Substrate processing method

Abstract

The present invention provides a substrate processing method that can effectively remove static electricity from the main surface of a substrate. [Solution] The substrate processing method comprises an acquisition step S2 and a static elimination step S3. In the acquisition step S2, charge information indicating the potential of the first main surface of a substrate having a first main surface and a second main surface on which an insulating film is formed is acquired. The static elimination step S4, after the acquisition step S2, includes an average potential adjustment step in which the substrate is rotated around a predetermined rotation axis under processing conditions based on the charge information, while a rinsing liquid is supplied to the second main surface of the substrate.

Description

Technical Field

[0004] ,

[0006] , , ,

[0005] , , ,

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

Background Art

[0002] Conventionally, a single wafer processing apparatus that supplies a processing liquid to the main surface of a wafer to process the wafer has been disclosed (for example, Patent Document 1). In Patent Document 1, while the surface of the wafer is positively charged, isopropyl alcohol is supplied so that metal ions (cations) in the isopropyl alcohol do not adhere to the surface of the wafer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the main surface of a substrate is charged, if a processing liquid having a low electrical resistivity is discharged toward the main surface of the substrate, a large current may occur between the substrate and the processing liquid. The magnitude of this current increases as the charge amount of the substrate increases. Such a large current may cause a defect in the configuration of the main surface of the substrate. For example, there is a risk that the insulating film may be broken down.

[0005] Therefore, an object of the present disclosure is to provide a substrate processing method capable of appropriately discharging the charge on the main surface of the substrate.

Means for Solving the Problems

[0006] The substrate processing method comprises an acquisition step of acquiring charge information indicating the potential of the first main surface of a substrate having a first main surface and a second main surface on which an insulating film is formed, and a static elimination step that includes, after the acquisition step, an average potential adjustment step of supplying a rinsing liquid to the second main surface of the substrate while rotating the substrate around a predetermined rotation axis under processing conditions based on the charge information. [Effects of the Invention]

[0007] The main surface of the circuit board can be properly discharged. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic plan view showing an example of the configuration of a substrate processing apparatus. [Figure 2] Figure 2 is a block diagram schematically showing an example of the internal configuration of the control unit. [Figure 3] Figure 3 is a schematic diagram showing a first example of the configuration of the measurement unit. [Figure 4] Figure 4 is a schematic diagram showing the first example of the configuration of the processing unit. [Figure 5] Figure 5 is a schematic graph showing an example of the potential distribution of the first and second main surfaces of the substrate. [Figure 6] Figure 6 is a flowchart showing a first example of the operation of the substrate processing apparatus. [Figure 7] Figure 7 is a flowchart showing an example of the specific operation of the wet step. [Figure 8] Figure 8 is a schematic graph showing an example of the potential distribution of the first main surface of the substrate after wet treatment. [Figure 9] Figure 9 is a flowchart showing an example of the specific operation of the acquisition step. [Figure 10] Figure 10 is a flowchart showing an example of the specific operation of the static elimination step. [Figure 11] Figure 11 is a schematic diagram showing an example of the processing unit in the potential equalization step. [Figure 12] FIG. 12 is a diagram schematically showing a movement mode of the rinse nozzle. [Figure 13] FIG. 13 is a diagram schematically showing an example of a potential distribution on the first main surface of the substrate after the potential equalization step. [Figure 14] FIG. 14 is a diagram schematically showing an example of a state of adjusting the rinse liquid according to the liquid application position. [Figure 15] FIG. 15 is a diagram schematically showing an example of a state of the processing unit in the average potential adjustment step. [Figure 16] FIG. 16 is a graph schematically showing an example of a potential distribution on the first main surface of the substrate after the average potential adjustment step. [Figure 17] FIG. 17 is a diagram schematically showing a second example of the configuration of the processing unit. [Figure 18] FIG. 18 is a diagram schematically showing an example of a state of the processing unit in the potential equalization step. [Figure 19] FIG. 19 is a diagram schematically showing an example of the execution timing of the average potential adjustment step and the potential equalization step. [Figure 20] FIG. 20 is a flowchart showing a second example of the operation of the substrate processing apparatus. [Figure 21] FIG. 21 is a flowchart showing a first example of the operation of the wet processing with static elimination. [Figure 22] FIG. 22 is a diagram schematically showing an example of a state of processing the substrate along the flowchart of FIG. 21. [Figure 23] FIG. 23 is a flowchart showing a second example of the operation of the wet processing with static elimination. [Figure 24] [[ID=CO37]]FIG. 24 is a diagram schematically showing an example of a state of the substrate along the flowchart of FIG. 23. [Figure 25] FIG. 25 is a diagram schematically showing a second example of the configuration of the measurement unit. [Figure 26] FIG. 26 is a diagram schematically showing an example of the configuration of the tower.

MODE FOR CARRYING OUT THE INVENTION

[0009] The embodiments will be described in detail below with reference to the drawings. Note that, for the purpose of ease of understanding, the dimensions and number of parts in the drawings are exaggerated or simplified as needed. Also, parts with similar configurations and functions are denoted by the same reference numerals, and redundant explanations are omitted in the following description.

[0010] Furthermore, in the following explanations, similar components will be denoted by the same symbols, and their names and functions will also be the same. Therefore, detailed explanations of them may be omitted to avoid redundancy.

[0011] Furthermore, even if ordinal numbers such as "first" or "second" are used in the following descriptions, these terms are used for convenience to facilitate understanding of the embodiments and are not limited to the order that may result from these ordinal numbers.

[0012] When expressions indicating relative or absolute positional relationships are used (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.), unless otherwise specified, such expressions shall 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 tolerance or a range in which equivalent functionality is obtained. When expressions indicating equality are used (e.g., "identical," "equal," "homogeneous," etc.), unless otherwise specified, such expressions shall not only strictly represent a state in which there is a quantitatively exact equality but also represent a state in which there is a difference within a tolerance or a range in which equivalent functionality is obtained. When expressions indicating shape are used (e.g., "quadrilateral" or "cylindrical"), unless otherwise specified, such expressions shall not only strictly represent the geometrically exact shape but also represent a shape with features such as concavities or chamfers within a range in which equivalent effects are obtained. When expressions such as "possess," "equip," "include," or "have" a single component are used, such expressions are not exclusive expressions that exclude the existence of other components. When the expression "at least one of A, B, and C" is used, it includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0013] <First Embodiment> <Overall configuration of the substrate processing equipment> Figure 1 is a schematic plan view showing an example of the configuration of the substrate processing apparatus 100. The substrate processing apparatus 100 is a single-wafer processing apparatus that processes substrates W one at a time.

[0014] The substrate W is, for example, a semiconductor wafer, a substrate for liquid crystal displays, an organic electroluminescence (EL) substrate, a flat panel display (FPD) substrate, an optical display substrate, a magnetic disk substrate, an optical disk substrate, a magneto-optical disk substrate, a photomask substrate, or a solar cell substrate. The substrate W has a thin, flat shape with a first main surface Wa and a second main surface Wb (see also Figure 3). The second main surface Wb is the surface opposite to the first main surface Wa.

[0015] In the following, the substrate W is assumed to be a semiconductor wafer. As an example, the substrate W is a silicon substrate. The substrate W has, for example, a disc shape. The diameter of the substrate W is, for example, about 300 mm, and the thickness of the substrate W is, for example, about 0.5 mm or more and about 3 mm or less. The first main surface Wa of the substrate W is the surface on which the semiconductor device is formed. Various semiconductor films, insulating films (i.e., dielectric films) and metal films can be formed on the first main surface Wa of the substrate W. For example, an interlayer insulating film, as referred to in post-processing, may be formed on the first main surface Wa of the substrate W, and for example, a low-k film may be applied to the interlayer insulating film.

[0016] The second main surface Wb of the substrate W is, for example, a surface on which no semiconductor devices are formed. An insulating film is formed on, for example, the entire surface of the second main surface Wb of the substrate W. The insulating film is, for example, a silicon oxide film. This insulating film may be formed by a film deposition apparatus (not shown) different from the substrate processing apparatus 100. For example, the substrate W is transported to the film deposition apparatus before being transported to the substrate processing apparatus 100. The film deposition apparatus forms an insulating film on the entire surface of the second main surface Wb of the substrate W by a film deposition method such as chemical vapor deposition (film deposition step). The thickness of the insulating film on the second main surface Wb is set to, for example, several tens of nm or more. As an example, the thickness of the insulating film may be 20 nm or more, 50 nm or more, or 100 nm or more. Then, the substrate W after film deposition is placed in a substrate carrier (hereinafter referred to as carrier C), and the carrier C is transported from the film deposition apparatus to the substrate processing apparatus 100 by a transport apparatus (not shown).

[0017] In the example shown in Figure 1, the substrate processing apparatus 100 includes an indexer block 110, a processing block 120, and a control unit 90. The processing block 120 is primarily responsible for processing the substrate W, while the indexer block 110 is primarily responsible for transporting the substrate W between the outside of the substrate processing apparatus 100 and the processing block 120.

[0018] The indexer block 110 includes a load port 111 and a first transport section 112. A carrier C is placed on the load port 111. Multiple substrates W are housed on the carrier C, for example, arranged with spacing between them in the vertical direction. In the example shown in Figure 1, multiple load ports 111 are arranged.

[0019] The first transport unit 112 is a transport robot capable of removing unprocessed substrates W from carriers C placed on each load port 111. The first transport unit 112 may also be called an indexer robot. The first transport unit 112 transports the unprocessed substrates W removed from the carriers C to the processing block 120. The processing block 120 can process the unprocessed substrates W. The first transport unit 112 can also receive processed substrates W from the processing block 120 and transport the processed substrates W to the carriers C on the load ports 111.

[0020] In the example shown in Figure 1, the processing block 120 includes a plurality of processing units 1 and a second transport unit 122. The second transport unit 122 is a transport robot capable of transporting substrates W between the first transport unit 112 and the plurality of processing units 1. In the example shown in Figure 1, the processing block 120 also includes a mounting unit 123. The mounting unit 123 is, for example, a shelf on which a plurality of substrates W can be placed in a vertically aligned manner. The first transport unit 112 places unprocessed substrates W on the mounting unit 123. The second transport unit 122 removes the unprocessed substrates W from the mounting unit 123 and transports the substrates W to the processing unit 1. The processing unit 1 processes the substrates W. The configuration of the processing unit 1 will be described later. The second transport unit 122 removes the processed substrates W from the processing unit 1 and transports the substrates W to the mounting unit 123. The first transport unit 112 removes the substrate W from the mounting unit 123 and transports the substrate W to the carrier C of the load port 111.

[0021] In the example shown in Figure 1, multiple (for example, four) processing units 1 are arranged to surround the second transport unit 122 in a plan view. This second transport unit 122 may also be called a center robot. At each position in the plan view, multiple processing units 1 may be stacked vertically. In other words, multiple (four in the figure) towers TW, each composed of multiple processing units 1 stacked vertically, may be arranged to surround the second transport unit 122.

[0022] In the example shown in Figure 1, the substrate processing apparatus 100 is equipped with a measurement unit 8. The measurement unit 8 acquires charge information indicating the potential of the first main surface Wa of the substrate W. The specific configuration of the measurement unit 8 will be described in detail later.

[0023] In the example shown in Figure 1, the measuring unit 8 is located on the mounting section 123. The second transport section 122 is capable of transporting the substrate W between the mounting section (in this case, the measuring unit 8) and the processing unit 1. In the example shown in Figure 1, the second transport section 122 includes a hand H1 and a hand movement drive unit HD1. The hand H1 has, for example, a plate-like shape and is positioned so that its thickness direction is aligned with the vertical direction. The substrate W is placed on the hand H1. The hand H1 supports or holds the substrate W.

[0024] The hand movement drive unit HD1 moves the hand H1. The hand movement drive unit HD1 includes, for example, an arm drive unit, a rotation drive unit, and a lifting drive unit. The arm drive unit includes a plurality of arms AM1 connected to each other and a motor that adjusts the connection angle between the arms AM1. One end of the connected body including the plurality of arms AM1 is connected to the hand H1, and the other end is connected to the rotation drive unit. The motor adjusts the connection angle of the arms AM1, allowing the hand H1 to be moved in a horizontal plane. The rotation drive unit includes a motor and rotates the hand H1 and the arm drive unit together around a vertical rotation axis. The lifting drive unit raises and lowers the rotation drive unit, the arm drive unit, and the hand H1 together. The lifting drive unit includes a drive source such as a motor and a power transmission unit such as a ball screw mechanism that transmits the driving force of the drive source. The hand movement drive unit HD1 is controlled by the control unit 90.

[0025] The contact portion of the hand H1 with the substrate W may be insulating. This contact portion of the hand H1 may be formed of, for example, synthetic resin or ceramics. In this case, the second transport unit 122 can transport the substrate W while maintaining the charged state of the substrate W.

[0026] The control unit 90 comprehensively controls the substrate processing apparatus 100. Specifically, the control unit 90 controls the first transport unit 112, the second transport unit 122, and the processing unit 1. Figure 2 is a schematic block diagram showing 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 in Figure 2, the data processing unit 91 and the storage unit 92 are interconnected via a bus 93. The data processing unit 91 may be, for example, an arithmetic processing unit such as a CPU (Central Processor Unit). The storage unit 92 may include a non-temporary storage unit (e.g., ROM (Read Only Memory)) 921 and a temporary storage unit (e.g., RAM (Random Access Memory)) 922. The non-temporary storage unit 921 may store, for example, a program that defines the processing to be executed by the control unit 90. By executing this program, the data processing unit 91 enables the control unit 90 to execute the processing defined in the program. Of course, some or all of the processing performed by the control unit 90 may be performed by hardware such as dedicated logic circuits.

[0027] In the example shown in Figure 2, the control unit 90 is electrically connected to the storage unit 94. The storage unit 94 is a non-temporary storage unit, such as a memory or hard disk. Various types of data are stored in the storage unit 94, such as recipe data indicating the processing procedure for the substrate W. The control unit 90 can read data from the storage unit 94 and control the substrate processing apparatus 100 based on the data.

[0028] <Measurement Unit> Figure 3 is a schematic diagram showing a first example of the configuration of the measurement unit 8. The measurement unit 8 acquires charge information indicating the charge of the first main surface Wa of the substrate W. In the example of Figure 3, the measurement unit 8 includes a substrate placement section 81 and a sensor 82. The substrate placement section 81 supports or holds the substrate W in a horizontal position. Here, a horizontal position means that the thickness direction of the substrate W is aligned with the vertical direction. The substrate placement section 81 may be, for example, a mounting table on which the substrate W is placed, a plurality of pins that support the substrate W, or a suction stage that holds the substrate W by suction.

[0029] Sensor 82 acquires charge information of the first main surface Wa of the substrate W supported or held by the substrate placement section 81. Sensor 82 is, for example, a surface potential sensor. For example, a surface potential sensor has a sensing electrode and measures the potential of the object to be measured by detecting the induced potential generated in the sensing electrode according to the potential of the object to be measured. Sensor 82 measures the potential of the first main surface Wa of the substrate W placed on the substrate placement section 81 and outputs charge information indicating the measurement result to the control unit 90.

[0030] In the example shown in Figure 3, the substrate W is placed on the substrate mounting area 81 with its first main surface Wa facing upwards, and the sensor 82 is positioned above the substrate mounting area 81. In the example shown in Figure 3, the sensor 82 is positioned to face a portion of the substrate W in the vertical direction. As an example, the sensor 82 measures the potential of a portion (measurement area) of the first main surface Wa of the substrate W.

[0031] The sensor 82 may acquire charge information indicating the potential distribution of the first main surface Wa of the substrate W. In the example shown in Figure 3, the measurement unit 8 includes a sensor movement drive unit 83 that moves the sensor 82 relative to the substrate W. The sensor movement drive unit 83 moves the sensor 82 along the first main surface Wa of the substrate W. For example, the sensor movement drive unit 83 moves the sensor 82 so that the measurement area on the first main surface Wa of the substrate W moves radially. The sensor movement drive unit 83 includes a drive source such as a motor and a power transmission unit that transmits the driving force of the drive source to the sensor 82. The power transmission unit includes, for example, a ball screw mechanism. The sensor movement drive unit 83 is controlled by the control unit 90.

[0032] While the sensor 82 is being moved by the sensor movement drive unit 83, the sensor 82 measures the potential of the measurement area. The sensor movement drive unit 83 may stop the sensor 82 at multiple measurement positions along the movement path, and the sensor 82 may measure the potential of the measurement area at each measurement position. By measuring the potential in multiple measurement areas, the potential distribution of the first main surface Wa of the substrate W can be obtained.

[0033] <Overview of the processing unit> Figure 4 is a schematic diagram illustrating a first example of the configuration of processing unit 1. Note that not all processing units 1 belonging to the substrate processing apparatus 100 need to have the configuration exemplified in Figure 4. It is sufficient that at least one processing unit 1 of the substrate processing apparatus 100 has the configuration exemplified in Figure 4.

[0034] As described later, the processing unit 1 can perform static discharge processing on the first main surface Wa of the substrate W. In addition, the processing unit 1 can also perform wet processing on the substrate W. Wet processing, as referred to here, is a process in which various processing liquids are sequentially supplied to the substrate W, and after sequentially performing processing on the substrate W according to the type of processing liquid, the substrate W is dried.

[0035] As shown in Figure 4, the processing unit 1 includes a substrate holding unit 2, a first discharge unit 3, and a second discharge unit 4. In the example in Figure 4, the processing unit 1 is also provided with a chamber 10. The chamber 10 has a box shape, and its internal space corresponds to the processing space for processing the substrate W. The chamber 10 is provided with an openable and closable discharge port (not shown). The second transport unit 122 transports unprocessed substrates W into the chamber 10 through the discharge port and discharges processed substrates W from the chamber 10 through the discharge port.

[0036] The substrate holder 2 is located inside the chamber 10 and holds the substrate W in a horizontal position while rotating the substrate W around the rotation axis Q1. The rotation axis Q1 is an axis that passes through the center of the substrate W and is aligned vertically. Such a substrate holder 2 may also be called a spin chuck. Here, the substrate holder 2 holds the substrate W in a position where the first main surface Wa faces upward. In other words, the first main surface Wa corresponds to the top surface. Hereafter, the circumferential and radial directions with respect to the rotation axis Q1 will be simply referred to as the circumferential direction and the radial direction, respectively.

[0037] In the example shown in Figure 3, the substrate holder 2 includes a spin base 21, chuck pins 22, and a rotation drive unit 23. The spin base 21 has a plate-like shape (e.g., a disc shape) and is positioned so that its thickness direction is aligned with the vertical direction. Multiple chuck pins 22 are provided on the upper surface of the spin base 21. The multiple chuck pins 22 are provided at equal intervals along the circumferential direction with respect to the rotation axis Q1. The multiple chuck pins 22 are provided so as to be displaceable between the holding position and the release position, which will be described below. The holding position is the position in which the chuck pins 22 contact the periphery of the substrate W. The multiple chuck pins 22 hold the substrate W by stopping at their respective holding positions. Figure 3 shows the chuck pins 22 stopped at the holding position. The release position is the position in which each chuck pin 22 is separated from the substrate W. The multiple chuck pins 22 release the substrate W by stopping at their respective release positions. The substrate holding section 2 also includes a pin drive section (not shown) that displaces the chuck pin 22. The pin drive section includes, for example, a drive source such as a motor and an air cylinder, and is controlled by the control section 90.

[0038] At least the portion of the substrate holding part 2 that contacts the substrate W is insulating. As a specific example, the chuck pin 22 of the substrate holding part 2 is insulating. The chuck pin 22 may be made of a synthetic resin such as a fluororesin. As a result, the substrate holding part 2 can hold the substrate W while maintaining the charged state of the substrate W.

[0039] The rotary drive unit 23 includes a shaft 231 and a motor 232. The upper end of the shaft 231 is connected to the lower surface of the spin base 21, and the shaft 231 extends from the lower surface of the spin base 21 along the rotation axis Q1. The motor 232 is controlled by the control unit 90 and rotates the shaft 231 around the rotation axis Q1. As a result, the spin base 21, chuck pin 22, and substrate W rotate together around the rotation axis Q1.

[0040] The substrate holding section 2 does not necessarily need to have chuck pins 22. For example, the substrate holding section 2 may hold the substrate W using a chuck method such as a vacuum chuck, an electrostatic chuck, or a Bernoulli chuck.

[0041] The second discharge unit 4 discharges the rinsing liquid toward the second main surface Wb of the substrate W held by the substrate holding unit 2. The rinsing liquid is, for example, pure water (deionized water) or carbon dioxide water.

[0042] As shown in Figure 4, the second discharge unit 4 includes a second nozzle 40. The second nozzle 40 is located within the chamber 10 and discharges the rinsing liquid toward the second main surface Wb of the substrate W held by the substrate holding unit 2. In the example in Figure 4, the second main surface Wb corresponds to the lower surface of the substrate W, so the second nozzle 40 is located below the substrate W held by the substrate holding unit 2. For example, the second nozzle 40 is a straight nozzle that discharges the processing liquid in a continuous flow state.

[0043] In the example shown in Figure 4, the second nozzle 40 is positioned perpendicular to the center of the second main surface Wb of the substrate W. The second nozzle 40 has a discharge port at its upper end and discharges the rinsing liquid toward the center of the second main surface Wb of the substrate W.

[0044] The second nozzle 40 is connected to the downstream end of the supply pipe 41, and the upstream end of the supply pipe 41 is connected to the rinse fluid supply source. In the example in Figure 4, a through hole is formed in the center of the spin base 21, and the shaft 231 is a hollow shaft. At least a portion of the second nozzle 40 is located inside the through hole of the spin base 21, and a portion of the supply pipe 41 extends vertically inside the spin base 21 and the shaft 231. The supply pipe 41 is provided with a supply valve 42 and a flow control valve 43. The supply valve 42 switches the supply pipe 41 open and closed. The flow control valve 43 adjusts the flow rate of the rinse fluid flowing through the supply pipe 41. The flow control valve 43 may be a mass flow controller. The supply valve 42 and the flow control valve 43 are controlled by a control unit 90.

[0045] The second nozzle 40 discharges rinsing liquid toward the second main surface Wb of the substrate W while the substrate W is rotating due to the substrate holding unit 2. In other words, the control unit 90 opens the supply valve 42 when the substrate holding unit 2 is rotating the substrate W. As a result, the rinsing liquid from the second nozzle 40 lands on the center of the second main surface Wb of the substrate W. This rinsing liquid is affected by the centrifugal force accompanying the rotation of the substrate W and flows radially outward along the second main surface Wb of the substrate W, scattering outward from the periphery of the substrate W. The rinsing liquid hardly reacts chemically with the substrate W. On the other hand, as the rinsing liquid flows along the second main surface Wb of the substrate W, friction between the rinsing liquid and the second main surface Wb of the substrate W causes the second main surface Wb of the substrate W to become negatively charged. Here, since an insulating film is formed on the second main surface Wb of the substrate W, inductive charging occurs on the substrate W. This inductive charging can change the potential of the first main surface Wa of the substrate W to the positive side. For example, if the potential of the first main surface Wa of the substrate W is negative before the rinse liquid is discharged by the second discharge unit 4, the discharge of the rinse liquid by the second discharge unit 4 can change the potential of the first main surface Wa of the substrate W to the positive side. In other words, the potential of the first main surface Wa of the substrate W can be brought closer to zero.

[0046] Figure 5 is a schematic graph showing an example of the potential distribution of the first main surface Wa and the second main surface Wb of the substrate W. In Figure 5, graph G0a shows the potential distribution of the first main surface Wa before the rinsing liquid is discharged by the second discharge unit 4. Graphs G1b to G3b show the potential distribution of the second main surface Wb of the substrate W after the rinsing liquid has been discharged. The discharge time of the rinsing liquid by the second discharge unit 4 differs in graphs G1b to G3b. The discharge time in graph G1b is the shortest, and the discharge time in graph G3b is the longest. Therefore, at the same position, the potential in graph G2b is lower than the potential in graph G1b, and the potential in graph G3b is lower than the potential in graph G2b.

[0047] Graphs G1a to G3a show the potential distribution of the first main surface Wa of the substrate W after the rinse liquid is discharged by the second discharge unit 4. The discharge time in graph G1a is equal to the discharge time in graph G1b. In other words, graphs G1a and G1b show the potentials of the first main surface Wa and the second main surface Wb of the substrate W after the second discharge unit 4 has discharged the rinse liquid to the substrate W with the shortest possible discharge time. The same applies to graphs G2a and G2b, and to graphs G3a and G3b.

[0048] As can be seen from Figure 5, the more negative the potential of the second main surface Wb of the substrate W becomes, the more positively charged the first main surface Wa of the substrate W becomes. Moreover, while the potential distribution of the second main surface Wb of the substrate W generally decreases near the point of contact of the rinse liquid and increases towards the radially outward direction, the potential distribution of the first main surface Wa of the substrate W is not affected by the potential distribution of the second main surface Wb of the substrate W and shifts almost parallel to the in-plane average value of the potential of the second main surface Wb. For this reason, if the first main surface Wa of the substrate W is negatively charged before the rinse liquid is discharged by the second discharge unit 4, the potential of the first main surface Wa of the substrate W can be brought closer to zero in response to the negative charging of the second main surface Wb of the substrate W due to the discharge by the second discharge unit 4.

[0049] Referring to Figure 4, the first discharge unit 3 discharges the processing liquid toward the first main surface Wa of the substrate W held by the substrate holding unit 2. As shown in Figure 4, the first discharge unit 3 includes at least one first nozzle 30. The first nozzle 30 is located within the chamber 10 and discharges the processing liquid toward the first main surface Wa of the substrate W held by the substrate holding unit 2. Here, since the first main surface Wa corresponds to the upper surface of the substrate W, the first nozzle 30 is located above the substrate W held by the substrate holding unit 2. The first nozzle 30 is, for example, a straight nozzle that discharges the processing liquid in a continuous flow state.

[0050] In the example shown in Figure 4, multiple first nozzles 30 are provided. In the example shown in Figure 4, the multiple first nozzles 30 include a first chemical nozzle 30ca, a second chemical nozzle 30cb, a rinse nozzle 30r, and a drying nozzle 30i.

[0051] The first chemical nozzle 30ca discharges a chemical solution as a processing solution. The chemical solution is a liquid that chemically reacts with the substrate W. For example, the chemical solution includes a liquid for cleaning, etching, or hydrophobizing the substrate W. The cleaning or etching solution includes, for example, hydrofluoric acid (including dilute hydrofluoric acid), a mixture of ammonia water, hydrogen peroxide, and pure water (SC1), a mixture of hydrochloric acid, hydrogen peroxide, and pure water (SC2), a mixture of sulfuric acid and hydrogen peroxide (SPM), or phosphoric acid. Hereinafter, the chemical solution discharged by the first chemical nozzle 30ca will be referred to as the first chemical solution.

[0052] The second chemical nozzle 30cb discharges a chemical solution different from the first chemical solution (hereinafter referred to as the second chemical solution) as the processing solution. As a specific example, the first chemical solution is hydrofluoric acid, and the second chemical solution is SC1.

[0053] The rinse nozzle 30r discharges the rinse solution as the processing solution. The drying solution nozzle 30i discharges the drying solution as the processing solution. The drying solution may be a liquid with higher volatility than the rinse solution, and may also be a liquid with lower surface tension than the rinse solution. The drying solution may be an organic solvent, and a more specific example is isopropyl alcohol.

[0054] In the example shown in Figure 4, the first nozzles 30 are connected to the processing liquid supply source through their respective supply pipes 31. For example, the first chemical nozzle 30ca is connected to the first chemical supply source through supply pipe 31ca, the second chemical nozzle 30cb is connected to the second chemical supply source through supply pipe 31cb, the rinse nozzle 30r is connected to the rinse liquid supply source through supply pipe 31r, and the drying liquid nozzle 30i is connected to the drying liquid supply source through supply pipe 31i.

[0055] Each supply pipe 31 is provided with a supply valve 32 and a flow control valve 33. For example, supply pipe 31ca is provided with a supply valve 32ca and a flow control valve 33ca, supply pipe 31cb is provided with a supply valve 32cb and a flow control valve 33cb, supply pipe 31r is provided with a supply valve 32r and a flow control valve 33r, and supply pipe 31i is provided with a supply valve 32i and a flow control valve 33i. The supply valve 32 switches the supply pipe 31 open and closed, and the flow control valve 33 adjusts the flow rate of the processed liquid flowing through the supply pipe 31. The flow control valve 33 may also be a mass flow controller. The supply valve 32 and the flow control valve 33 are controlled by the control unit 90. In the following, in order to distinguish the supply valves 32, the last letter of the supply pipe 31 to be controlled may be appended to the end of the code of the supply valve 32. For example, supply valve 32ca is the supply valve 32 provided in supply pipe 31ca. The same applies to the flow control valve 33.

[0056] In the example shown in Figure 4, the nozzle movement drive unit 35 is connected to the first nozzle 30. For example, the nozzle movement drive unit 35ca is connected to the first chemical nozzle 30ca, the nozzle movement drive unit 35cb is connected to the second chemical nozzle 30cb, the nozzle movement drive unit 35r is connected to the rinse nozzle 30r, and the nozzle movement drive unit 35i is connected to the drying nozzle 30i.

[0057] The nozzle movement drive unit 35 moves the first nozzle 30 between the processing position and the standby position, which will be described below. The processing position is the position where the first nozzle 30 discharges the processing liquid toward the first main surface Wa of the substrate W, for example, a position perpendicular to the center of the first main surface Wa of the substrate W. In the example in Figure 4, the rinse nozzle 30r located in the processing position is shown. The standby position is a position where the first nozzle 30 does not discharge the processing liquid toward the first main surface Wa of the substrate W, for example, a position radially outside the substrate W. The standby position is a position that does not interfere with the transport path of the substrate W by the second transport unit 122. In the example in Figure 4, the first chemical nozzle 30ca, the second chemical nozzle 30cb, and the drying nozzle 30i located in their respective standby positions are shown.

[0058] Figure 4 shows an example of the specific configuration of the nozzle movement drive unit 35. In the example of Figure 4, the nozzle movement drive unit 35 includes an arm 351, a support column 352, and a drive source 353. The support column 352 is located radially outward from the guard 7 (described later) and extends vertically. The arm 351 extends horizontally, its tip connected to the discharge head, and its base connected to the support column 352. The drive source 353 is controlled by the control unit 90 and rotates the support column 352 in forward and reverse directions within a predetermined angular range around its central axis Q2. The drive source 353 includes, for example, a motor. When the support column 352 rotates in forward and reverse directions within a predetermined angular range around the central axis Q2, the discharge head reciprocates along the circumferential direction with respect to the central axis Q2. The support column 352 is installed such that the processing position and standby position are located on the movement trajectory of the discharge head. Note that the nozzle movement drive unit 35 is not necessarily limited to the configuration shown in Figure 4, and may include, for example, a linear motion mechanism such as a linear motor.

[0059] The first nozzle 30 discharges the processing liquid toward the first main surface Wa of the substrate W while the substrate W is rotating due to the substrate holding unit 2. The processing liquid that lands on the first main surface Wa of the substrate W is affected by the centrifugal force accompanying the rotation of the substrate W and flows radially outward, scattering outward from the periphery of the substrate W. The processing liquid acts on the first main surface Wa of the substrate W as it flows along it. As a result, processing is performed on the first main surface Wa of the substrate W according to the type of processing liquid. In addition, as the processing liquid flows along the first main surface Wa of the substrate W, the friction between the processing liquid and the substrate W can cause the first main surface Wa of the substrate W to become charged. For example, when a chemical solution such as hydrofluoric acid or SC1 and a rinsing solution each flow along the first main surface Wa of the substrate W, the first main surface Wa of the substrate W becomes negatively charged.

[0060] In the example shown in Figure 4, the processing unit 1 is provided with a guard 7 and a guard lifting drive unit 71. The guard 7 has a cylindrical shape with the rotation axis Q1 as its central axis and surrounds the substrate holding part 2. The guard 7 can catch the processing liquid and heat transfer medium scattered from the periphery of the substrate W. The guard lifting drive unit 71 raises and lowers the guard 7 between the upper position and the lower position, which will be described below. The upper position is the position where the upper end of the guard 7 is vertically above the substrate W held by the substrate holding part 2. When the guard 7 is in the upper position, it can catch the processing liquid and heat transfer medium scattered from the periphery of the substrate W. The lower position is a position lower than the upper position, for example, the position where the upper end of the guard 7 is vertically below the upper surface of the spin base 21.

[0061] <An example of the operation of a substrate processing device> Next, a first example of the operation of the substrate processing apparatus 100 will be described. Figure 6 is a flowchart of a first example of the operation of the substrate processing apparatus 100. The control unit 90 causes the substrate processing apparatus 100 to execute the steps in Figure 6 according to a pre-set procedure. Below, an overview of each step will be described with reference to Figure 6, and then specific examples of each step will be described.

[0062] In the example shown in Figure 6, first, in the wet step S1, the processing unit 1 performs a wet treatment on the substrate W. In this wet treatment, the processing unit 1 treats the first main surface Wa of the substrate W with a processing solution, as described later, and then dries the substrate W. As a result of this wet treatment, the first main surface Wa of the substrate W becomes negatively charged, as described later.

[0063] Next, in acquisition step S2, the measurement unit 8 acquires charge information indicating the charge state of the first main surface Wa of the substrate W. Specifically, as described later, the sensor 82 measures the potential of the first main surface Wa of the substrate W and outputs the measurement result as charge information to the control unit 90.

[0064] Next, in the determination step S3, the control unit 90 determines, based on the charge information, whether or not static discharge is necessary on the first main surface Wa of the substrate W, as described later.

[0065] When it is determined that static discharge is necessary, in the static discharge step S4, the processing unit 1 performs a static discharge process to bring the in-plane average potential of the first main surface Wa of the substrate W closer to zero. The in-plane average potential here is an index that shows the average magnitude of the potential of the first main surface Wa of the substrate W, and refers to the average value of the potential at multiple locations within the first main surface Wa. In the static discharge step S4, as described later, the processing unit 1 supplies rinsing liquid to the second main surface Wb of the substrate W, thereby negatively charging the second main surface Wb of the substrate W. This negative charging is induced, causing the potential of the first main surface Wa of the substrate W to move to the positive side (i.e., zero). When it is determined that static discharge is unnecessary, the execution of the static discharge step S4 is omitted.

[0066] <Wet Step S1> Figure 7 is a flowchart illustrating a specific example of the operation of the wet step S1. First, in the holding step S11, the control unit 90 controls the second transport unit 122 to transport the substrate W into the chamber 10 and controls the substrate holding unit 2 to hold the substrate W. As a specific example, the control unit 90 controls the pin drive unit to move the multiple chuck pins 22 to their respective holding positions. This causes the substrate holding unit 2 to hold the substrate W.

[0067] Next, in the first chemical step S12, the processing unit 1 supplies the first chemical solution to the first main surface Wa of the substrate W. Specifically, first, the control unit 90 controls the nozzle movement drive unit 35ca to move the first chemical solution nozzle 30ca to the processing position, controls the guard lifting drive unit 71 to raise the guard 7 to the upper position, and controls the substrate holding unit 2 to rotate the substrate W around the rotation axis Q1. The substrate holding unit 2 may continue to rotate the substrate W until the end of the wet processing. Then, the control unit 90 opens the supply valve 32ca. As a result, the first chemical solution nozzle 30ca discharges the first chemical solution toward the center of the first main surface Wa of the rotating substrate W. The first chemical solution acts on the first main surface Wa of the substrate W, and the first chemical solution processing is performed on the first main surface Wa of the substrate W. In addition, the first main surface Wa of the substrate W may become electrically charged due to friction between the first chemical solution and the substrate W. For example, if hydrofluoric acid is used as the first chemical solution, the first main surface Wa of the substrate W may become negatively charged.

[0068] When the first chemical treatment is sufficiently performed, the treatment unit 1 terminates the first chemical treatment. For example, when a predetermined first chemical treatment time has elapsed since the supply valve 32ca was opened, the control unit 90 closes the supply valve 32ca. The elapsed time is measured by a timer circuit (not shown) belonging to the control unit 90. The control unit 90 controls the nozzle movement drive unit 35ca to move the first chemical nozzle 30ca to the standby position.

[0069] Next, in the rinsing step S13, the processing unit supplies rinsing liquid to the first main surface Wa of the substrate W. The rinsing liquid is, for example, pure water. Specifically, the control unit 90 controls the nozzle movement drive unit 35r to move the rinsing nozzle 30r to the processing position, and then opens the supply valve 32r. As a result, the rinsing nozzle 30r discharges the rinsing liquid toward the center of the first main surface Wa of the substrate W. The rinsing liquid that has come into contact with the first main surface Wa of the substrate W is subjected to centrifugal force and flows radially outward, scattering from the periphery of the substrate W. At this time, the rinsing liquid pushes the first chemical solution radially outward, so the processing liquid on the first main surface Wa of the substrate W is replaced from the first chemical solution to the rinsing liquid (rinsing process). In addition, the friction between this rinsing liquid and the substrate W causes the first main surface Wa of the substrate W to become even more negatively charged.

[0070] When the rinsing process is complete, the processing unit 1 terminates the rinsing process. For example, when a predetermined first rinsing time has elapsed since the supply valve 32r was opened, the control unit 90 closes the supply valve 32r.

[0071] Next, in the second chemical step S14, the processing unit 1 supplies the second chemical solution to the first main surface Wa of the substrate W. Specifically, the control unit 90 controls the nozzle movement drive unit 35cb to move the second chemical solution nozzle 30cb to the processing position, and then opens the supply valve 32cb. As a result, the second chemical solution nozzle 30cb discharges the second chemical solution toward the center of the first main surface Wa of the rotating substrate W. The second chemical solution acts on the first main surface Wa of the substrate W, thereby performing the second chemical solution treatment on the first main surface Wa of the substrate W. Furthermore, in cases such as when SC1 is used as the second chemical solution, the friction between the first chemical solution and the substrate W may cause the first main surface Wa of the substrate W to become even more negatively charged.

[0072] When the second chemical treatment is sufficiently performed, the treatment unit 1 terminates the second chemical treatment. For example, when a predetermined second chemical treatment time has elapsed since the supply valve 32cb was opened, the control unit 90 closes the supply valve 32cb. The control unit 90 controls the nozzle movement drive unit 35cb to move the second chemical nozzle 30cb to the standby position.

[0073] Next, in the rinsing step S15, the processing unit supplies the rinsing solution to the first main surface Wa of the substrate W. Specifically, the control unit 90 opens the supply valve 32r. As a result, the processing solution on the first main surface Wa of the substrate W is replaced from the second chemical solution to the rinsing solution. In addition, the friction between this rinsing solution and the substrate W causes the first main surface Wa of the substrate W to become even more negatively charged.

[0074] When the rinsing process is complete, the processing unit 1 terminates the rinsing process. For example, when a predetermined second rinsing time has elapsed since the supply valve 32r was opened, the control unit 90 closes the supply valve 32r. The control unit 90 controls the nozzle movement drive unit 35r to move the rinsing nozzle 30r to the standby position.

[0075] Next, in the drying step S16, the processing unit supplies the drying liquid to the first main surface Wa of the substrate W. Specifically, the control unit 90 controls the nozzle movement drive unit 35i to move the drying liquid nozzle 30i to the processing position, and then opens the supply valve 32i. As a result, the processing liquid on the first main surface Wa of the substrate W is replaced from the rinsing liquid to the drying liquid.

[0076] When the replacement of the rinsing liquid with the drying liquid is sufficient, the processing unit 1 terminates the supply of the drying liquid. For example, when a predetermined drying time has elapsed since the supply valve 32i was opened, the control unit 90 closes the supply valve 32i. The control unit 90 controls the nozzle movement drive unit 35i to move the drying liquid nozzle 30i to the standby position.

[0077] Next, in drying step S17, the processing unit dries the substrate W. Specifically, the control unit 90 controls the substrate holding unit 2 to increase the rotation speed of the substrate W (so-called spin drying).

[0078] When the substrate W is sufficiently dry, the processing unit 1 terminates the drying process. For example, when a predetermined drying time has elapsed since the rotation speed was increased, the control unit 90 controls the substrate holding unit 2 to stop the rotation of the substrate W. The control unit 90 also causes the guard lifting drive unit 71 to lower the guard 7.

[0079] Next, in the release step S18, the control unit 90 controls the substrate holding unit 2 to release the substrate W, and then the second transport unit 122 transports the wet-treated substrate W.

[0080] As described above, the processing unit 1 can perform a wet treatment on the first main surface Wa of the substrate W. On the other hand, this wet treatment causes the first main surface Wa of the substrate W to become negatively charged. Figure 8 is a schematic graph showing an example of the potential distribution of the first main surface Wa of the substrate W after the wet treatment. In the example in Figure 8, the potential distribution of the first main surface Wa of the substrate W has a downward convex shape, with the potential at its lowest point at the point where the processing liquid is applied. This is because there is a large amount of friction between the processing liquid and the substrate W at the point where the processing liquid is applied to the first main surface Wa of the substrate W. In the example above, the processing liquid is applied to the central part of the first main surface Wa of the substrate W, so in the example in Figure 8, the potential distribution of the first main surface Wa has a downward convex shape, with the potential at its lowest point in the central part of the substrate W.

[0081] <Electrical Potential Measurement> Next, an example of the specific operation of acquisition step S2 will be described. Figure 9 is a flowchart showing an example of the specific operation of acquisition step S2. As shown in Figure 9, first, in the loading step S21, the second transport unit 122 loads the substrate W into the measurement unit 8. As a result, the substrate W is placed in the substrate placement unit 81. Since at least the contact portion of the hand H1 of the second transport unit 122 with the substrate W is insulating, the second transport unit 122 can transport the substrate W from the processing unit 1 to the measurement unit 8 while maintaining the charged state of the substrate W.

[0082] Next, in measurement step S22, the sensor 82 measures the potential of the first main surface Wa of the substrate W. As a specific example, the control unit 90 controls the sensor movement drive unit 83 to move the sensor 82 along the first main surface Wa of the substrate W. This causes the measurement area of ​​the sensor 82 to move on the first main surface Wa of the substrate W. For example, the sensor movement drive unit 83 moves the sensor 82 so that the measurement area moves radially from the periphery to the center of the first main surface Wa of the substrate W. The sensor 82 measures the potential of the first main surface Wa of the substrate W at multiple measurement positions along the movement path and outputs charge information indicating the measurement results to the control unit 90. This charge information is used to determine the processing conditions used in the static elimination step S4, as described later.

[0083] The control unit 90 may control the sensor movement drive unit 83 to move the sensor 82 in two dimensions. This allows the sensor 82 to measure the potential distribution across the entire surface of the first main surface Wa of the substrate W. On the other hand, the control unit 90 may move the sensor 82 in only one direction along the radial direction. This is because if the radial position is the same, the potential is considered to be approximately the same even if the circumferential position is different. This makes it possible to improve the throughput of the measurement step S22 while reducing the amount of charge information data.

[0084] Next, in the unloading step S23, the second transport unit 122 unloads the measured substrate W.

[0085] <Judgment> In the determination step S3, the control unit 90 determines whether or not static discharge is necessary based on the charge information. As a specific example, the control unit 90 may calculate a representative value of the potential and determine whether or not static discharge is necessary based on this representative value. The representative value of the potential is an index indicating the magnitude of the potential of the first main surface Wa of the substrate W, and may be, for example, the maximum value, average value, or median value of the potential. The control unit 90 may compare the representative value of the potential with a predetermined potential reference value. The control unit 90 may determine that static discharge is necessary when the absolute value of the representative value is greater than or equal to the predetermined potential reference value, and determine that static discharge is unnecessary when the absolute value of the representative value is less than the potential reference value. The control unit 90 executes the static discharge step S4 when it determines that static discharge is necessary, and does not execute the static discharge step S4 when it determines that static discharge is unnecessary.

[0086] <Static removal> Next, an example of the specific operation of the static elimination step S4 will be described. Figure 10 is a flowchart showing an example of the specific operation of the static elimination step S4. In the example in Figure 10, first, in the condition determination step S41, the control unit 90 determines the processing conditions based on the charge information acquired in the measurement step S22. The processing conditions here include the average processing conditions used in the average potential adjustment step S44 described later. The processing conditions may also include the uniform processing conditions used in the potential equalization step S43 described later. Specific examples of the average processing conditions and uniform processing conditions will be described in detail later.

[0087] Next, in the loading step S42, similar to the holding step S11, the control unit 90 controls the second transport unit 122 to load the substrate W into the processing unit 1 and controls the substrate holding unit 2 to hold the substrate W.

[0088] Next, in the potential equalization step S43, the processing unit 1 supplies rinsing liquid to the first main surface Wa of the substrate W. Figure 11 is a schematic diagram showing an example of the processing unit 1 in the potential equalization step S43. First, the control unit 90 controls the nozzle movement drive unit 35r to move the rinsing nozzle 30r to the processing position, controls the guard lifting drive unit 71 to raise the guard 7 to the upper position, and controls the substrate holding unit 2 to rotate the substrate W around the rotation axis Q1. The substrate holding unit 2 may continue to rotate the substrate W until the static elimination is completed. Then, the control unit 90 opens the supply valve 32r. As a result, rinsing liquid is discharged from the rinsing nozzle 30r toward the first main surface Wa of the substrate W. The rinsing liquid is, for example, pure water.

[0089] The processing unit 1 supplies rinsing solution to the first main surface Wa of the substrate W in such a way that it equalizes the potential distribution of the first main surface Wa of the substrate W. That is, since the amount of charge at the point where the rinsing solution is applied is greater than the amount of charge at other points, the processing unit 1 equalizes the potential distribution of the first main surface Wa of the substrate W by adjusting the point where the rinsing solution is applied.

[0090] For example, the control unit 90 controls the nozzle movement drive unit 35r to move the rinse nozzle 30r between the first processing position and the second processing position, which will be described below. The first processing position is radially different from the second processing position. The first processing position may be on the opposite side of the center of the substrate W from the second processing position in a plan view. A plan view here means viewing the object with the line of sight aligned with the vertical direction. As an example, the first and second processing positions are on the peripheral side of the substrate W, opposite each other from the center of the substrate W. The movement of the rinse nozzle 30r causes the liquid application position to move radially on the first main surface of the substrate W. The control unit 90 may also control the nozzle movement drive unit 35r to move the rinse nozzle 30r back and forth between the first processing position and the second processing position.

[0091] The control unit 90 controls each part of the processing unit 1 based on the uniform processing conditions determined in the condition determination step S41. The uniform processing conditions include, for example, information on the rotation speed of the substrate W (target value), the first discharge time of the rinse liquid (target value), the flow rate of the rinse liquid (target value), and the movement pattern of the rinse nozzle 30r (target value of the movement speed and target value of the movement range). The information on the position of the rinse nozzle 30r may include information showing the change in the position of the rinse nozzle 30r over time, and may also include information showing the change in the movement speed of the rinse nozzle 30r over time.

[0092] In the condition determination step S41, the control unit 90 determines the uniform processing conditions as follows. That is, in the potential equalization step S43, the control unit 90 determines the uniform processing conditions so that the potential distribution of the first main surface Wa of the substrate W can be equalized. As an example, the control unit 90 may determine the movement mode of the rinse nozzle 30r based on the charge information as follows. That is, the rinse nozzle 30r is moved at a lower speed the further the potential is from the bottom value at the application position (here, a position on the peripheral side of the substrate W). Figure 12 is a schematic diagram showing the movement mode of the rinse nozzle 30r. As can be seen from Figure 12, under uniform processing conditions, the movement speed of the rinse nozzle 30r is set relatively high near the center where the potential is at the bottom value, and relatively low near the peripheral part where the potential is far from the bottom value. As a result, the rinse liquid is applied for a longer application time the further the potential is from the bottom value at the application position (here, the peripheral part). Therefore, the potential at the liquid application site can be reduced more significantly, allowing the value to be brought closer to the bottom value more appropriately.

[0093] To explain more generally, we introduce a first and second liquefaction position. The first liquefaction position differs from the second liquefaction position in the radial direction. The difference between the potential and the bottom value at the first liquefaction position is called the first potential difference, and the difference between the potential and the bottom value at the second liquefaction position is called the second potential difference. Here, immediately before the static elimination step S4, the first potential difference is assumed to be greater than the second potential difference. In other words, in the potential distribution of the charge information, the first potential difference is assumed to be greater than the second potential difference. That is, the second liquefaction position is closer to the center of the substrate W than the first liquefaction position.

[0094] Under uniform processing conditions, the control unit 90 may set the movement speed of the rinse nozzle 30r at the first liquid application position to be lower than the movement speed of the rinse nozzle 30r at the second liquid application position. This makes the liquid application time at the first liquid application position longer than the liquid application time at the second liquid application position. As a result, the potential at the first liquid application position can be lowered more significantly than the potential at the second liquid application position. Therefore, the potentials at the first and second liquid application positions can be brought closer to their respective bottom values, and the potential distribution can be made uniform. The movement speed of the rinse nozzle 30r may be adjusted more finely. In other words, the movement speed may be set according to multiple liquid application positions that are spaced closer together.

[0095] Figure 13 schematically shows an example of the potential distribution of the first main surface Wa of the substrate W after the potential equalization step S43. In the example in Figure 13, the potential distribution before the potential equalization step S43 is shown by a dashed line. In the example in Figure 13, the processing unit 1 causes the peripheral area of ​​the substrate W to become more negatively charged, and as a result, the potential distribution is equalized. In the example in Figure 13, the change in potential in the potential equalization step S43 is schematically shown by dashed arrows.

[0096] Incidentally, the correspondence between the application time of the rinse solution at a certain application location and the amount of change in potential at that application location is set in advance by simulation or experiment. Correspondence information showing this correspondence is stored in, for example, the memory unit 94. In the condition determination step S41, the control unit 90 determines uniform processing conditions (e.g., moving speed) based on the charge information and correspondence information so that the potential distribution of the first main surface Wa of the substrate W is made uniform. As an example, the control unit 90 determines the moving speed of the rinse nozzle 30r according to the application location so that, for example, the difference between the maximum and minimum values ​​in the potential distribution is less than or equal to a predetermined first potential difference reference value. The first potential difference reference value may be, for example, 2.0V, 1.0V, 0.5V, or 0.1V. The in-plane average value of the potential of the first main surface Wa after the potential uniformization step S43 may be, for example, about -50V.

[0097] Furthermore, although the example above adjusts the movement speed of the rinse nozzle 30r, this is not necessarily the only method. For example, in the condition determination step S41, the control unit 90 may determine the flow rate of the rinse liquid based on the charge information as follows: That is, the further the potential is from the bottom value at the application position (in this case, the peripheral position), the larger the flow rate of the rinse liquid is applied. Figure 14 is a schematic diagram showing an example of how the rinse liquid is adjusted according to the application position. As can be seen from Figure 14, under uniform processing conditions, the flow rate of the rinse liquid is set relatively small near the center where the potential is at the bottom value, and relatively large near the peripheral area where the potential is far from the bottom value. As a result, the further the potential is from the bottom value at the application position, the larger the flow rate of the rinse liquid is applied. Therefore, the potential at the application position can be brought closer to the bottom value. More generally, the control unit 90 sets the flow rate of the rinse liquid at the first application position to be larger than the flow rate of the rinse liquid at the second application position. Furthermore, the flow rate of the rinse solution may be adjusted more precisely. In other words, the flow rate may be set according to multiple application points that are spaced closer together.

[0098] Incidentally, the relationship between the flow rate of the rinse solution at a certain application location and the amount of change in potential at that application location is set in advance by simulation or experiment. This relationship information is stored in, for example, the memory unit 94. In the condition determination step S41, the control unit 90 determines the uniform processing conditions (flow rate of the rinse solution according to the application location) based on the charge information and the relationship information so that the potential distribution of the first main surface Wa of the substrate W becomes uniform.

[0099] When the potential distribution becomes sufficiently uniform, the processing unit 1 stops supplying the rinse fluid. For example, when a predetermined first discharge time has elapsed since the supply valve 32r was opened, the control unit 90 closes the supply valve 32r.

[0100] Next, in the average potential adjustment step S44, the processing unit 1 supplies rinse liquid to the second main surface Wb of the substrate W. Figure 15 is a schematic diagram showing an example of the processing unit 1 in the average potential adjustment step S44. The control unit 90 opens the supply valve 42. As a result, rinse liquid is discharged from the second nozzle 40 toward the center of the second main surface Wb of the rotating substrate W. The rinse liquid flows radially outward along the second main surface Wb of the substrate W and splashes outward from the periphery of the substrate W. At this time, the friction between the rinse liquid and the second main surface Wb of the substrate W causes the second main surface Wb of the substrate W to become negatively charged. Due to the induced charging associated with this negative charge, the potential of the first main surface Wa of the substrate W is offset to the positive side.

[0101] The processing unit 1 supplies rinsing solution to the second main surface Wb of the substrate W so as to bring the in-plane average value of the potential of the first main surface Wa of the substrate W closer to zero. Specifically, the control unit 90 controls each part of the processing unit 1 based on the average processing conditions determined in the condition determination step S41. The average processing conditions include, for example, the rotation speed of the substrate W (target value), the second discharge time of the rinsing solution (target value), and the flow rate of the rinsing solution (target value).

[0102] In the condition determination step S41, the control unit 90 determines the average processing conditions as follows: In the average potential adjustment step S44, the control unit 90 determines the average processing conditions so that the in-plane average value of the potential of the first main surface Wa of the substrate W can be within a predetermined potential range including zero. As an example, the control unit 90 determines the rotation speed of the substrate W, the discharge time of the rinse liquid, and the flow rate of the rinse liquid so that the absolute value of the in-plane average value of the potential is less than or equal to a predetermined potential reference value. The potential reference value may be, for example, 1V, 0.5V, or 0.1V.

[0103] Figure 16 is a schematic graph showing an example of the potential distribution of the first main surface Wa of the substrate W after the average potential adjustment step S44. In the example in Figure 16, the potential distribution immediately before the average potential adjustment step S44 is shown by a dashed line. In the example in Figure 16, the change in potential during the average potential adjustment step S44 is schematically shown by dashed arrows. As shown in Figure 16, when the second main surface Wb of the substrate W becomes negatively charged, the potential distribution of the first main surface Wa is offset (shifted) to the positive side by an amount corresponding to the amount of charge.

[0104] When the in-plane average value falls within a predetermined potential range, the processing unit 1 terminates the supply of rinse fluid. For example, when a predetermined second discharge time has elapsed since the supply valve 42 was opened, the control unit 90 closes the supply valve 42.

[0105] Next, in the drying step S45, similar to the drying step S16, the processing unit 1 supplies the drying liquid to the first main surface Wa of the substrate W, and in the drying step S46, similar to the drying step S17, the substrate W is dried. Next, in the release step S47, the substrate holding unit 2 releases the substrate W, and the second transport unit 122 transports the statically discharged substrate W. This statically discharged substrate W is then wet-processed by another processing unit 1 or another substrate processing device (not shown).

[0106] As described above, after the wet step S1, the processing unit 1 supplies the rinse solution to the second main surface Wb of the substrate W under processing conditions based on the charge information (average potential adjustment step S44). This makes it possible to bring the in-plane average value of the potential of the first main surface Wa of the substrate W closer to zero. In other words, even if the first main surface Wa of the substrate W becomes negatively charged by the wet step S1, the average potential adjustment step S44 makes it possible to bring the in-plane average value of the potential of the first main surface Wa of the substrate W closer to zero. To put it another way, the processing unit 1 can properly discharge the first main surface Wa of the substrate W. Therefore, even if a processing solution with low electrical resistivity is supplied to the first main surface Wa of the substrate W during the subsequent wet processing, the possibility of a large current flowing between the first main surface Wa of the substrate W and the processing solution can be reduced.

[0107] In the example described above, the thickness of the insulating film on the second main surface Wb of the substrate W is, for example, 20 nm or more. Therefore, sufficient inductive charging can be generated on the substrate W, and the potential of the first main surface Wa of the substrate W can be more appropriately offset to the positive side.

[0108] Furthermore, in the example described above, the processing unit 1 also performs a process to equalize the potential distribution on the first main surface Wa of the substrate W (potential equalization step S43). As a result, the potential can be brought close to zero across the entire first main surface Wa of the substrate W. Therefore, the possibility of a large current flowing between the first main surface Wa of the substrate W and the processing solution during the subsequent wet processing can be further reduced.

[0109] Furthermore, in the above example, the liquid application position can be changed by moving the rinse nozzle 30r. Therefore, compared to a configuration in which rinse liquid is discharged from multiple nozzles toward multiple liquid application positions, the potential distribution of the first main surface Wa of the substrate W can be made uniform with a simpler configuration.

[0110] In the average potential adjustment step S44, the second discharge unit 4 may dispense the rinse liquid at any position on the second main surface Wb of the substrate W, but in the specific example described above, it is dispensed in the center. As a result, the rinse liquid flows along the entire surface of the second main surface Wb, and the entire surface of the second main surface Wb can be negatively charged. In comparison, if the rinse liquid is dispensed at the periphery of the second main surface Wb of the substrate W, the rinse liquid will negatively charge only the part of the second main surface Wb outside the periphery. As a result, the overall charge of the second main surface Wb is small. Conversely, by dispensing the rinse liquid at the center of the second main surface Wb of the substrate W, the second main surface Wb of the substrate W can be negatively charged more efficiently, and the charge of the second main surface Wb can be increased. Consequently, the potential distribution of the first main surface Wa of the substrate W can be more efficiently offset to the positive side.

[0111] Furthermore, in the example described above, the average potential adjustment step S44 is completed before the drying step S45 begins. In other words, in the drying step S45, the rinsing solution, which is less volatile than the drying solution, is not supplied to the substrate W. Therefore, the substrate W can be dried more quickly.

[0112] <Electrical resistivity> Figure 17 is a schematic diagram showing a second example of the configuration of the processing unit 1. The processing unit 1 in the second example differs from the processing unit 1 in the first example in terms of the specific configuration of the first discharge unit 3. In the second example, the first discharge unit 3 is capable of dispensing a first rinse liquid and a second rinse liquid, respectively, as rinse liquids. The electrical resistivity of the first rinse liquid is higher than that of the second rinse liquid. For example, the first rinse liquid is pure water, and the second rinse liquid is carbon dioxide water.

[0113] In the example shown in Figure 17, the supply pipe 31r branches into two upstream, with the upstream end of one branch connected to the first rinse liquid supply source and the upstream end of the other branch connected to the second rinse liquid supply source. The supply pipe 31r is provided with a switching unit that switches the rinse liquid supplied to the rinse nozzle 30r between the first rinse liquid and the second rinse liquid. In the example shown in Figure 18, the switching unit includes supply valves 32ra and 32rb. Supply valve 32ra is provided in one branch pipe, and supply valve 32rb is provided in the other branch pipe. A flow control valve 33ra is also provided in one branch pipe, and a flow control valve 33rb is also provided in the other branch pipe. These supply valves and flow control valves are controlled by the control unit 90.

[0114] An example of the operation of the processing unit 1 in the second example is the same as in the first example. However, a specific example of the operation in the potential equalization step S43 differs. In the processing unit 1 in the second example, in the potential equalization step S43, the first rinse liquid nozzle and the second rinse liquid nozzle are switched according to the liquid application position. Figure 18 is a schematic diagram showing an example of the processing unit 1 in the potential equalization step S43. As shown in Figure 18, the first discharge unit 3 discharges the second rinse liquid, which has a relatively low electrical resistivity, to the second liquid application position where the potential is relatively close to the bottom value, and discharges the first rinse liquid, which has a relatively high electrical resistivity, to the first liquid application position where the potential is relatively far from the bottom value. In other words, in the condition determination step S41, the control unit 90 sets the first rinse liquid as the processing liquid to be discharged toward the first liquid application position and the second rinse liquid as the processing liquid to be discharged toward the second liquid application position under uniform processing conditions.

[0115] The higher the electrical resistivity of the rinse solution, the greater the amount of charge (i.e., the decrease in potential) due to friction between the rinse solution and the substrate W. Therefore, at the first application point, the friction between the highly resistive first rinse solution and the substrate W can further lower the potential at the first application point. In other words, the potential at the first application point can be brought closer to the bottom value more appropriately.

[0116] On the other hand, at the second rinsing point, although static charge is generated due to friction between the second rinse solution and the substrate W, the amount of charge (i.e., the decrease in potential) is smaller than that of the first rinse solution. Furthermore, since the second potential difference is smaller than the first potential difference, by discharging the second rinse solution at the second rinsing point, the potential at the second rinsing point can be brought closer to the bottom value more appropriately.

[0117] Furthermore, compared to the case where the first rinse solution is discharged to the second application position, the flow rate of the second rinse solution to the second application position can be set to be relatively large. By setting a larger flow rate for the second rinse solution, coverage at the second application position can be maintained more appropriately. Conversely, this reduces the possibility of insufficient rinse solution on the first main surface Wa of the substrate W at the second application position, leading to exposure to the outside. As a result, the possibility of particles adhering to the first main surface Wa of the substrate W can also be reduced.

[0118] In particular, in the example described above, the second rinsing solution is located closer to the center of the substrate W than the first rinsing solution, which can easily lead to insufficient coverage. However, by using a second rinsing solution with low electrical resistivity for the second rinsing solution, it is possible to bring the potential at the second rinsing solution closer to the bottom value while improving coverage.

[0119] The first immersion range from which the first rinse solution is discharged and the second immersion range from which the second rinse solution is discharged are determined in the condition determination step S41 as one of the uniform processing conditions. For example, the control unit 90 may determine the first and second immersion ranges based on the charge information acquired in the measurement step S22. As an example, the control unit 90 may determine the second immersion range to be a range in which the potential is less than or equal to a predetermined percentage of the bottom value. The correspondence between the flow rate of the first rinse solution, the immersion time, and the change in potential, and the correspondence between the flow rate of the second rinse solution, the immersion time, and the change in potential are set in advance by experimentation or the like. Based on the charge information acquired in the measurement step S22 and the above correspondence information, the control unit 90 determines the uniform processing conditions such that the difference between the maximum and minimum values ​​of the potential is, for example, 1V or less.

[0120] <Execution timing of the average potential adjustment step and the potential equalization step> In the example in Figure 10, the average potential adjustment step S44 is performed after the potential equalization step S43. However, this is not necessarily the case. Figure 19 is a schematic diagram showing an example of the timing of the execution of the average potential adjustment step S44 and the potential equalization step S43. As shown in Figure 19(a), the average potential adjustment step S44 may be performed in parallel with the potential equalization step S43. The start time of the average potential adjustment step S44 may be at the same time as, before, or after the start time of the potential equalization step S43. Similarly, the end time of the average potential adjustment step S44 may be at the same time as, before, or after the end time of the potential equalization step S43. In other words, at least a portion of the average potential adjustment step S44 may be performed in parallel with at least a portion of the potential equalization step S43. When at least a portion of the average potential adjustment step S44 is performed in parallel with at least a portion of the potential equalization step S43 in this way, the throughput of static elimination can be improved.

[0121] Furthermore, as shown in Figure 19(b), the average potential adjustment step S44 may be performed before the potential equalization step S43.

[0122] <Charged electricity brought in by the customer> In some cases, a substrate W with a negatively charged first main surface Wa is fed into the substrate processing apparatus 100. In other words, a charged substrate W may be contained within the carrier C.

[0123] Figure 20 is a flowchart showing a second example of the operation of the substrate processing apparatus 100. In the example in Figure 20, the acquisition step S2, the determination step S3, the static elimination step S4, and the wet step S1 are performed in this order. In the example in Figure 20, if it is determined in the determination step S3 that static elimination is unnecessary, the static elimination step S4 is not performed and the wet step S1 is performed. On the other hand, if it is determined in the determination step S3 that static elimination is necessary, the static elimination step S4 and the wet step S1 are performed consecutively. In this case, the drying step S45, the drying step S46, the holding release step S47 (Figure 10), and the holding step S11 (Figure 7) may be omitted. In other words, in the processing unit 1, the condition determination step S41 to the average potential adjustment step S44 (Figure 10) and the first chemical solution step S12 to the holding release step S18 (Figure 7) may be performed in this order. Even in this case, at the start of the first chemical solution step S12, the potential of the first main surface Wa of the substrate W is low, so the possibility of a large current being generated between the substrate W and the first chemical solution can be reduced.

[0124] <Pre-measurement> Incidentally, if the charged state of the substrate W before the wet step S1 is determined, and the processing conditions for the wet step S1 are determined, then the potential distribution of the first main surface Wa of the substrate W after the wet step S1 will be roughly the same. In other words, if the wet step S1 is performed sequentially on multiple substrates W, the potential distribution of the first main surface Wa of each substrate W will be roughly the same.

[0125] Therefore, a wet treatment may be performed on the substrate W in advance under the same processing conditions as the wet step S1. This substrate W may be a substrate used in an actual product, or it may be a sample substrate. The potential of the first main surface Wa of the substrate W after the wet treatment may be measured by the sensor 82 (acquisition step). This allows the user to obtain the potential distribution of the first main surface Wa of the substrate W after the wet treatment. The user may then determine the average processing conditions to bring the in-plane average value of the potential of this first main surface Wa within a predetermined range by experimentation or the like. In other words, the average processing conditions may be determined by experimentation on a substrate W different from the substrate W on which the wet step S1 is actually performed.

[0126] As described above, the average processing conditions can be obtained in advance. In other words, the user determines the average processing conditions by experimentally performing the wet step S1, acquisition step S2, and condition determination step S41 in advance. Similarly, the user may determine the uniform processing conditions in advance through experiments or other means. The user also stores processing condition information (recipe information) indicating the average processing conditions and the uniform processing conditions in the storage unit 94 in advance.

[0127] <Wet treatment with static elimination> Processing unit 1 may perform an average potential adjustment step S44 during wet processing, and similarly, it may perform a potential equalization step S43 during wet processing. Hereinafter, wet processing including the average potential adjustment step S44 will also be referred to as wet processing with static elimination. Figure 21 is a flowchart showing a first example of the operation of wet processing with static elimination. Figure 22 is a schematic diagram showing an example of processing on the substrate W according to the flowchart in Figure 21.

[0128] In the example shown in Figure 21, the holding step S51, the first chemical solution step S52, the rinsing step S53, and the second chemical solution step S54 are performed in this order. The holding step S51, the first chemical solution step S52, the rinsing step S53, and the second chemical solution step S54 are the same as the holding step S11, the first chemical solution step S12, the rinsing step S13, and the second chemical solution step S14, respectively. As a result, the first chemical solution, the rinsing solution, and the second chemical solution are supplied to the first main surface Wa of the substrate W in this order.

[0129] In the example shown in Figure 21, in the rinsing step S55 following the second chemical step S54, the processing unit 1 supplies rinsing liquid to the first main surface Wa of the substrate W. Specifically, the control unit 90 controls each part of the processing unit 1 based on uniform processing conditions, causing the first dispensing unit 3 to dispense rinsing liquid at multiple application locations on the first main surface Wa of the substrate W. As a result, the first dispensing unit 3 replaces the processing liquid on the first main surface Wa of the substrate W from the second chemical solution to the rinsing liquid while simultaneously homogenizing the potential distribution on the first main surface Wa of the substrate W. Conversely, the uniform processing conditions are set in advance through experiments or other means so as to achieve both the replacement of the second chemical solution with the rinsing liquid and the homogenization of the potential distribution.

[0130] In the example shown in Figure 22, the substrate W in the fourth position is shown where the rinsing step S55 is being performed. In this rinsing step S55, similar to the potential equalization step S43, the nozzle movement drive unit 35r moves the rinse nozzle 30r along the first main surface Wa of the substrate W between the first and second processing positions. Furthermore, the rinse nozzle 30r discharges the rinse liquid with a longer immersion time and / or a larger flow rate and / or a higher electrical resistivity as the immersion position is further from the bottom potential value. This allows for more appropriate equalization of the potential distribution on the first main surface Wa of the substrate W. In other words, in the rinsing step S55, the potential distribution on the first main surface Wa of the substrate W can be equalized while performing a rinsing process that washes away the first chemical solution on the first main surface Wa of the substrate W with the rinse liquid. This rinsing step S55 can also be called a potential equalization step. In other words, the potential equalization step includes the rinsing step S55.

[0131] Once both the substitution of the second chemical solution with the rinsing solution and the homogenization of the potential distribution have been sufficiently achieved, the processing unit 1 terminates the supply of the rinsing solution to the first main surface Wa of the substrate W. For example, when a predetermined rinsing time has elapsed since the supply valve 32r was opened, the control unit 90 closes the supply valve 32r. The control unit 90 controls the nozzle movement drive unit 35r to move the rinsing nozzle 30r to the standby position.

[0132] Next, in the average potential adjustment step S56, the processing unit 1 supplies rinsing liquid to the second main surface Wb of the substrate W. The average potential adjustment step S56 is the same as the average potential adjustment step S44.

[0133] Next, the drying step S57, drying step S58, and release step S59 are performed in this order. The drying step S57, drying step S58, and release step S59 are the same as the drying step S16, drying step S17, and release step S18, respectively.

[0134] As described above, the processing unit 1 can perform wet processing while removing static electricity from the first main surface Wa of the substrate W.

[0135] Figure 23 is a flowchart showing a second example of the operation of the wet treatment with static elimination. Figure 24 is a schematic diagram showing an example of the state of the substrate W according to the flowchart in Figure 23. Here, the average potential adjustment step S56 is performed in parallel with the supply of the treatment solution to the first main surface Wa of the substrate W. In the example in Figure 23, the average potential adjustment step S56 is performed in parallel with the first chemical solution step S52, the rinse solution step S53, the second chemical solution step S54, and the rinse solution step S55.

[0136] According to this, the completion time of the average potential adjustment step S56 can be made earlier compared to the example in Figure 21. In other words, the throughput of the wet treatment with static elimination can be improved. Moreover, in steps in which the average potential adjustment step S56 is performed in parallel, the amount of charge on the first main surface Wa of the substrate W can be reduced. That is, by supplying the treatment liquid to the first main surface Wa of the substrate W, the potential of the first main surface Wa of the substrate W is lowered, while by supplying the rinsing liquid to the second main surface Wb of the substrate W, the potential of the first main surface Wa of the substrate W can be changed to the positive side. As a result, the amount of negative charge on the first main surface Wa of the substrate W can be reduced in each step, and the possibility of a large current flowing between the substrate W and the treatment liquid can be reduced.

[0137] The flow rate and discharge time of the rinsing liquid supplied to the second main surface Wb of the substrate W in each step may be set so that the absolute value of the minimum (negative) potential in the potential distribution of the first main surface Wa is less than or equal to a predetermined second potential difference reference value. The second potential difference reference value may be the same as the first potential difference reference value, which is the allowable value of the in-plane average value after the drying step S58, or it may be greater than the first potential difference reference value. The second potential difference reference value may be, for example, 10V or 5V. This makes it possible to appropriately reduce the amount of negative charge on the first main surface Wa of the substrate W in each step.

[0138] Note that the average potential adjustment step S56 does not necessarily have to be performed in parallel with all of the first chemical solution step S52, the rinse solution step S53, the second chemical solution step S54, and the rinse solution step S55. At least a portion of the average potential adjustment step S56 may be performed in parallel with at least a portion of the first chemical solution step 52 to the rinse solution step S55. This can also improve throughput. The throughput can be improved most if the average potential adjustment step S56 is completed before the rinse solution step S55 is completed.

[0139] Furthermore, as schematically shown by the double-dotted arrows in Figures 22 and 24, the rinse nozzle 30r may also move between the first and second processing positions in the rinse liquid step S53. In other words, the rinse liquid step S53 may also function as a potential equalization step. To put it another way, the potential equalization step may include the rinse liquid step S53. This makes it possible to reduce the variation in the potential distribution of the first main surface Wa in the rinse liquid step S53. Moreover, since both the rinse liquid step S53 and the rinse liquid step S55 function as potential equalization steps, the discharge time of the rinse liquid solely for the purpose of equalizing the potential distribution can be shortened. That is, even though the replacement with the rinse liquid is complete, if the potential distribution is still uneven, it is necessary to continue discharging the rinse liquid, but the discharge time of such rinse liquid can be shortened. This further improves throughput.

[0140] The first chemical solution step S52 may also function as a potential equalization step. In other words, the potential equalization step may include the first chemical solution step (corresponding to the chemical solution step) S52 and the rinse step S53. According to this, in the potential equalization step, the potential distribution of the first main surface Wa of the substrate W can be equalized while performing chemical treatment, which treats the first main surface Wa of the substrate W with the chemical solution, and rinsing, which washes away the chemical solution with the rinse step. That is, the potential distribution of the first main surface Wa of the substrate W can be equalized in the first chemical solution step S52 and the rinse step S53. Alternatively, the first chemical solution step S52 may prioritize chemical treatment of the substrate W and may not function as a potential equalization step. That is, the first chemical solution nozzle 30ca may not move during the discharge of the first chemical solution. The same applies to the second chemical solution step (corresponding to the chemical solution step) S54.

[0141] <Measurement Unit> Figure 25 is a schematic diagram showing a second example of the configuration of the measurement unit 8. In the example of Figure 25, the measurement unit 20 includes a plurality of sensors 82. The plurality of sensors 82 each measure the potential of different measurement areas on the first main surface Wa of the substrate W, which is supported or held by the substrate placement portion 81. For example, the plurality of sensors 82 may each measure the potential of multiple measurement areas on the first main surface Wa of the substrate W that are at different radial positions. For example, the plurality of sensors 82 may be arranged with spacing along the radial direction.

[0142] In measurement step S22, all of the multiple sensors 82 measure the potential and output the measurement results to the control unit 90. This allows the control unit 90 to acquire charge information, including multiple potentials measured by the multiple sensors 82.

[0143] The measurement unit 8 may include a sensor movement drive unit 83 that moves a plurality of sensors 82 together. The sensor movement drive unit 83 may move the plurality of sensors 82 along their arrangement direction (i.e., radial direction).

[0144] Since multiple sensors 82 are provided, the throughput of the measurement step S22 can be improved.

[0145] <Location of the measuring unit> In the example described above, the measuring unit 8 is located on the mounting section 123, which is situated between the first transport section 112 and the second transport section 122. However, the position of the measuring unit 8 is not necessarily limited to this. Figure 26 is a schematic diagram showing an example of the configuration of a tower TW. As shown in Figure 26, the measuring unit 8 may be aligned vertically with the processing unit 1. In other words, one or more processing units 1 and measuring units 8 may be stacked vertically on top of each other to form a tower TW.

[0146] <Sensor location> In the example described above, the sensor 82 is located in a measurement unit 8 separate from the processing unit 1. However, the sensor 82 may also be located in the processing unit 1. In other words, the sensor 82 may be located inside the chamber 10. In this case, the sensor 82 measures the potential of the first main surface Wa of the substrate W held by the substrate holding unit 2.

[0147] As described above, the substrate processing apparatus 100 and the substrate processing method have been described in detail, but the above description is illustrative in all respects, and this disclosure is not limited thereto. Furthermore, the various modifications described above can be applied in combination as long as they do not contradict each other. And it is understood that a number of modifications not illustrated can be conceivable without falling outside the scope of this disclosure.

[0148] This disclosure includes the following aspects:

[0149] The first embodiment is a substrate processing method comprising: an acquisition step of acquiring charge information indicating the potential of the first main surface of a substrate having a first main surface and a second main surface on which an insulating film is formed; and a static discharge step including, after the acquisition step, an average potential adjustment step of supplying a rinsing liquid to the second main surface of the substrate while rotating the substrate around a predetermined rotation axis under processing conditions based on the charge information.

[0150] A second embodiment is a substrate processing method according to the first embodiment, wherein in the average potential adjustment step, the rinsing liquid is supplied to the central part of the second main surface of the substrate.

[0151] A third embodiment is a substrate processing method according to the first or second embodiment, wherein the charge information is information indicating the potential distribution of the first main surface of the substrate, and the static elimination step further comprises a potential equalization step in which, while rotating the substrate around the rotation axis under uniform processing conditions based on the charge information, processing liquid is discharged from a nozzle to each liquid contact position on the first main surface of the substrate to equalize the potential distribution of the first main surface.

[0152] A fourth aspect is a substrate processing method according to the third aspect, wherein at least a portion of the potential equalization step is performed in parallel with at least a portion of the average potential adjustment step.

[0153] A fifth aspect is a substrate processing method according to the third or fourth aspect, wherein in the potential equalization step, the nozzle is moved along the first main surface of the substrate while the processing liquid is discharged from the nozzle.

[0154] The sixth aspect is a substrate processing method according to the fifth aspect, wherein, in the charge information, if the first potential difference between the bottom value of the potential on the first main surface of the substrate and the potential at the first liquid deposition position on the first main surface of the substrate is greater than the second potential difference between the bottom value and the potential at the second liquid deposition position on the first main surface of the substrate, then, under the uniform processing conditions, the movement speed of the nozzle at the first liquid deposition position is set higher than the movement speed of the nozzle at the second liquid deposition position.

[0155] The seventh aspect is a substrate processing method according to any one of the third to sixth aspects, wherein, in the charge information, if the first potential difference between the bottom value of the potential on the first main surface of the substrate and the potential at the first liquid deposition position on the first main surface of the substrate is greater than the second potential difference between the bottom value and the potential at the second liquid deposition position on the first main surface of the substrate, then, under the uniform processing conditions, the flow rate of the processing liquid discharged toward the first liquid deposition position is set to be greater than the flow rate of the processing liquid discharged toward the second liquid deposition position.

[0156] The eighth aspect is a substrate processing method according to any one of the third to seventh aspects, wherein, in the charge information, if the first potential difference between the bottom value of the potential at the first main surface of the substrate and the potential at the first liquid deposition position on the first main surface of the substrate is greater than the second potential difference between the bottom value and the potential at the second liquid deposition position on the first main surface of the substrate, then, under the uniform processing conditions, a first rinse liquid is set as the processing liquid discharged toward the first liquid deposition position, and a second rinse liquid having a lower electrical resistivity than the first rinse liquid is set as the processing liquid discharged toward the second liquid deposition position.

[0157] The ninth aspect is a substrate processing method according to any one of the first to eighth aspects, further comprising a wet step of performing a wet treatment on the substrate before the acquisition step.

[0158] The tenth aspect is a substrate processing method according to any one of the first to eighth aspects, further comprising a wet step of performing a wet treatment on the substrate after the static elimination step.

[0159] An eleventh aspect is a substrate processing method according to any one of the third to eighth aspects, further comprising a chemical solution step of supplying a chemical solution to the first main surface of the substrate before the potential equalization step, wherein the potential equalization step includes a rinsing solution step in which the nozzle discharges a rinsing solution as the processing solution.

[0160] The twelfth aspect is a substrate processing method according to any one of the third to eighth aspects, wherein the potential equalization step includes a chemical solution step in which the nozzle supplies a chemical solution as the processing liquid, and a rinsing liquid step in which the nozzle supplies a rinse as the processing liquid.

[0161] According to the first embodiment, the second main surface of the substrate can be negatively charged by supplying rinsing liquid to the second main surface of the substrate. This negative charge induces charging in the substrate, which can offset the potential of the first main surface of the substrate to the positive side. In the average potential adjustment step, the rinsing liquid is supplied to the second main surface of the substrate under processing conditions based on the charge information, so that the in-plane average value of the potential of the first main surface of the substrate can be brought close to zero.

[0162] According to the second embodiment, since the rinsing liquid flows over the entire surface of the second main surface of the substrate, the entire surface of the second main surface of the substrate can be negatively charged. This makes it possible to charge the second main surface of the substrate more efficiently.

[0163] According to the third embodiment, the potential distribution of the first main surface of the substrate is made uniform, so that the potential can be brought close to zero across the entire first main surface of the substrate.

[0164] According to the fourth embodiment, throughput can be improved.

[0165] According to the fifth embodiment, the liquid application position can be changed by moving the nozzle. Therefore, compared to an embodiment in which rinsing liquid is discharged from multiple nozzles toward multiple liquid application positions, the potential distribution of the first main surface of the substrate can be made uniform with a simpler configuration.

[0166] According to the sixth embodiment, since the nozzle's movement speed at the first liquid application position is higher than the nozzle's movement speed at the second liquid application position, the application time for the rinse liquid at the first liquid application position is longer than the application time for the rinse liquid at the second liquid application position. The longer the application time, the greater the decrease in potential at that liquid application position, so the decrease in potential at the first liquid application position is greater than the decrease in potential at the second liquid application position. The first potential difference between the potential at the first liquid application position and the bottom value is greater than the second potential difference between the potential at the second liquid application position and the bottom value, so both the potential at the first liquid application position and the potential at the second liquid application position can be brought appropriately closer to the bottom value.

[0167] According to the seventh embodiment, the larger the flow rate, the greater the potential drop at the liquid contact point. Since the first flow rate at the first liquid contact point is greater than the second flow rate at the second liquid contact point, the potential drop at the first liquid contact point is greater than the potential drop at the second liquid contact point. Since the first potential difference between the potential at the first liquid contact point and the bottom value is greater than the second potential difference between the potential at the second liquid contact point and the bottom value, both the potential at the first liquid contact point and the potential at the second liquid contact point can be brought appropriately closer to the bottom value.

[0168] According to the eighth embodiment, the greater the electrical resistivity, the greater the potential drop at the liquid application position. Since the first rinse solution with high electrical resistivity is applied to the first liquid application position and the second rinse solution with low electrical resistivity is applied to the second liquid application position, the potential drop at the first liquid application position is greater than the potential drop at the second liquid application position. The first potential difference between the potential at the first liquid application position and the bottom value is greater than the second potential difference between the potential at the second liquid application position and the bottom value, so both the potential at the first liquid application position and the potential at the second liquid application position can be brought appropriately closer to the bottom value.

[0169] According to the ninth aspect, even if the first main surface of the substrate becomes negatively charged by wet processing, the in-plane average value of the potential of the first main surface of the substrate can be brought close to zero.

[0170] According to the tenth embodiment, even if a processing solution with low electrical resistivity is supplied to the first main surface of the substrate by wet processing, the possibility of a large current being generated between the first main surface of the substrate and the processing solution can be reduced.

[0171] According to the eleventh embodiment, in the potential equalization step, the potential distribution on the first main surface of the substrate can be made uniform while performing a rinsing process in which the chemical solution on the first main surface of the substrate is washed away with a rinsing solution.

[0172] According to the twelfth embodiment, in the potential equalization step, the potential distribution of the first main surface of the substrate can be made uniform while performing a chemical treatment in which the first main surface of the substrate is treated with a chemical solution and a rinsing treatment in which the chemical solution is washed away with a rinsing solution. [Explanation of symbols]

[0173] S1 Wet Step S2 Acquisition Steps S4 Static Elimination Step S43 Potential equalization step S44 Average potential adjustment step S52 Chemical Solution Step (First Chemical Solution Step) S53, S55 Rinse liquid step S54 Chemical Solution Step (Second Chemical Solution Step) 30 nozzles (first nozzle) Q1 Rotation axis W board Wa First Main Surface Wb 2nd principal surface

Claims

1. An acquisition step to acquire charge information indicating the potential of the first main surface of a substrate having a first main surface and a second main surface on which an insulating film is formed, After the acquisition step, a static elimination step is performed which includes an average potential adjustment step in which the substrate is rotated around a predetermined rotation axis while a rinsing liquid is supplied to the second main surface of the substrate under processing conditions based on the charge information, and A substrate processing method comprising:

2. A substrate processing method according to claim 1, A substrate processing method comprising supplying the rinsing liquid to the central part of the second main surface of the substrate in the average potential adjustment step.

3. A substrate processing method according to claim 1 or claim 2, The charge information is information indicating the potential distribution of the first main surface of the substrate, A substrate processing method wherein the static discharge step further comprises a potential equalization step, in which the substrate is rotated around the rotation axis under uniform processing conditions based on the charge information, and processing liquid is discharged from a nozzle to each liquid contact position on the first main surface of the substrate, thereby equalizing the potential distribution on the first main surface.

4. A substrate processing method according to claim 3, A substrate processing method comprising performing at least a portion of the potential equalization step in parallel with at least a portion of the average potential adjustment step.

5. A substrate processing method according to claim 3, A substrate processing method comprising the potential equalization step, wherein the nozzle is moved along the first main surface of the substrate while the processing liquid is discharged from the nozzle.

6. A substrate processing method according to claim 5, In the aforementioned charging information, if the first potential difference between the bottom value of the potential on the first main surface of the substrate and the potential at the first liquid deposition position on the first main surface of the substrate is greater than the second potential difference between the bottom value and the potential at the second liquid deposition position on the first main surface of the substrate, then, under the uniform processing conditions, the movement speed of the nozzle at the first liquid deposition position is set higher than the movement speed of the nozzle at the second liquid deposition position.

7. A substrate processing method according to claim 3, In the aforementioned charge information, if the first potential difference between the bottom value of the potential at the first main surface of the substrate and the potential at the first liquid deposition position on the first main surface of the substrate is greater than the second potential difference between the bottom value and the potential at the second liquid deposition position on the first main surface of the substrate, then, under the uniform processing conditions, the flow rate of the processing liquid discharged toward the first liquid deposition position is set to be greater than the flow rate of the processing liquid discharged toward the second liquid deposition position.

8. A substrate processing method according to claim 3, In the aforementioned charge information, if the first potential difference between the bottom value of the potential on the first main surface of the substrate and the potential at the first liquid deposition position on the first main surface of the substrate is greater than the second potential difference between the bottom value and the potential at the second liquid deposition position on the first main surface of the substrate, then, under the uniform processing conditions, the processing liquid discharged toward the first liquid deposition position is set to be a first rinse liquid, and the processing liquid discharged toward the second liquid deposition position is set to be a second rinse liquid having a lower electrical resistivity than the first rinse liquid.

9. A substrate processing method according to claim 1 or claim 2, A substrate processing method further comprising a wet step of performing a wet treatment on the substrate before the acquisition step.

10. A substrate processing method according to claim 1 or claim 2, A substrate processing method further comprising a wet step of performing a wet treatment on the substrate after the static discharge step.

11. A substrate processing method according to claim 3, Prior to the potential equalization step, the system further comprises a chemical solution step of supplying a chemical solution to the first main surface of the substrate, A substrate processing method comprising a potential equalization step, a rinsing step in which the nozzle discharges a rinsing liquid as the processing liquid.

12. A substrate processing method according to claim 3, The aforementioned potential equalization step is, The process includes a chemical solution step in which the nozzle supplies the chemical solution as the processing liquid, The nozzle supplies rinse as the processing liquid in a rinsing liquid step, and A substrate processing method, including the following.

Images