Substrate processing apparatus and substrate processing method

Abstract

To provide a technique capable of improving uniformity of processing relative to a substrate by enlarging a size of a plasma reactor.SOLUTION: A substrate processing device includes: a substrate holding unit 3; a plurality of guards 7; a plasma reactor 1; a first elevation mechanism 15; and a second elevation mechanism 75. The substrate holding unit 3 holds a substrate W. The plurality of guards 7 has a cylindrical shape of surrounding the substrate holding unit 3 and is concentrically provided. The plasma reactor 1 is provided vertically above the substrate holding unit 3 and extends outward from a peripheral edge of the substrate W in a plan view. The plasma reactor 1 radiates plasma to the substrate W in a state where the plurality of guards 7 is positioned at a lower position where an upper end 711 of an inner peripheral surface of an outermost circumference guard 7A is positioned vertically lower than an upper surface of the substrate W and the plasma reactor 1 is positioned at a plasma processing position close to the substrate W.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a substrate processing method.

Background Art

[0002] Conventionally, a substrate processing apparatus that irradiates a substrate with plasma has been proposed (for example, Patent Documents 1 and 2). In Patent Document 1, the substrate processing apparatus includes a spin chuck that rotates the substrate in a horizontal posture, a plasma nozzle that irradiates plasma onto the upper surface of the substrate, a processing liquid nozzle that discharges a processing liquid onto the upper surface of the substrate, a nozzle moving unit that moves each nozzle, a guard for receiving the processing liquid scattered from the periphery of the substrate, and a guard elevating unit that raises and lowers the guard.

[0003] In Patent Document 1, with the guard in an elevated state, the substrate processing apparatus discharges the processing liquid from the processing liquid nozzle onto the upper surface of the rotating substrate to form a liquid film of the processing liquid on the upper surface of the substrate. Then, the substrate processing apparatus reciprocates the plasma nozzle along the upper surface of the rotating substrate to irradiate the entire surface of the substrate with plasma. Thereby, the substrate can be dried while suppressing pattern collapse.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to appropriately irradiate a substrate with plasma, it is desirable to bring the plasma reactor closer to the substrate. This is because when the plasma reactor is away from the substrate, the plasma or active species disappear before reaching the substrate.

[0006] In order to irradiate the substrate with plasma more uniformly, it is desirable to arrange a flat plasma reactor so as to face the upper surface of the substrate. This is because such a flat plasma can irradiate the plasma over a wide range with respect to the upper surface of the substrate.

[0007] However, in a flat plasma reactor, it has been found that the temperature at the periphery is significantly lower than the temperature at the center. Therefore, even if a flat plasma reactor is designed to be sized such that the entire upper surface of the substrate can be irradiated with plasma, the temperature at the peripheral portion of the substrate may be significantly lower than the temperature at the central portion. In this case, due to the temperature difference, the degree of processing on the substrate may vary.

[0008] In order to solve this problem, if the size of the plasma reactor in plan view is further increased, the plasma reactor may interfere with the guard.

[0009] Therefore, an object of the present disclosure is to provide a technique capable of improving the uniformity of processing on a substrate by enlarging the size of a plasma reactor.

Means for Solving the Problem

[0010] A first aspect of the substrate processing apparatus includes a substrate holding unit that holds a substrate, a plurality of guards having a cylindrical shape surrounding the substrate holding unit and provided concentrically, and a plasma reactor provided vertically above the substrate holding unit and spreading outward beyond the periphery of the substrate held by the substrate holding unit in plan view, a first elevating mechanism that relatively raises and lowers the plasma reactor with respect to the substrate holding unit, and a second elevating mechanism that relatively raises and lowers the plurality of guards with respect to the substrate holding unit. In a processing state where the upper end of the inner peripheral surface of the outermost guard among the plurality of guards is positioned at a lower position vertically below the upper surface of the substrate and the plasma reactor is positioned at a plasma processing position close to the substrate, the plasma reactor irradiates the substrate with plasma.

[0011] A second aspect of the substrate processing apparatus is the substrate processing apparatus according to the first aspect, wherein in the processing state, the distance between the plasma reactor and the outermost guard is narrower than the distance between the outermost guard and the substrate holding unit.

[0012] A third aspect of the substrate processing apparatus is the substrate processing apparatus according to the second aspect, wherein in the processing state, the plasma reactor abuts against the guard in the vertical direction.

[0013] A fourth aspect of the substrate processing apparatus is the substrate processing apparatus according to the third aspect, wherein on at least one of the lower surface of the portion of the plasma reactor outside the periphery of the substrate and the upper surface of the outermost guard, an elastic seal member that adheres closely to the other is provided.

[0014] A fifth aspect of the substrate processing apparatus is the substrate processing apparatus according to the second aspect, wherein the lower surface of the portion of the plasma reactor outside the periphery of the substrate forms, together with the upper surface of the outermost guard in the processing state, a labyrinth structure having irregularities in the radial direction.

[0015] A sixth aspect of the substrate processing apparatus is the substrate processing apparatus according to any one of the first to fifth aspects, wherein the outer portion of the plasma reactor outside the periphery of the substrate has a ring shape protruding downward, the inner diameter of the outer portion is larger than the diameter of the substrate, and in the processing state, the lower surface of the outer portion is located below the upper surface of the substrate held by the substrate holding unit.

[0016] A seventh aspect of the substrate processing apparatus is the substrate processing apparatus according to the sixth aspect, wherein the inner diameter of the outer portion of the plasma reactor is equal to or less than the upper opening diameter of the outermost guard.

[0017] The eighth aspect of the substrate processing apparatus is the substrate processing apparatus according to the sixth or seventh aspect, wherein the substrate holding portion includes a spin base facing the substrate vertically below the substrate, and the inner diameter of the outer portion is larger than the diameter of the spin base.

[0018] The ninth aspect of the substrate processing apparatus is the substrate processing apparatus according to any one of the sixth to eighth aspects, wherein the plasma reactor includes an electrode assembly to which power for plasma is supplied, and the outer portion supports the electrode assembly from below.

[0019] The tenth aspect of the substrate processing apparatus is the substrate processing apparatus according to any one of the first to ninth aspects, further comprising a nozzle for supplying a processing liquid to the main surface of the substrate held by the substrate holding portion, wherein the substrate holding portion includes a rotation mechanism for rotating the substrate around a rotation axis along the vertical direction, and the nozzle discharges the processing liquid and the substrate holding portion rotates the substrate in a state where the second elevating mechanism relatively raises at least the outermost guard to an upper position with respect to the substrate holding portion, and the upper position is a position where the upper end is vertically above the upper surface of the substrate.

[0020] The first aspect of the substrate processing method includes a holding step of holding a substrate by a substrate holding portion, a lighting step of lighting a plasma reactor provided at a position facing the upper surface of the substrate held by the substrate holding portion and spreading outward of the substrate in a plan view, and a moving step of positioning the guard at a lower position where the upper end of the outermost guard among a plurality of concentrically provided guards having a cylindrical shape surrounding the substrate holding portion is lower than the substrate held by the substrate holding portion with respect to the substrate holding portion, and moving the plasma reactor to a plasma processing position close to the upper surface of the substrate.

[0021] A second aspect of the substrate processing method is the substrate processing method according to the first aspect, wherein the moving step includes a guard moving step of moving at least the outermost guard relative to the substrate holding portion to the lower position, and after the guard moving step, a plasma moving step of moving the plasma reactor relative to the substrate holding portion to the plasma processing position.

[0022] A third aspect of the substrate processing method is the substrate processing method according to the first aspect, wherein the moving step includes a guard moving step of moving at least the outermost guard relative to the substrate holding portion to the lower position, and in parallel with the guard moving step, a plasma moving step of moving the plasma reactor relative to the substrate holding portion to the plasma processing position.

Advantages of the Invention

[0023] According to the first aspect of the substrate processing apparatus and the first aspect of the substrate processing method, in the processing state, the guard can be positioned vertically below the plasma reactor. Therefore, the size of the plasma reactor in plan view can be designed large regardless of the guard. For this reason, the central portion of the plasma reactor with relatively uniform temperature can be opposed to the entire surface of the substrate, and the plasma reactor can irradiate the substrate with plasma, improving the uniformity of the processing on the substrate.

[0024] According to the second aspect of the substrate processing apparatus, the atmosphere between the plasma reactor and the substrate is more likely to pass through the gap between the guard and the substrate holding portion than through the gap between the plasma reactor and the guard, and is more likely to be exhausted to the outside through the exhaust portion. That is, it is possible to suppress the atmosphere from flowing out of the guard through the gap between the plasma reactor and the guard.

[0025] According to the third aspect of the substrate processing apparatus, it is possible to further suppress the atmosphere from flowing out of the guard.

[0026] According to the fourth aspect of the substrate processing apparatus, it is possible to further suppress the atmosphere from flowing out of the guard.

[0027] According to the fifth aspect of the substrate processing apparatus, while suppressing the outflow of the atmosphere to the outside of the guard, gas can be introduced into the guard through the gap between the plasma reactor and the outermost guard from the outside of the guard. Therefore, the atmosphere between the plasma reactor and the substrate can be replaced with a clean atmosphere.

[0028] According to the sixth aspect of the substrate processing apparatus, the outer portion can function as a guard.

[0029] According to the seventh aspect of the substrate processing apparatus, the atmosphere flowing vertically downward along the inner peripheral surface of the outer peripheral edge portion is less likely to collide with the upper surface of the guard and easily passes through the gap between the guard and the substrate holding portion.

[0030] According to the eighth aspect of the substrate processing apparatus, the atmosphere flowing vertically downward along the inner peripheral surface of the outer peripheral edge portion is less likely to collide with the upper surface of the spin base and easily passes through the gap between the guard and the substrate holding portion.

[0031] According to the ninth aspect of the substrate processing apparatus, the outer portion that supports the electrode assembly can function as a guard. Therefore, the manufacturing cost of the plasma reactor can be reduced compared to the case where a member that functions as a guard is separately provided in the plasma reactor.

[0032] According to the tenth aspect of the substrate processing apparatus, the processing liquid scattered from the periphery of the substrate can be received by the guard.

[0033] According to the second aspect of the substrate processing method, the collision between the plasma reactor and the guard can be suppressed.

[0034] According to the third aspect of the substrate processing method, the throughput can be improved.

Brief Description of the Drawings

[0035]

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Embodiments for Carrying Out the Invention

[0036] Hereinafter, embodiments will be described with reference to the accompanying drawings. Note that the components described in this embodiment are merely examples, and are not intended to limit the scope of the present disclosure only to them. In the drawings, for ease of understanding, the dimensions or numbers of each part may be exaggerated or simplified as necessary.

[0037] Expressions indicating relative or absolute positional relationships (such as "in one direction", "along one direction", "parallel", "orthogonal", "center", "concentric", "coaxial", etc.) represent not only strictly representing the positional relationship, but also a state in which the angle or distance is displaced within a range where the same degree of function can be obtained with tolerances, unless otherwise specified. Expressions indicating equal states (such as "identical", "equal", "homogeneous", etc.) represent not only strictly quantitatively equal states, but also states in which there are differences with tolerances or the same degree of function can be obtained, unless otherwise specified. Expressions indicating shapes (such as "quadrilateral shape" or "cylindrical shape") represent not only geometrically strictly representing the shape, but also shapes having, for example, unevenness or chamfers within a range where the same degree of effect can be obtained, unless otherwise specified. The expression of "comprising", "having", "including", or "possessing" one component is not an exclusive expression excluding the existence of other components. The expression "at least any one of A, B, and C" includes only A, only B, only C, any two of A, B, and C, and all of A, B, and C.

[0038] <First Embodiment> <Overall Configuration of Substrate Processing Apparatus> FIG. 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus 100. The substrate processing apparatus 100 is a single-wafer processing apparatus that processes one substrate W to be processed at a time.

[0039] The substrate W is, for example, a semiconductor substrate and has a disk shape. Note that in addition to a semiconductor substrate, various substrates such as a glass substrate for a photomask, a glass substrate for a liquid crystal display, a glass substrate for a plasma display, a substrate for a FED (Field Emission Display), a substrate for an optical disk, a substrate for a magnetic disk, and a substrate for a magneto-optical disk can be applied to the substrate W. Also, the shape of the substrate is not limited to a disk shape, and various shapes such as a rectangular plate shape can be adopted.

[0040] The substrate processing apparatus 100 includes a load port 101, an index robot 110, a main transfer robot 120, a plurality of processing units 130, and a control unit 90.

[0041] The plurality of load ports 101 are arranged side by side along a horizontal one direction. Each load port 101 is an interface unit for loading and unloading the substrate W into and out of the substrate processing apparatus 100. A carrier C, which is a substrate container for accommodating the substrate W, is carried into each load port 101 from the outside. Each load port 101 holds the carried-in carrier C.

[0042] The index robot 110 is a transfer robot that transfers the substrate W between the carrier C held by each load port 101 and the main transfer robot 120. The index robot 110 is movable along the direction in which the load ports 101 are arranged and can stop at a position facing each carrier C. The index robot 110 can perform an operation of taking out the substrate W from each carrier C and an operation of delivering the substrate W to each carrier C.

[0043] The main transfer robot 120 is a transfer robot that transfers the substrate W between the index robot 110 and each processing unit 130. The main transfer robot 120 can perform an operation of receiving the substrate W from the index robot 110 and an operation of delivering the substrate W to the index robot 110. Also, the main transfer robot 120 can perform an operation of loading the substrate W into each processing unit 130 and an operation of unloading the substrate W from each processing unit 130.

[0044] The substrate processing apparatus 100 is provided with, for example, 12 processing units 130. Specifically, four towers each including three vertically stacked processing units 130 are provided so as to surround the main transfer robot 120. In FIG. 1, one of the processing units 130 stacked in three stages is schematically shown. Note that the number of processing units 130 in the substrate processing apparatus 100 is not limited to 12 and may be changed as appropriate.

[0045] The main transfer robot 120 is provided so as to be surrounded by four towers. The main transfer robot 120 carries an unprocessed substrate W received from the index robot 110 into each processing unit 130. Each processing unit 130 processes the substrate W. Further, the main transfer robot 120 carries out the processed substrate W from each processing unit 130 and delivers it to the index robot 110.

[0046] The control unit 90 controls the operations of the respective components of the substrate processing apparatus 100. FIG. 2 is a functional block diagram schematically showing an example of the internal configuration of the control unit 90. The control unit 90 is an electronic circuit and has, 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 interconnected via a bus 93. The data processing unit 91 may be an arithmetic processing device such as a CPU (Central Processor Unit). The storage unit 92 may have a non-temporary storage unit (for example, ROM (Read Only Memory) or a hard disk) 921 and a temporary storage unit (for example, RAM (Random Access Memory)) 922. A program that defines the processes executed by the control unit 90 may be stored in the non-temporary storage unit 921. By the data processing unit 91 executing this program, the control unit 90 can execute the processes defined in the program. Of course, part or all of the processes executed by the control unit 90 may be executed by hardware.

[0047] <Processing Unit> FIG. 3 is a diagram schematically showing an example of the configuration of the processing unit 130. Note that not all the processing units 130 belonging to the substrate processing apparatus 100 need to have the configuration shown in FIG. 3, and it is sufficient if at least one processing unit 130 has the configuration.

[0048] The processing unit 130 illustrated in FIG. 3 is an apparatus that performs a process using plasma on a substrate W. The substrate W is, for example, a semiconductor substrate and has a disk shape. Although the size of the substrate W is not particularly limited, its diameter R1 is, for example, about 300 mm. Although the process using plasma does not need to be particularly limited, as a more specific example, it includes an organic matter removal process. The organic matter removal process is a process of removing organic matter on the main surface of the substrate W, and a resist can be applied as the organic matter. When the organic matter is a resist, the organic matter removal process can also be said to be a resist removal process.

[0049] The processing unit 130 includes a plasma reactor 1, a substrate holding unit 3, and a guard 7. In the example of FIG. 3, the processing unit 130 also includes a chamber 80. The chamber 80 forms a processing chamber for processing the substrate W and houses various components described later.

[0050] The substrate holding unit 3 is provided in the chamber 80 and holds the substrate W in a horizontal posture. The horizontal posture here means a posture in which the thickness direction of the substrate W is along the vertical direction. In the example of FIG. 3, the substrate holding unit 3 includes a spin base 31 and a plurality of chuck pins 32. The spin base 31 has a disk shape and is provided vertically below the substrate W. The spin base 31 is provided in a posture in which its thickness direction is along the vertical direction. The plurality of chuck pins 32 are erected on the upper surface of the spin base 31 and grip the periphery of the substrate W. Note that the substrate holding unit 3 does not necessarily need to have the chuck pins 32. For example, the substrate holding unit 3 may suck the lower surface of the substrate W to adsorb the substrate W.

[0051] In the example of FIG. 3, the substrate holding unit 3 further includes a rotation mechanism 33 that rotates the substrate W around the rotation axis Q1. The rotation axis Q1 passes through the central portion of the substrate W and is an axis along the vertical direction. The rotation mechanism 33 includes, for example, a shaft 34 and a motor 35. The upper end of the shaft 34 is connected to the lower surface of the spin base 31. The motor 35 rotates the shaft 34 around the rotation axis Q1 to rotate the spin base 31. Thereby, the substrate W held by the plurality of chuck pins 32 rotates around the rotation axis Q1. Such a substrate holding unit 3 may also be called a spin chuck. Hereinafter, the radial direction with respect to the rotation axis Q1 will simply be referred to as the radial direction.

[0052] In the example of FIG. 3, the processing unit 130 also includes a nozzle 4. The nozzle 4 is provided in the chamber 80 and is used for supplying the processing liquid to the substrate W. The nozzle 4 is connected to the processing liquid supply source 44 via the supply pipe 41. The processing liquid supply source 44 includes, for example, a tank (not shown) for storing the processing liquid. The processing liquid includes, for example, at least one chemical solution among sulfuric acid, sulfate, peroxymonosulfuric acid, and peroxymonosulfate. A valve 42 is interposed in the supply pipe 41. When the valve 42 is opened, the processing liquid from the processing liquid supply source 44 is supplied to the nozzle 4 through the supply pipe 41 and discharged from the discharge port 4a of the nozzle 4.

[0053] In the example of FIG. 3, the nozzle 4 is movably provided by a nozzle moving mechanism 45. The nozzle moving mechanism 45 moves the nozzle 4 between the nozzle processing position and the nozzle standby position. The nozzle processing position is a position where the nozzle 4 discharges the processing liquid toward the main surface (e.g., the upper surface) of the substrate W. The nozzle processing position is, for example, vertically above the substrate W and is a position facing the central portion of the substrate W in the vertical direction. The nozzle standby position is, for example, a position radially outside the periphery of the substrate W. In FIG. 3, the nozzle 4 stopped at the nozzle standby position is shown.

[0054] The nozzle movement mechanism 45 has, for example, a ball screw mechanism or an arm pivoting mechanism. The arm pivoting mechanisms all include an arm (not shown), a support column, and a motor. The arm has a rod-like shape extending horizontally, with the nozzle 4 connected to the tip of the arm and the base end of the arm connected to the support column. The support column extends along the vertical direction and is provided rotatably about its central axis. By rotating the support column with the motor, the arm pivots and the nozzle 4 moves along the circumferential direction about the central axis. The support column is provided such that a nozzle processing position and a nozzle standby position are located on the movement path of the nozzle 4.

[0055] When the valve 42 opens with the nozzle 4 positioned at the nozzle processing position, the processing liquid is discharged from the nozzle 4 toward the upper surface of the substrate W (see also FIG. 7). By rotating the substrate W with the substrate holding unit 3, the processing liquid spreads over the upper surface of the substrate W by centrifugal force and scatters outward from the periphery of the substrate W. Thereby, a liquid film F1 of the processing liquid is formed on the upper surface of the substrate W.

[0056] The nozzle 4 may sequentially discharge a plurality of types of processing liquids. In this case, the nozzle 4 may be connected to another processing liquid supply source (not shown) through a supply pipe (not shown) branched from the supply pipe 41. Alternatively, a plurality of nozzles 4 may be provided, and each nozzle 4 may be connected to a plurality of processing liquid supply sources. The nozzle movement mechanism 45 may move a plurality of nozzles 4 integrally or individually. As the processing liquid, for example, a rinse liquid such as pure water and isopropyl alcohol can be applied.

[0057] The guard 7 is provided in the chamber 80 and has a cylindrical shape for surrounding the substrate holding unit 3 and the substrate W held by the substrate holding unit 3. The guard 7 is provided to receive the processing liquid scattered from the periphery of the substrate W.

[0058] In the example of FIG. 3, each of the guards 7 includes a cylindrical portion 71, an inclined portion 72, and an upper end portion 73 that surround the substrate holding portion 3. The inclined portion 72 is inclined so as to approach the rotation axis Q1 as it goes vertically upward. That is, the inner diameter and the outer diameter of the inclined portion 72 become smaller as it goes vertically upward. The upper end of the cylindrical portion 71 is continuous with the lower end of the inclined portion 72, and the cylindrical portion 71 extends along the vertical direction. In the example of FIG. 3, the upper end of the inclined portion 72 is continuous with the outer peripheral edge of the upper end portion 73. The upper end portion 73 has a ring-shaped plate-like shape that extends horizontally. In the example of FIG. 3, the upper surface and the lower surface of the upper end portion 73 are parallel to the horizontal plane. The inner peripheral edge of the upper end portion 73 forms the upper opening of the guard 7.

[0059] In the example of FIG. 3, the processing unit 130 includes a plurality of guards 7. The plurality of guards 7 are provided concentrically and all surround the substrate holding portion 3. In the example of FIG. 3, two guards 7 are provided. Hereinafter, the outermost guard 7 is referred to as guard 7A, and the innermost guard 7 is also referred to as guard 7B.

[0060] The guard 7 is provided so as to be movable up and down by a guard elevating mechanism 75 (corresponding to the second elevating mechanism). The guard elevating mechanism 75 moves the guard 7 up and down between the upper position and the guard standby position. The upper position is the position where the guard 7 receives the processing liquid. Specifically, it is the position where the upper end 711 of the inner peripheral surface of the guard 7 is vertically above the upper surface of the substrate W. The guard standby position is, for example, the position where the upper surface of the upper end portion 73 of the guard 7 is vertically below the upper surface of the spin base 31. In the example of FIG. 3, the guard 7 stopped at the guard standby position is shown. The guard elevating mechanism 75 may include, for example, a ball screw mechanism and a motor that applies a driving force to the ball screw mechanism, or may include an air cylinder. When a plurality of guards 7 are provided, the guard elevating mechanism 75 moves the guards 7 up and down individually.

[0061] When the guard lifting mechanism 75 raises the guards 7A and 7B to the upper position, the processing liquid scattered from the periphery of the substrate W is received by the inner peripheral surface of the guard 7B and flows down along the inner peripheral surface of the guard 7B. The processing liquid flowing down along the inner peripheral surface of the guard 7B is received by the cup 76. The processing liquid is recovered, for example, into a tank of the same type of processing liquid supply source through the recovery pipe 77 connected to the cup 76.

[0062] When the guard lifting mechanism 75 lowers the guard 7B to the guard standby position and raises the guard 7A to the upper position, the processing liquid scattered from the periphery of the substrate W is received by the inner peripheral surface of the guard 7A and flows down along the inner peripheral surface of the guard 7A. The processing liquid flowing down along the inner peripheral surface of the guard 7A is received by a cup (not shown). The processing liquid is recovered, for example, into a tank of the same type of processing liquid supply source through a recovery pipe (not shown) connected to the cup.

[0063] As described above, by providing the plurality of guards 7, the processing liquid can be recovered according to its type.

[0064] The plasma reactor 1 is a plasma generating device that generates plasma, and is provided at a position facing the upper surface of the substrate W held by the substrate holding portion 3 in the vertical direction within the chamber 80. The plasma reactor 1 is connected to the plasma power supply 16 and plasmatizes the surrounding gas by receiving power from the power supply 16. Here, as an example, the plasma reactor 1 generates plasma under atmospheric pressure. The atmospheric pressure here is, for example, 80% or more and 120% or less of the standard atmospheric pressure.

[0065] The plasma reactor 1 is a flat plasma reactor having a flat shape. The plasma reactor 1 extends radially outward beyond the peripheral edge of the substrate W in a plan view. The outer peripheral edge of the plasma reactor 1 has, for example, a circular shape in a plan view, and its outer diameter R2 is larger than the diameter R1 of the substrate W. In the example of FIG. 3, the outer diameter R2 of the plasma reactor 1 is larger than the inner diameter (corresponding to the upper opening diameter) R3 of the upper end portion 73 of the guard 7. According to this structure, the portion of the plasma reactor 1 outside the peripheral edge of the substrate W faces the upper end portion 73 of the guard 7 in the vertical direction. An example of the specific internal configuration of the plasma reactor 1 will be described in detail later.

[0066] The plasma reactor 1 is provided so as to be movable up and down by a plasma lifting mechanism 15 (corresponding to a first lifting mechanism). The plasma lifting mechanism 15 moves the plasma reactor 1 up and down between a plasma processing position and a plasma standby position. The plasma processing position is the position when processing the substrate W using the plasma from the plasma reactor 1. At the plasma processing position, the distance between the plasma reactor 1 and the upper surface of the substrate W is, for example, about several millimeters (specifically, about 2 mm). The plasma standby position is the position when no processing using plasma is performed on the substrate W, and is a position vertically above the plasma processing position. In FIG. 3, the plasma reactor 1 stopped at the plasma standby position is shown. The plasma lifting mechanism 15 may include, for example, a ball screw mechanism and a motor that applies a driving force to the ball screw mechanism, or may include an air cylinder.

[0067] The plasma reactor 1 can move from the plasma standby position to the plasma processing position in a state where the nozzle 4 is retracted to the nozzle standby position and all the guards 7 are lowered to, for example, the guard standby position. The plasma reactor 1 moves to the plasma processing position, for example, in a state where a liquid film F1 of a processing liquid is formed on the upper surface of the substrate W (see also FIG. 9).

[0068] The plasma reactor 1 irradiates the upper surface of the substrate W with plasma in a processing state where the guard 7 is in the lower position (for example, the guard standby position) and the plasma reactor 1 is in the plasma processing position. When the plasma reactor 1 generates plasma, various active species are generated. For example, when air is plasmaized, 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 (here sulfuric acid) on the upper surface of the substrate W. Thereby, the processing performance of the processing liquid is enhanced. Specifically, by the reaction of the active species and sulfuric acid, caroic acid with high processing performance (here oxidation power) is generated. Caroic acid is also called peroxymonosulfuric acid. When the caroic acid acts on the resist of the substrate W, the resist can be oxidized and removed.

[0069] By the way, due to the generation of plasma, the temperature around the plasma reactor 1 becomes high. For example, the temperature reaches about 100 degrees Celsius, and more specifically, from 200 degrees Celsius to 350 degrees Celsius. As a result, the processing liquid on the upper surface of the substrate W is likely to evaporate, and the atmosphere immediately above the substrate W contains a large amount of volatile components of the processing liquid. When such a processing liquid atmosphere diffuses into the chamber 80, the volatile components of the processing liquid may adhere to the members in the chamber 80 and cause problems. Therefore, in order to suppress the diffusion of such a processing liquid atmosphere, the processing unit 130 is provided with an air supply unit 81 and an exhaust unit 82.

[0070] In the example of FIG. 3, the air supply unit 81 is provided on the ceiling of the chamber 80. The air supply unit 81 inhales gas (for example, air) from the outside of the chamber 80, removes impurities of the gas with a filter, and supplies the gas after removal to the inside of the chamber 80. Thereby, a so-called downflow is formed in the chamber 80. The air supply unit 81 is, for example, a fan filter unit.

[0071] In the example of FIG. 3, the exhaust portion 82 includes a cylindrical member 83 and an exhaust pipe 84. The cylindrical member 83 is provided in the chamber 80. The cylindrical member 83 has a cylindrical shape and surrounds the guard 7 from the outer peripheral side of the outermost periphery guard 7. The cylindrical member 83 is provided on the floor surface of the chamber 80. The upstream end of the exhaust pipe 84 is connected to the lower portion of the cylindrical member 83, and the downstream end of the exhaust pipe 84 is connected to a suction mechanism (not shown). The processing liquid atmosphere above the substrate W flows into the upstream end of the exhaust pipe 84 through the inside of the guard 7 and is discharged to the outside of the chamber 80 through the exhaust pipe 84. In FIG. 3, the flow of this air current is schematically shown by the dashed arrow.

[0072] Next, a specific example of the configuration of the plasma reactor 1 will be described. FIG. 4 is a cross-sectional view schematically showing an example of the configuration of the plasma reactor 1, and FIG. 5 is a plan view schematically showing an example of the configuration of the plasma reactor 1. In the examples of FIGS. 4 and 5, the plasma reactor 1 includes an electrode assembly 10 and a holding member 20.

[0073] In the examples of FIGS. 4 and 5, the electrode assembly 10 includes a first electrode portion 11 and a second electrode portion 12. The first electrode portion 11 has a comb shape including a plurality of first linear electrodes 111 and a first collective electrode 112. The second electrode portion 12 also has a comb shape including a plurality of second linear electrodes 121 and a second collective electrode 122.

[0074] The first linear electrode 111 and the second linear electrode 121 are formed of a conductive material such as a metal material (e.g., tungsten), and have a rod shape (e.g., a cylindrical shape) extending along a horizontal longitudinal direction. In the example of FIG. 5, in a plan view, the first linear electrode 111 and the second linear electrode 121 are provided parallel to each other, and are alternately arranged in an arrangement direction perpendicular to the longitudinal direction and horizontal. The first collective electrode 112 connects the ends (base ends) on one side in the longitudinal direction of the plurality of first linear electrodes 111 to each other. The second collective electrode 122 connects the ends (base ends) on the other side in the longitudinal direction of the plurality of second linear electrodes 121 to each other. In the example of FIG. 5, the first collective electrode 112 and the second collective electrode 122 have a flat plate shape in the form of arcs of substantially the same diameter that curve toward opposite sides. The first collective electrode 112 and the second collective electrode 122 are formed of a conductive material such as a metal material (e.g., aluminum).

[0075] In the examples of FIGS. 4 and 5, each first linear electrode 111 is covered by a first dielectric 13, and each second linear electrode 121 is covered by a second dielectric 14. The first dielectric 13 and the second dielectric 14 are formed of a dielectric material such as quartz and ceramics. Each of the first dielectric 13 and the second dielectric 14 has, for example, a cylindrical shape extending along the longitudinal direction. The first linear electrode 111 is inserted into the first dielectric 13 along the longitudinal direction, and the second linear electrode 121 is inserted into the second dielectric 14 along the longitudinal direction. Thereby, it is possible to suppress the first linear electrode 111 and the second linear electrode 121 from being sputtered by plasma. As a result, contamination of the substrate W due to sputtered particles can be suppressed.

[0076] In the examples of FIGS. 4 and 5, the plasma reactor 1 is provided with a partition member 17. The partition member 17 is formed of a dielectric material such as quartz and ceramics. The partition member 17 has, for example, a disc shape, and is provided in a posture in which its thickness direction is along the vertical direction. The first linear electrode 111 and the first dielectric 13 are provided on the upper surface of the partition member 17, and the second linear electrode 121 and the second dielectric 14 are provided on the lower surface of the partition member 17.

[0077] The holding member 20 is formed of an insulating material such as a fluororesin, and integrally holds the first electrode portion 11, the second electrode portion 12, the first dielectric 13, the second dielectric 14, and the partition member 17. For example, the holding member 20 has a ring shape centered on the rotation axis Q1 in a plan view. In the example of FIG. 4, the holding member 20 includes an upper member 21 and a lower member 22 that are connected to each other. The upper member 21 and the lower member 22 sandwich at least each of the first collective electrode 112 and the second collective electrode 122 from opposite sides in the vertical direction. The lower member 22 contacts and supports the lower surfaces of at least each of the first collective electrode 112 and the second collective electrode 122.

[0078] In such a plasma reactor 1, the holding member 20 protrudes vertically above and below the electrode assembly 10. That is, the ring-shaped upper member 21 protrudes vertically above the electrode assembly 10, and the ring-shaped lower member 22 protrudes below the electrode assembly 10. The inner peripheral surface 23 of the ring-shaped lower member 22 is, for example, a cylindrical surface centered on the rotation axis Q1. In the example of FIG. 4, the inner peripheral surface 23 of the lower member 22 is located radially outside the periphery of the substrate W. That is, the inner diameter R21 of the lower member 22 is larger than the diameter R1 of the substrate W. In the example of FIG. 4, the lower surface 24 of the lower member 22 is parallel to the horizontal plane.

[0079] The first electrode portion 11 and the second electrode portion 12 are electrically connected to the plasma power source 16. The power source 16 has, for example, a switching power supply circuit (not shown), and outputs a plasma voltage between the first electrode portion 11 and the second electrode portion 12. As a specific example, the power source 16 outputs a high-frequency voltage as the plasma voltage. Thereby, an electric field for plasma is generated between the first linear electrode 111 and the second linear electrode 121. In response to the electric field, the gas around the first linear electrode 111 and the second linear electrode 121 is turned into plasma (so-called dielectric barrier discharge).

[0080] In the example of FIG. 4, the proximal end and the distal end of the first linear electrode 111 are located radially outside the periphery of the substrate W, and the proximal end and the distal end of the second linear electrode 121 are located radially outside the periphery of the substrate W. The same may apply to all the first linear electrodes 111 and all the second linear electrodes 121. According to this structure, the plasma reactor 1 can generate plasma in a two-dimensional range wider than the upper surface of the substrate W in a plan view, and can act on the active species more uniformly on the upper surface of the substrate W.

[0081] <Operation Example of Substrate Processing Apparatus> Next, an example of the operation of the processing unit 130 will be described. FIG. 6 is a flowchart showing an example of the operation of the processing unit 130. First, the substrate holding unit 3 holds the substrate W (step S1: holding step). Specifically, the main transfer robot 120 passes the unprocessed substrate W to the substrate holding unit 3, and the substrate holding unit 3 holds the substrate W.

[0082] Next, the processing unit 130 forms a liquid film F1 of the processing liquid on the upper surface of the substrate W (step S2: liquid film forming step). FIG. 7 is a diagram schematically showing an example of the state of the processing unit 130 in the liquid film forming step. As illustrated in FIG. 7, the nozzle moving mechanism 45 moves the nozzle 4 to the nozzle processing position, and the guard lifting mechanism 75 raises the guard 7 to the upper position. In the example of FIG. 7, both the guard 7A and the guard 7B are located at the upper position. Then, the substrate holding unit 3 rotates the substrate W around the rotation axis Q1, and the valve 42 opens. Thereby, the processing liquid is supplied from the discharge port 4a of the nozzle 4 toward the upper surface of the rotating substrate W. Here, sulfuric acid is supplied as the processing liquid. The processing liquid adhering to the upper surface of the substrate W spreads on the upper surface of the substrate W. Thereby, the liquid film F1 of the processing liquid is formed on the upper surface of the substrate W. Note that the processing liquid scattered from the periphery of the substrate W is received by the inner peripheral surface of the guard 7B.

[0083] When the liquid film F1 of the processing liquid is formed, the valve 42 closes to stop the supply of the processing liquid, and the nozzle moving mechanism 45 moves the nozzle 4 to the nozzle standby position. Further, the substrate holding unit 3 reduces the rotation speed of the substrate W. More specifically, the substrate holding unit 3 reduces the rotation speed to a speed at which the liquid film F1 on the upper surface of the substrate W can be maintained (for example, 40 rpm or less) (so-called paddle processing). The rotation speed of the substrate W may be zero. The film thickness of the liquid film F1 is, for example, 0.1 mm or more and 2.0 mm or less, and preferably about 0.2 mm. In other words, the discharge amount of the processing liquid and the rotation speed of the substrate W in the liquid film forming step are adjusted so that the film thickness of the liquid film F1 becomes this target value.

[0084] Next, the processing unit 130 performs plasma processing on the substrate W (step S3: plasma processing step). FIG. 8 is a flowchart showing a specific example of the plasma processing step, and FIG. 9 is a diagram schematically showing an example of the state of the processing unit 130 in the plasma processing step.

[0085] In the example of FIG. 8, first, the guard lifting mechanism 75 lowers the guard 7 to the lower position (step S31: guard movement step). The lower position here is a position where the upper end 711 of the inner peripheral surface of the outermost guard 7A is vertically below the upper surface of the substrate W held by the substrate holding unit 3. As a specific example of the lower position, a position where the upper end 711 of the guard 7A is vertically below the lower surface of the substrate W may be adopted, a position where the upper end 711 of the guard 7A is below the upper surface of the spin base 31 may be adopted, or the guard standby position may be adopted. Here, the guard standby position is adopted as the lower position. That is, the guard lifting mechanism 75 lowers the guards 7A and 7B to the guard standby position.

[0086] Next, the power supply 16 outputs a plasma voltage to the plasma reactor 1 (step S32: lighting step). Thereby, plasma is generated around the plasma reactor 1. Note that the lighting step may be executed before the guard movement step.

[0087] Next, the plasma lifting mechanism 15 lowers the plasma reactor 1 from the plasma standby position to the plasma processing position (step S33: plasma movement step). In a state where the plasma reactor 1 is positioned at the plasma processing position, the plasma reactor 1 can irradiate the substrate W with plasma (step S34: plasma irradiation step). In other words, the plasma processing position is a position close to the substrate W to such an extent that the substrate W can be irradiated with plasma.

[0088] FIG. 9 shows the state of the processing unit 130 in the plasma irradiation step. In the example of FIG. 9, the plasma reactor 1 is positioned at the plasma processing position, and irradiates the liquid film F1 on the upper surface of the substrate W with plasma to supply active species to the liquid film F1. Thereby, the processing performance of the processing liquid is improved, and the processing liquid acts on the substrate W with high processing performance. More specifically, oxygen radicals react with sulfuric acid to generate caroic acid, and the caroic acid removes the resist on the substrate W.

[0089] In this plasma irradiation step, the substrate holding unit 3 may rotate the substrate W at a low speed (for example, 40 rpm or less), or may stop the rotation of the substrate W. When the substrate W rotates, the active species act more uniformly on the substrate W, so that the uniformity of the processing on the substrate W can be improved.

[0090] Then, when the resist on the substrate W is sufficiently removed, the plasma lifting mechanism 15 raises the plasma reactor 1 to the plasma standby position, and the power supply 16 stops the voltage output (step S35).

[0091] Next, the processing unit 130 performs a rinse process on the upper surface of the substrate W (step S4: rinse step). Specifically, the processing unit 130 supplies a rinse liquid from the nozzle 4 to the upper surface of the rotating substrate W, and replaces the processing liquid on the upper surface of the substrate W with the rinse liquid.

[0092] Next, the processing unit 130 performs a drying process on the substrate W (step S5: drying step). For example, the substrate holding unit 3 rotates the substrate W at a rotational speed higher than that in the plasma processing step to dry the substrate W (so-called spin drying). Next, the main transfer robot 120 unloads the processed substrate W from the processing unit 130.

[0093] <Effects of the Embodiment> As described above, in the present embodiment, in the plasma processing step, the guard 7 stops at the lower position where its upper end 711 is below the lower surface of the substrate W, and the plasma reactor 1 stops at the plasma processing position (see FIG. 9). That is, the upper end of the guard 7A is at a lower position compared to the case where the guard 7 is in the upper position. Therefore, even if the size of the plasma reactor 1 in plan view is increased, the plasma reactor 1 can descend to a plasma processing position closer to the substrate W without physically interfering with the guard 7. That is, by lowering the guard 7A located below the plasma reactor 1 to a lower position, the plasma reactor 1 can also be lowered further downward.

[0094] Here, the temperature distribution of the plasma reactor 1 will be described. When the plasma reactor 1 generates plasma, the temperature rises due to the generation of plasma. FIG. 10 is a graph showing an example of the spatial temperature distribution around the plasma reactor 1. The horizontal axis indicates the radial distance from the center of the plasma reactor 1 (i.e., the rotation axis Q1), and the vertical axis indicates the temperature at a position 10 mm vertically below the plasma reactor 1.

[0095] In the example of FIG. 10, the plasma generation region where plasma is generated is also shown. As can be understood from FIG. 10, in the region between the center of the plasma reactor 1 and the intermediate position about 130 mm radially away from the center, although the temperature gradually decreases as the distance from the center increases, the amount of decrease is relatively small. On the other hand, in the region between the intermediate position and the peripheral position of the plasma generation region (the position where the distance is about 150 mm), the temperature decreases more steeply as the distance from the center increases. That is, the temperature at the periphery of the plasma generation region becomes significantly lower than the temperature at the center of the plasma generation region.

[0096] And since the plasma reactor 1 approaches the substrate W in the plasma irradiation process, the temperature distribution on the upper surface of the substrate W is affected by the temperature distribution of the plasma reactor 1. Therefore, when the size of the plasma reactor 1 in plan view is about the same as that of the substrate W, even if the entire upper surface of the substrate W can be irradiated with plasma, the temperature at the periphery of the substrate W becomes lower than the temperature at the central portion. For this reason, a difference in the degree of processing occurs between the central portion and the peripheral portion of the substrate W.

[0097] In contrast, in the present embodiment, in the plasma irradiation process, since the guard 7 is located vertically below the plasma reactor 1, the outer diameter R2 and the inner diameter R21 of the plasma reactor 1 can be designed independently of the inner diameter R3 of the guard 7. Therefore, the size of the plasma reactor 1 can be increased to make the plasma generation region wider. Specifically, the size of the plasma reactor 1 can be designed such that a region with a more uniform temperature distribution faces the entire upper surface of the substrate W. According to this structure, the temperature distribution on the upper surface of the substrate W can be made more uniform, and the uniformity of the processing on the substrate W can be improved.

[0098] <Gap between the plasma reactor 1 and the guard 7> In the example of FIG. 9, in the plasma processing step, since the guard 7 is stopped at the guard standby position, a relatively wide gap is formed between the lower member 22 of the plasma reactor 1 and the upper end portion 73 of the guard 7A.

[0099] Now, when the plasma reactor 1 generates plasma, as described above, the surrounding temperature rises to several hundred degrees Celsius, so the processing liquid on the substrate W is likely to evaporate. Therefore, the atmosphere between the substrate W and the plasma reactor 1 contains a large amount of volatile components of the processing liquid.

[0100] In the present embodiment, although the air supply section 81 and the exhaust section 82 (see FIG. 3) are provided, the wider the gap between the plasma reactor 1 and the guard 7, the more the processing liquid atmosphere can flow out of the guard 7 through the gap. In the example of FIG. 9, a part of the possible flow of the processing liquid atmosphere is schematically shown by the dashed arrow. The possibility of the outflow of this processing liquid atmosphere outside the guard 7 increases as the rotation speed of the substrate W in the plasma processing step increases.

[0101] Therefore, in order to suppress such outflow, in the plasma processing step, the guard lifting mechanism 75 may position the guard 7A at a guard intermediate position higher than the guard standby position. FIG. 11 is a diagram schematically showing an example of the state of the processing unit 130 in the plasma processing step, and FIG. 12 is an enlarged view showing a part (specifically, the region surrounded by the dashed line) of the processing unit 130 of FIG. 11 in an enlarged manner.

[0102] In the examples of FIGS. 11 and 12, the plasma reactor 1 stops at the plasma processing position, and the guard 7A stops at the guard intermediate position. The guard intermediate position is a position where the distance D1 between the plasma reactor 1 located at the plasma processing position and the outermost guard 7A is narrower than the distance D2 between the guard 7A and the substrate holding portion 3. In the example of FIG. 12, the distance D1 is the distance between the lower surface 24 of the lower member 22 of the plasma reactor 1 and the upper surface of the upper end portion 73 of the guard 7A, and the distance D2 is the distance between the inner peripheral edge of the upper end portion 73 of the guard 7A and the side surface of the spin base 31. Even when the guard 7A stops at the guard intermediate position, the upper end 711 of the inner peripheral surface of the guard 7A is located below the upper surface of the substrate W, so the guard intermediate position is also included in the concept of the lower position.

[0103] If the guard 7A stops at the intermediate position of the guard, the interval D1 becomes narrower than the interval D2, so the processing liquid atmosphere flows more easily through the gap between the guard 7A and the substrate holding part 3 than through the gap between the plasma reactor 1 and the guard 7A. According to this, it is possible to suppress the outflow of the processing liquid atmosphere outside the guard 7 and its diffusion into the chamber 80.

[0104] Also, when the substrate holding part 3 rotates the substrate W in the plasma processing step, the processing liquid may scatter from the peripheral edge of the substrate W. If the interval D1 is less than or equal to the interval D2, this processing liquid also hardly passes through the gap between the plasma reactor 1 and the guard 7 and easily flows down through the gap between the guard 7 and the substrate holding part 3. Therefore, it is possible to suppress the outflow of the processing liquid outside the guard 7.

[0105] Also, when the interval D1 becomes narrower, the negative pressure inside the guard 7 is strengthened by the exhaust by the exhaust part 82. For this reason, the flow velocity of the air flow passing radially inward through the gap between the plasma reactor 1 and the guard 7 from the outside of the guard 7 increases. Due to this air flow, it becomes difficult for the processing liquid atmosphere and the processing liquid to pass radially outward through the gap between the plasma reactor 1 and the guard 7, and the outflow of the processing liquid atmosphere and the processing liquid outside the guard 7 is further suppressed.

[0106] <Outer part of the plasma reactor> In the above example, the lower member 22 (corresponding to the outer part) located outside the peripheral edge of the substrate W in the plasma reactor 1 has a ring shape and protrudes vertically downward from the electrode assembly 10. The lower surface 24 of this lower member 22 is located vertically below the upper surface of the substrate W in the plasma processing step (see FIGS. 9, 11, and 12). That is, in the processing state where the plasma reactor 1 is located at the plasma processing position, the lower surface 24 of the lower member 22 is located vertically below the lower surface of the substrate W. In this case, the inner peripheral surface 23 of the lower member 22 can surround the space above the substrate W. Therefore, the lower member 22 can function substantially as a part of the guard.

[0107] Specifically, when the processing liquid atmosphere between the plasma reactor 1 and the substrate W flows radially outward, it collides with the inner peripheral surface 23 of the lower member 22 and flows vertically downward along the inner peripheral surface 23. Further, even if the processing liquid scatters radially outward from the peripheral edge of the substrate W, the processing liquid collides with the inner peripheral surface 23 of the lower member 22 and also flows vertically downward along the inner peripheral surface 23. In the example of FIG. 12, the flow of the processing liquid atmosphere and the processing liquid is schematically indicated by arrows of a two-dot chain line.

[0108] According to this structure, since it is difficult for the processing liquid atmosphere and the processing liquid to pass through the gap between the plasma reactor 1 and the guard 7 radially outward, it is possible to suppress the processing liquid atmosphere and the processing liquid that flow out of the guard 7.

[0109] As illustrated in FIG. 12, the lower end peripheral edge 231 of the inner peripheral surface 23 of the lower member 22 may be located radially inward of the inner peripheral edge of the upper end portion 73 of the guard 7. In other words, the inner diameter R21 of the lower member 22 is smaller than the inner diameter R3 of the guard 7. According to this structure, the processing liquid atmosphere and the processing liquid that flow vertically downward along the inner peripheral surface 23 of the lower member 22 can pass through the gap between the guard 7 and the substrate holding portion 3 with little collision with the upper surface of the guard 7. Therefore, it is possible to further suppress the outflow of the processing liquid atmosphere and the processing liquid outside the guard 7.

[0110] Further, as illustrated in FIG. 12, the lower end peripheral edge 231 of the inner peripheral surface 23 of the lower member 22 may be located radially outward of the peripheral edge of the substrate holding portion 3 (that is, the side surface of the spin base 31). In other words, the inner diameter R21 of the lower member 22 is larger than the diameter R4 of the spin base 31. According to this structure, the processing liquid atmosphere and the processing liquid that flow vertically downward along the inner peripheral surface 23 of the lower member 22 are less likely to collide with the upper surface of the spin base 31.

[0111] Since the spin base 31 rotates around the rotation axis Q1, if the processing liquid atmosphere and the processing liquid collide with the upper surface of the spin base 31, they may flow radially outward again under the influence of centrifugal force. As a result, the possibility of the processing liquid atmosphere and the processing liquid flowing out of the guard increases.

[0112] On the other hand, if the inner diameter R21 of the lower member 22 is larger than the diameter R4 of the spin base 31, the processing liquid atmosphere and the processing liquid that collide with the spin base 31 can be reduced, so that the outflow of the processing liquid atmosphere and the processing liquid to the outside of the guard 7 can be further suppressed.

[0113] Moreover, the lower member 22 that supports the electrode assembly 10 from below can function as a guard. Therefore, the manufacturing cost of the plasma reactor 1 can be reduced as compared with the case where a member that functions as a guard is separately provided in the plasma reactor 1.

[0114] <Guard 7A and Guard 7B> In the examples of FIGS. 11 and 12, in the plasma processing step, the guard lifting mechanism 75 raises not only the outermost guard 7A but also the other guards 7B to a position higher than the guard standby position. According to this, the distance between the guard 7A and the guard 7B becomes narrow, so that the possibility of the processing liquid flowing into the space between the guard 7A and the guard 7B can be reduced, and more processing liquid can flow down to the cup 76. For this reason, more processing liquid can be appropriately recovered.

[0115] <Moving Timing of Plasma Reactor and Guard> In the example of FIG. 8, the plasma movement step (step S33) is performed after the guard movement step (step S31). That is, after the guard 7 stops at the lower position, the plasma lifting mechanism 15 starts to lower the plasma reactor 1. According to this, it is possible to more surely avoid the plasma reactor 1 and the guard 7 from colliding at a high speed.

[0116] On the other hand, the plasma movement process may be performed in parallel with the guard movement process. In short, the descending speeds and descending timings of the plasma reactor 1 and the guard 7 only need to be adjusted so that the plasma reactor 1 does not collide with the guard 7 at a high speed. For example, the plasma lifting mechanism 15 may lower the plasma reactor 1 so that the plasma reactor 1 arrives at the plasma processing position after the guard 7 arrives at the lower position.

[0117] When the plasma movement process and the guard movement process are performed in parallel, the throughput of the process can be improved.

[0118] <Guard intermediate position> In the above example, in the plasma processing step, the plasma reactor 1 and the outermost guard 7A are separated from each other in the vertical direction (see, for example, FIG. 12). However, it is not necessarily limited to this, and the plasma reactor 1 and the guard 7A may be in contact with each other in the vertical direction. In other words, as the guard intermediate position, a position where the outermost guard 7A contacts the plasma reactor 1 in the vertical direction may be adopted.

[0119] FIG. 13 is an enlarged view schematically showing an example of the state of the processing unit 130 in the plasma processing step. In the example of FIG. 13, the lower surface 24 of the lower member 22 of the plasma reactor 1 is in contact with the upper surface of the upper end portion 73 of the outermost guard 7A.

[0120] According to this, the gap between the lower member 22 of the plasma reactor 1 and the upper end portion 73 of the guard 7A can be further reduced, so that the processing liquid atmosphere and the outflow of the processing liquid to the outside of the guard 7 can be further suppressed.

[0121] <Second Embodiment> FIG. 14 is a diagram schematically showing an example of the configuration of the processing unit 130A according to the second embodiment, and FIG. 15 is an enlarged view showing an example of the state of the processing unit 130A in the plasma processing step in an enlarged manner. The configuration of the processing unit 130A according to the second embodiment is the same as that of the processing unit 130 according to the first embodiment, except for the presence or absence of the elastic seal member 5.

[0122] In the examples of FIGS. 14 and 15, the seal member 5 is provided on the outermost peripheral guard 7A. That is, the guard 7A includes a cylindrical portion 71, an inclined portion 72, an upper end portion 73, and the seal member 5. The seal member 5 is formed of an elastic member, and is formed of an elastic resin such as silicone and rubber, for example. The seal member 5 is attached to the upper surface of the upper end portion 73 of the guard 7A and faces the plasma reactor 1 in the vertical direction. The seal member 5 is in close contact with the lower surface 24 of the lower member 22 of the plasma reactor 1 in the plasma processing step as described later. Thereby, the adhesion between the plasma reactor 1 and the guard 7A can be improved.

[0123] The seal member 5 has a ring shape centered on the rotation axis Q1, and its lower end is attached to the upper surface of the upper end portion 73. In the example of FIG. 15, the seal member 5 has a bent shape. Specifically, the seal member 5 includes an upper ring portion 51 and a lower ring portion 52. The upper ring portion 51 has a ring inclined shape in which the inner diameter and the outer diameter become smaller as it goes from vertically above to vertically below. The lower ring portion 52 has a ring inclined shape in which the inner diameter and the outer diameter become larger as it goes from vertically above to vertically below, and the upper end of the lower ring portion 52 is continuous with the lower end of the upper ring portion 51. Such a seal member 5 can be easily elastically deformed so that the distance between the upper end of the upper ring portion 51 and the lower end of the lower ring portion 52 becomes narrow.

[0124] An example of the operation of the processing unit 130A is the same as that in the first embodiment. However, as illustrated in FIG. 15, in the plasma processing step, the guard elevating mechanism 75 moves the guard 7A to a guard intermediate position where the lower surface 24 of the lower member 22 of the plasma reactor 1 abuts against the upper end of the seal member 5. At this time, the seal member 5 is elastically deformed by being pressed vertically downward by the plasma reactor 1 and is in close contact with the plasma reactor 1.

[0125] According to this, almost no gap is generated between the plasma reactor 1 and the guard 7A. Therefore, in the plasma processing step, it is possible to further suppress or avoid the outflow of the processing liquid atmosphere and the processing liquid outside the guard 7.

[0126] FIG. 16 is a diagram schematically showing a modified example of the processing unit 130A. In the example of FIG. 16, the seal member 5 is provided on the plasma reactor 1. In other words, the plasma reactor 1 includes the seal member 5. The seal member 5 is attached to the lower surface 24 of the lower member 22 of the plasma reactor 1 and faces the upper end portion 73 of the guard 7A in the vertical direction. An example of the specific shape of the seal member 5 is as described above.

[0127] Also in this modified example, in the plasma processing step, the plasma reactor 1 abuts against the guard 7A in the vertical direction. Specifically, the lower end of the seal member 5 of the plasma reactor 1 abuts against the upper surface of the upper end portion 73 of the guard 7A. At this time, the seal member 5 is elastically deformed by being pressed vertically downward by the plasma reactor 1. That is, as the guard intermediate position, the position where the lower end of the seal member 5 located at the plasma processing position is in close contact with the upper surface of the guard 7A is adopted.

[0128] Also by this, in the plasma processing step, it is possible to further suppress or avoid the outflow of the processing liquid atmosphere and the processing liquid outside the guard 7.

[0129] In the above example, although the seal member 5 is provided only on one of the plasma reactor 1 and the guard 7A, it may be provided on both. In this case, in the plasma treatment step, the seal member 5 of the plasma reactor 1 and the seal member 5 of the guard 7A may be in close contact in the vertical direction.

[0130] <Third Embodiment> FIG. 17 is a diagram schematically showing an example of the configuration of the processing unit 130B according to the third embodiment, and FIG. 18 is an enlarged view showing an example of the state of the processing unit 130B in the plasma treatment step. The configuration of the processing unit 130B according to the third embodiment is the same as that of the processing unit 130 according to the first embodiment, except for the presence or absence of the labyrinth structure 55.

[0131] The labyrinth structure 55 is realized by the uneven shapes of the plasma reactor 1 and the guard 7A (see FIG. 18). Hereinafter, specific examples will be described.

[0132] In the example of FIG. 18, the lower member 22 of the plasma reactor 1 protrudes vertically downward from the electrode assembly 10, and the lower member 22 forms a convex portion. Further, in the example of FIG. 18, convex portions 74 and 78 are provided on the upper surface of the upper end portion 73 of the guard 7A. The convex portion 74 protrudes vertically upward from the upper surface of the upper end portion 73 at a position radially inside the lower member 22. The convex portion 78 protrudes vertically upward from the upper surface of the upper end portion 73 at a position radially outside the lower member 22. In other words, a concave portion (groove) 79 is formed on the upper surface of the upper end portion 73 of the guard 7A at a position facing the lower member 22 in the vertical direction. The concave portion 79 is formed by the convex portions 74 and 78. Each of the convex portions 74 and 78 has, for example, a ring shape centered on the rotation axis Q1. In this case, the concave portion 79 also has a ring shape centered on the rotation axis Q1.

[0133] As illustrated in FIG. 18, in a processing state where the plasma reactor 1 is positioned at the plasma processing position and the guard 7A is positioned at the lower position, the lower member 22, which is a convex portion of the plasma reactor 1, is loosely inserted into the concave portion 79 of the guard 7A. That is, the lower surface 24 of the lower member 22 is positioned vertically below both the upper end of the convex portion 74 and the upper end of the convex portion 78. However, the lower surface of the lower member 22 is separated from the bottom surface of the concave portion 79. The lower member 22 of the plasma reactor 1 is positioned between the convex portion 74 and the convex portion 78 in the radial direction and faces each of them with a gap therebetween.

[0134] The lower member 22 of the plasma reactor 1, the convex portion 74 of the guard 7A, and the convex portion 78 form a labyrinth structure 55 that exhibits concavities and convexities in the radial direction. According to this structure, the gap between the plasma reactor 1 and the guard 7A functions as a labyrinth seal. Therefore, in the plasma processing step, it is possible to suppress the processing liquid atmosphere and the processing liquid from flowing out to the outside through the gap between the plasma reactor 1 and the guard 7A.

[0135] Also, since a gap is formed between the plasma reactor 1 and the guard 7A, gas outside the guard 7 can flow into the guard 7A through this gap and be discharged to the outside through the exhaust portion 82. Thus, clean gas can be made to flow into the guard 7A. For this reason, the atmosphere above the substrate W can be made cleaner.

[0136] As described above, the substrate processing apparatus 100 and the substrate processing method have been described in detail. However, the above description is illustrative in all aspects and the substrate processing apparatus 100 and the substrate processing method are not limited thereto. An infinite number of variations not illustrated can be assumed without departing from the scope of this disclosure. The respective configurations described in the above embodiments and respective variations can be appropriately combined or omitted as long as they do not conflict with each other.

[0137] For example, although the plasma lifting mechanism 15 lifts the plasma reactor 1, it is not necessarily limited to this. Since the plasma lifting mechanism 15 only needs to lift the plasma reactor 1 relative to the substrate holding unit 3, the substrate holding unit 3 may be lifted, or both the plasma reactor 1 and the substrate holding unit 3 may be lifted. Also, since the guard lifting mechanism 75 only needs to lift the guard 7 relative to the substrate holding unit 3, the substrate holding unit 3 may be lifted, or both the substrate holding unit 3 and the guard 7 may be lifted.

[0138] Also, the processing of the substrate W is not necessarily limited to the resist removal process. For example, it is applicable to all processes that can improve the processing ability of the processing liquid by active species.

Explanation of reference numerals

[0139] 1 Plasma reactor 22 Outer part (lower member) 15 First lifting mechanism (plasma lifting mechanism) 3 Substrate holding unit 33 Rotation mechanism 7, 7A, 7B Guard 75 Second lifting mechanism (guard lifting mechanism) S1 Holding process S31 Guard movement process S32 Lighting process S33 Plasma movement process

Claims

1. a substrate holding part for holding a substrate; a plurality of guards having a cylindrical shape surrounding the substrate holding part and provided concentrically; a plasma reactor provided vertically above the substrate holding part and spreading outward beyond the periphery of the substrate held by the substrate holding part in a plan view; a first elevating mechanism for relatively raising and lowering the plasma reactor with respect to the substrate holding part; a second elevating mechanism for relatively raising and lowering the plurality of guards with respect to the substrate holding part and comprising; in a processing state in which the plurality of guards are positioned at a lower position where the upper end of the inner peripheral surface of the outermost guard among the plurality of guards is vertically below the upper surface of the substrate, and the plasma reactor is positioned at a plasma processing position close to the substrate, the plasma reactor irradiates the substrate with plasma, a substrate processing apparatus.

2. The substrate processing apparatus according to claim 1, wherein in the processing state, the distance between the plasma reactor and the outermost guard is narrower than the distance between the outermost guard and the substrate holding part, a substrate processing apparatus.

3. The substrate processing apparatus according to claim 2, wherein in the processing state, the plasma reactor abuts against the guard in the vertical direction, a substrate processing apparatus.

4. The substrate processing apparatus according to claim 3, wherein an elastic seal member that adheres tightly to the other is provided on at least one of the lower surface of the portion of the plasma reactor outside the periphery of the substrate and the upper surface of the outermost guard, a substrate processing apparatus.

5. The substrate processing apparatus according to claim 2, wherein the lower surface of the portion of the plasma reactor outside the periphery of the substrate forms a labyrinth structure with unevenness in the radial direction together with the upper surface of the outermost guard in the processing state, a substrate processing apparatus.

6. The substrate processing apparatus according to any one of claims 1 to 5, wherein the outer portion of the plasma reactor outside the periphery of the substrate has a ring shape protruding downward, the inner diameter of the outer portion is larger than the diameter of the substrate, and in the processing state, the lower surface of the outer portion is positioned below the upper surface of the substrate held by the substrate holding part, a substrate processing apparatus.

7. The substrate processing apparatus according to claim 6, A substrate processing apparatus, wherein an inner diameter of the outer portion of the plasma reactor is equal to or less than an upper opening diameter of the outermost guard.

8. The substrate processing apparatus according to claim 6 or 7, wherein the substrate holding portion includes a spin base facing the substrate vertically below the substrate, and an inner diameter of the outer portion is larger than a diameter of the spin base.

9. The substrate processing apparatus according to any one of claims 6 to 8, wherein the plasma reactor includes an electrode assembly to which power for plasma is supplied, and the outer portion supports the electrode assembly from below.

10. The substrate processing apparatus according to any one of claims 1 to 9, further comprising a nozzle for supplying a processing liquid to a main surface of the substrate held by the substrate holding portion, wherein the substrate holding portion includes a rotation mechanism for rotating the substrate around a rotation axis along a vertical direction, the nozzle discharges the processing liquid, and the substrate holding portion rotates the substrate in a state where the second elevating mechanism relatively raises at least the outermost guard to an upper position with respect to the substrate holding portion, wherein the upper position is a position where an upper end is vertically above an upper surface of the substrate.

11. A substrate holding step of holding a substrate by a substrate holding portion, a lighting step of lighting a plasma reactor provided at a position facing an upper surface of the substrate held by the substrate holding portion and extending outward of the substrate in a plan view, and a moving step of positioning the guard at a lower position where an upper end of the outermost guard among a plurality of concentrically provided guards having a cylindrical shape surrounding the substrate holding portion is lower than the substrate held by the substrate holding portion with respect to the substrate holding portion, and moving the plasma reactor to a plasma processing position close to the upper surface of the substrate. A substrate processing method comprising the above steps.

12. The substrate processing method according to claim 11, wherein the moving step includes a guard moving step of relatively moving at least the outermost guard to the lower position with respect to the substrate holding portion, and a plasma moving step of relatively moving the plasma reactor to the plasma processing position with respect to the substrate holding portion after the guard moving step. A substrate processing method comprising the above steps.

13. The substrate processing method according to claim 11, wherein the moving step A guard moving step of moving at least the outermost guard relative to the substrate holding part to the lower position, A plasma moving step of moving the plasma reactor relative to the substrate holding part to the plasma processing position in parallel with the guard moving step, A substrate processing method including the above steps.

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