Design method for plasma generator

Abstract

To provide a technique capable of solving a problem of heat resistance.SOLUTION: A plasma generation device 1 includes a plurality of first electrode members 211 and a plurality of second electrode members 221. The plurality of first electrode members 211 extend along the longitudinal direction D1 and are arranged side by side in the arrangement direction D2 intersecting the longitudinal direction D1. The second electrode members 221 are mutually provided between the plurality of first electrode members 211 in plan view in a direction D3 orthogonal to the arrangement direction D2 and the longitudinal direction D1. The pitch between the plurality of first electrode members 211 and the plurality of second electrode members 221 is set such that the temperatures of the plurality of first electrode members 211 and the plurality of second electrode members 221 are 600 degrees or less.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a plasma generating device and a method for designing a plasma generating device. [Background technology]

[0002] Plasma sources that generate plasma under atmospheric pressure have been proposed (for example, Patent Document 1). In Patent Document 1, the plasma source includes a plurality of first linear conductors, a plurality of second linear conductors, and a plate-shaped isolating member. The plurality of first linear conductors are arranged parallel to one another on one side of the isolating member, and the plurality of second linear conductors are arranged parallel to one another on the other side of the isolating member. The first linear conductors and the second linear conductors do not face each other in the thickness direction of the isolating member, and the first linear conductors and the second linear conductors are arranged alternately when viewed along the thickness direction.

[0003] In such a plasma source, an AC voltage is applied between the first linear conductor and the second linear conductor, thereby generating plasma around the plasma source. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-61759 Summary of the Invention [Problem to be solved by the invention]

[0005] When the plasma generator operates, the temperature of the plasma generator rises. If the temperature of the plasma generator becomes too high, a problem occurs in terms of heat resistance.

[0006] Therefore, an object of the present disclosure is to provide a technique that can solve the problem of heat resistance. [Means for solving the problem]

[0011] A first aspect of the method for designing a plasma generation device includes a step of determining a temperature tolerance for a plasma generation device including a plurality of first electrode members each extending along a longitudinal direction and arranged side by side in an arrangement direction intersecting the longitudinal direction, and a plurality of second electrode members each arranged between the plurality of first electrode members in a planar view seen from a direction perpendicular to the arrangement direction and the longitudinal direction, and a step of determining a narrower pitch between the plurality of first electrode members and the plurality of second electrode members as the tolerance is higher.

[0012] A second aspect of the method for designing a plasma generation device includes the steps of: determining, as a reference power, the power to be supplied to a plasma generation device including a plurality of first electrode members each extending along a longitudinal direction and arranged side by side in an arrangement direction intersecting the longitudinal direction; and a plurality of second electrode members each arranged between the plurality of first electrode members in a planar view seen from a direction perpendicular to the arrangement direction and the longitudinal direction, so that the emission intensity of plasma generated by the plasma generation device is equal to or greater than a predetermined intensity; and determining the pitch between the plurality of first electrode members and the plurality of second electrode members based on the reference power and an allowable temperature value of the plasma generation device. [Effects of the Invention]

[0013] P The design method of the plasma generator can solve the problem of heat resistance. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a plan view schematically illustrating an example of a configuration of a substrate processing system. [Figure 2] FIG. 2 is a block diagram schematically illustrating an example of the internal configuration of a control unit. [Figure 3] FIG. 1 is a diagram schematically illustrating an example of a configuration of a substrate processing apparatus. [Figure 4] 1 is a side cross-sectional view schematically showing an example of the configuration of a plasma generating device. [Figure 5]FIG. 1 is a plan view schematically illustrating an example of the configuration of a plasma generating device. [Figure 6] 10 is a graph showing an example of a voltage waveform and a current waveform when the electrode pitch is 6 mm. [Figure 7] 10 is a graph showing an example of a voltage waveform and a current waveform when the electrode pitch is 10 mm. [Figure 8] 10 is a graph showing an example of a voltage waveform and a current waveform when the electrode pitch is 12 mm. [Figure 9] 10 is a graph showing the relationship between temperature and power of a plasma generating device. [Figure 10] 1 is a flowchart showing an example of a method for designing a plasma generation device. [Figure 11] 1 is a graph showing the relationship between plasma emission intensity and power. [Figure 12] FIG. 1 is a plan view schematically illustrating an example of the configuration of a plasma generating device. [Figure 13] 1 is a side cross-sectional view schematically showing an example of the configuration of a plasma generating device. [Figure 14] 1 is a side cross-sectional view schematically showing an example of the configuration of a plasma generating device. [Figure 15] 1 is a graph showing the relationship between pulse width and temperature. [Figure 16] 10 is a graph showing the relationship between pulse width and voltage. [Figure 17] 1 is a graph showing the relationship between pulse width and current. [Figure 18] 1 is a graph showing the relationship between pulse width and instantaneous power. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments will be described with reference to the accompanying drawings. Note that the components described in the embodiments are merely examples and are not intended to limit the scope of the present disclosure. In the drawings, the dimensions or number of each part may be exaggerated or simplified as necessary for ease of understanding.

[0016] When expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) are used, unless otherwise specified, the expressions not only strictly represent the positional relationship but also represent a state in which there is a relative displacement in terms of angle or distance within a range in which tolerance or equivalent functionality is obtained. When expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) are used, the expressions not only represent a state in which there is strict quantitative equality but also represent a state in which there is a difference within which tolerance or equivalent functionality is obtained, unless otherwise specified. When expressions indicating a shape (e.g., "rectangular shape" or "cylindrical shape," etc.) are used, the expressions not only represent a geometrically strict shape but also represent a shape with, for example, irregularities or chamfers within a range in which equivalent effects are obtained, unless otherwise specified. When the expressions "comprise," "include," "have," "includes," "includes," or "have" are used to describe one component, the expressions are not exclusive expressions that exclude the presence of other components. When the phrase "at least one of A, B, and C" is used, the phrase includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0017] <Overall configuration of substrate processing system> 1 is a plan view schematically showing an example of the configuration of a substrate processing system 900 to which a plasma generating device is applied. The substrate processing system 900 is a single-wafer processing apparatus that processes substrates W to be processed one by one.

[0018] The substrate W is, for example, a semiconductor substrate having a disk shape. In addition to semiconductor substrates, various substrates can be used for the substrate W, such as glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FED (Field Emission Displays), substrates for organic EL (Electro-Luminescence) display devices, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, ceramic substrates, and solar cell substrates. The shape of the substrate is not limited to a disk shape, and various other shapes, such as a rectangular plate shape, can be used.

[0019] The substrate processing system 900 includes a load port 901 , an indexer robot 902 , a main transport robot 903 , a plurality of substrate processing apparatuses 100 , and a control unit 90 .

[0020] The multiple load ports 901 are arranged side by side in one horizontal direction. Each load port 901 is an interface unit for loading and unloading substrates W into and from the substrate processing system 900. A carrier C that stores a substrate W is loaded into each load port 901 from the outside. Each load port 901 is a container holding mechanism that holds the loaded carrier C. As the carrier C, a FOUP (Front Opening Unified Pod) that stores the substrate W in an enclosed space, a SMIF (Standard Mechanical Interface) pod, or an OC (Open Cassette) that exposes the substrate W to the outside air may be used.

[0021] The indexer robot 902 is a transport robot that transports substrates W between the carriers C held on each load port 901 and the main transport robot 903. The indexer robot 902 is movable along the direction in which the load ports 901 are arranged, and can stop at a position facing each carrier C. The indexer robot 902 can perform the operation of removing substrates W from each carrier C and the operation of handing over substrates W to each carrier C.

[0022] The main transport robot 903 is a transport robot that transports substrates W between the indexer robot 902 and each substrate processing apparatus 100. The main transport robot 903 may also be called a center robot. The main transport robot 903 can receive substrates W from the indexer robot 902 and deliver substrates W to the indexer robot 902. The main transport robot 903 can also transport substrates W into each substrate processing apparatus 100 and transport substrates W out of each substrate processing apparatus 100. In the example of FIG. 1 , the substrate processing system 900 includes a substrate platform 904. In this case, the indexer robot 902 transports substrates W between the load port 901 and the substrate platform 904, and the main transport robot 903 transports substrates W between the substrate platform 904 and each substrate processing apparatus 100.

[0023] The indexer robot 902 , the substrate placement unit 904 , and the main transport robot 903 transport substrates W between the respective substrate processing apparatuses 100 and the load port 901 .

[0024] The substrate processing system 900 is provided with, for example, 12 substrate processing apparatuses 100. Specifically, four towers, each of which has three substrate processing apparatuses 100 stacked vertically, are provided to surround the main transport robot 903. In FIG. 1, one of the three-tiered substrate processing apparatuses 100 is shown schematically. The number of substrate processing apparatuses 100 in the substrate processing system 900 is not limited to 12 and may be changed as appropriate.

[0025] The main transport robot 903 is arranged so as to be surrounded by four towers. The main transport robot 903 carries the unprocessed substrates W received from the indexer robot 902 into each substrate processing apparatus 100. Each substrate processing apparatus 100 processes the substrate W. In addition, the main transport robot 903 carries out processed substrates W from each substrate processing apparatus 100 and hands them over to the indexer robot 902.

[0026] The unprocessed substrate W is taken out of the carrier C by the indexer robot 902. Then, the unprocessed substrate W is transferred to the main transport robot 903 via, for example, the substrate placement part 904.

[0027] The main transport robot 903 carries the unprocessed substrate W into the substrate processing apparatus 100. Then, the substrate processing apparatus 100 processes the substrate W.

[0028] The substrate W that has been processed in the substrate processing apparatus 100 is removed from the substrate processing apparatus 100 by the main transport robot 903. The processed substrate W is then transported via another substrate processing apparatus 100 as necessary, and then transferred to the indexer robot 902, for example, via the substrate placement unit 904. The indexer robot 902 loads the processed substrate W into a carrier C. In this manner, the substrate W is processed.

[0029] The control unit 90 controls the operation of each component of the substrate processing system 900. FIG. 2 is a functional block diagram schematically illustrating an example of the internal configuration of the control unit 90. The control unit 90 is an electronic circuit and includes, for example, a data processing unit 91 and a storage unit 92. In the specific example of FIG. 2, the data processing unit 91 and the storage unit 92 are connected to each other via a bus 93. The data processing unit 91 may be, for example, an arithmetic processing device such as a CPU (Central Processor Unit). The storage unit 92 may include a non-transitory storage unit (e.g., a ROM (Read Only Memory), a rewritable memory, or a hard disk) 921 and a temporary storage unit (e.g., a RAM (Random Access Memory)) 922. The non-transitory storage unit 921 may store, for example, a program that defines the processing to be performed by the control unit 90. The data processing unit 91 executes this program, allowing the control unit 90 to perform the processing defined in the program. Of course, some or all of the processing performed by the control unit 90 does not necessarily have to be realized by software and may be executed by hardware such as a dedicated logic circuit. In the example of FIG. 2, a storage device 94, an input unit 96, a display unit 97, and a communication unit 98 are connected to the bus 93.

[0030] The memory unit 921 stores a basic program. The memory unit 922 is used as a work area when the data processing unit 91 performs predetermined processing. The memory unit 94 is composed of a non-volatile memory device such as a flash memory or a hard disk drive. The input unit 96 is composed of various switches or a touch panel, and receives input setting instructions such as processing recipes from an operator. The display unit 97 is composed of, for example, a liquid crystal display device and lamps, and displays various information under the control of the data processing unit 91. The communication unit 98 has a data communication function via a LAN (Local Area Network), etc.

[0031] A plurality of modes for controlling each component in the substrate processing system 900 of FIG. 1 are preset in the storage device 94. When the data processing unit 91 executes the processing program 94P, one of the plurality of modes is selected, and each component is controlled in that mode. The processing program 94P may be stored in a recording medium. Using this recording medium, the processing program 94P can be installed in the control unit 90.

[0032] The control unit 90 may include a main control unit and multiple local control units. The main control unit controls the entire substrate processing system 900, and a local control unit is provided for each substrate processing apparatus 100. The local control unit is capable of communicating with the main control unit and controls the substrate processing apparatus 100 based on instructions from the main control unit. Each of the main control unit and the local control unit includes a data processing unit 91 and a storage unit 92, for example, as in FIG. 2 .

[0033] <Substrate processing equipment> Fig. 3 is a diagram schematically illustrating an example of the configuration of the substrate processing apparatus 100. It is not necessary for all of the substrate processing apparatuses 100 belonging to the substrate processing system 900 to have the configuration shown in Fig. 3, but it is sufficient for at least one of the substrate processing apparatuses 100 to have the configuration.

[0034] The substrate processing apparatus 100 illustrated in FIG. 3 is an apparatus that performs a plasma-based process on a substrate W. The plasma-based process is not particularly limited, but specific examples include a process for removing organic matter adhering to the substrate W, or a process for metal etching on the substrate W. The organic matter adhering to the substrate W is, for example, a used resist film (hereinafter simply referred to as resist). The resist is, for example, a resist that has been used as an implantation mask for an ion implantation process. The process for removing the resist may also be called a resist removal process. The following description will be given using the resist removal process as an example. The substrate W is, for example, a semiconductor substrate and has a disk shape. The size of the substrate W is not particularly limited, but its diameter is, for example, approximately 300 mm.

[0035] 3 may be surrounded by the chamber 80 in FIG. 1. The pressure inside the chamber 80 may be approximately atmospheric pressure (e.g., 0.5 atmospheres or more and 2 atmospheres or less). In other words, the plasma processing described below may be atmospheric pressure plasma processing performed at atmospheric pressure.

[0036] In the example of FIG. 3, the substrate processing apparatus 100 includes a plasma generating device 1, a substrate holder 11, a nozzle 12, and a guard 13.

[0037] The substrate holding unit 11 holds the substrate W in a horizontal position. Here, a horizontal position means a position in which the thickness direction of the substrate W is aligned with the vertical direction. In the example of FIG. 3, the substrate holding unit 11 includes a stage 111 and a plurality of chuck pins 112. The stage 111 has a disk shape and is provided vertically below the substrate W. The stage 111 is provided with its thickness direction aligned with the vertical direction. The stage 111 may also be called a spin base. The plurality of chuck pins 112 are provided in an upright position on the outer periphery of the upper surface of the stage 111 and grip (clamp) the periphery of the substrate W. Note that the substrate holding unit 11 does not necessarily have to have the chuck pins 112. For example, the substrate holding unit 11 may hold the substrate W by suction by sucking the underside of the substrate W.

[0038] In the example of FIG. 3, the substrate holder 11 further includes a rotation mechanism 113, which rotates the substrate W around a rotation axis Q1. The rotation axis Q1 is an axis that passes through the center of the substrate W and is aligned in the vertical direction. The rotation mechanism 113 includes, for example, a shaft 114 and a motor 115. The upper end of the shaft 114 is connected to the lower surface of the stage 111 and extends from the lower surface of the stage 111 along the rotation axis Q1. The motor 115 rotates the shaft 114 around the rotation axis Q1, thereby rotating the stage 111. As a result, the substrate W held by the multiple chuck pins 112 rotates around the rotation axis Q1. Such a substrate holder 11 may also be called a spin chuck.

[0039] The nozzle 12 is used to supply a processing liquid to the substrate W. The nozzle 12 is connected to a processing liquid supply source 124 via a supply pipe 121. That is, a downstream end of the supply pipe 121 is connected to the nozzle 12, and an upstream end of the supply pipe 121 is connected to the processing liquid supply source 124. The processing liquid supply source 124 includes, for example, a tank (not shown) that stores the processing liquid and supplies the processing liquid to the supply pipe 121. The processing liquid may be, for example, hydrochloric acid, hydrofluoric acid, phosphoric acid, nitric acid, sulfuric acid, sulfate, peroxosulfuric acid, peroxosulfate, hydrogen peroxide, tetramethylammonium hydroxide, a mixture of ammonia and hydrogen peroxide (SC1), a mixture of hydrochloric acid and hydrogen peroxide (SC2), or a liquid containing deionized water (DIW). In this embodiment, a process using sulfuric acid as the processing liquid will be described.

[0040] This embodiment mainly describes a process for removing resist formed on the upper surface of the substrate W. In this case, the processing liquid is assumed to be a liquid containing at least one of sulfuric acid, sulfate, peroxosulfuric acid, and peroxosulfate, or a liquid containing hydrogen peroxide.

[0041] 3, a valve 122 and a flow rate adjuster 123 are provided in the supply pipe 121. When the valve 122 is opened, the processing liquid from the processing liquid supply source 124 is supplied to the nozzle 12 through the supply pipe 121 and is discharged from the discharge port 12a of the nozzle 12. In other words, the valve 122 switches between supplying and stopping the processing liquid from the processing liquid supply source 124 to the nozzle 12. The flow rate adjuster 123 adjusts the flow rate of the processing liquid flowing through the supply pipe 121. The flow rate adjuster 123 is, for example, a mass flow controller.

[0042] In the example of FIG. 3, the nozzle 12 is provided so as to be movable by a nozzle moving mechanism 15. The nozzle moving mechanism 15 moves the nozzle 12 between a first processing position and a first standby position. The first processing position is a position where the nozzle 12 ejects the processing liquid toward the main surface (e.g., the upper surface) of the substrate W. More specifically, the first processing position is, for example, a position vertically above the substrate W and facing the center of the substrate W in the vertical direction. The first standby position is a position where the nozzle 12 does not eject the processing liquid toward the main surface of the substrate W and is farther away from the substrate W than the first processing position. The first standby position is also a position where the nozzle 12 does not interfere with the transport path of the substrate W by the main transport robot 120. As a specific example, the first standby position is a position radially outward from the periphery of the substrate W. FIG. 3 shows the nozzle 12 stopped at the first standby position.

[0043] The nozzle movement mechanism 15 has an actuator such as a ball screw mechanism or an arm rotation mechanism. The arm rotation mechanism includes an arm, a support column, and a motor, all of which are not shown. The arm has a horizontally extending rod shape, and the nozzle 12 is connected to the tip of the arm and the base end of the arm is connected to the support column. The support column extends vertically and is rotatable around its central axis. When the motor rotates the support column, the arm rotates and the nozzle 12 moves circumferentially around the central axis. The support column is provided so that a first processing position and a first standby position are located on the movement path of the nozzle 12.

[0044] When the nozzle 12 is positioned at the first processing position and the valve 122 is opened while the substrate holder 11 is rotating the substrate W, the processing liquid is discharged from the nozzle 12 toward the upper surface of the rotating substrate W. The processing liquid lands on the upper surface of the substrate W, spreads over the upper surface of the substrate W as the substrate W rotates, and splashes outward from the periphery of the substrate W. As a result, a liquid film of the processing liquid is formed on the upper surface of the substrate W.

[0045] When multiple types of processing liquids are expected, multiple nozzles 12 may be provided corresponding to the respective processing liquids. The nozzles 12 supply the processing liquid to the substrate W so that a liquid film of the processing liquid is formed on the upper surface of the substrate W.

[0046] The guard 13 has a cylindrical shape that surrounds the substrate W held by the substrate holder 11. The processing liquid that splashes from the periphery of the substrate W hits the inner peripheral surface of the guard 13 and flows vertically downward along the inner peripheral surface. The processing liquid flows, for example, through a recovery pipe (not shown) and is recovered in a tank of the processing liquid supply source 124. This allows the processing liquid to be reused.

[0047] The plasma generator 1 is a device that generates plasma and may also be called a plasma source or a plasma reactor. The plasma generator 1 is provided at a position vertically facing the main surface (e.g., the upper surface) of the substrate W held by the substrate holder 11. In the example of FIG. 3, the plasma generator 1 is provided vertically above the upper surface of the substrate W so as to cover the entire substrate W. The plasma generator 1 is connected to a power source 8 and receives power from the power source 8 to convert the surrounding gas into plasma. Note that, as an example, the plasma generator 1 is an atmospheric pressure plasma source that generates plasma under atmospheric pressure. The atmospheric pressure here is, for example, 50% or more and 200% or less of standard atmospheric pressure. An example of a specific configuration of the plasma generator 1 will be described in detail later.

[0048] As shown in Fig. 3, a plasma moving mechanism 14 may be provided. The plasma moving mechanism 14 moves the plasma generator 1 relative to the substrate W held by the substrate holder 11. Specifically, the plasma moving mechanism 14 moves the plasma generator 1 back and forth between a second processing position and a second standby position. The second processing position is a position where the substrate W is processed using plasma from the plasma generator 1. At the second processing position, the distance between the plasma generator 1 and the upper surface of the substrate W is, for example, about several mm.

[0049] The second standby position is a position when no plasma processing is performed on the substrate W, and is a position farther from the substrate W than the second processing position. The second standby position is also a position where the plasma generator 1 does not interfere with the transport path of the substrate W by the main transport robot 120. As a specific example, the second standby position is a position vertically above the second processing position. In this case, the plasma moving mechanism 14 raises and lowers the plasma generator 1 in the vertical direction. FIG. 3 shows the plasma generator 1 stopped at the second standby position. The plasma moving mechanism 14 has a moving mechanism such as a ball screw mechanism or an air cylinder.

[0050] For example, the plasma generator 1 can move from the second standby position to the second processing position while the nozzle 12 is retracted to the first standby position. For example, when a liquid film of the processing liquid is formed on the upper surface of the substrate W by discharging the processing liquid from the nozzle 12 at the first processing position, the valve 122 is closed and the nozzle moving mechanism 15 moves the nozzle 12 from the first processing position to the first standby position. Meanwhile, for example, while the plasma generator 1 is located at the second standby position, the power supply 8 outputs a voltage to the plasma generator 1. This causes the plasma generator 1 to generate plasma at a position farther from the substrate W than the second processing position. At this time, for example, the plasma generator 1 generates plasma while the nozzle 12 supplies a liquid film of the processing liquid to the upper surface of the substrate W at the first processing position, thereby reducing the waiting time until plasma generation. Thereafter, the plasma moving mechanism 14 moves the plasma generator 1 from the second standby position to the second processing position. In this way, the nozzle 12 is not located directly above the substrate W, so the plasma generator 1 can be brought closer to the upper surface of the substrate W. In other words, the second processing position can be set closer to the substrate W.

[0051] This also causes the plasma generator 1 to generate plasma near the upper surface of the substrate W toward the liquid film of the processing liquid on the upper surface of the substrate W. Various active species are generated as a result of this plasma generation. For example, when air is converted into plasma, various active species such as oxygen radicals, hydroxyl radicals, and ozone gas can be generated. These active species act on the upper surface of the substrate W. As a specific example, the active species act on the liquid film of the processing liquid (sulfuric acid in this case) on the upper surface of the substrate W. This improves the processing performance of the processing liquid. Specifically, the reaction between the active species and sulfuric acid produces Caro's acid, which has high processing performance (oxidizing power in this case). Caro's acid is also known as peroxomonosulfuric acid. When this Caro's acid acts on the resist on the substrate W, it can oxidize and remove the resist.

[0052] As described above, the processing performance of the processing liquid can be improved by the active species acting on the processing liquid on the main surface of the substrate W. Therefore, the processing of the substrate W can be performed quickly.

[0053] <Plasma generator 1> Next, a more detailed example of each component of the plasma generator 1 will be described. Fig. 4 is a side cross-sectional view that schematically shows an example of the configuration of the plasma generator 1, and Fig. 5 is a plan view that schematically shows an example of the configuration of the plasma generator 1. Fig. 4 shows a cross section taken along line AA in Fig. 5. In the examples of Figs. 4 and 5, the plasma generator 1 is a planar plasma source and includes a first electrode unit 21 and a second electrode unit 22.

[0054] In the examples of Figures 4 and 5, the first electrode section 21 includes a plurality of first electrode members (first linear electrodes) 211 and a first assembly electrode 212, and the second electrode section 22 includes a plurality of second electrode members (second linear electrodes) 221 and a second assembly electrode 222.

[0055] The first electrode members 211 are formed of a conductive material such as a metal material (e.g., tungsten) and have a rod-like shape (e.g., a cylindrical shape) extending along the longitudinal direction D1. The multiple first electrode members 211 are arranged side by side in an arrangement direction D2 that intersects (here, orthogonal to) the longitudinal direction D1, and ideally are arranged parallel to each other.

[0056] The first assembly electrode 212 is made of a conductive material such as a metal material (e.g., aluminum) and connects the ends (base ends) of the multiple first electrode members 211 on one side in the longitudinal direction D1. In the example of Fig. 5, the first assembly electrode 212 has an arc-shaped flat plate shape that bulges out toward one side in the longitudinal direction D1. The multiple first electrode members 211 extend from the first assembly electrode 212 toward the other side in the longitudinal direction D1.

[0057] The second electrode members 221 are formed of a conductive material such as a metal material (e.g., tungsten) and have a rod-like shape (e.g., a cylindrical shape) extending along the longitudinal direction D1. The multiple second electrode members 221 are arranged side by side in the arrangement direction D2, ideally parallel to one another. Each second electrode member 221 is arranged between two adjacent first electrode members 211 in a plan view (i.e., when viewed along a direction D3 perpendicular to the longitudinal direction D1 and the arrangement direction D2). That is, the multiple second electrode members 221 are respectively arranged between the multiple first electrode members 211 in a plan view. In the example of FIG. 5, the first electrode members 211 and the second electrode members 221 are arranged alternately in the arrangement direction D2 in a plan view. The first electrode members 211 do not face the second electrode members 221 in the direction D3.

[0058] The second assembly electrode 222 is made of a conductive material such as a metal material (e.g., aluminum), and connects the ends (base ends) of the multiple second electrode members 221 on the other side in the longitudinal direction D1. In the example of Fig. 5, the second assembly electrode 222 bulges out on the opposite side from the first assembly electrode 212, and has an arc-shaped flat plate shape with approximately the same diameter as the first assembly electrode 212. The multiple second electrode members 221 extend from the second assembly electrode 222 toward one side in the longitudinal direction D1.

[0059] 4 and 5, each first electrode member 211 is covered by a first dielectric member 31. The multiple first dielectric members 31 are formed of a dielectric material such as quartz or ceramics. For example, each first dielectric member 31 has a cylindrical shape extending along the longitudinal direction D1, and the first electrode member 211 is inserted into the first dielectric member 31 along the longitudinal direction D1. The illustrated first dielectric member 31 may also be referred to as a first dielectric tube. Covering the first electrode member 211 with the first dielectric member 31 can prevent the substrate W from being contaminated by the first electrode member 211 being sputtered by plasma.

[0060] 4 and 5, each second electrode member 221 is covered by a second dielectric member 32. The multiple second dielectric members 32 are formed of a dielectric material such as quartz or ceramics. For example, each second dielectric member 32 has a cylindrical shape extending along the longitudinal direction D1, and the second electrode member 221 is inserted into the second dielectric member 32 along the longitudinal direction D1. The illustrated second dielectric member 32 may also be referred to as a second dielectric tube. Covering the second electrode member 221 with the second dielectric member 32 can prevent the substrate W from being contaminated by the second electrode member 221 being sputtered by plasma.

[0061] In the examples of FIGS. 4 and 5, the plasma generator 1 is provided with a dielectric member 33. The dielectric member 33 is made of a dielectric material such as quartz or ceramics. In the example shown, the dielectric member 33 has a plate-like shape. The dielectric member 33 is provided with its thickness direction aligned with direction D3. In the example of FIG. 5, the main surfaces 33a and 33b of the dielectric member 33 have a circular shape in a plan view. The thickness of the dielectric member 33 (the distance between the main surfaces 33a and 33b) is set to, for example, about several hundred μm (e.g., 300 μm).

[0062] The first electrode portion 21 and the first dielectric member 31 are provided on the main surface 33a side of the dielectric member 33, and the second electrode portion 22 and the second dielectric member 32 are provided on the main surface 33b side of the dielectric member 33. Specifically, the first dielectric member 31 is provided on the main surface 33a side of the dielectric member 33, and the second dielectric member 32 is provided on the main surface 33b side of the dielectric member 33.

[0063] The plasma generator 1 is installed in the substrate processing apparatus 100 with its main surface 33a facing the processing target (here, the substrate W). Specifically, the plasma generator 1 is installed with the direction D3 aligned vertically and with its main surface 33a facing the top surface of the substrate W. The plasma generator 1 faces the substrate W in the vertical direction.

[0064] As illustrated in Fig. 4, the plasma generator 1 may be provided with a holding member 34. Note that the holding member 34 is omitted in Fig. 5 to avoid complication of the drawing. The holding member 34 is formed of an insulating material such as a fluorine-based resin, and integrally holds the first electrode unit 21, the second electrode unit 22, the first dielectric member 31, the second dielectric member 32, and the dielectric member 33. The holding member 34 has a ring shape in plan view with approximately the same diameter as the first collection electrode 212 and the second collection electrode 222, and holds the first collection electrode 212 and the second collection electrode 222 in the direction D3.

[0065] In the example of FIG. 4, the tip of the first dielectric member 31 is held by the holding member 34. Specifically, the tip of the first dielectric member 31 is embedded in the holding member 34. Therefore, both ends of the portion consisting of the first electrode member 211 and the first dielectric member 31 are held by the holding member 34. This makes it possible to hold both ends of this portion. In the example of FIG. 4, the tip of the second dielectric member 32 is also held by the holding member 34. Therefore, the holding member 34 can also hold both ends of the portion consisting of the second electrode member 221 and the second dielectric member 32.

[0066] The first electrode unit 21 and the second electrode unit 22 are electrically connected to a plasma power supply 8. More specifically, the first electrode assembly 212 of the first electrode unit 21 is electrically connected to a first output terminal 8a of the power supply 8 via a wiring 81, and the second electrode assembly 222 of the second electrode unit 22 is electrically connected to a second output terminal 8b of the power supply 8 via a wiring 82. The power supply 8 has a switching power supply circuit such as an inverter circuit, and outputs a voltage for plasma between the first electrode unit 21 and the second electrode unit 22. As a more specific example, the power supply 8 outputs a high-frequency voltage as the voltage for plasma between the first electrode unit 21 and the second electrode unit 22. The power supply 8 may also be, for example, a pulse power supply, and may output a high-frequency voltage between the first electrode unit 21 and the second electrode unit 22 during an ON period in each of a plurality of cycles. This allows plasma to be ignited mainly during the ON period. The output of the power supply 8 is controlled by a control unit 90. Therefore, it can be said that the plasma generator 1 is controlled by the control unit 90.

[0067] The power supply 8 outputs a voltage between the first electrode unit 21 and the second electrode unit 22, thereby generating an electric field for plasma between the first electrode member 211 and the second electrode member 221. In response to this electric field, the gas surrounding the first electrode member 211 and the second electrode member 221 turns into plasma. Conversely, the power supply 8 applies a voltage between the first electrode unit 21 and the second electrode unit 22 sufficient to turn the gas into plasma. When the power supply 8 is a pulsed power supply, this voltage is, for example, a high-frequency voltage of 10 kV or more and several tens of kHz. The frequency here is, for example, the reciprocal of the period, and will hereinafter also be referred to as the pulse frequency.

[0068] According to the above-described flat plasma generator 1, the first electrode members 211 and the second electrode members 221 extending along the horizontal longitudinal direction D1 are alternately arranged in the horizontal arrangement direction D2. Therefore, the plasma generator 1 can generate plasma over a wide range in a plan view.

[0069] <Temperature of Plasma Generator 1> When the plasma generator 1 receives power from the power source 8 and generates plasma, the temperature of the plasma generator 1 rises due to Joule heat from the first electrode unit 21 and the second electrode unit 22 and heat generated by the plasma. If this temperature rises too much, problems such as heat resistance may arise. For example, if the first electrode member 211 and the second electrode member 221 are made of tungsten, the first electrode member 211 and the second electrode member 221 will become red hot if the temperature exceeds 600 degrees Celsius, which may cause problems with heat resistance.

[0070] In this embodiment, in order to suppress or avoid such a temperature rise exceeding the allowable value, attention is focused on the pitch between the first electrode member 211 and the second electrode member 221. Hereinafter, the pitch between the first electrode members 211 (referred to as the electrode pitch) is introduced as a parameter related to the pitch between the first electrode member 211 and the second electrode member 221. Here, the pitch between the first electrode member 211 and the second electrode member 221 in a plan view is half the electrode pitch.

[0071] The inventors fabricated multiple plasma generators 1 with different electrode pitches and conducted experiments using each plasma generator 1. More specifically, the output voltage (magnitude and frequency) of the power supply 8 was controlled so that the temperature of the plasma generator 1 (here, the temperature of the first electrode member 211 and the second electrode member 221) was 400 degrees Celsius, and the voltage and current were measured. Figures 6 to 8 are graphs showing examples of voltage waveforms and current waveforms as experimental results. Figure 6 shows the experimental results when the electrode pitch was 6 mm, Figure 7 shows the experimental results when the electrode pitch was 10 mm, and Figure 8 shows the experimental results when the electrode pitch was 12 mm.

[0072] Here, a pulsed power supply is used as the power supply 8. In this case, as illustrated in FIGS. 6 to 8, a high-frequency current flows at predetermined cycles. This is because the power supply 8 applies a high-frequency voltage between the first electrode unit 21 and the second electrode unit 22 during the on-period within the predetermined cycle. The examples in FIGS. 6 to 8 show the voltage waveform and current waveform for one cycle (= 50 μs: i.e., pulse frequency = 20 kHz), and the period in which the voltage fluctuates in the positive range and the period in which the voltage fluctuates in the negative range correspond to the on-period. In the examples in FIGS. 6 to 8, the on-period is 3 μs. Here, the magnitude of the output voltage of the power supply 8 was controlled so that the temperature was 400°C.

[0073] The table below shows the maximum absolute values ​​of voltage Vmax and current Imax extracted from the experimental results of FIGS.

[0074] [Table 1]

[0075] As can be seen from Table 1, the wider the electrode pitch, the greater the power required to raise the temperature to 400°C. Conversely, if the power is the same, the narrower the electrode pitch, the higher the temperature will be.

[0076] Fig. 9 is a graph illustrating the relationship between the temperature of the plasma generator 1 and the output power to the plasma generator 1 for each electrode pitch. In the example of Fig. 9, three graphs G1 to G3 are shown. Graph G1 shows the relationship when the electrode pitch is 6 mm, graph G2 shows the relationship when the electrode pitch is 10 mm, and graph G3 shows the relationship when the electrode pitch is 12 mm.

[0077] As can be seen from Fig. 9, for the same power, the wider the electrode pitch, the lower the temperature of the plasma generator 1. Also, as can be seen from Fig. 9, for the same electrode pitch, the higher the power, the higher the temperature of the plasma generator 1. In other words, the temperature of the plasma generator 1 has a positive correlation with the power and a negative correlation with the electrode pitch.

[0078] As described above, experiments by the inventors have revealed that the temperature of the plasma generator 1 depends not only on the magnitude of the power but also on the width of the electrode pitch.

[0079] Therefore, in this embodiment, the electrode pitch is set so that the temperature of the plasma generator 1 is equal to or lower than an allowable value (for example, 600 degrees Celsius). An example of a method for designing the electrode pitch will be described in detail below.

[0080] 10 is a flowchart showing an example of a method for designing the plasma generator 1. The designer determines a reference power for the power to be supplied to the plasma generator 1 (step S1: power setting step). The reference power here is the power used to determine the electrode pitch in step S3, which will be described later. For example, the designer may use the maximum power or rated power that can be output by the power supply 8 as the reference power.

[0081] Next, the designer determines the allowable temperature value (step S2: allowable temperature setting step). The designer may determine the allowable temperature value from the viewpoint of the heat resistance of the plasma generation device 1. For example, the allowable temperature value is determined to be 600 degrees Celsius.

[0082] Next, the designer determines the electrode pitch based on the correspondence relationship between the temperature of the plasma generator 1 when the reference power is output and the electrode pitch (for example, FIG. 9) so that the temperature is below an allowable value (step S3: electrode pitch design step). The correspondence relationship can be obtained in advance, for example, by experiment or simulation.

[0083] In step S3, the designer should determine a narrower electrode pitch as the temperature tolerance increases. This is because the wider the electrode pitch, the more difficult it is to generate plasma. For example, the longer the period from the start of power supply until stable plasma generation. Therefore, from the perspective of stably generating plasma around the plasma generator 1 in a shorter period of time, a narrower electrode pitch is preferable. Therefore, in step S3, the designer should determine the electrode pitch as narrow as possible as long as the temperature remains below the tolerance. As a more specific example, the designer may determine the minimum value of the range of electrode pitches at which the temperature remains below the tolerance as the electrode pitch.

[0084] As described above, the temperature of the plasma generator 1 can be kept below the allowable value by designing the electrode pitch. 600 degrees Celsius can be adopted as the allowable temperature value. This makes it possible to suppress or prevent the first electrode member 211 and the second electrode member 221 from becoming red-hot when the first electrode member 211 and the second electrode member 221 are made of tungsten.

[0085] The output power to the plasma generator 1 can be controlled by the output voltage of the power supply 8. Therefore, the electrode pitch will be explained from the viewpoint of the output voltage as well. That is, the electrode pitch can be determined so that the temperature of the plasma generator 1 is equal to or lower than the allowable temperature when the power supply 8 is outputting the maximum voltage (or rated voltage).

[0086] <Electrode pitch design based on plasma effects> In the above example, the plasma generator 1 is used to remove resist from the substrate W. Therefore, the electrode pitch may be determined with a focus on the resist removal process using the plasma generator 1. This will be specifically described below.

[0087] First, we will discuss the power to the plasma generator 1. As the power increases, the plasma generator 1 can generate plasma with a higher electron density. As the plasma electron density increases, the plasma emission intensity increases. This also increases the amount of activated species generated by the plasma. By increasing the activated species, more activated species can act on the processing liquid on the substrate W, thereby increasing the resist removal rate on the substrate W and more quickly achieving a resist stripping rate of 100%.

[0088] Figure 11 is a graph showing an example of the relationship between plasma emission intensity and power. In the example of Figure 11, three types of plot points are shown with different shapes. The first plot point is shown as a black circle and represents the relationship when the electrode pitch is 12 mm. The second plot point is shown as a black square and represents the relationship when the electrode pitch is 10 mm. The third plot point is shown as a black triangle and represents the relationship when the electrode pitch is 6 mm.

[0089] As can be seen from Figure 11, the plasma emission intensity increases as the power increases. In other words, the plasma emission intensity has a positive correlation with the power. On the other hand, the plasma emission intensity is almost independent of the electrode pitch. Therefore, if the power is the same, the plasma emission intensity when the electrode pitch is wide will be almost the same as when the electrode pitch is narrow.

[0090] The higher the emission intensity of the plasma, the greater the amount of activated species generated, and therefore the greater the effect of the plasma (hereinafter referred to as the plasma effect). Here, since the resist is removed from the substrate W, the resist stripping rate can be used as an index of the plasma effect.

[0091] The plasma effect has a positive correlation with the plasma emission intensity, which in turn has a positive correlation with the power, and the plasma effect also has a positive correlation with the power, whereas the plasma emission intensity is almost independent of the electrode pitch, so the plasma effect is also almost independent of the electrode pitch.

[0092] Furthermore, as described above, the temperature of the plasma generator 1 increases as the power increases, but decreases as the electrode pitch increases.

[0093] Based on the above findings, it can be seen that the plasma temperature rise can be mitigated by increasing the power to enhance the plasma effect (here, the stripping rate) while widening the electrode pitch. The table below shows an example of experimental results.

[0094] [Table 2]

[0095] According to Table 2, when the electrode pitch is 10 mm, the separation rate is 87% when the temperature of the plasma generator 1 is 420°C, and is 100% when the temperature is 500°C. On the other hand, when the electrode pitch is 12 mm, the separation rate is 100% when the temperature of the plasma generator 1 is 430°C. In other words, by setting the electrode pitch wider, the temperature of the plasma generator 1 can be reduced when the plasma generator 1 is supplied with power to achieve a separation rate of 100%.

[0096] Therefore, in designing the electrode pitch, a reference power may be set based on the plasma effect, and the electrode pitch may be determined based on this reference power. Specifically, in step S1, the designer may determine the reference power as the power at which the plasma effect (here, the stripping rate) is equal to or greater than a predetermined effect. This reference power is determined, for example, by experiment or simulation. Since the plasma effect has a positive correlation with the plasma emission intensity, the designer may also determine the reference power so that the plasma emission intensity is equal to or greater than a predetermined intensity.

[0097] As mentioned above, the plasma effect has a positive correlation with the power supplied to the plasma generator 1, but is almost independent of the electrode pitch. Therefore, even if the electrode pitch has not yet been determined, the reference power can be determined based on a predetermined plasma effect (plasma emission intensity) in step S1. Next, the designer performs steps S2 and S3. This allows the electrode pitch to be determined.

[0098] As described above, in this embodiment, the reference power for the power supplied to the plasma generator 1 is determined based on the plasma effect without using information about the electrode pitch. Then, in step S3, the electrode pitch is determined based on the reference power and the temperature tolerance. This design method was first conceived by noting that the plasma emission intensity is almost independent of the electrode pitch. In other words, if the plasma emission intensity also depends on the electrode pitch, the power cannot be determined independently of the electrode pitch in step S1. Therefore, it is difficult to determine the power and electrode pitch to achieve both the temperature and the plasma effect. For example, a complex method is required to optimize the plasma effect and temperature while changing the values ​​of the power and electrode pitch.

[0099] In contrast, in this embodiment, in step S1, the reference power is determined based on the plasma effect without using the electrode pitch value, and in step S3, the electrode pitch is determined based on the reference power and the temperature tolerance, so that the electrode pitch can be designed using a very simple method. Furthermore, with a plasma generator 1 designed in this way, even if power to obtain a predetermined plasma effect is supplied to the plasma generator 1, the temperature of the plasma generator 1 can be kept below the tolerance.

[0100] <Plasma Generator 1A> Fig. 12 is a plan view schematically showing an example of the configuration of plasma generator 1A, and Figs. 13 and 14 are side cross-sectional views schematically showing an example of the configuration of plasma generator 1A. Fig. 13 shows a CC cross section of Fig. 12, and Fig. 14 shows a DD cross section of Fig. 12. As shown in Figs. 12 to 14, plasma generator 1A includes a first electrode unit 21, a second electrode unit 22, and a dielectric member 35.

[0101] The dielectric member 35 is formed of a dielectric material such as quartz or ceramics and covers both the first electrode member 211 and the second electrode member 221. In the illustrated example, the dielectric member 35 has a plate-like shape and is disposed with its thickness direction aligned with direction D3. The dielectric member 35 has a first main surface 35a, a second main surface 35b, and a side surface 35c. The first main surface 35a and the second main surface 35b face each other in direction D3 and are, for example, flat surfaces perpendicular to direction D3. The side surface 35c connects the periphery of the first main surface 35a and the periphery of the second main surface 35b. In the example of FIG. 12, the dielectric member 35 has a disk shape, so the first main surface 35a and the second main surface 35b are circular flat surfaces, and the side surface 35c is a cylindrical surface. The thickness of the dielectric member 35 is, for example, approximately 5 mm.

[0102] The dielectric member 35 is formed with first holes 36 into which the first electrode members 211 are inserted and second holes 37 into which the second electrode members 221 are inserted.

[0103] Each first hole 36 extends along the longitudinal direction D1, and one end thereof opens in the side surface 35c of the dielectric member 35. Each first electrode member 211 is inserted into the first hole 36 along the longitudinal direction D1. Since the dielectric member 35 covers each first electrode member 211 in this manner, it is possible to prevent contamination of the substrate W caused by each first electrode member 211 being sputtered by plasma.

[0104] Each second hole 37 extends along the longitudinal direction D1, and the other end thereof opens at the side surface 35c of the dielectric member 35. Each second electrode member 221 is inserted into the second hole 37 along the longitudinal direction D1. Since the dielectric member 35 covers each second electrode member 221 in this manner, it is possible to prevent contamination of the substrate W caused by each second electrode member 221 being sputtered by plasma.

[0105] 14, the plurality of first electrode members 211 and the plurality of second electrode members 221 are provided on the same plane, and therefore the plurality of first holes 36 and the plurality of second holes 37 are also formed on the same plane.

[0106] In the example of FIG. 14 , the distance between the first electrode member 211 and the first main surface 35a of the dielectric member 35 is narrower than the distance between the first electrode member 211 and the second main surface 35b of the dielectric member 35. Similarly, the distance between the second electrode member 221 and the first main surface 35a of the dielectric member 35 is narrower than the distance between the second electrode member 221 and the second main surface 35b of the dielectric member 35. In other words, the first electrode member 211 and the second electrode member 221 are located closer to the first main surface 35a than to the second main surface 35b. Therefore, the first hole 36 and the second hole 37 are also located closer to the first main surface 35a than to the second main surface 35b. The distance between the first electrode member 211 and the first main surface 35a is set to, for example, approximately 0.3 mm, and the distance between the second electrode member 221 and the first main surface 35a is also set to, for example, approximately 0.3 mm.

[0107] The plasma generator 1A is disposed in a position where the first main surface 35a faces the processing object (here, the substrate W). The gas in the vicinity of the first main surface 35a is converted into plasma by the plasma generator 1A as described below, and activated species from the plasma act on the processing object.

[0108] 12, the first collection electrode 212 and the second collection electrode 222 are provided outside the dielectric member 35. Therefore, the base end of the first electrode member 211 protrudes outward from the side surface 35c of the dielectric member 35 and is connected to the first collection electrode 212, and the base end of the second electrode member 221 protrudes outward from the side surface 35c of the dielectric member 35 and is connected to the second collection electrode 222. The first collection electrode 212 and the second collection electrode 222 are connected to a plasma power supply 8 (see FIG. 12), and the voltage output of this power supply 8 generates an electric field for plasma between the first electrode member 211 and the second electrode member 221. In the above example, the gap between the first electrode member 211 and the first main surface 35a and the gap between the second electrode member 221 and the first main surface 35a are narrow, so that the electric field easily acts on the gas near the first main surface 35a of the dielectric member 35, and the gas can be easily converted into plasma.

[0109] On the other hand, in the above example, the distance between the first electrode member 211 and the second main surface 35b and the distance between the second electrode member 221 and the second main surface 35b are wide, so the electric field is less likely to act on the gas near the second main surface 35b. This makes it possible to suppress the generation of unnecessary plasma that does not contribute to the processing of the substrate W. Moreover, the thickness between the first main surface 35a and the second main surface 35b of the dielectric member 35 can be increased, so the strength and rigidity of the dielectric member 35 can be improved.

[0110] Incidentally, since the dielectric member 35 in the plasma generator 1A has a plate-like shape that covers both the first electrode member 211 and the second electrode member 221, the volume of the dielectric member 35 is larger than the total volume of the first dielectric member 31, the second dielectric member 32, and the dielectric member 33 of the plasma generator 1. Therefore, in order to generate plasma in the plasma generator 1A, the power supply 8 needs to supply a larger amount of power between the first electrode unit 21 and the second electrode unit 22. As a more specific example, the output voltage of the power supply 8 is set to about 15 kV, and the output frequency of the power supply 8 is set to about 60 kHz or less.

[0111] Furthermore, in the above example, the single dielectric member 35 covers the first electrode member 211 and the second electrode member 221, so the shape of the plasma generator 1A is simpler than that of the plasma generator 1. In particular, in the above example, the first main surface 35a of the dielectric member 35 is flat, so the shape is simpler than that of the plasma generator 1 in which a step shape is formed by the first dielectric member 31 and the dielectric member 33. Therefore, even if the processing liquid on the substrate W to be processed volatilizes and adheres to the plasma generator 1A (for example, the first main surface 35a), it is easy to remove the processing liquid by cleaning the plasma generator 1A.

[0112] <Temperature of plasma generator 1A> The inventors confirmed that in this plasma generator 1A, as in the plasma generator 1, the temperature depends not only on the power but also on the electrode pitch. Specifically, the inventors fabricated multiple plasma generators 1A with different electrode pitches and conducted experiments using each plasma generator 1A. Here, the inventors fabricated plasma generators 1A with electrode pitches of 10 mm and 12 mm, respectively, and controlled the output voltage of the power supply 8 so that the temperature of the plasma generator 1A would be 200 degrees Celsius. The table below shows the experimental results.

[0113] [Table 3]

[0114] As can be seen from Table 3, the wider the electrode pitch, the greater the power required to raise the temperature to 200 degrees Celsius. Conversely, if the power is the same, the narrower the electrode pitch, the higher the temperature will be.

[0115] Therefore, in the plasma generator 1A as well, the electrode pitch is set so that the temperature is below an allowable value (for example, 600 degrees Celsius). An example of the electrode pitch design method is the same as that shown in Fig. 10. In other words, the electrode pitch design method for the plasma generator 1 can also be applied to the plasma generator 1A.

[0116] The inventors also confirmed that the temperature rise of the plasma generator 1A can be mitigated by increasing the electrode pitch while increasing the power to enhance the plasma effect (here, the resist stripping rate), just as in the plasma generator 1. The table below shows an example of experimental results.

[0117] [Table 4]

[0118] According to Table 4, when the electrode pitch is 10 mm, the separation rate is 70% when the temperature of the plasma generator 1 is 200 degrees Celsius, and when the power is increased and the temperature reaches 250 degrees Celsius, the separation rate is 100%. In other words, the plasma effect can be increased by increasing the power. On the other hand, when the electrode pitch is 12 mm, the separation rate is 100% when the temperature of the plasma generator 1 reaches 200 degrees Celsius. In other words, by increasing the power and increasing the plasma effect, the rise in plasma temperature can be mitigated by setting a wide electrode pitch.

[0119] Furthermore, the shapes of the first electrode unit 21 and the second electrode unit 22 of the plasma generator 1A are the same as those of the plasma generator 1, and plasma is generated by the electric field between the first electrode unit 21 and the second electrode unit 22. Therefore, as with the plasma generator 1, it is presumed that the plasma emission intensity of the plasma generator 1A does not depend on the width or narrowness of the electrode pitch. Therefore, even in the plasma generator 1A, the reference power can be determined based on a predetermined plasma effect (plasma emission intensity, i.e., the stripping rate) before the electrode pitch has been determined (step S1). Next, the designer performs steps S2 and S3. This allows the electrode pitch to be determined using a very simple method.

[0120] As described above, in the plasma generator 1A as well, the electrode pitch can be determined in the same manner as in the plasma generator 1.

[0121] For reference, FIGS. 15 to 18 are shown here. FIGS. 15 to 18 are graphs that schematically show examples of experimental results for the plasma generation device 1A. Specifically, FIG. 15 is a graph showing the relationship between pulse width and temperature, FIG. 16 is a graph showing the relationship between pulse width and voltage, FIG. 17 is a graph showing the relationship between pulse width and current, and FIG. 18 is a graph showing the relationship between pulse width and instantaneous power. In each figure, graph G1 shows the graph when the electrode pitch is 12 mm, and graph G2 shows the graph when the electrode pitch is 10 mm.

[0122] In each diagram, the pulse width is used as the horizontal axis. The wider the pulse width, the longer the time that power is supplied to the plasma generator 1A, and so the power (input power) supplied to the plasma generator 1 tends to increase as the pulse width increases. As can be seen from FIG. 15, if the power is the same, the temperature of the plasma generator 1A decreases as the electrode pitch increases. Also, as can be seen from FIG. 15, if the power is the same, the voltage increases as the electrode pitch increases.

[0123] As described above, the plasma generator 1, 1A and the design method of the plasma generator 1, 1A have been described in detail, but the above description is merely an example in all aspects, and the plasma generator 1, 1A and the design method of the plasma generator 1, 1A are not limited thereto. It is understood that countless variations not exemplified can be envisioned without departing from the scope of this disclosure. The configurations described in the above embodiments and variations can be combined or omitted as appropriate as long as they are not mutually contradictory.

[0124] In the above example, the allowable temperature of the plasma generator 1, 1A is set from the viewpoint of the heat resistance of the material, but this is not necessarily limited to this. For example, when the plasma generator 1, 1A is located at the second processing position, the allowable temperature may be set to a temperature below the boiling point of the processing liquid, or the allowable temperature may be set based on the degree of thermal damage to the substrate W.

[0125] In the above example, the plasma generator 1 is provided with the dielectric member 33, but the dielectric member 33 does not have to be provided, and the first electrode portion 21 and the second electrode portion 22 may be provided on the same plane.

[0126] Furthermore, for example, in the plasma generation device 1A, the first electrode section 21 and the second electrode section 22 may be provided at different positions in the direction D3. Specifically, the first electrode member 211 and the second electrode member 221 may be provided at different positions in the direction D3.

[0127] Furthermore, the processing for the substrate W is not necessarily limited to resist removal processing. For example, the present invention can be applied to the removal of metal films and all other processing in which the processing performance of a processing liquid can be improved by using activated species.

[0128] Furthermore, it is not always necessary to supply a processing liquid to the substrate W. For example, as a plasma-based process, plasma or activated species may be applied directly to the upper surface of the substrate W. One example of such a process is a surface modification process of the substrate W. In this case, the contact angle of the liquid on the main surface of the substrate W when the liquid is supplied to the main surface can be used as an indicator of the plasma effect.

[0129] Furthermore, the plasma generating apparatus 1, 1A does not necessarily have to be used for processing the substrate W, but may be used for processing other objects. [Explanation of symbols]

[0130] 1,1A Plasma Generator 211 first electrode member 221 second electrode member 35 Dielectric materials 36 1st hole 37 2nd hole S1 process (power setting process) S2 process (allowable temperature setting process) S3 process (electrode pitch design process)

Claims

1. determining a temperature tolerance of a plasma generating device including a plurality of first electrode members each extending along a longitudinal direction and arranged side by side in an arrangement direction intersecting the longitudinal direction, and a plurality of second electrode members each arranged between the plurality of first electrode members in a plan view seen from a direction perpendicular to the arrangement direction and the longitudinal direction; determining a pitch between the plurality of first electrode members and the plurality of second electrode members to be narrower as the tolerance is higher; A method for designing a plasma generating device, comprising:

2. determining, as a reference power, an electric power to be supplied to a plasma generating device including a plurality of first electrode members each extending along a longitudinal direction and arranged side by side in an arrangement direction intersecting the longitudinal direction, and a plurality of second electrode members each arranged between the plurality of first electrode members in a plan view seen from a direction perpendicular to the arrangement direction and the longitudinal direction, so that the emission intensity of plasma generated by the plasma generating device is equal to or greater than a predetermined intensity; determining a pitch between the plurality of first electrode members and the plurality of second electrode members based on the reference power and an allowable temperature value of the plasma generating device; A method for designing a plasma generating device, comprising:

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