TWI908765B - Inductively coupled antenna and plasma treatment device - Google Patents

Abstract

[Project] To provide an inductively coupled antenna and a plasma processing apparatus that improves the uniformity of plasma density. [Solution] A rectangular frame-shaped inductively coupled antenna, characterized by having a facing surface opposite to the mounting surface, forming an induced electric field for generating the aforementioned plasma within a processing container for plasma processing of a rectangular substrate placed on a mounting surface of a mounting stage, and comprising: a planar portion in which four antenna lines are wound at 90° offsets on the facing surface; and a longitudinally wound portion in which, at the ends of each antenna line, a winding axis parallel to the facing surface and intersecting the corners of the rectangular frame is formed, while sharing a bottom planar portion of the facing surface, and the antenna lines are wound longitudinally.

Description

Inductively coupled antenna and plasma treatment device

This disclosure relates to an inductively coupled antenna and a plasma treatment device.

Patent document 1 discloses an antenna element configured such that a plurality of antenna lines are wound in the same plane, with the number of turns at the corners exceeding the number of turns at the center of the edges, forming an overall spiral shape. [Prior Art Documents] [Patent Documents]

[Patent Document 1] Japanese Patent Application Publication No. 2012-59762

[The problem this invention aims to solve]

This disclosure provides an inductively coupled antenna and a plasma processing device that improves the uniformity of plasma density. [Means for solving the problem]

The inductively coupled antenna disclosed herein is a rectangular frame-shaped inductively coupled antenna that forms an induced electric field for generating the aforementioned plasma within a processing container for plasma processing of a rectangular substrate placed on a mounting surface of a mounting stage, and has a facing surface opposite to the aforementioned mounting surface. Its features include: a planar portion in which four antenna lines are wound at 90° angles apart on the facing surface; and a longitudinally wound portion where, at the ends of each antenna line, a winding axis parallel to the facing surface and intersecting the corners of the rectangular frame is formed, sharing a bottom planar portion with the aforementioned facing surface while being wound longitudinally. [Effects of the Invention]

According to this disclosure, an inductively coupled antenna and a plasma processing device that "improves the uniformity of plasma density" can be provided.

The following description, with reference to the accompanying drawings, illustrates the gas supply method and substrate processing apparatus (inductively coupled plasma apparatus) 10 of the embodiments disclosed herein. Furthermore, in this specification and drawings, substantially identical constituent elements are sometimes given the same symbols and repeated descriptions are omitted.

[Substrate Processing Apparatus of the First Embodiment] Referring to FIG1, a substrate processing apparatus 10 of the first embodiment of this disclosure will be described. FIG1 is a longitudinal cross-sectional view showing an example of the substrate processing apparatus 10 of the first embodiment.

The substrate processing apparatus 10 shown in Figure 1 is an inductively coupled plasma (ICP) processing apparatus that performs various substrate processing methods on a rectangular substrate G (hereinafter referred to as "substrate") for a flat panel display (FPD). The substrate G is primarily made of glass, but sometimes transparent synthetic resins are used depending on the application. The substrate processing includes etching or CVD (Chemical Vapor Deposition) film deposition processes. Examples of FPDs include liquid crystal displays (LCDs), electroluminescent displays (ELs), and plasma display panels (PDPs). The substrate G, in addition to having a patterned circuit on its surface, also includes a support substrate. Furthermore, the planar dimensions of the substrate used in FPDs have increased dramatically with each generation. The planar dimensions of the substrate G processed by the substrate processing apparatus 10 include, for example, dimensions ranging from approximately 1500mm × 1800mm in the 6th generation to approximately 3000mm × 3400mm in the 10.5th generation. Also, the thickness of the substrate G is approximately 0.2mm to several millimeters.

The substrate processing apparatus 10 shown in Figure 1 includes: a rectangular box-shaped processing container 20; a substrate mounting stage 70 with a rectangular shape when viewed from above, which is disposed inside the processing container 20 and holds the substrate G; and a control unit 90. In addition, the processing container may also be a cylindrical box-shaped or an elliptical box-shaped, etc. In this form, the substrate mounting stage is also circular or elliptical, and the substrate placed on the substrate mounting stage is also circular, etc.

The processing container 20 is divided into two spaces, upper and lower, by a metal window 50. The upper space, namely the antenna chamber A, is formed by the upper chamber 13, and the lower space, namely the processing area S (processing chamber), is formed by the lower chamber 17. In the processing container 20, at the boundary between the upper chamber 13 and the lower chamber 17, a rectangular ring-shaped support frame 14 is provided, protruding inwards from the processing container 20, and the metal window 50 is installed on the support frame 14.

The upper chamber 13 of the antenna chamber A is formed by the side wall 11 and the top plate 12, and the whole is made of a metal such as aluminum or aluminum alloy.

The lower chamber 17, which has a processing area S, is formed by a side wall 15 and a bottom plate 16, and is made entirely of a metal such as aluminum or an aluminum alloy. The side wall 15 is grounded by a grounding wire 21.

Furthermore, the support frame 14 is formed of a conductive metal such as aluminum or aluminum alloy, and can also be called a metal frame.

At the upper end of the side wall 15 of the lower chamber 17, a rectangular ring-shaped (endless) sealing groove 22 is formed. Sealing components 23 such as O-rings are embedded in the sealing groove 22, and the abutment surface of the support frame 14 holds the sealing components 23, thereby forming a sealing structure between the lower chamber 17 and the support frame 14.

On the side wall 15 of the lower chamber 17, there is an inlet/outlet 18 for moving the substrate G into and out of the lower chamber 17. The inlet/outlet 18 is configured to be freely opened and closed by a gate valve 24. A conveying chamber (not shown) containing a conveying mechanism is adjacent to the lower chamber 17 and controls the opening and closing of the gate valve 24. The substrate G is moved in and out of the lower chamber 17 through the inlet/outlet 18 by means of the conveying mechanism.

Furthermore, the bottom plate 16 of the lower chamber 17 has a plurality of vent ports 19, each of which is connected to a gas exhaust pipe 25, which is connected to an exhaust device 27 via a switch valve 26. The gas exhaust pipe 25, the switch valve 26, and the exhaust device 27 together form a gas exhaust section 28. The exhaust device 27 is configured as a vacuum pump, including a turbine molecular pump, which freely evacuates the lower chamber 17 to a predetermined vacuum level during the manufacturing process. Additionally, a pressure gauge (not shown) is installed at a suitable location in the lower chamber 17, and the monitoring information from the pressure gauge is sent to the control unit 90.

The substrate mounting stage 70 has: a substrate 73; and an electrostatic chuck 76 formed on the top surface 73a of the substrate 73.

The substrate 73 is rectangular in shape when viewed from above, and has planar dimensions similar to those of the FPD mounted on the substrate mounting stage 70. For example, the substrate 73 has planar dimensions similar to those of the mounted substrate G, with the length of the long side being approximately 1800mm to 3400mm and the length of the short side being approximately 1500mm to 3000mm. The thickness of the substrate 73 relative to these planar dimensions is, for example, approximately 50mm to 100mm.

The substrate 73 has a temperature-regulating medium flow path 72a that meanders to cover the entire rectangular plane area, and is formed of stainless steel, aluminum, or an aluminum alloy. Alternatively, the substrate 73 may not be a single component as shown in the example, but rather a laminate of an upper substrate and a lower substrate. In this case, the temperature-regulating medium flow path 72a may be located on either the lower substrate or the upper substrate.

On the bottom plate 16 of the lower chamber 17, there is a box-shaped pedestal 78 made of insulating material with segments on the inside, and the substrate mounting platform 70 is mounted on the segments of the pedestal 78.

On the substrate 73, an electrostatic chuck 76 is formed for directly mounting the substrate G. The electrostatic chuck 76 has: a dielectric film, i.e., a ceramic layer 74, formed by sputtering ceramic such as alumina; and a conductive layer 75 (electrode), which is embedded inside the ceramic layer 74 and has an electrostatic adsorption function.

The conductive layer 75 is connected to the DC power supply 85 via the power supply line 84. When the switch (not shown) provided in the power supply line 84 is turned on by the control unit 90, a DC voltage is applied from the DC power supply 85 to the conductive layer 75, thereby generating a Coulomb force. By means of this Coulomb force, the substrate G is electrostatically attracted to the electrostatic chuck 76 and held in a state of being placed on the substrate 73.

The substrate 73 constituting the substrate mounting stage 70 is provided with a temperature-regulating medium flow path 72a that meanders to cover the entire area of a rectangular plane. At both ends of the temperature-regulating medium flow path 72a, there are: a delivery pipe 72b for supplying temperature-regulating medium to the temperature-regulating medium flow path 72a; and a return pipe 72c for discharging the temperature-regulating medium that has flowed through the temperature-regulating medium flow path 72a and been heated or cooled.

As shown in Figure 1, a delivery flow path 87 and a return flow path 88 are respectively connected to the delivery pipe 72b and the return pipe 72c. The delivery flow path 87 and the return flow path 88 are connected to a temperature control means, such as a cooler 86. The cooler 86 includes: a main body for controlling the temperature or discharge flow rate of the temperature-regulating medium; and a pump for pressurizing the temperature-regulating medium (both not shown). The temperature-regulating medium is, for example, a refrigerant, such as Galden (registered trademark) or Fluorinert (registered trademark). The delivery flow path 87, the return flow path 88, and the cooler 86 constitute a temperature control device 89.

The substrate 73 is equipped with a temperature sensor such as a thermocouple, and the monitoring information from the temperature sensor is constantly transmitted to the control unit 90. Furthermore, based on the transmitted monitoring information, the control unit 90 performs temperature control on the substrate 73 and the substrate G. More specifically, the control unit 90 adjusts the temperature or flow rate of the temperature-regulating medium supplied from the cooler 86 to the delivery flow path 87. Moreover, temperature control of the substrate mounting stage 70 is performed by circulating the temperature-regulating medium, which has undergone temperature or flow rate adjustment, through the temperature-regulating medium flow path 72a. Additionally, the temperature sensor, such as a thermocouple, can also be installed, for example, on the electrostatic chuck 76.

A segment is formed on the outer periphery of the electrostatic chuck 76 and the substrate 73 and the upper surface of the base 78. A rectangular focusing ring 79 is mounted on this segment. With the focusing ring 79 positioned in the segment, its upper surface is lower than the upper surface of the electrostatic chuck 76. The focusing ring 79 is formed of a ceramic such as alumina or quartz.

Below the substrate 73, a power supply component 80 is connected. At the lower end of the power supply component 80, a power supply line 81 is connected, which is connected to a bias power supply, i.e., a high-frequency power supply 83, via an impedance matching circuit 82. A high-frequency power of, for example, 3.2 MHz is applied to the substrate mounting stage 70 from the high-frequency power supply 83, thereby generating an RF bias voltage and attracting ions generated by the high-frequency power supply 59 (described below as the source for plasma generation) to the substrate G. Therefore, in the plasma etching process, both the etching rate and etching selectivity can be improved simultaneously. In this way, the substrate mounting stage 70 holds the substrate G and forms a bias electrode for generating the RF bias voltage. At this point, the portion that becomes the ground potential inside the chamber functions as the opposite electrode of the bias electrode and forms the return circuit for high-frequency power. Alternatively, the metal window 50 can also be incorporated into the return circuit for high-frequency power.

The metal window 50 is formed by a plurality of segmented metal windows 57. The number of segmented metal windows 57 forming the metal window 50 (6 in the cross-sectional direction in Figure 1) can be set to various numbers such as 12 or 24.

Each segmented metal window 57 is insulated from the supporting frame 14 or adjacent segmented metal windows 57 by an insulating component 56. Here, the insulating component 56 is formed of a fluoropolymer such as PTFE (Polytetrafluoroethylene).

The dividing metal window 57 comprises a conductor plate 30 and a spray plate 40. Both the conductor plate 30 and the spray plate 40 are formed of a non-magnetic, conductive, and corrosion-resistant metal, or a metal with a corrosion-resistant surface finish, such as aluminum or aluminum alloys, or stainless steel. The corrosion-resistant surface finish includes, for example, anodizing or ceramic spraying. Furthermore, a paste coating applied by anodizing or ceramic spraying can also be applied to the underside of the spray plate 40 facing the treatment area S. The conductor plate 30 can also be grounded via a grounding wire (not shown). The spray plate 40 and the conductor plate 30 are joined together in a mutually conductive manner.

As shown in Figure 1, above each of the segmented metal windows 57, there is a spacer (not shown) formed by an insulating component, and a high-frequency antenna 54 is disposed separately from the conductor plate 30 through the spacer. The high-frequency antenna 54 is formed by "winding an antenna wire made of a metal with good conductivity, such as copper, into a loop or spiral shape". For example, multiple loop antenna wires can also be disposed.

Furthermore, a power supply component 57a extending above the upper chamber 13 is connected to the high-frequency antenna 54. A power supply line 57b is connected to the upper end of the power supply component 57a, and the power supply line 57b is connected to the high-frequency power supply 59 via an impedance matching device 58. A high-frequency power of, for example, 13.56 MHz is applied to the high-frequency antenna 54 from the high-frequency power supply 59, thereby inducing a current in the segmented metal window 57. This induced current in the segmented metal window 57 forms an induced electric field within the lower chamber 17. This induced electric field plasmaizes the processing gas supplied from the spray plate 40 to the processing area S, generating an inductively coupled plasma, and providing ions from the plasma to the substrate G. In addition, each segmented metal window 57 has its own high-frequency antenna, and can also perform control of applying high-frequency power to each high-frequency antenna individually.

High-frequency power supply 59 is the source for plasma generation. High-frequency power supply 83, connected to substrate mounting stage 70, acts as a bias source to attract and energize the generated ions. In this way, plasma is generated at the ion source using inductive coupling, and the other power source, the bias source, is connected to substrate mounting stage 70 for ion energy control. This allows for independent plasma generation and ion energy control, thereby increasing process flexibility. The frequency of the high-frequency power output from high-frequency power supply 59 is preferably set within the range of 0.1~500MHz.

The metal window 50 is formed by a plurality of segmented metal windows 57, each segmented metal window 57 being suspended from the top plate 12 of the upper chamber 13 by a plurality of hangers (not shown). Since the high-frequency antenna 54, which helps in the generation of plasma, is disposed above the segmented metal windows 57, the high-frequency antenna 54 is suspended from the top plate 12 via the segmented metal windows 57.

A gas diffusion groove 32 is formed on the underside of the conductor plate body 31 that forms the conductor plate 30. Alternatively, the gas diffusion groove can also be formed on the top of the spray plate. Furthermore, the shape of the gas diffusion groove includes not only elongated concave shapes but also planar concave shapes.

The spray plate body 41 forming the spray plate 40 has a plurality of gas discharge holes 42. The gas discharge holes 42 penetrate the spray plate body 41 and are connected to the gas diffusion channel 32 of the guide plate 30 and the treatment area S.

As shown in Figure 1, the gas inlet pipes 55 of each of the segmented metal windows 57 are gathered in one place in the antenna chamber A. The gas inlet pipes 55 extending upwards are airtightly connected to the supply port 12a of the top plate 12 of the upper chamber 13. Moreover, the gas inlet pipes 55 are connected to the processing gas supply source 64 via an airtightly sealed gas supply pipe 61.

At a midway point in the gas supply pipe 61, a flow controller 63, similar to a switch valve 62 and a mass flow controller, is installed. The gas supply device 60 is formed by the gas supply pipe 61, the switch valve 62, the flow controller 63, and the processing gas supply source 64. Furthermore, in order to supply gas to multiple areas within the processing area S, the gas supply pipe 61 branches midway, and each branch pipe is connected to a switch valve, a flow controller, and a processing gas supply source (not shown) corresponding to the type of processing gas.

In the plasma treatment, the treatment gas supplied from the gas supply device 60 is supplied through the gas supply pipe 61 and the gas inlet pipe 55 to the gas diffusion channels 32 of the guide plates 30 of each of the partition metal windows 57. Moreover, the gas from each gas diffusion channel 32 is discharged into the treatment area S through the gas discharge holes 42 of each spray plate 40.

Furthermore, each segmented metal window 57 can also have its own high-frequency antenna, enabling control to apply high-frequency power to each high-frequency antenna individually.

The control unit 90 controls the operation of various components of the board processing apparatus 10, such as the cooler 86 or high-frequency power supplies 59 and 83, the gas supply device 60, and the gas exhaust unit 28 based on monitoring information transmitted from the pressure gauge. The control unit 90 includes a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The CPU executes predetermined processes according to a recipe stored in the memory area of RAM or ROM. The recipe contains control information for the board processing apparatus 10 relative to the process conditions. The control information includes, for example, gas flow rate or pressure within the processing container 20, temperature within the processing container 20 or temperature of the substrate 73, and process time.

The programs used in the recipe and control unit 90 can be, for example, stored on a hard drive, optical disc, or other similar disk. Furthermore, the recipes can also be set and read from the control unit 90 while stored in a memory medium that can be read by a portable computer, such as a CD-ROM, DVD, or memory card. The control unit 90 also includes a user interface with input devices such as a keyboard or mouse for inputting commands, a display device such as a monitor that visually displays the operating status of the board processing device 10, and an output device such as a printer.

Figure 2 is a plan view showing one example of the arrangement of the metal window 50 and the high-frequency antenna 54. In Figure 2, the direction from the center of the metal window 50 towards its outer periphery is defined as the radial direction, and the direction following the outer periphery of the metal window 50 is defined as the circumferential direction. Furthermore, the shape and arrangement of the high-frequency antenna 54 in Figure 2 are schematic illustrations and are not limited to the shape or arrangement shown in Figure 2.

The metal window 50 is divided into a plurality of segmented metal windows 57 by an insulating component 56. Specifically, the metal window 50 is divided into 3 segments in the radial direction. Furthermore, the metal window 50, which is divided into 3 segments in the radial direction, is then divided into 4, 8, and 12 segments in the circumferential direction, starting from the center.

Furthermore, the metal window 50 divided by the insulating member 56 has: a first dividing line 51 extending from the four corners of the metal window 50 at a 45° angle; and a second dividing line 52 parallel to the long side of the two intersection points of the two first dividing lines 51 that enclose the short side of the metal window 50. Here, the length of the short side of the metal window 50 is set to W. The radial width of the triangular area enclosed by the short side of the metal window 50 and the two first dividing lines 51 is W/2. Also, the radial width of the trapezoidal area enclosed by the long side of the metal window 50, the two first dividing lines 51, and the second dividing line 52 is W/2. By configuring the high-frequency antenna 54 in this way, the number of turns and the radial width are made equal in both the triangular and trapezoidal regions, thereby ensuring that the electric field strength of the induced electric field formed by the segmented metal window 57 is equal. This results in the formation of a uniform plasma.

Furthermore, relative to the circumferential direction of each side, the metal windows 50 divided by the insulating components 56 are divided into three on the outer periphery and two on the middle side. This configuration increases the number of divisions of the metal windows 50 while reducing the size of each individual metal window 57, allowing for fine adjustment of the electric field intensity distribution of the induced electric field. This enables more precise and accurate control of the plasma distribution.

The high-frequency antenna 54 comprises: an outer antenna 110; a middle antenna 120; and an inner antenna 130. The outer antenna 110, middle antenna 120, and inner antenna 130 are planar regions that generate an induced electric field conducive to plasma generation; specifically, they are planar frame-shaped regions 141, 142, and 143. The frame-shaped regions 141, 142, and 143 are formed facing the conductor plate 30 and opposite the substrate G. Furthermore, the frame-shaped regions 141, 142, and 143 are arranged concentrically, collectively forming a rectangular plane corresponding to the rectangular substrate G.

Furthermore, the frame-shaped region 141 corresponding to the outer antenna 110 is disposed on the outer periphery of the divided metal window 57 among the three metal windows 50 divided in the radial direction. The frame-shaped region 142 corresponding to the middle antenna 120 is disposed on the middle divided metal window 57 among the three metal windows 50 divided in the radial direction. The frame-shaped region 143 corresponding to the inner antenna 130 is disposed on the central divided metal window 57 among the three metal windows 50 divided in the radial direction.

The outer antenna 110 is, for example, a planar antenna configured as a spiral (in Figure 2, it is depicted as concentric for convenience). The planar whole formed by each antenna facing the conductor plate 30 constitutes a frame-shaped area 141. However, the shape of the outer antenna 110 in Figure 2 is not limited to this.

The intermediate antenna 120 is configured as a spiral planar antenna, and the overall planar structure formed by each antenna facing the conductor plate 30 constitutes a frame-shaped region 142. Alternatively, the intermediate antenna 120 can be a multi-layered (quadruple) antenna formed by winding multiple antenna lines (e.g., four) made of conductive materials such as copper. The arrangement area of the antenna lines of the intermediate antenna 120 constitutes the frame-shaped region 142.

The inner antenna 130 is configured as a spiral planar antenna, and the overall planar structure formed by each antenna facing the conductor plate 30 constitutes a frame-shaped region 143. The inner antenna 130 can also be a multi-layer (double) antenna formed by winding multiple antenna lines (e.g., two) made of conductive materials such as copper. Alternatively, the inner antenna 130 can be configured as a single antenna line wound into a spiral shape. The arrangement area of the antenna lines in the inner antenna 130 constitutes a frame-shaped region 143.

Furthermore, the high-frequency antenna 54 is not limited to having three ring antennas (outer antenna 110, middle antenna 120, and inner antenna 130), but can also be composed of two or more ring antennas. Also, the outer antenna 110 can be a shape other than a spiral planar antenna, such as a multi-segmented ring antenna, which is a ring-shaped arrangement of a plurality of antenna segments that are longitudinally wound relative to the conductor plate 30.

<Center Antenna> Next, an example of the center antenna 120 will be further explained using Figures 3 and 4. Figure 3 is a plan view of an example of the center antenna 120. Figure 4 is a perspective view of an example of the center antenna 120.

As shown in Figure 3, the central antenna 120 is formed by winding the four antenna lines 121-124 at 90° intervals, creating a spiral-shaped quadruple antenna. Figure 3 also illustrates the shadow cast on one of the four antenna lines 121-124, making it easier to distinguish from the other antenna lines 122-124. Furthermore, in the following explanation, the long side of the central antenna 120 will be defined as the X direction, the short side as the Y direction, and the height direction (vertical direction) as the Z direction.

Antenna 121 has: a first corner portion 121a; a first side portion 121b; a second corner portion 121c; a second side portion 121d; a third corner portion 121e; and a connecting portion 121f. The first side portion 121b, the second corner portion 121c, the second side portion 121d, and the third corner portion 121e are disposed on opposing surfaces facing the mounting surface of the substrate mounting stage 70, forming a planar portion of the central antenna 120. A connecting portion 121 is formed at one end of antenna 121. The connecting portion 121f is connected to a high-frequency power supply 59 via a power supply component 57a (see FIG. 1). At the other end (terminal end) of antenna 121, a first corner portion 121a is formed as a longitudinally wound portion. The other end of antenna 121 is connected to the ground potential (not shown).

Similarly, antenna 122 has: a first corner portion 122a; a first side portion 122b; a second corner portion 122c; a second side portion 122d; a third corner portion 122e; and a connecting portion 122f. Antenna 123 has: a first corner portion 123a; a first side portion 123b; a second corner portion 123c; a second side portion 123d; a third corner portion 123e; and a connecting portion 123f. Antenna 124 has: a first corner portion 124a; a first side portion 124b; a second corner portion 124c; a second side portion 124d; a third corner portion 124e; and a connecting portion 124f. Connecting portions 122f~124f are connected to high-frequency power supply 59 via power supply component 57a (see Figure 1). The other end of antennas 122-124 is connected to the ground potential (not shown).

At the corners of the frame-shaped area 142 (see Figure 2), first corner portions 121a to 124a are respectively arranged. Inside the first corner portion 121a of antenna 121, the second corner portion 124c of antenna 124 and the third corner portion 123e of antenna 123 are arranged. Similarly, inside the first corner portion 122a of antenna 122, the second corner portion 121c of antenna 121 and the third corner portion 124e of antenna 124 are arranged. Inside the first corner portion 123a of antenna 123, the second corner portion 122c of antenna 122 and the third corner portion 121e of antenna 121 are arranged. Inside the first corner 124a of antenna 124, the second corner 123c of antenna 123 and the third corner 122e of antenna 122 are disposed.

The edge between the corner of the frame-shaped region 142 with the first corner portion 121a and the corner of the frame-shaped region 142 with the first corner portion 122a is the first edge portion 121b of the antenna line 121 and the second edge portion 124d of the antenna line 124. The first edge portion 121b and the second edge portion 124d that form the planar portion of the intermediate antenna 120 are part (edges) of the frame-shaped region 142 that constitutes the generation of an induced electric field that facilitates plasma generation.

The first side portion 121b has: a straight portion 121b1; a curved portion 121b2; and a straight portion 121b3. The second side portion 124d has: a straight portion 124d1; a curved portion 124d2; and a straight portion 124d3. The straight portions 121b1 and 124d1 are arranged with a predetermined interval. The straight portions 121b3 and 124d3 are arranged with a predetermined interval. The straight portions 121b3 and 124d1 are arranged on the same line. The curved portions 121b2 and 124d2 are located at the center of the edge of the frame-shaped area 142.

Similarly, the edge between the corner of the frame-shaped region 142 with the first corner portion 122a and the corner of the frame-shaped region 142 with the first corner portion 123a is the first edge 122b of the antenna 122 and the second edge 121d of the antenna 121. The first edge 122b and the second edge 121d forming the planar portion of the intermediate antenna 120 are part (edges) of the frame-shaped region 142 that constitutes the generation of an induced electric field that facilitates plasma generation. The edge between the corner of the frame-shaped region 142 with the first corner portion 123a and the corner of the frame-shaped region 142 with the first corner portion 124a is the first edge 123b of the antenna 123 and the second edge 122d of the antenna 122. The first side 123b and the second side 122d of the planar portion forming the intermediate antenna 120 constitute part (side) of the frame-shaped region 142 that facilitates the generation of an induced electric field in the plasma. The side between the corner of the frame-shaped region 142 where the first corner 124a is disposed and the corner of the frame-shaped region 142 where the first corner 121a is disposed is the first side 124b of the antenna line 124 and the second side 123d of the antenna line 123 disposed. The first side 124b and the second side 123d of the planar portion forming the intermediate antenna 120 constitute part (side) of the frame-shaped region 142 that facilitates the generation of an induced electric field in the plasma. Furthermore, the first side 122b, 123b, 124b, the second side 121d, 122d, and 123d each have the same curved portion as the first side 121b and the second side 124d.

As shown in Figure 4, the first corner portion 121a of antenna line 121 includes: antenna lines 211-213; antenna lines 221-223; antenna lines 231-232; and antenna lines 241-242.

The first corner portion 121a of the antenna 121 is configured as a longitudinally wound portion in which the antenna is wound in a longitudinal direction that is orthogonal to the surface of the substrate G (conductor plate 30), i.e., the longitudinal direction. Furthermore, the winding axis of the first corner portion 121a is parallel to the opposing surface facing the mounting surface of the substrate mounting stage 70, and intersects the corner of the frame-shaped area 142 when viewed from above.

Antenna lines 211-213 are disposed on an opposing surface facing the mounting surface of the substrate mounting stage 70. That is, the bottom planar portion 201 formed by antenna lines 211-213 of the first corner portion 121a shares an opposing surface facing the mounting surface. Furthermore, antenna lines 211-213 forming the first corner portion 121a of the bottom planar portion 201, the second corner portion 124c of antenna line 124 forming the planar portion of the intermediate antenna 120, and the third corner portion 123e of antenna line 123 constitute part (corner) of a frame-shaped region 142 that facilitates the generation of an induced electric field for plasma. In addition, the second corner portion 124c of antenna line 124 and the third corner portion 123e of antenna line 123 also share an opposing surface facing the mounting surface with antenna lines 211-213.

Specifically, the three antenna lines 211-213 are arranged on opposite sides to form an L-shape, creating a corner. That is, antenna lines 211-213 each have a straight section extending in the +Y direction (from one end towards the corner), a 90° bend at the corner, and a straight section extending in the +X direction (from the corner towards the other end). Furthermore, the straight sections on one end of antenna lines 211-213 are arranged parallel to each other with a predetermined interval (the distance between the approach surfaces of one antenna and the approach surfaces of the other antenna) G1. Similarly, the straight sections on the other end of antenna lines 211-213 are arranged parallel to each other with a predetermined interval G1. The predetermined interval G1 is preferably between 10mm and 30mm. This prevents abnormal discharges between antenna lines.

At the other end of antenna lines 211-213, antenna lines 221-223 extending in the +Z direction (away from the opposite plane) are respectively connected. At one end of antenna lines 212-213, antenna lines 241-242 extending in the +Z direction (away from the opposite plane) are respectively connected. Antenna lines 221-223 and 241-242 form two sides that are vertically installed on both sides of the bottom flat portion 201. Furthermore, the upper ends of antenna lines 221-222 and the upper ends of antenna lines 241-242 are respectively connected by horizontally extending antenna lines 231-232. The upper ends of antenna lines 221-222 are connected to one end of antenna lines 231-232, and the upper ends of antenna lines 241-242 are connected to the other end of antenna lines 231-232. Antenna lines 231-232 form the upper part of the first corner portion 121a. Furthermore, the upper surface of the first corner portion 121a formed by antenna lines 231-232 is formed parallel to the opposing surface (bottom plane portion 201). Antenna line 223 is connected to a ground potential (not shown).

In the first corner 121a shown in Figures 3 and 4, antenna line 231 is formed as a straight line connecting the upper end of antenna line 221 and the upper end of antenna line 241 (extending at an angle). Antenna line 232 is also formed as a straight line connecting the upper end of antenna line 222 and the upper end of antenna line 242 (extending at an angle).

Additionally, antenna lines 231 and 232 can also be bent into an L-shape, corresponding to the shape of antenna lines 211-213, and connected to antenna lines 221-222 and 241-242. That is, antenna line 231 has a straight section extending in the -X direction (from one end of antenna line 231 towards the corner), a corner bent at 90°, and a straight section extending in the -Y direction (from the corner towards the other end of antenna line 231). The straight section at one end of antenna line 231 is configured to overlap with the straight section at the other end of antenna line 211 when viewed from above. The straight section at the other end of antenna 231 is configured to overlap with the straight section at one end of antenna 212 when viewed from above. Similarly, antenna 232 can also be formed in an L-shape by forming a corner.

The second corner portion 124c of antenna 124 is disposed inside the corners of the three antennas 211-213. The third corner portion 123e of antenna 123 is disposed inside the corners of the three antennas 211-213 and the second corner portion 124c of antenna 124. Furthermore, antennas 211-213, the second corner portion 124c, and the third corner portion 123e are disposed at predetermined intervals G1.

The first corner portion 122a of antenna 122, the first corner portion 123a of antenna 123 and the first corner portion 124a of antenna 124 also have the same structure as the first corner portion 121a of antenna 121.

With this configuration, the intermediate antenna 120 allows the number of turns at the corners of the frame-shaped region 142 to be greater than the number of turns at the center of the frame-shaped region 142. Specifically, in one example of the intermediate antenna 120 shown in Figures 3 and 4, the number of turns at the corners is set to 5, and the number of turns at the center of the edge is set to 2. By making the number of turns at the corners greater than the number of turns at the center of the edge, the induced electric field at the corners of the frame-shaped region 142 is enhanced. This strengthens the plasma (increases plasma density) at the corners of the frame-shaped region 142, where plasma density tends to be weaker. This, in turn, improves the uniformity of plasma density on the substrate G.

Furthermore, although the number of antenna lines 211 to 213 arranged on the opposing surfaces of the first corner portions 121a to 124a is described as three, the number is not limited to this. By changing the number of antenna lines arranged on the opposing surfaces of the first corner portions 121a to 124a, the generation of the electric field generated by the intermediate antenna 120 can be controlled.

Next, using Figures 5 through 7, an example of another intermediate antenna 120A will be explained. Figure 5 is a plan view of another example of intermediate antenna 120A. Figure 6 is a perspective view of another example of intermediate antenna 120A. Figure 7 is a front view of another example of intermediate antenna 120A.

As shown in Figure 5, antenna 121 differs in the construction of its second corner portion 121c and third corner portion 121e. The second corner portion 121c of antenna 121 is an extension of the first corner portion 122a of antenna 122. The third corner portion 121e of antenna 121 is an extension of the first corner portion 123a of antenna 123. The same applies to antennas 122-124.

As shown in Figure 6, in the first corner 121a of antenna 121, the second corner 124c of antenna 124 and the third corner 123e of antenna 123 are rotated outward.

The second corner portion 124c of antenna 124 has: a connecting portion 124c1; an external turning portion 124c2; and a connecting portion 124c3.

The outer rotating portion 124c2 is formed in an L-shape by forming a corner. That is, the outer rotating portion 124c2 has a straight section extending in the +Y direction, a corner that bends at 90°, and a straight section extending in the +X direction. Furthermore, the outer rotating portion 124c2 is configured to overlap the corner of the antenna 213 when viewed from above. Also, as shown in Figure 7, the outer rotating portion 124c2 is configured to have a gap of height H from the upper end of the antenna 213 to the lower end of the outer rotating portion 124c2 when viewed from above. Here, the height H is preferably set to be less than or equal to a predetermined gap G1 (H≦G1). Furthermore, the height H is preferably set to be greater than or equal to a gap between the outer rotating portion 124c2 and the antenna 213 where abnormal discharge does not occur. By configuring the external rotating part 124c2 in this way, the induced electric field of the external rotating part 124c2 helps to generate plasma.

Connecting portion 124c1 connects one end of the first side portion 124b to the other end of the outer turning portion 124c2. Connecting portion 124c1 has: an upright portion that rises from, for example, one end of the first side portion 124b; and an extension portion that extends from the inside of the corner to the outside and connects to the other end of the outer turning portion 124c2. Connecting portion 124c3 connects the other end of the second side portion 124d to one end of the outer turning portion 124c2. Connecting portion 124c3 has: an upright portion that rises from, for example, the other end of the second side portion 124d; and an extension portion that extends from the inside of the corner to the outside and connects to one end of the outer turning portion 124c2.

Similarly, the third corner portion 123e of antenna 123 has: a connecting portion 123e1; an outer turning portion 123e2; and a connecting portion 123e3. The outer turning portion 123e2 is configured to overlap the corner portion of antenna 212 when viewed from above.

With this configuration, the intermediate antenna 120A can have more turns at the corners of the frame-shaped region 142 than at the center of the edge of the frame-shaped region 142. Furthermore, the intermediate antenna 120A can have the other antenna lines, namely the second corner 124c of antenna line 124 and the third corner 123e of antenna line 123, which are located at the first corner 121a of the longitudinal winding portion of antenna line 122, positioned on the outer side of the corner. This enhances the induced electric field at the corners of the frame-shaped region 142.

Furthermore, while the intermediate antenna 120A shown in Figures 5 and 6 is illustrated by rotating two of the second corner portions 124c and 123e outwards, it is not limited to this configuration and may also be configured to rotate only one of the third corner portions 123e outwards. In this case, the rotated portion 123e2 of the third corner portion 123e is positioned to overlap the corner of the antenna line 213 when viewed from above. Alternatively, it may be configured to rotate three or more outwards. Furthermore, it is preferable that the number of outward rotations is less than half the number of turns at the corners of the frame-shaped area 142.

Next, using Figures 8 and 9, we will further illustrate an example of another intermediate antenna 120B. Figure 8 is a plan view of another example of intermediate antenna 120A. Figure 9 is a perspective view of another example of intermediate antenna 120A.

As shown in Figure 8, antenna line 121 differs in the structure of its second corner portion 121c and third corner portion 121e. The second corner portion 121c of antenna line 121 is laid obliquely inside the corner by taking a shortcut within the first corner portion 122a of antenna line 122. The third corner portion 121e of antenna line 121 is laid obliquely inside the corner by taking a shortcut within the first corner portion 123a of antenna line 123. The same applies to antenna lines 122-124.

As shown in Figure 9, in the first corner 121a of antenna line 121, the antenna lines on the opposite surface (antenna lines forming the bottom plane portion 201), namely the third corner 123e of antenna line 123, the second corner 124c of antenna line 124, and the inner antenna lines of antenna lines 211-213, namely the third corner 123e of antenna line 123 and the second corner 124c of antenna line 124, are formed without forming corners and are short-circuited in a straight line. That is, the second corner 124c is formed by short-circuiting the end of the antenna line (first side portion 124b) arranged along one side of the frame-shaped region 142 with the end of the antenna line (second side portion 124d) arranged along the other side of the frame-shaped region 142 in a straight line. Furthermore, the third corner portion 123e is a straight-line short circuit between the end of the antenna line (second side portion 123d) arranged along one side of the frame-shaped area 142 and the end of the antenna line (connecting portion 123f) arranged along the other side of the frame-shaped area 142.

With this configuration, the central antenna 120B allows the number of turns at the corners of the frame-shaped region 142 to be greater than the number of turns at the center of the frame-shaped region 142's edge. This enhances the induced electric field at the corners of the frame-shaped region 142. Furthermore, the central antenna 120B promotes the generation of an electric field on the inner side of the corners.

Furthermore, the intermediate antenna 120B shown in Figures 8 and 9 is illustrated by shorting two wires, namely the third corner portion 123e and the second corner portion 124c, in a straight line. However, it is not limited to this configuration and may also be configured to short-circuit only one wire, the third corner portion 123e. Alternatively, it may be configured to short-circuit three or more wires.

Other embodiments may also be implemented by combining other constituent elements with the components listed in the above embodiments. Furthermore, this disclosure is not limited to any of the components shown herein. In this regard, changes may be made without departing from the spirit of this disclosure, and may be appropriately determined according to its application.

For example, the substrate processing apparatus 10 in Figure 1 is described as an inductively coupled plasma processing apparatus having a metal window 50 as a processing container 20 as a window component, but it is not limited to this and can also be an inductively coupled plasma processing apparatus having a dielectric window as a window component. Furthermore, it can also be a plasma processing apparatus of other types.

Figure 10 is a plan view of one example of the intermediate antenna 120C. In the intermediate antennas 120 (120A, 120B) shown in Figure 3, etc., the example is illustrated by having a curved portion (121b2, 124d2) of the antenna line provided in the center of the side of the frame-shaped area 142, but it is not limited to this. As shown in Figure 10, the curved portion (121b2, 124d2) may also be provided near the corner of the frame-shaped area 142.

In Figure 2, although the description uses antenna lines 121-124 of the middle antenna 120 with longitudinally wound portions (121a-124a) as an example, it is not limited to this. The inner antenna 130 may also be configured as a quadruple antenna composed of antenna lines with longitudinally wound portions.

G: Substrate 10: Substrate Processing Apparatus 50: Metal Window (Window Component) 54: High-Frequency Antenna (Antenna Unit) 57: Segmented Metal Window 70: Substrate Mounting Stage (Mounting Stage) 120: Intermediate Antenna (Inductively Coupled Antenna) 121~124: Antenna Lines 121a~124a: First Corner (Longitudinal Winding Section) 121b~124b: First Edge (Planar Section) 121c~124c: Second Corner (Planar Section) 121d~124d: Second Edge (Planar Section) 121e~124e: Third Corner (Planar Section) 121f~124f: Connecting Section 123e2, 124c2: Outer Turning Section (Laminated Section) 121b2, 124d2: Curved Section 142: Frame-shaped Area (Rectangular Frame) 201: Bottom Plane Section 211~213: Antenna Line (Bottom Plane Section) 221, 222: Antenna Line (Side Section) 231, 232: Antenna Line (Upper Section) 241, 242: Antenna Line (Side Section)

[Fig. 1] A longitudinal sectional view showing an example of the substrate processing apparatus of the first embodiment. [Fig. 2] A plan view showing an example of the arrangement of the metal window and the high-frequency antenna. [Fig. 3] A plan view showing an example of the intermediate antenna. [Fig. 4] A perspective view showing an example of the intermediate antenna. [Fig. 5] A plan view showing another example of the intermediate antenna. [Fig. 6] A perspective view showing another example of the intermediate antenna. [Fig. 7] A front view showing another example of the intermediate antenna. [Fig. 8] A plan view showing another example of the intermediate antenna. [Fig. 9] A perspective view showing another example of the intermediate antenna. [Fig. 10] A plan view showing another example of the intermediate antenna.

120: Center Antenna 121~124: Antenna Lines 121a: First Corner 121b: First Side 121b1: Straight Section 121b2: Curved Section 121b3: Straight Section 121c: Second Corner 121d: Second Side 121e: Third Corner 121f: Connecting Section 122a: First Corner 122b: First Side 122c: Second Corner 122d: Second Side 122e: Third Corner 122f: Connecting Section 123a: First Corner 123b: First Side 123c: Second Corner 123d: Second Side 123e: Third Corner 123f: Connecting part 124a: First corner 124b: First side 124c: Second corner 124d: Second side 124d1: Straight part 124d2: Curved part 124d3: Straight part 124e: Third corner 124f: Connecting part 211~213: Antenna line (bottom flat part) G1: Predetermined interval

Claims (7)

An inductively coupled antenna is described as follows: "Within a processing container for plasma processing of a rectangular substrate placed on a mounting surface of a mounting stage, an induced electric field is formed to generate the aforementioned plasma, exhibiting a rectangular frame shape having a facing surface opposite to the aforementioned mounting surface, wherein the number of turns at the corners of the rectangular frame is greater than the number of turns at the center of the aforementioned rectangular frame's edge." Its characteristic feature is that it has: a planar portion, within the aforementioned... In the opposing surface, the four antennas are staggered by 90° and wound around each other; and in the longitudinal winding section, at the end of each of the aforementioned antennas, a winding axis parallel to the opposing surface and intersecting the corner of the aforementioned rectangular frame is wound around, forming a bottom plane portion shared with the aforementioned opposing surface, while also being longitudinally wound. The aforementioned antennas, those arranged along the edge of the aforementioned rectangular frame, have curved portions. As in the inductively coupled antenna of claim 1, the aforementioned longitudinally wound portion has: two sides, erected on both sides of the aforementioned bottom planar portion; and an upper portion, located between the two sides, facing the aforementioned bottom planar portion. As in claim 2, the inductively coupled antenna, wherein, in the aforementioned upper portion, the antenna line is a straight line connecting the antenna lines on the two sides. As in claim 2, the inductively coupled antenna, wherein, in the aforementioned upper portion, the antenna lines are curved and connected between the antenna lines on the two sides in a manner corresponding to the shape of the aforementioned bottom plane portion. For any of claims 1-4, the inductively coupled antenna, wherein the other antennas disposed inside the corner of the aforementioned bottom planar portion of the antenna have: a layered portion separately disposed above the antennas constituting the outer corner of the aforementioned bottom planar portion. For any of the inductively coupled antennas in claims 1-4, the other antennas disposed inside the corner of the aforementioned bottom plane portion of an antenna are short-circuited in a straight line between the end of the antenna disposed along one side of the aforementioned rectangular frame and the end of the antenna disposed along the other side of the aforementioned rectangular frame. A plasma processing apparatus comprises: a processing container for processing a rectangular substrate by plasma, having a window structure on its upper part; a mounting stage within the processing container, having a mounting surface for mounting the rectangular substrate; and an inductively coupled antenna within the processing container, forming an induced electric field for generating the plasma, having a facing surface opposite to the mounting surface, wherein the number of turns at the corners of the rectangular frame is greater than the number of turns at the center of the edge of the rectangular frame. The plasma processing apparatus is characterized by... The aforementioned inductively coupled antenna has: a planar portion in which four antenna lines are wound at 90° offsets on the opposing surface; and a longitudinally wound portion where, at the end of each antenna line, a winding axis parallel to the opposing surface and intersecting the corner of the rectangular frame is formed, creating a bottom planar portion sharing the opposing surface while being wound longitudinally. The antenna lines, particularly those arranged along the edge of the rectangular frame, have curved portions.