as a “substrate”) when viewed from the plane for a flat panel display (hereinafter referred to as “FPD”). Glass is mainly used as the substrate material, and transparent synthetic resin, etc. may also be used depending on the application. Here, the substrate processing includes etching processing, film formation processing using a CVD (Chemical Vapor Deposition) method, etc. Examples of the FPD include a liquid crystal display (LCD), an electroluminescence (EL), a plasma display panel (PDP), etc. The substrate includes a support substrate in addition to a form in which a circuit is patterned on its surface. In addition, the planar dimensions of the substrate for FPD are becoming larger along with the progress of the generation, and the planar dimensions of the substrate (G) processed by the plasma processing device (100) include at least the dimensions from about 1500 mm x 1800 mm of the 6th generation to about 3000 mm x 3400 mm of the 10.5th generation, for example. In addition, the thickness of the substrate (G) is about 0.2 mm to several mm.

The plasma processing device (100) shown in Fig. 1 has a rectangular box-shaped processing vessel (20), a substrate placement table (70) having a rectangular shape when viewed from a plane and placed inside the processing vessel (20) and on which a substrate (G) is placed, and a control unit (90). In addition, the processing vessel may have a shape such as a cylindrical box or an oval cylindrical box, and in this shape, the substrate placement table is also circular or oval, and the substrate placed on the substrate placement table is also circular, etc.

The processing vessel (20) is divided into two spaces, upper and lower, by a metal window (30). The upper space, the antenna room (A), is formed by the upper chamber (13), and the lower space, the processing room (S), is formed by the lower chamber (17). In the processing vessel (20), a rectangular ring-shaped support frame (14) is positioned so as to protrude into the inside of the processing vessel (20) at a position that is the boundary between the upper chamber (13) and the lower chamber (17), and a metal window (30) is attached to the support frame (14).

The upper chamber (13) forming the antenna room (A) is formed by a side wall (11) and a ceiling plate (12), and is formed entirely of a metal such as aluminum or an aluminum alloy.

The lower chamber (17) having a processing room (S) inside is formed by a side wall (15) and a bottom plate (16), and is formed entirely of a metal such as aluminum or an aluminum alloy. In addition, the side wall (15) is grounded by a grounding wire (21).

In addition, the support frame (14) is formed of a metal such as conductive aluminum or an aluminum alloy, and may be referred to as a metal frame.

At the upper end of the side wall (15) of the lower chamber (17), a rectangular annular (continuous) seal groove (22) is formed, and a sealing member (23) such as an O-ring is fitted into the seal groove (22), so that the sealing member (23) is maintained in contact with the support frame (14), thereby forming a sealing structure of the lower chamber (17) and the support frame (14).

In the side wall (15) of the lower chamber (17), an inlet/outlet (18) for loading/unloading a substrate (G) into/out of the lower chamber (17) is provided, and the inlet/outlet (18) is configured to be openable/closeable by a gate valve (24). A return room (not shown) containing a return mechanism is adjacent to the lower chamber (17), and by controlling the opening/closing of the gate valve (24), the substrate (G) is loaded/unloaded through the inlet/outlet (18) by the return mechanism.

In addition, a plurality of exhaust ports (19) are provided on the bottom plate (16) of the lower chamber (17), and a gas exhaust pipe (25) is connected to each exhaust port (19), and the gas exhaust pipe (25) is connected to an exhaust device (27) via an opening/closing valve (26). A gas exhaust section (28) is formed by the gas exhaust pipe (25), the opening/closing valve (26), and the exhaust device (27). The exhaust device (27) has a vacuum pump such as a turbo molecular pump, and is configured to be capable of vacuumizing the inside of the lower chamber (17) to a predetermined vacuum level during the process. In addition, a pressure gauge (not shown) is installed at an appropriate location in the lower chamber (17), and monitor information by the pressure gauge is transmitted to the control unit (90).

The substrate placement table (70) has a substrate (71) and an electrostatic chuck (76) formed on the upper surface (71a) of the substrate (71).

The shape of the substrate (71) when viewed from the plane is rectangular, and has the same plane dimensions as the substrate (G) placed on the substrate placement stand (70). The length of the long side of the substrate (71) can be set to about 1800 mm to 3400 mm, and the length of the short side can be set to about 1500 mm to 3000 mm. With respect to the plane dimensions, the thickness of the substrate (71) can be, for example, about 50 mm to 100 mm.

In the substrate (71), a temperature control medium path (72a) is provided so as to cover the entire area of the rectangular plane, and is formed of stainless steel, aluminum, an aluminum alloy, or the like. In addition, the temperature control medium path (72a) may be provided in the electrostatic chuck (76). In addition, the substrate (71) may be formed by a laminated body of two parts, such as aluminum or an aluminum alloy, rather than a single part as in the illustrated example.

On the bottom plate (16) of the lower chamber (17), a box-shaped pedestal (78) formed of an insulating material and having a stepped portion on the inside is fixed, and a substrate placement stand (70) is placed on the stepped portion of the pedestal (78).

An electrostatic chuck (76) is formed on the upper surface (71a) of the substrate (71) on which a substrate (G) is directly placed. The electrostatic chuck (76) has a ceramic layer (74) which is a dielectric film formed by spraying ceramics such as alumina, and a conductive layer (75) (electrode) embedded in the interior of the ceramic layer (74) and having an electrostatic adsorption function.

The conductive layer (75) is connected to a DC power source (85) via a power supply line (84). When a switch (not shown) intervening in the power supply line (84) is turned on by the control unit (90), a DC voltage is applied from the DC power source (85) to the conductive layer (75), thereby generating a Coulomb force. By this Coulomb force, the substrate (G) is electrostatically attracted to the upper surface of the electrostatic chuck (76) and is maintained in a state of being placed on the upper surface (71a) of the base (71).

A temperature control medium path (72a) is provided on the substrate (71) constituting the substrate arrangement stand (70) so as to cover the entire area of the rectangular plane. At both ends of the temperature control medium path (72a), a transfer pipe (72b) through which a temperature control medium is supplied to the temperature control medium path (72a) and a return pipe (72c) through which a temperature control medium heated by circulating the temperature control medium path (72a) is discharged are connected.

As shown in Fig. 1, the transfer pipe (72b) and the return pipe (72c) are respectively connected with a transfer path (87) and a return path (88), and the transfer path (87) and the return path (88) are connected with a chiller (86). The chiller (86) has a main body that controls the temperature and discharge flow rate of a temperature control medium, and a pump that supplies the temperature control medium (neither shown). In addition, a refrigerant is applied as the temperature control medium, and Galden (registered trademark) or Fluorinert (registered trademark) is applied as the refrigerant. The temperature control form illustrated is a form in which a temperature control medium is circulated in the substrate (71), but the substrate (71) may have a heater or the like built in, and the temperature may be regulated by the heater, or the temperature may be regulated by both the temperature control medium and the heater. In addition, instead of the heater, temperature control accompanied by heating may be performed by circulating a high-temperature temperature control medium. In addition, the heater, which is a resistor, is formed of a compound of tungsten, molybdenum, or one of these metals with alumina, titanium, or the like. In addition, in the illustrated example, a temperature control medium path (72a) is formed in the substrate (71), but, for example, an electrostatic chuck (76) may have a temperature control medium path.

A temperature sensor (not shown) such as a thermocouple is arranged in the substrate (71), and monitor information by the temperature sensor is transmitted to the control unit (90) from time to time. Then, based on the transmitted monitor information, temperature control of the substrate (71) and the substrate (G) is executed by the control unit (90). More specifically, the temperature or flow rate of the temperature control medium supplied from the chiller (86) to the transfer path (87) is adjusted by the control unit (90). Then, the temperature control medium, whose temperature or flow rate has been adjusted, is circulated in the temperature control medium path (72a), thereby executing temperature control of the substrate placement table (70). In addition, the temperature sensor such as a thermocouple may be arranged, for example, in the electrostatic chuck (76).

A step portion is formed by the outer periphery of the electrostatic chuck (76) and the substrate (71) and the upper surface of the pedestal (78), and a rectangular frame-shaped focus ring (79) is arranged in this step portion. When the focus ring (79) is installed in the step portion, the upper surface of the focus ring (79) is set to be lower than the upper surface of the electrostatic chuck (76). The focus ring (79) is formed of ceramics such as alumina or quartz, etc.

On the lower surface of the substrate (71), a power supply member (80) is connected. A power supply line (81) is connected to the lower end of the power supply member (80), and the power supply line (81) is connected to a high-frequency power supply (83), which is a bias power supply, through a matching device (82) that performs impedance matching. When high-frequency power of, for example, 3.2 MHz is applied to the substrate placement stand (70) from the high-frequency power supply (83), an RF bias is generated, and ions generated from the high-frequency power supply (56), which is a source for plasma generation described below, can be attracted to the substrate (G). Therefore, in the plasma etching process, it becomes possible to increase both the etching rate and the etching selectivity. In this way, the substrate placement stand (70) forms a bias electrode that generates an RF bias by placing the substrate (G). At this time, the part that becomes the ground potential inside the chamber functions as the counter electrode of the bias electrode, thereby forming a return circuit of high-frequency power. In addition, the metal window (30) may be formed as part of the return circuit of high-frequency power.

The metal window (30) is formed by a plurality of split metal windows (31). The number of split metal windows (31) forming the metal window (30) (9 shown in FIG. 2) can be set to various numbers, such as 12 or 24.

The split metal window (31) has a conductor plate (32) and a shower plate (34). Both the conductor plate (32) and the shower plate (34) are formed of a non-magnetic, conductive, corrosion-resistant metal or a metal with a corrosion-resistant surface treatment, such as aluminum, an aluminum alloy, or stainless steel. The corrosion-resistant surface treatment is, for example, an anodic oxidation treatment or ceramic spraying. In addition, the exposed surface (34a) of the shower plate (34) facing the processing room (S) may be subjected to a plasma coating by an anodic oxidation treatment or ceramic spraying. The conductor plate (32) is grounded via a grounding wire (not shown), and the shower plate (34) is also grounded via the conductor plate (32) to which it is mutually connected.

Each of the split metal windows (31) constituting the metal window (30) is suspended from the ceiling plate (12) of the upper chamber (13) by a plurality of suspenders (not shown). A spacer (not shown) formed by an insulating material is arranged above each split metal window (31), and a high-frequency antenna (51) (an example of an inductively coupled antenna) is arranged spaced apart from the conductor plate (32) by the spacer. The high-frequency antenna (51) contributes to the generation of plasma and is formed by winding an antenna wire formed of a highly conductive metal such as copper in a ring or spiral shape. For example, multiple ring-shaped antenna wires may be arranged. The high-frequency antenna (51) is suspended from the ceiling plate (12) via the split metal window (31) by being arranged on the upper surface of the split metal window (31).

On the lower surface of the conductor plate (32), a gas diffusion groove (33) is formed, and a through hole (32b) is provided that connects the gas diffusion groove (33) and the upper surface (32a). A gas introduction pipe (52) is embedded in this through hole (32b). On the shower plate (34), a plurality of gas discharge holes (35) are provided that connect the gas diffusion groove (33) of the conductor plate (32) and the processing chamber (S). The shower plate (34) is fastened to the lower surface of the outer region of the gas diffusion groove (33) of the conductor plate (32) by a metal screw (not shown). In addition, the gas diffusion groove may be provided on the upper surface of the shower plate.

Each split metal window (31) is electrically insulated from the support frame (14) or the adjacent split metal window (31) by an insulating member (37). Here, the insulating member (37) is formed of a fluorine resin such as PTFE (Polytetrafluoroethylene).

The cross-section (37a) of the insulating member (37) facing the processing room (S) is flush with the exposed surface (34a) of the shower plate (34) facing the processing room (S), and an insulating cover member (38) (an example of the first cover member) is arranged across the exposed surface (34a) of the adjacent shower plate (34) while covering the cross-section (37a) of the insulating member (37). This cover member (38) is formed of ceramics such as alumina.

The insulating member (37) is formed of a resin such as PTFE, which has high insulating performance and is lightweight, but the plasma resistance of the resin is not high compared to ceramics such as alumina. In addition, it is difficult to perform plasma-resistant coating on the surface of the resin by anodizing treatment or ceramic spraying.

Therefore, in the plasma processing device (100), the cross-section (37a) of the insulating member (37) on the processing room (S) side is covered with, for example, a cover member (38) made of ceramics, thereby protecting the insulating member (37) from the plasma. Each insulating member (37) that mutually insulates the support frame (14) and the dividing metal window (31) or adjacent dividing metal windows (31) is covered with the cover member (38), and is made so that it cannot be seen from the processing room (S) side in Fig. 2.

As shown in Fig. 2, each cover member (38) completely covers the insulating member (37) and intersects with each other in the intersection area (J). Then, in the intersection area (J), the cover member (39) (an example of the second cover member) covers a plurality of the first cover members (38) and is fastened to the split metal window (31) with a metal fastening screw (not shown in Fig. 2), and the screw head of the fastening screw is covered with a screw cover (44), thereby forming a fastening structure (40). This fastening structure (40) will be described in detail below.

Returning to Fig. 1, a power supply member (53) extending upward from the upper chamber (13) is connected to the high-frequency antenna (51), a power supply line (54) is connected to the upper end of the power supply member (53), and the power supply line (54) is connected to a high-frequency power source (56) through a matching device (55) that performs impedance matching.

When high frequency power of, for example, 13.56 MHz is applied from a high frequency power source (56) to a high frequency antenna (51), an induced electric field is formed within the lower chamber (17). By this induced electric field, the processing gas supplied from the shower plate (34) to the processing chamber (S) is converted into plasma, thereby generating an inductively coupled plasma, and ions in the plasma are provided to the substrate (G).

The high-frequency power source (56) is a source for generating plasma, and the high-frequency power source (83) connected to the substrate placement table (70) serves as a bias source that attracts the generated ions and provides them with kinetic energy. In this way, the ion source generates plasma using inductive coupling, and by connecting a bias source, which is a separate power source, to the substrate placement table (70) to control ion energy, the generation of plasma and the control of ion energy are performed independently, thereby increasing the degree of freedom of the process.

As shown in Fig. 1, the gas introduction pipes (52) of each split metal window (31) are combined into one location within the antenna room (A), and the gas introduction pipes (52) extending upward hermetically penetrate the supply port (12a) opened in the ceiling plate (12) of the upper chamber (13). In addition, the gas introduction pipes (52) are connected to a processing gas supply source (64) via a hermetically coupled gas supply pipe (61).

An on-off valve (62) and a flow controller (63) such as a mass flow controller are interposed at an intermediate position of a gas supply pipe (61). A processing gas supply section (60) is formed by the gas supply pipe (61), the on-off valve (62), the flow controller (63), and the processing gas supply source (64). In addition, the gas supply pipe (61) branches off in the middle, and an on-off valve, a flow controller, and a processing gas supply source according to the type of processing gas are connected to each branch pipe (not shown).

In plasma treatment, the treatment gas supplied from the treatment gas supply unit (60) is supplied to the gas diffusion groove (33) of the conductor plate (32) of each split metal window (31) through the gas supply pipe (61) and the gas introduction pipe (52). Then, the gas is discharged from each gas diffusion groove (33) to the treatment room (S) through the gas discharge hole (35) of each shower plate (34).

In addition, the gas introduction pipes (52) of each split metal window (31) may not be combined into one, but may each be individually connected to a processing gas supply unit (60), so that the supply control of the processing gas may be performed for each split metal window (31). In addition, the gas introduction pipes (52) of a plurality of split metal windows (31) located on the outside of the metal window (30) may be combined into one, and the gas introduction pipes (52) of a plurality of split metal windows (31) located on the inside of the metal window (30) may be separately combined into one, so that each gas introduction pipe (52) is individually connected to a processing gas supply unit (60), so that the supply control of the processing gas may be performed. That is, in the former form, the supply control of the processing gas is performed for each split metal window (31), and in the latter form, the supply control of the processing gas is performed by dividing the metal window (30) into an external region and an internal region.

In addition, each split metal window (31) may have its own high-frequency antenna, and control may be performed so that high-frequency power is individually applied to each high-frequency antenna.

The control unit (90) controls the operation of each component of the plasma processing device (100), such as the chiller (86), the high-frequency power supply (59, 83), the processing gas supply unit (60), and the gas exhaust unit (28) based on monitor information transmitted from the pressure gauge. The control unit (90) has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU executes a predetermined process according to a recipe (process recipe) stored in the memory area of the RAM or ROM. In the recipe, control information of the plasma processing device (100) for process conditions is set. The control information includes, for example, a gas flow rate, a pressure inside the processing vessel (20), a temperature inside the processing vessel (20), a temperature of the substrate (71), a process time, and the like.

The program applied by the recipe and control unit (90) may be stored, for example, in a hard disk, a compact disk, an optical magneto-disk, etc. In addition, the recipe, etc. may be stored in a portable computer-readable storage medium such as a CD-ROM, DVD, or memory card, and set in the control unit (90) and read. In addition, the control unit (90) has a user interface such as an input device such as a keyboard or mouse for performing input operations of commands, a display device such as a display for visualizing the operating status of the plasma processing device (100), and an output device such as a printer.

[Fastening structure and fastening method according to the first embodiment]

Next, with reference to FIGS. 2 to 4, an example of a fastening structure and a fastening method according to the first embodiment will be described. Here, FIG. 3 is an enlarged view of section III of FIG. 2, and is a drawing showing an intersection area of a plurality of cover members, and FIG. 4 is a drawing viewed in the direction of arrows IV-IV of FIG. 3, and is a longitudinal cross-sectional view of an example of a fastening structure according to the first embodiment.

As shown in Fig. 2, in each intersection area (J) where a plurality of first cover members (38) intersect, a second cover member (39) covers a plurality of first cover members (38), and the second cover members (39) and the first cover members (38) are laminated and fastened to a split metal window (31), thereby forming a fastening structure (40). As shown in Fig. 3, three first cover members (38) cover two insulating members (37) that intersect in a T shape when viewed from the plane, and the ends of each first cover member (38) are arranged with a slight gap (H) between them in the intersection area (J).

In Fig. 3, the end of the central first cover member (38A) extending in the longitudinal direction is cut off on the left and right sides, and the end of the left and right first cover members (38B, 30C) are loosely fitted with a gap (H) in the cut-off area.

The width dimension of the short side of the first cover member (38) is set to a dimension that covers the insulating member (37) and is arranged over the peripheral edge of the split metal window (31) on the side of the insulating member (37). Therefore, even if plasma enters from the side of the first cover member (38), the plasma is suppressed from reaching the insulating member (37).

In the intersection area (J), the second cover member (39) is arranged so as to cover the end portion of each first cover member (38). As described in detail below, the second cover member (39) is a cover member made of ceramics, or a cover member having a ceramic sprayed film formed on the surface of a metal base portion. In this way, in the intersection area (J), the end portion of each first cover member (38) and the gap (H) between the ends are completely covered with the second cover member (39), thereby preventing plasma from entering the gap (H).

As shown in Fig. 4, the exposed surface (34a) facing the processing room (S) of the shower plate (34) forming the split metal window (31) and the cross-section (37a) of the insulating member (37) are covered with a first cover member (38) made of ceramics, and a second cover member (39) made of ceramics is laminated in the same manner on the surface of the first cover member (38).

The first cover member (38) and the second cover member (39) each have through holes (38a, 39a). In addition, the shower plate (34) also has a through hole (34b), and the conductor plate (32) has a screw hole (32c), and the through hole (34b) and the screw hole (32c) are in communication.

The exposed surface (34a) of the shower plate (34) and the cross-section (37a) of the insulating member (37) are covered with a first cover member (38) and a second cover member (39) that are laminated with each other, through holes (38a, 39a, 34b) and screw holes (32c) are connected to each other, and a metal fastening screw (41) is inserted and penetrated into the formed connecting holes.

The fastening screw (41) has a screw head portion (42) and a screw shaft portion (43), and a tip-end protruding screw (43a) having a diameter reduced from that of the general portion of the screw shaft portion (43) is provided at the tip end of the screw shaft portion (43). The fastening screw (41) is inserted and penetrated into a connecting hole formed by the through holes (38a, 39a, 34b), and the tip-end protruding screw (43a) is screw-connected to the screw hole (32c), whereby the first cover member (38) and the second cover member (39) are fastened to the split metal window (31) via the fastening screw (41).

The screw head (42) of the fastening screw (41) is covered by a screw cover (44). The screw cover (44) has a first base portion (45) made of metal that comes into contact with the screw head (42), and a first protective film (46) that is a ceramic spray film that covers at least a portion of the surface of the first base portion (45). Here, “at least a portion of the surface of the first base portion (45)” means including at least a surface of the first base portion (45) that is exposed to the treatment chamber (S) and exposed to plasma.

On the side of the screw head (42), a first screw groove (42a) is formed. Meanwhile, the first base portion (45) of the screw cover (44) has a concave portion (45a), and a second screw groove (45b) is formed on the wall surface of the concave portion (45a). Then, by screwing the first screw groove (42a) and the second screw groove (45b), the screw cover (44) is fixed to the screw head (42) in a state where the concave portion (45a) covers the screw head (42).

As described above, the exposed surface (34a) of the shower plate (34) and the cross-section (37a) of the insulating member (37) are covered by the first cover member (38) and the second cover member (39) that are laminated with each other, and the first cover member (38) and the second cover member (39) are fastened to the split metal window (31) through the fastening screw (41). Then, the fastening structure (40) is formed by covering the screw head (42) provided by the fastening screw (41) with the screw cover (44).

Here, the first base portion (45) is formed of a non-magnetic conductive metal, such as aluminum, an aluminum alloy, or stainless steel, similarly to the split metal window (31). Among these, considering corrosion resistance, stainless steel is preferable because it has good corrosion resistance to chlorine-based gases, such as BCl ₃ (boron trichloride) gas and Cl ₂ (chlorine) gas, which are etching gases.

Meanwhile, the first protective film (46) is formed by a ceramic coating having high plasma resistance, and as the ceramic, yttrium-containing ceramics are used. As the yttrium-containing ceramic, any one of Y ₂ O ₃ (yttria), YOF (yttrium oxyfluoride), YF ₃ (yttrium fluoride), etc., or a mixture thereof, is used. In addition, a coating that mixes ceramics other than yttrium-containing ceramics and yttrium-containing ceramics may also be used.

In addition, by making the surface of the first protective film (46) an as-sprayed surface having a surface roughness of about 7 ㎛, the deposition catch performance of the first protective film (46) is improved, so that peeling of the attached deposition can be effectively suppressed. In addition, the "deposition" is an attachment such as a precursor gas or a generated reaction product introduced in the plasma processing performed by the plasma processing device (100).

In a conventional fastening structure, a screw head of a metal fastening screw is covered with a ceramic screw cover (ceramic cap). The screw head of the fastening screw is protected from plasma by the ceramic cap, but since the ceramic cap is not conductive, a vertical electric field does not occur in the ceramic cap. In addition, the electric field generated by the screw head covered by the ceramic cap has difficulty penetrating the ceramic cap, and even if it does, it is very weak. Therefore, while the screw head of the fastening screw is protected from plasma by the ceramic cap, depositions are likely to adhere to the surface of the ceramic cap. When the depositions adhered to the surface of the ceramic cap are peeled off, this can lead to the generation of particles.

Therefore, in the fastening structure (40), by applying a screw cover (44) having a first base portion (45) made of metal that comes into contact with the screw head portion (42) and a first protective film (46) made of ceramics that covers at least the surface of the first base portion (45) exposed to plasma, the screw cover (44) can be brought into the same potential as the split metal window (31) through the fastening screw (41).

Since the screw cover (44) has the same potential as the split metal window (31), a vertical electric field is generated in the screw cover (44), and the adhesion of the deposition to the surface of the screw cover (44) can be suppressed by the sputtering force by the plasma. The first protective film (46) covering the surface of the screw cover (44) is an insulating material as a ceramic sprayed film, but since the thickness of the ceramic sprayed film is thin, the electric field generated in the first base portion (45) has sufficient strength to penetrate the ceramic sprayed film and attract the plasma. In addition, by suppressing the adhesion of the deposition, particles caused by the deposition being peeled off can be reduced. In addition, by reducing the particles, the maintenance cycle of the plasma processing device (100) can be extended.

Here, the method of forming the fastening structure (40) (fastening method according to the embodiment) is roughly explained.

This fastening method is a method of fastening a cover member that is arranged across the exposed surfaces of a plurality of metal members, which are arranged inside a processing vessel (20) that generates plasma and have exposed surfaces exposed to plasma. Here, the exposed surface exposed to plasma is, for example, an exposed surface (34a) of a shower plate (34). In addition, the plurality of metal members is, for example, a plurality of split metal windows (31). In addition, the cover member is, for example, a first cover member (38) and a second cover member (39) made of ceramics that are mutually laminated.

In this method, the metal member such as the split metal window (31) has a screw hole (e.g., a screw hole (32c) of the conductor plate (32)), and the first cover member (38) and the second cover member (39) have insulating properties and have through holes (38a, 39a).

The fastening method includes a process of fastening a cover member (38, 39) to a metal member, a split metal window (31), by screwing a metal fastening screw (41) having a screw head (42) through a through hole (38a, 39a) and into a screw hole (32c).

In addition, the fastening method has a process of covering a screw head (42) with a screw cover (44) having a first base portion (45) made of metal and a first protective film (46) which is a ceramic coating that covers at least a portion of the surface of the first base portion (45).

According to this fastening method, a fastening structure (40) can be formed that can suppress the attachment of deposition to the surface of the screw cover (44) and reduce particles caused by peeling off of the deposition.

[Contracting structure according to the second embodiment]

Next, with reference to Fig. 5, an example of a fastening structure according to the second embodiment will be described. Here, Fig. 5 is a drawing corresponding to Fig. 4, and is a longitudinal cross-sectional view of an example of a fastening structure according to the second embodiment.

The fastening structure (40A) shown in Fig. 5 differs from the fastening structure (40) in that the second cover member (39A) has a second base member (39B) made of metal that comes into contact with the first cover member (38) and the first base member (45), and a second protective film (39C) formed by a ceramic spray film that covers at least a portion of the surface of the second base member (39B). Here, “at least a portion of the surface of the second base member (39B)” means including at least a surface of the second base member (39B) that is exposed to the processing chamber (S) and exposed to plasma.

The second base portion (39B) is formed of a non-magnetic conductive metal, such as aluminum, an aluminum alloy, or stainless steel, similarly to the split metal window (31). Among these, considering corrosion resistance, stainless steel is preferable because it has good corrosion resistance to chlorine-based gases, such as BCl ₃ (boron trichloride) gas and Cl ₂ (chlorine) gas, which are etching gases.

Meanwhile, the second protective film (39C) is formed by a highly plasma-resistant ceramic spray film, and as the ceramic, yttrium-containing ceramics are used. As the yttrium-containing ceramic, any one of Y ₂ O ₃ (yttria), YOF (yttrium oxyfluoride), YF ₃ (yttrium fluoride), etc., or a mixture thereof, is used. In addition, a spray film that mixes ceramics other than yttrium-containing ceramics and yttrium-containing ceramics may also be used.

According to the fastening structure (40A), the second base portion (39B) made of metal constituting the second cover member (39A) comes into contact with the first base portion (45) made of metal constituting the screw cover (44) or the screw head portion (42) that is screw-connected with the first base portion (45), so that the second cover member (39A) and the screw cover (44) have the same potential as the split metal window (31). As a result, a vertical electric field is generated in the second cover member (39A) and the screw cover (44), and the attachment of the deposition to the surfaces of the second cover member (39A) and the screw cover (44) can be suppressed by the sputtering force by the plasma. Therefore, the attachment suppression effect of the deposition becomes even more widespread, and the particle reduction effect caused by the peeling off of the deposition is further enhanced.

[Contracting structure according to the third embodiment]

Next, with reference to Fig. 6, an example of a fastening structure according to the third embodiment will be described. Here, Fig. 6 is a longitudinal cross-sectional view of an example of a fastening structure according to the third embodiment.

In the intersection area (J), when the cover member (38, 39A) is secured across the adjacent split metal window (31) with two fastening screws, since the second cover member (39A) is made of metal, the adjacent split metal window (31) is electrically connected through the second cover member (39A) and the two fastening screws (41).

Therefore, in the fastening structure (40B), an insulating member (49) is provided between the screw head (42) of at least one of the two fastening screws (41) on the left and right of the center line (CL) and the second cover member (39A).

According to the fastening structure (40B), when the cover member (38, 39A) is fastened with two fastening screws (41) across the adjacent split metal windows (31), the electrical conductivity between the adjacent split metal windows (31) is eliminated.

[Contracting structure according to the fourth embodiment]

Next, with reference to Fig. 7, an example of a fastening structure according to the fourth embodiment will be described. Here, Fig. 7 is a longitudinal cross-sectional view of an example of a fastening structure according to the fourth embodiment.

In the same manner as the fastening structure (40B) according to the third embodiment, when the cover member (38, 39A) is fastened with two fastening screws across the adjacent split metal window (31) in the intersection area (J), the adjacent split metal window (31) becomes electrically conductive through the second cover member (39A) and the two fastening screws (41).

Therefore, in the fastening structure (40C), a fastening screw (41A) having a screw head portion (42A) and a screw shaft portion (43A) formed of an insulating material is applied to at least one of the two fastening screws on the left and right of the center line (CL) (the fastening screw on the right in the illustrated example).

According to the fastening structure (40C), when the cover member (38, 39A) is fastened with two fastening screws (41, 41A) across the adjacent split metal windows (31), the electrical conductivity between the adjacent split metal windows (31) is eliminated.

[Contracting structure according to the fifth embodiment]

Next, with reference to Fig. 8, an example of a fastening structure according to the fifth embodiment will be described. Here, Fig. 8 is a longitudinal cross-sectional view of an example of a fastening structure according to the fifth embodiment.

The fastening structure of the present embodiment is a form in which a spring screw structure is applied to the fastening structure (40, 40A, 40B, 40C) described above. This spring screw structure is a form in which a spring holder (48) having a through hole (48a) is arranged at the bottom portion of the inside of the through hole (38a, 39a) at a position corresponding to the screw hole (32c), and a coil spring (47) is arranged inside the spring holder.

The fastening screw (41) penetrates the through hole (48a) of the bottom of the coil spring (47) and the spring holder (48), and is fastened by screwing the tip protruding screw (43a) into the screw hole (32c). At this time, the spring holder (48) is compressed in the axial direction of the screw shaft (43) by the screw head (42). In addition, the screw cover (44) is attached to the spring holder (48), not to the screw head (42).

A screw groove (48b) is provided on the outer side of the upper portion of the spring holder (48), and is screw-connected with a second screw groove (45b) provided in a concave portion (45a) of the screw cover (44). The screw head (42) and the screw cover (44) do not come into direct contact.

By means of the fastening structure (40D) equipped with the above structure, deformation due to pressure difference during vacuuming or deformation due to heat can be absorbed by the coil spring (47), thereby preventing damage caused by cracks in the cover member (38, 39) formed of ceramics.

Regarding the configurations exemplified in the above embodiments, other embodiments may be possible by combining other components, and further, the present disclosure is not limited at all to the configurations shown herein. In this regard, changes may be made within a range that does not deviate from the spirit of the present disclosure, and may be appropriately determined according to the form of application.

For example, although the plasma processing device (100) of the city example has been described as an inductively coupled plasma processing device, it may be a plasma processing device of another type. Specifically, an electron cyclotron resonance plasma (ECP), a helicon wave plasma (HWP), or a capacitively coupled plasma (CCP) may be mentioned. In addition, a microwave excited surface wave plasma (SWP) may be mentioned. Any of these plasma processing devices, including an ICP, can independently control the ion flux and ion energy, so that the etching shape or selectivity can be freely controlled, and an electron density as high as about 10 ¹¹ to 10 ¹³ cm ^-3 can be obtained.

20: Processing container
31: Split metal window (metal part)
34a: exposed surface
38: Absence of cover (first cover member)
38a: Through hole
39, 39A: Cover member (second cover member)
39a: Through hole
40, 40A: Fastening structure
41: Fastening screw
42: Screw head
44: Screw cover
45: 1st base section
46: 1st shield

Claims (12)

A plurality of metal members, which are arranged inside a processing vessel and have an exposed surface and screw holes that are exposed to plasma generated inside the processing vessel,
A cover member arranged across the exposed surface of the plurality of above metal members, having insulating properties and having a through hole,
A metal fastening screw having a screw head and fastening the cover member to the metal member by passing through the through hole and screwing into the screw hole, and
A screw cover covering the screw head and having a recessed portion
With,
The screw cover has a first metal base portion that comes into contact with the screw head portion, and a first protective film that is a ceramic coating that covers at least a portion of the surface of the first base portion.
On the side of the above screw head, a first screw groove is formed,
A second screw groove is formed on the wall surface of the concave portion of the screw cover,
A fastening structure in which the first screw groove and the second screw groove are screw-connected, and the fastening screw and the metal member are connected, so that the first base portion and the metal member are electrically connected. A fastening structure in claim 1, wherein the ceramic soldering film is formed by yttrium-containing ceramics. A fastening structure according to claim 1 or 2, wherein the ceramic soldering film covers a surface of the first base portion that is exposed to the plasma. In paragraph 1 or 2,
A fastening structure in which the first screw groove and the second screw groove are screw-connected, and the concave portion covers the screw head. A plasma processing device having a processing vessel for generating plasma and processing a substrate,
A plurality of metal members, which are arranged inside the above processing vessel and have an exposed surface exposed to the plasma and a screw hole,
A cover member arranged across the exposed surface of the plurality of above metal members, having insulating properties and having a through hole,
A metal fastening screw having a screw head and fastening the cover member to the metal member by passing through the through hole and screwing into the screw hole, and
A screw cover covering the screw head and having a recessed portion
With,
The screw cover has a first metal base portion that comes into contact with the screw head portion, and a first protective film that is a ceramic coating that covers at least a portion of the surface of the first base portion.
On the side of the above screw head, a first screw groove is formed,
A second screw groove is formed on the wall surface of the concave portion of the screw cover,
A plasma processing device in which the first screw groove and the second screw groove are screw-connected, and the fastening screw and the metal member are connected, so that the first base portion and the metal member are electrically connected. A plasma processing device in claim 5, wherein the ceramic coating is formed by yttrium-containing ceramics. A plasma treatment device according to claim 5 or 6, wherein the ceramic coating covers a surface of the first base portion that is exposed to the plasma. In claim 5 or 6, the processing vessel has a processing room for generating the plasma to process the substrate, and an antenna room in which an inductive coupling antenna is arranged.
A plasma processing device in which the above metal member is a split metal window, and a plurality of the above split metal windows are arranged side by side to form a metal window separating the processing room and the antenna room. In the 8th paragraph, the plurality of split metal windows are separated by an insulating member,
A plasma processing device, wherein the cover member is arranged across the exposed surfaces of the plurality of split metal windows while covering the insulating member. In the 9th paragraph, the cover member has a first cover member made of ceramics and a second cover member laminated on the first cover member,
The above first cover member covers the insulating member,
The second cover member has a second base part made of metal that contacts the first cover member and the first base part, and a second protective film formed by a ceramic spray film that covers at least a portion of the surface of the second base part.
The second cover member covers a plurality of the first cover members in an intersection area where the plurality of the first cover members intersect,
A plasma processing device, wherein the above fastening screw penetrates through each of the through holes provided in the first cover member and the second cover member and is screw-engaged into the screw hole provided in the split metal window to fasten the first cover member and the second cover member to the split metal window. A plasma processing device having a processing vessel for generating plasma and processing a substrate,
A plurality of metal members, which are arranged inside the above processing vessel and have an exposed surface exposed to the plasma and a screw hole,
A cover member arranged across the exposed surface of the plurality of above metal members, having insulating properties and having a through hole,
A metal fastening screw having a screw head and fastening the cover member to the metal member by passing through the through hole and screwing into the screw hole;
Screw cover covering the above screw head
With,
The above screw cover has a first metal base portion that comes into contact with the screw head portion, and a first protective film that is a ceramic coating that covers at least a portion of the surface of the first base portion.
The above processing vessel has a processing room for generating the plasma to process the substrate, and an antenna room in which an inductive coupling antenna is placed.
The above metal member is a split metal window, and by arranging a plurality of the split metal windows in parallel, a metal window separating the processing room and the antenna room is formed.
The plurality of above-mentioned split metal windows are separated by an insulating member,
The above cover member is arranged across the exposed surface of the plurality of split metal windows while covering the insulating member,
The above cover member has a first cover member made of ceramics and a second cover member laminated on the first cover member.
The above first cover member covers the insulating member,
The second cover member has a second base part made of metal that contacts the first cover member and the first base part, and a second protective film formed by a ceramic spray film that covers at least a portion of the surface of the second base part.
The second cover member covers a plurality of the first cover members in an intersection area where the plurality of the first cover members intersect,
A plasma processing device, wherein the above fastening screw penetrates through each of the through holes provided in the first cover member and the second cover member and is screw-engaged into the screw hole provided in the split metal window to fasten the first cover member and the second cover member to the split metal window. A method of fastening a cover member that is arranged across the exposed surfaces of a plurality of metal members, each metal member being arranged inside a processing vessel and having an exposed surface exposed to plasma generated inside the processing vessel,
The above metal member has a screw hole, and the cover member has insulation and has a through hole.
A process for fastening the cover member to the metal member by screwing a metal fastening screw having a screw head through the through hole and into the screw hole,
A process for covering a screw head with a first base portion made of metal, a first protective film which is a ceramic coating covering at least a portion of the surface of the first base portion, and a screw cover having a concave portion.
Including,
On the side of the above screw head, a first screw groove is formed,
A second screw groove is formed on the wall surface of the concave portion of the screw cover,
A fastening method in which the first screw groove and the second screw groove are screw-connected, and the fastening screw and the metal member are connected, thereby electrically conducting the first base portion and the metal member.

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