Substrate processing apparatus and substrate processing method

Abstract

To provide a substrate processing apparatus and a substrate processing method that can accurately specify process liquid in a process liquid nozzle during suck back operation.SOLUTION: A substrate processing apparatus 100 comprises a nozzle 136, a supply unit 135, a liquid return unit 160, a near infrared light source 140, a near infrared imaging unit 150, and a control unit 102. The nozzle 136 supplies process liquid L to a substrate W. The supply unit 135 supplies the process liquid L to the nozzle 136. The near infrared light source 140 irradiates an area including a leading end 136a of the nozzle 136 with a near infrared ray. The control unit 102 stops supply of the process liquid L performed by the supply unit 135, and causes the liquid return unit 160 to pull back the process liquid L in the nozzle 136 to an upstream side. The control unit 102 causes the near infrared imaging unit 150 to pick up an image of the process liquid L moving to the upstream side in the nozzle 136. The control unit 102 specifies the position of an outer edge of the process liquid L in the nozzle 136 on the basis of a picked-up image.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method. [Background technology]

[0002] There is known a substrate processing apparatus that processes a substrate by supplying a processing liquid to the substrate (see, for example, Patent Document 1). Patent Document 1 describes a substrate processing apparatus that includes a supply nozzle that supplies the processing liquid to the substrate, a pipe as a liquid supply path that supplies the processing liquid to the supply nozzle, and a supply valve disposed in the pipe. The supply valve functions as a suck-back valve. When the processing liquid is not being supplied from the supply nozzle, the supply valve generates negative pressure in the suction chamber and draws in the front surface of the processing liquid from the tip of the supply nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-126886 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a substrate processing apparatus such as that described in Patent Document 1, a suck-back valve prevents processing liquid from dropping from the supply nozzle by retracting the front surface of the processing liquid from the tip of the supply nozzle when processing liquid is not being supplied from the supply nozzle.

[0005] However, when the suck-back valve is switched, it is difficult to confirm whether the processing liquid in the supply nozzle has been drawn back normally. Specifically, since the processing liquid used in substrate processing is generally transparent, the processing liquid cannot be detected by a general CCD camera. For this reason, the processing liquid in the supply nozzle may not be identified with high accuracy. Hereinafter, drawing back the processing liquid in the nozzle to the upstream side may be referred to as suck-back.

[0006] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a substrate processing apparatus and a substrate processing method that are capable of identifying the processing liquid in the processing liquid nozzle during suck back with high accuracy. [Means for solving the problem]

[0007] According to one aspect of the present invention, a substrate processing apparatus includes a substrate holding unit, a processing liquid nozzle, a supply unit, a liquid return unit, a near-infrared light source, a near-infrared imaging unit, and a control unit. The substrate holding unit holds a substrate and rotates the substrate. The processing liquid nozzle supplies a processing liquid to an upper surface of the substrate. The supply unit supplies the processing liquid to the processing liquid nozzle. The liquid return unit draws the processing liquid in the processing liquid nozzle upstream. The near-infrared light source irradiates an area including a tip of the processing liquid nozzle with near-infrared light. The near-infrared imaging unit generates an image of the processing liquid irradiated with the near-infrared light from the near-infrared light source. The control unit controls the supply unit, the liquid return unit, and the near-infrared imaging unit. The control unit stops the supply of the processing liquid by the supply unit, and draws the processing liquid in the processing liquid nozzle upstream by the liquid return unit. The control unit images the processing liquid moving upstream in the processing liquid nozzle by the near-infrared imaging unit. The control unit identifies a position of an outer edge of the treatment liquid in the treatment liquid nozzle based on the captured image.

[0008] In one embodiment, the control unit identifies a position of a downstream edge of the processing liquid in the processing liquid nozzle based on the captured image.

[0009] In one embodiment, the control unit calculates a speed at which the processing liquid moves upstream inside the processing liquid nozzle, based on the identified position of the downstream edge of the processing liquid.

[0010] In one embodiment, the control unit captures an image of the processing liquid moving upstream inside the processing liquid nozzle with the near-infrared imaging unit at a predetermined time after the liquid returning unit starts to return the processing liquid in the processing liquid nozzle to the upstream side, and the control unit calculates the speed based on the identified position of the downstream edge of the processing liquid and the predetermined time.

[0011] In one embodiment, the control unit calculates a distance from a tip of the treatment liquid nozzle to a downstream edge of the treatment liquid based on the captured image, and calculates the velocity based on the calculated distance and the predetermined time.

[0012] In one embodiment, the control unit causes the near-infrared imaging unit to capture images of the processing liquid moving upstream inside the processing liquid nozzle a plurality of times at predetermined time intervals, and the control unit calculates the velocity based on positions of a downstream edge of the processing liquid in the plurality of captured images and the predetermined time.

[0013] In one embodiment, the treatment liquid nozzle has a liquid flow path through which the treatment liquid passes, and the control unit identifies a center line of the liquid flow path based on the captured image, and the control unit calculates the velocity based on a length of movement of a downstream edge of the treatment liquid along the center line of the liquid flow path and the predetermined time.

[0014] In one embodiment, the control unit determines whether or not an abnormality has occurred based on the identified position of the outer edge of the treatment liquid. If the control unit determines that the abnormality has occurred, the control unit changes at least one of a timing to start drawing back the treatment liquid upstream and a timing to stop drawing back the treatment liquid upstream based on the identified position of the outer edge of the treatment liquid.

[0015] In one embodiment, the control unit identifies the type of the treatment liquid based on the captured image.

[0016] In one embodiment, the near-infrared light source includes a plurality of near-infrared light sources emitting near-infrared rays having different peak wavelengths from each other, the control unit acquires type information indicating a type of the treatment liquid, and the control unit changes the near-infrared light source that irradiates an area including the tip of the treatment liquid nozzle based on the acquired type information.

[0017] According to another aspect of the present invention, a substrate processing method includes the steps of holding a substrate and rotating the substrate, supplying a processing liquid to a processing liquid nozzle and supplying the processing liquid from the processing liquid nozzle onto an upper surface of the substrate, pulling back the processing liquid in the processing liquid nozzle upstream after stopping the supply of the processing liquid, irradiating an area including the tip of the processing liquid nozzle with near-infrared rays, generating an image of the processing liquid irradiated with the near-infrared rays and moving upstream through the processing liquid nozzle, and identifying a position of an outer edge of the processing liquid in the processing liquid nozzle based on the image.

[0018] In one embodiment, in the specifying step, a position of a downstream edge of the processing liquid in the processing liquid nozzle is specified based on the captured image.

[0019] In one embodiment, the substrate processing method includes a step of calculating a speed at which the processing liquid moves upstream inside the processing liquid nozzle based on the identified position of a downstream edge of the processing liquid.

[0020] In one embodiment, in the process of generating the captured image, an image of the processing liquid moving upstream within the processing liquid nozzle is captured a predetermined time after the processing liquid in the processing liquid nozzle starts to return to the upstream side, and in the calculation process, the velocity is calculated based on the identified position of the downstream edge of the processing liquid and the predetermined time.

[0021] In one embodiment, in the calculating step, a distance from the tip of the processing liquid nozzle to a downstream edge of the processing liquid is calculated based on the captured image, and the speed is calculated based on the calculated distance and the specified time.

[0022] In one embodiment, in the process of generating the captured image, the processing liquid moving upstream within the processing liquid nozzle is imaged multiple times at a predetermined time interval, and in the calculation process, the velocity is calculated based on the position of the downstream edge of the processing liquid in the multiple captured images and the predetermined time.

[0023] In one embodiment, in the identifying step, a center line of a liquid flow path through which the processing liquid of the processing liquid nozzle passes is identified based on the captured image, and in the calculating step, the velocity is calculated based on the length traveled by the downstream edge of the processing liquid along the center line of the liquid flow path and the specified time.

[0024] In one embodiment, the substrate processing method includes a step of determining whether or not an abnormality has occurred based on the identified position of the outer edge of the processing liquid, and if it is determined that an abnormality has occurred, a step of changing at least one of the timing for starting to draw the processing liquid back upstream and the timing for stopping the drawing back of the processing liquid upstream based on the identified position of the outer edge of the processing liquid.

[0025] In one embodiment, in the identifying step, the type of the treatment liquid is identified based on the captured image.

[0026] In one embodiment, the near-infrared light source includes a plurality of near-infrared light sources emitting near-infrared rays having different peak wavelengths from each other, and the substrate processing method includes the steps of: acquiring type information indicating a type of the processing liquid; and changing the near-infrared light source that irradiates an area including a tip of the processing liquid nozzle based on the acquired type information. Effect of the Invention

[0027] According to the present invention, it is possible to provide a substrate processing apparatus and a substrate processing method capable of identifying the processing liquid in the processing liquid nozzle during suck back with high accuracy. [Brief description of the drawings]

[0028] [Figure 1] 1 is a schematic plan view of a substrate processing apparatus according to an embodiment of the present invention; [Diagram 2] 2 is a schematic diagram of a substrate processing unit in the substrate processing apparatus; FIG. [Diagram 3] FIG. 2 is a block diagram of the substrate processing apparatus. [Figure 4] FIG. 2 is a flow diagram of a substrate processing method according to the present embodiment. [Diagram 5] 2 is a schematic diagram showing a configuration around a liquid returning unit of the substrate processing apparatus of the present embodiment; FIG. [Figure 6] FIG. 13 is a schematic diagram showing the tip portion of the nozzle during suck back. [Figure 7] FIG. 13 is a schematic diagram showing the tip portion of the nozzle during suck back. [Figure 8] FIG. 13 is a schematic diagram showing the tip portion of the nozzle during suck back. [Figure 9] FIG. 13 is a schematic diagram showing the tip portion of the nozzle during suck back. [Figure 10] FIG. 13 is a schematic diagram showing the tip portion of the nozzle during suck back. [Figure 11] FIG. 13 is a schematic diagram showing a state in which the treatment liquid is separated in the nozzle during suck back. [Figure 12] 4 is a flow diagram of a substrate processing step in the substrate processing method of the present embodiment. FIG. [Figure 13] 1 is a schematic diagram of a substrate processing unit in a substrate processing apparatus equipped with a plurality of near-infrared light sources. [Figure 14] FIG. 11 is a flow diagram of a substrate processing process in an example in which the near-infrared light source includes a plurality of near-infrared light sources. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of a substrate processing apparatus and a substrate processing method according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference symbols and will not be described repeatedly. In this specification, to facilitate understanding of the invention, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other may be described. Typically, the X-axis and the Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction.

[0030] First, a substrate processing apparatus 100 according to the present embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic plan view of the substrate processing apparatus 100.

[0031] 1, the substrate processing apparatus 100 processes a substrate W. The substrate processing apparatus 100 processes the substrate W by performing at least one of etching, surface treatment, property imparting, treatment film formation, removal of at least a portion of a film, and cleaning.

[0032] The substrate W is used as a semiconductor substrate. The substrate W includes a semiconductor wafer. For example, the substrate W has a substantially circular disk shape. Here, the substrate processing apparatus 100 processes the substrates W one by one.

[0033] 1, the substrate processing apparatus 100 includes a plurality of substrate processing units 110, a fluid cabinet 10A, a fluid box 10B, a plurality of load ports LP, an indexer robot IR, a center robot CR, and a controller 101. The controller 101 controls the load ports LP, the indexer robot IR, the center robot CR, and the substrate processing units 110.

[0034] Each load port LP accommodates a plurality of stacked substrates W. The indexer robot IR transports the substrates W between the load port LP and the center robot CR. Note that a placement stage (path) on which the substrate W is temporarily placed may be provided between the indexer robot IR and the center robot CR, and the substrate W may be indirectly transferred between the indexer robot IR and the center robot CR via the placement stage. The center robot CR transports the substrates W between the indexer robot IR and the substrate processing units 110. Each of the substrate processing units 110 discharges a processing liquid onto the substrate W to process the substrate W. The fluid cabinet 10A accommodates a processing liquid. Note that the fluid cabinet 10A may accommodate a gas.

[0035] The substrate processing units 110 form a plurality of towers TW (four towers TW in FIG. 1) arranged to surround the center robot CR in a plan view. Each tower TW includes the substrate processing units 110 stacked vertically (three substrate processing units 110 in FIG. 1). Each fluid box 10B corresponds to a plurality of towers TW. The processing liquid in the fluid cabinet 10A is supplied to all the substrate processing units 110 included in the tower TW corresponding to the fluid box 10B via any of the fluid boxes 10B. Also, the gas in the fluid cabinet 10A is supplied to all the substrate processing units 110 included in the tower TW corresponding to the fluid box 10B via any of the fluid boxes 10B.

[0036] The control device 101 controls various operations of the substrate processing apparatus 100. The control device 101 includes a control unit 102 and a storage unit 104. The control unit 102 has a processor. The control unit 102 has, for example, a central processing unit (CPU). Alternatively, the control unit 102 may have a general-purpose computer.

[0037] The storage unit 104 includes a main storage device and an auxiliary storage device. The main storage device is, for example, a semiconductor memory. The auxiliary storage device is, for example, a semiconductor memory and / or a hard disk drive. The storage unit 104 may include a removable medium. The control unit 102 executes a computer program stored in the storage unit 104 to perform a substrate processing operation.

[0038] The storage unit 104 stores data. The data includes recipe data. The recipe data includes information indicating a plurality of recipes. Each of the plurality of recipes defines the processing content and processing procedure for the substrate W.

[0039] The storage unit 104 may also store the luminance value or brightness of the reference treatment liquid, or may store a reference image obtained by capturing an image of the reference treatment liquid.

[0040] Next, the substrate processing unit 110 in the substrate processing apparatus 100 of this embodiment will be described with reference to Fig. 2. Fig. 2 is a schematic diagram of the substrate processing unit 110 in the substrate processing apparatus 100.

[0041] The substrate processing unit 110 includes a chamber 112, a substrate holding part 120, a processing liquid supply part 130, a near-infrared light source 140, and a near-infrared imaging part 150. The chamber 112 accommodates the substrate holding part 120, and at least a part of the processing liquid supply part 130, the near-infrared light source 140, and the near-infrared imaging part 150.

[0042] The chamber 112 has a generally box-like shape with an internal space. The chamber 112 accommodates the substrate W. Here, the substrate processing unit 110 is a single-wafer type that processes the substrate W one by one, and the chamber 112 accommodates the substrate W one by one. The substrate W is accommodated in the chamber 112 and is processed in the chamber 112.

[0043] The substrate holding unit 120 holds the substrate W. The substrate holding unit 120 holds the substrate W horizontally so that the upper surface (front surface) Wa of the substrate W faces upward and the lower surface (back surface) Wb of the substrate W faces vertically downward. The substrate holding unit 120 also rotates the substrate W while holding it. The upper surface Wa of the substrate W may be flattened. Alternatively, the upper surface Wa of the substrate W may be provided with a device surface, or a pillar-shaped laminate with a recess may be provided. The substrate holding unit 120 rotates the substrate W while holding it.

[0044] For example, the substrate holding unit 120 may be of a clamping type that clamps an end of the substrate W. Alternatively, the substrate holding unit 120 may have any mechanism that holds the substrate W from its lower surface Wb. For example, the substrate holding unit 120 may be of a vacuum type. In this case, the substrate holding unit 120 holds the substrate W horizontally by adsorbing the center of the lower surface Wb of the substrate W, which is a non-device formation surface, to its upper surface. Alternatively, the substrate holding unit 120 may combine a clamping type that brings multiple chuck pins into contact with the peripheral edge surface of the substrate W with a vacuum type.

[0045] For example, the substrate holding unit 120 includes a spin base 121, a chuck member 122, a shaft 123, an electric motor 124, and a housing 125. The chuck member 122 is provided on the spin base 121. The chuck member 122 chucks the substrate W. Typically, the spin base 121 is provided with a plurality of chuck members 122.

[0046] The shaft 123 is a hollow shaft. The shaft 123 extends vertically along the rotation axis Ax. The spin base 121 is coupled to the upper end of the shaft 123. The substrate W is placed above the spin base 121.

[0047] The spin base 121 is disk-shaped. The chuck member 122 horizontally supports the substrate W. The shaft 123 extends downward from the center of the spin base 121. The electric motor 124 applies a rotational force to the shaft 123. The electric motor 124 rotates the shaft 123 in a rotational direction, thereby rotating the substrate W and the spin base 121 around the rotation axis Ax. The housing 125 surrounds the shaft 123 and the electric motor 124.

[0048] The processing liquid supply unit 130 supplies the processing liquid to the substrate W. Typically, the processing liquid supply unit 130 supplies the processing liquid to the upper surface Wa of the substrate W held by the substrate holding unit 120. Note that the processing liquid supply unit 130 may supply a plurality of types of processing liquid to the substrate W.

[0049] The processing liquid may be an etching liquid for etching the substrate W. Examples of the etching liquid include hydrofluoric nitric acid (a mixture of hydrofluoric acid (HF) and nitric acid (HNO3)), hydrofluoric acid, buffered hydrofluoric acid (BHF), ammonium fluoride, HFEG (a mixture of hydrofluoric acid and ethylene glycol), and phosphoric acid (H3PO4). The type of the etching liquid is not particularly limited, and may be, for example, acidic or alkaline.

[0050] Alternatively, the processing liquid may be a rinse liquid, such as deionized water (DIW), carbonated water, electrolytic ionized water, ozone water, ammonia water, diluted hydrochloric acid water, and reduced water (hydrogen water).

[0051] Alternatively, the treatment liquid may be an organic solvent. Typically, the volatility of the organic solvent is higher than that of the rinse liquid. Examples of the organic solvent include isopropyl alcohol (IPA), methanol, ethanol, acetone, hydrofluoro ether (HFE), propylene glycol monoethyl ether (PGEE), and propylene glycol monomethyl ether acetate (PGMEA).

[0052] The processing liquid supply unit 130 includes a pipe 132, a valve 134, a nozzle 136, and a moving mechanism 138. The nozzle 136 is an example of a "processing liquid nozzle" of the present invention. The processing liquid flows from a supply source through the pipe 132. The valve 134 opens and closes a flow path in the pipe 132. The nozzle 136 is connected to the pipe 132. In this embodiment, the pipe 132 and the valve 134 configure a supply unit 135 that supplies the processing liquid to the nozzle 136. The supply unit 135 may include, for example, a pump (not shown) that sends out the processing liquid from the supply source. The processing liquid flows through the nozzle 136, and the nozzle 136 ejects the processing liquid onto the upper surface Wa of the substrate W. It is preferable that the nozzle 136 is configured to be movable with respect to the substrate W.

[0053] The pipe 132 and the nozzle 136 are made of resin. The nozzle 136 transmits near-infrared light emitted from the near-infrared light source 140. In this embodiment, the pipe 132 and the nozzle 136 transmit near-infrared light emitted from the near-infrared light source 140. The pipe 132 and the nozzle 136 are not particularly limited, but are formed of, for example, PFA (perfluoroalkoxyalkane) or PTFE (polytetrafluoroethylene).

[0054] The movement mechanism 138 moves the nozzle 136 in the horizontal and vertical directions. Specifically, the movement mechanism 138 moves the nozzle 136 in the circumferential direction around a rotation axis that extends in the vertical direction. The movement mechanism 138 also raises and lowers the nozzle 136 in the vertical direction.

[0055] The moving mechanism 138 has an arm 138a, a shaft 138b, and a drive unit 138c. The arm 138a extends along the horizontal direction. The nozzle 136 is disposed at the tip of the arm 138a. The nozzle 136 is disposed at the tip of the arm 138a in a position that allows the nozzle 136 to supply a processing liquid toward the upper surface Wa of the substrate W held by the chuck member 122. More specifically, the nozzle 136 is coupled to the tip of the arm 138a and protrudes downward from the arm 138a. The base end of the arm 138a is coupled to the shaft 138b. The shaft 138b extends along the vertical direction.

[0056] The driving unit 138c has a rotation driving mechanism and an elevation driving mechanism. The rotation driving mechanism of the driving unit 138c rotates the shaft portion 138b about the rotation axis, and rotates the arm 138a along the horizontal plane about the shaft portion 138b. As a result, the nozzle 136 moves along the horizontal plane. More specifically, the nozzle 136 moves in the circumferential direction around the shaft portion 138b. The rotation driving mechanism of the driving unit 138c includes, for example, a motor capable of forward and reverse rotation.

[0057] The lifting drive mechanism of the drive unit 138c raises and lowers the shaft unit 138b in the vertical direction. The lifting drive mechanism of the drive unit 138c raises and lowers the shaft unit 138b, thereby raising and lowering the nozzle 136 in the vertical direction. The lifting drive mechanism of the drive unit 138c has a drive source such as a motor and a lifting mechanism, and the drive source drives the lifting mechanism to raise or lower the shaft unit 138b. The lifting mechanism includes, for example, a rack and pinion mechanism or a ball screw.

[0058] The near-infrared light source 140 emits at least near-infrared light. The near-infrared light source 140 irradiates an area including the tip 136a of the nozzle 136 with near-infrared light. The near-infrared light source 140 may irradiate the nozzle 136 and a part of the piping 132 with near-infrared light. The near-infrared light source 140 may also irradiate the nozzle 136 and at least a part of the substrate W with near-infrared light. The near-infrared light source 140 irradiates an area including a portion of the nozzle 136, for example, 10 mm to 200 mm upstream (toward the piping 132) from the tip 136a with near-infrared light.

[0059] For example, the near-infrared light source 140 emits near-infrared light having a wavelength in the range of 800 nm to 2.5 μm. Typically, the near-infrared light source 140 emits near-infrared light having a wavelength in the range of at least 800 nm to 1.5 μm. Note that the near-infrared light source 140 may emit visible light together with the near-infrared light.

[0060] For example, the near-infrared light emitted from the near-infrared light source 140 travels linearly along the optical axis. Alternatively, the near-infrared light emitted from the near-infrared light source 140 travels while diverging from the optical axis. It is preferable that the near-infrared light source 140 is disposed so that the optical axis of the near-infrared light source 140 passes through the nozzle 136.

[0061] The near-infrared imaging section 150 has a plurality of pixels. The near-infrared imaging section 150 is sensitive to at least near-infrared light. The near-infrared imaging section 150 captures an image of an area including the tip 136a of the nozzle 136 by receiving components of the near-infrared light emitted from the near-infrared light source 140 that are transmitted and / or reflected by the nozzle 136, the pipe 132, the substrate W, and the like, to generate a captured image. Therefore, the near-infrared imaging section 150 can capture an image of the processing liquid irradiated with the near-infrared light emitted from the near-infrared light source 140 to generate a captured image.

[0062] The near-infrared imaging section 150 images an area including the tip 136a of the nozzle 136. The near-infrared imaging section 150 may image the nozzle 136 and a part of the pipe 132. The near-infrared imaging section 150 may also image the nozzle 136 and at least a part of the substrate W. The near-infrared imaging section 150 may image the entire interior of the chamber 112. The area imaged by the near-infrared imaging section 150 does not have to match the area irradiated by the near-infrared light source 140.

[0063] In the near-infrared imaging section 150, the frame rate may be 30 fps or 60 fps. Alternatively, the frame rate may be 120 fps.

[0064] The near-infrared imaging unit 150 may include a SWIR (Short Wavelength Infra-Red) image sensor. In this case, the near-infrared imaging unit 150 detects near-infrared rays having a wavelength in the range of 800 nm to 2.5 μm, for example.

[0065] The near-infrared imaging section 150 may be sensitive to visible light as well as near-infrared light, or may switch between receiving near-infrared light and visible light.

[0066] The near-infrared imaging section 150 captures an image of the surroundings centered on the imaging optical axis. Typically, the imaging optical axis is located at the center of the captured image. For example, the center of the captured image of the near-infrared imaging section 150 is located at the nozzle 136. In this case, the imaging optical axis of the near-infrared imaging section 150 is located at the nozzle 136. Alternatively, the center of the captured image of the near-infrared imaging section 150 may be located at the pipe 132 or the substrate W.

[0067] The near-infrared image capturing unit 150 captures an image of the tip portion including tip 136a of nozzle 136. It is preferable that the captured image can identify the processing liquid in nozzle 136. For example, it is preferable that the captured image can identify the position of the outer edge of the processing liquid moving in nozzle 136. It is also preferable that the captured image can identify the position of the downstream edge of the processing liquid moving in nozzle 136. Alternatively, it is preferable that the captured image can identify the outer edge of the processing liquid dropped from nozzle 136 onto substrate W. It is also preferable that the captured image can identify the position of the outer edge of the processing liquid moving in pipe 132.

[0068] When the substrate processing unit 110 is viewed in a plan view, the optical axis of the near-infrared light source 140 and the imaging optical axis of the near-infrared imaging section 150 pass through the nozzle 136. When the substrate processing unit 110 is viewed in a plan view, the near-infrared light source 140 and the near-infrared imaging section 150 may be disposed on opposite sides of the nozzle 136. When the substrate processing unit 110 is viewed in a plan view, the optical axis of the near-infrared light source 140 and the imaging optical axis of the near-infrared imaging section 150 may be coincident with each other or may be parallel. When the substrate processing unit 110 is viewed in a plan view, the optical axis of the near-infrared light source 140 and the imaging optical axis of the near-infrared imaging section 150 do not have to be parallel.

[0069] Here, the near-infrared light source 140 and the near-infrared image capturing section 150 are disposed inside the chamber 112. The near-infrared light source 140 and the near-infrared image capturing section 150 may be disposed fixed to each other.

[0070] The near-infrared light source 140 and the near-infrared imaging section 150 may be movable relative to the substrate W. For example, the near-infrared light source 140 and the near-infrared imaging section 150 are preferably movable in the horizontal direction and / or the vertical direction according to a moving mechanism controlled by the control section 102. When the near-infrared light source 140 and the near-infrared imaging section 150 move, the near-infrared light source 140 and the near-infrared imaging section 150 may be movable independently of each other. Alternatively, the near-infrared light source 140 and the near-infrared imaging section 150 may be movable as a unit.

[0071] The processing liquid may contain an organic substance. For example, in organic substances, bonds such as CH, CO, CN, and CF absorb specific wavelengths included in near infrared rays. Since the amount of absorption of a specific wavelength of near infrared rays is proportional to the amount of a component having a specific bonding group, the amount of a specific component present in the substrate W can be measured based on the near infrared rays reflected from the substrate W.

[0072] In this embodiment, the substrate processing apparatus 100 further includes a liquid returning unit 160. The liquid returning unit 160 is connected to the piping 132. The liquid returning unit 160 can suck back (suck back) the processing liquid in the nozzle 136 to the upstream side (the piping 132 side) when the supply of the processing liquid to the nozzle 136 by the supply unit 135 is stopped. The configuration of the liquid returning unit 160 will be described later.

[0073] The substrate processing apparatus 100 further includes a cup 180. The cup 180 collects the processing liquid scattered from the substrate W. The cup 180 moves up and down. For example, the cup 180 moves up vertically to the side of the substrate W during the period in which the processing liquid supply unit 130 supplies the processing liquid to the substrate W. In this case, the cup 180 collects the processing liquid scattered from the substrate W due to the rotation of the substrate W. Furthermore, when the period in which the processing liquid supply unit 130 supplies the processing liquid to the substrate W ends, the cup 180 moves down vertically from the side of the substrate W.

[0074] As described above, the control device 101 includes the control unit 102 and the memory unit 104. The control unit 102 controls the substrate holding unit 120, the processing liquid supply unit 130, the near-infrared light source 140, the near-infrared imaging unit 150, the liquid returning unit 160, and / or the cup 180. In one example, the control unit 102 controls the electric motor 124, the valve 134, the moving mechanism 138, the near-infrared light source 140, the near-infrared imaging unit 150, the liquid returning unit 160, and / or the cup 180.

[0075] According to the substrate processing apparatus 100 of this embodiment, the processing liquid irradiated with near-infrared light from the near-infrared light source 140 is imaged by the near-infrared imaging unit 150. More specifically, the processing liquid in the nozzle 136 is imaged by the near-infrared imaging unit 150. Typically, the nozzle 136 is transparent and transmits visible light and near-infrared light. The processing liquid is transparent and transmits visible light. On the other hand, the processing liquid often exhibits relatively strong absorption in the near-infrared region. Therefore, the outer edge of the processing liquid can be identified in the captured image of the area including the tip 136a of the nozzle 136 captured by the near-infrared imaging unit 150. Specifically, the luminance or brightness is high in the portion of the captured image showing the nozzle 136, the pipe 132, and the substrate W. On the other hand, the luminance or brightness is low in the portion of the captured image showing the processing liquid. Therefore, the outer edge of the processing liquid can be identified in the captured image.

[0076] Furthermore, the type of treatment liquid often exhibits a specific absorption in the near-infrared region. Therefore, in the captured image of the treatment liquid in the nozzle 136 captured by the near-infrared imaging unit 150, the luminance or brightness of the treatment liquid differs depending on the type of treatment liquid. Therefore, the type of treatment liquid can be identified based on the luminance or brightness of the treatment liquid in the captured image.

[0077] Alternatively, since different treatment liquids have different wavelengths at which they show strong absorption, the near-infrared light source 140 may change the wavelength of the emitted near-infrared light, thereby making it possible to easily identify the outer edge and type of the treatment liquid.

[0078] The substrate processing apparatus 100 of this embodiment is suitable for use in the manufacture of a semiconductor device having a semiconductor. Typically, in a semiconductor device, a conductive layer and an insulating layer are laminated on a base material. The substrate processing apparatus 100 is suitable for use in cleaning and / or processing (e.g., etching, changing characteristics, etc.) the conductive layer and / or insulating layer during the manufacture of the semiconductor device.

[0079] Next, a substrate processing apparatus 100 according to the present embodiment will be described with reference to Figures 1 to 3. Figure 3 is a block diagram of the substrate processing apparatus 100.

[0080] 3, the control device 101 controls various operations of the substrate processing apparatus 100. The control device 101 controls the indexer robot IR, the center robot CR, the substrate holding unit 120, the processing liquid supply unit 130, the near-infrared light source 140, the near-infrared imaging unit 150, the liquid return unit 160, and the cup 180. Specifically, the control device 101 controls the indexer robot IR, the center robot CR, the substrate holding unit 120, the processing liquid supply unit 130, the near-infrared light source 140, the near-infrared imaging unit 150, the liquid return unit 160, and the cup 180 by transmitting control signals to the indexer robot IR, the center robot CR, the substrate holding unit 120, the processing liquid supply unit 130, the near-infrared light source 140, the near-infrared imaging unit 150, the liquid return unit 160, and the cup 180.

[0081] The memory unit 104 also stores computer programs and data. The data includes recipe data. The recipe data includes information indicating a plurality of recipes. Each of the plurality of recipes specifies the processing content, processing procedure, and substrate processing conditions for the substrate W. The control unit 102 executes the computer programs stored in the memory unit 104 to perform substrate processing operations.

[0082] The recipe data also includes type information indicating the type of processing liquid supplied from the nozzle 136 to the substrate W. The storage unit 104 also pre-stores data associating the type of processing liquid with the luminance or brightness of the processing liquid in the reference image.

[0083] The control unit 102 controls the indexer robot IR to transfer the substrate W by the indexer robot IR.

[0084] The control unit 102 controls the center robot CR to transfer the substrate W by the center robot CR. For example, the center robot CR receives an unprocessed substrate W and carries the substrate W into any one of the multiple chambers 112. The center robot CR also receives a processed substrate W from the chamber 112 and carries the substrate W out.

[0085] The control unit 102 controls the substrate holding unit 120 to start rotation of the substrate W, change the rotation speed, and stop the rotation of the substrate W. For example, the control unit 102 can control the substrate holding unit 120 to change the rotation speed of the substrate holding unit 120. Specifically, the control unit 102 can change the rotation speed of the substrate W by changing the rotation speed of the electric motor 124 of the substrate holding unit 120.

[0086] The control unit 102 can control the valve 134 of the processing liquid supply unit 130 to switch the state of the valve 134 between an open state and a closed state. Specifically, the control unit 102 can control the valve 134 of the processing liquid supply unit 130 to open the valve 134, thereby allowing the processing liquid flowing through the pipe 132 toward the nozzle 136 to pass. In addition, the control unit 102 can stop the supply of the processing liquid flowing through the pipe 132 toward the nozzle 136 by controlling the valve 134 of the processing liquid supply unit 130 to close the valve 134.

[0087] The control unit 102 can control the movement mechanism 138 of the processing liquid supply unit 130 to move the nozzle 136. Specifically, the control unit 102 can control the movement mechanism 138 of the processing liquid supply unit 130 to move the nozzle 136 to above the upper surface Wa of the substrate W. In addition, the control unit 102 can control the movement mechanism 138 of the processing liquid supply unit 130 to move the nozzle 136 to a retracted position away from above the upper surface Wa of the substrate W.

[0088] The control unit 102 controls the near-infrared light source 140 and the near-infrared imaging unit 150 to capture an image of an area including the tip 136a of the nozzle 136 and generate a captured image. The control unit 102 controls the near-infrared light source 140 to irradiate the area including the tip 136a of the nozzle 136 with near-infrared light. The control unit 102 also controls the near-infrared imaging unit 150 to capture an image of an area including the tip 136a of the nozzle 136 and generate a captured image.

[0089] For example, the control unit 102 controls the near-infrared light source 140 and the near-infrared image capturing unit 150 to emit near-infrared light toward a region including the tip 136a of the nozzle 136, and to receive the near-infrared light transmitted through or reflected by each member in the near-infrared image capturing unit 150 to measure the luminance value or brightness. Note that the control unit 102 may control the near-infrared light source 140 and the near-infrared image capturing unit 150 to move the near-infrared light source 140 and the near-infrared image capturing unit 150 relative to the nozzle 136.

[0090] The control unit 102 identifies the outer edge of the treatment liquid in the captured image. For example, the control unit 102 identifies the outer edge of the treatment liquid in the captured image based on a luminance value or brightness in the captured image. In one example, the control unit 102 identifies the outer edge of the treatment liquid in the captured image based on a luminance value or brightness in the captured image and a luminance value or brightness of a reference treatment liquid stored in the storage unit 104. Alternatively, the control unit 102 identifies the outer edge of the treatment liquid in the captured image based on the captured image and the reference image.

[0091] Furthermore, the control unit 102 identifies the type of processing liquid in the captured image based on the luminance value or brightness in the captured image. The control unit 102 identifies the type of processing liquid in the captured image based on the luminance value or brightness in the captured image and the luminance value or brightness of a reference processing liquid stored in the storage unit 104. Alternatively, the control unit 102 identifies the type of processing liquid in the captured image based on the captured image and the reference image.

[0092] The control unit 102 controls the liquid return unit 160 to pull back the treatment liquid in the nozzle 136 to the upstream side (the pipe 132 side). That is, the control unit 102 controls the liquid return unit 160 to execute suck back. Specifically, the control unit 102 controls the valve 134 to stop the supply of the treatment liquid to the nozzle 136, and then controls the liquid return unit 160 to pull back the treatment liquid in the nozzle 136 to the upstream side (the pipe 132 side).

[0093] In this embodiment, the control unit 102 causes the near-infrared imaging unit 150 to capture an image of a region including the tip 136a of the nozzle 136 while the treatment liquid is moving upstream inside the nozzle 136. In other words, the control unit 102 causes the near-infrared imaging unit 150 to capture an image of the treatment liquid moving upstream inside the nozzle 136.

[0094] The control unit 102 may control the cup 180 to move the cup 180 relative to the substrate W. Specifically, the control unit 102 raises the cup 180 vertically upward to the side of the substrate W during the period during which the processing liquid supply unit 130 supplies the processing liquid to the substrate W. Furthermore, when the period during which the processing liquid supply unit 130 supplies the processing liquid to the substrate W ends, the control unit 102 lowers the cup 180 vertically downward from the side of the substrate W.

[0095] The substrate processing apparatus 100 of this embodiment is preferably used for forming semiconductor elements. For example, the substrate processing apparatus 100 is preferably used for processing a substrate W used as a semiconductor element having a stacked structure. The semiconductor element is a so-called 3D structure memory (storage device). As an example, the substrate W is preferably used as a NAND type flash memory.

[0096] Next, the substrate processing method of the present embodiment will be described with reference to Figs. 1 to 4. Fig. 4 is a flow diagram of the substrate processing method of the present embodiment. Step SC is an example of the "rotating step" and "supplying step" of the present invention. Step SD is an example of the "pulling back step" of the present invention. Step SE is an example of the "irradiating step" and "captured image generating step" of the present invention. Step SF is an example of the "identifying step" of the present invention.

[0097] 4, in step SA, the substrate W is loaded into the substrate processing apparatus 100. Specifically, the substrate W is loaded into the chamber 112 of the substrate processing unit 110 via the indexer robot IR and the center robot CR.

[0098] In step SB, the substrate holding part 120 holds the substrate W. Specifically, when the substrate W is carried into the chamber 112, it is held by the substrate holding part 120.

[0099] In step SC, the control unit 102 processes the substrate W. The substrate W is processed in the substrate processing unit 110. Typically, the substrate holding unit 120 holds and rotates the substrate W, and the processing liquid supply unit 130 supplies the processing liquid to the substrate W. The control unit 102 stops the supply of the processing liquid to the substrate W when a predetermined time has elapsed since starting the supply of the processing liquid to the substrate W.

[0100] In step SD, the control unit 102 controls the liquid returning unit 160 to return the processing liquid in the nozzle 136 to the upstream side (the pipe 132 side). This makes it possible to prevent the processing liquid from dropping from the nozzle 136 onto the substrate W.

[0101] In step SE, the control unit 102 controls the near-infrared imaging unit 150 to generate an image of an area including the tip 136a of the nozzle 136. In this embodiment, while the processing liquid in the nozzle 136 is moving upstream, the control unit 102 uses the near-infrared imaging unit 150 to image the area including the tip 136a of the nozzle 136. In other words, the control unit 102 uses the near-infrared imaging unit 150 to image the processing liquid moving upstream inside the nozzle 136. Specifically, the control unit 102 controls the near-infrared light source 140 to emit near-infrared light. The area including the tip 136a of the nozzle 136 is irradiated with near-infrared light emitted from the near-infrared light source 140. In addition, the control unit 102 controls the near-infrared imaging unit 150 to image at least a part of the area irradiated with near-infrared light. Specifically, the control unit 102 images the area including the tip 136a of the nozzle 136. By capturing an image of the area including the tip 136a of the nozzle 136 irradiated with near-infrared light from the near-infrared imaging section 150, the processing liquid can be imaged with high accuracy even if the processing liquid inside the nozzle 136 is substantially transparent.

[0102] In step SF, the controller 102 identifies the position of the outer edge of the treatment liquid in the nozzle 136 based on the captured image.

[0103] In step SG, the control unit 102 stops the rotation of the substrate W by the substrate holding part 120 and releases the holding of the substrate W by the substrate holding part 120. Note that the rotation of the substrate W by the substrate holding part 120 may be stopped in step SD, step SE, or step SF.

[0104] In step SH, the substrate W is unloaded from the substrate processing apparatus 100. Specifically, the substrate W is unloaded from the chamber 112 of the substrate processing unit 110 via the center robot CR and the indexer robot IR.

[0105] According to this embodiment, the control unit 102 controls the near-infrared imaging unit 150 to capture an image of a region including the tip 136a of the nozzle 136. In other words, the near-infrared imaging unit 150 captures an image of the treatment liquid being irradiated with near-infrared light from the near-infrared light source 140. Since the treatment liquid absorbs near-infrared light relatively strongly, the outer edge of the treatment liquid can be identified with high accuracy.

[0106] Furthermore, the control unit 102 captures an image of the processing liquid moving upstream inside the nozzle 136 by the near-infrared imaging unit 150. Therefore, the processing liquid inside the nozzle 136 during the suck-back can be identified with high accuracy.

[0107] Next, the liquid returning section 160 of the substrate processing apparatus 100 of this embodiment will be further described with reference to Fig. 5. Fig. 5 is a schematic diagram showing the configuration of the liquid returning section 160 and the periphery of the substrate processing apparatus 100 of this embodiment.

[0108] As shown in FIG. 5, the liquid return unit 160 has a pipe 161 and a valve 162. The pipe 161 is connected to the pipe 132. In this embodiment, the pipe 161 is connected to a portion of the pipe 132 between the valve 134 and the nozzle 136. In other words, the pipe 161 is connected to the pipe 132 upstream of the valve 134 and downstream of the nozzle 136. The processing liquid flows through the pipe 161 on the downstream side (the nozzle 136 side) of the connection portion of the pipe 132 to which the pipe 161 is connected. Note that, in this embodiment, the end (lower end) of the pipe 161 that is not connected to the pipe 132 is disposed at a position lower than the tip 136a of the nozzle 136.

[0109] The valve 162 opens and closes the flow path in the pipe 161. The nozzle 136 is connected to the pipe 161. The valve 162 is not particularly limited, but is, for example, an air valve. The valve 162 has, for example, a needle valve capable of changing the flow rate and / or a speed controller capable of changing the opening and closing speed.

[0110] The control unit 102 controls the valve 162 to open and close the flow path in the pipe 161. Specifically, the control unit 102 closes the flow path in the pipe 161 by the valve 162 while the supply unit 135 is supplying the treatment liquid to the nozzle 136. On the other hand, the control unit 102 controls the valve 162 to open the flow path in the pipe 161 for a predetermined time after the supply unit 135 stops supplying the treatment liquid to the nozzle 136. In this case, the control unit 102 changes the valve 162 from a closed state to an open state, causing a suck-back due to the siphon principle. That is, the treatment liquid in the nozzle 136 moves to the upstream side (the pipe 132 side). On the other hand, the control unit 102 changes the valve 162 from an open state to a closed state to stop the suck-back. That is, the movement of the treatment liquid in the nozzle 136 stops.

[0111] Furthermore, in this embodiment, the control unit 102 identifies the position of the downstream edge (lower surface) of the processing liquid in the nozzle 136 based on the captured image. Furthermore, the control unit 102 calculates the speed at which the processing liquid moves upstream inside the nozzle 136 based on the identified downstream edge position of the processing liquid.

[0112] For example, the control unit 102 causes the near-infrared imaging unit 150 to capture an image of the treatment liquid moving upstream inside the nozzle 136 when a first predetermined time has elapsed since the liquid returning unit 160 starts to pull the treatment liquid in the nozzle 136 back upstream. Then, the control unit 102 calculates the speed at which the treatment liquid moves upstream inside the nozzle 136 based on the first predetermined time (the time from when the treatment liquid starts to be returned upstream to when the treatment liquid is captured) and the position of the downstream edge of the treatment liquid in the captured image. Note that in the following description, the speed at which the treatment liquid moves upstream inside the nozzle 136 may be referred to as the speed of the treatment liquid.

[0113] Alternatively, for example, the control unit 102 captures images of the treatment liquid moving upstream inside the nozzle 136 multiple times at a second predetermined time interval using the near-infrared imaging unit 150. Then, the control unit 102 calculates the speed of the treatment liquid based on the positions of the downstream edge of the treatment liquid in the multiple captured images and the second predetermined time.

[0114] The control unit 102 determines whether the calculated velocity of the treatment liquid is within a preset velocity range. For example, when the control unit 102 determines that the calculated velocity of the treatment liquid is not within the preset velocity range, the control unit 102 executes a predetermined process. The predetermined process will be described later. The preset velocity range is stored in the storage unit 104.

[0115] Next, a method for calculating the velocity of the processing liquid L by the substrate processing apparatus 100 of this embodiment will be described with reference to Figs. 6 to 10 and Fig. 11 described later are schematic diagrams showing the tip portion of the nozzle 136 during suck back. Note that Figs. 6 to 10 and Fig. 11 described later correspond to images captured by the near-infrared imaging unit 150. In Figs. 6 to 10 and Fig. 11 described later, the processing liquid L is hatched to facilitate understanding.

[0116] First, a method for determining a center line M136 of the liquid flow path 136b of the nozzle 136 will be described with reference to FIG.

[0117] 6, the nozzle 136 has a liquid flow path 136b through which the treatment liquid L passes. The control unit 102 identifies a center line M136 of the liquid flow path 136b based on the captured image. The control unit 102 identifies the center line M136 of the liquid flow path 136b based on, for example, the position of the outer periphery of the nozzle 136 and / or the position of the inner periphery of the liquid flow path 136b in the captured image. Alternatively, the control unit 102 may identify the center line M136 of the liquid flow path 136b based on the position of the outer periphery of the treatment liquid L shown in FIG.

[0118] Next, a method for calculating the velocity of the processing liquid L will be described with reference to Figures 6 to 10. First, a method for imaging the processing liquid L in the nozzle 136 after a first predetermined time has elapsed since the processing liquid L in the nozzle 136 started to be drawn back upstream, and calculating the velocity of the processing liquid L based on the captured image will be described with reference to Figures 6 to 8.

[0119] 6, when the control unit 102 stops the supply of the processing liquid L to the nozzle 136 by the supply unit 135, the downstream edge (lower surface) La of the processing liquid L becomes substantially flush with the tip 136a of the nozzle 136. From this state, the control unit 102 opens the valve 162. This causes the processing liquid L in the nozzle 136 to be drawn back to the upstream side. In other words, the drawing back (suck-back) of the processing liquid L begins.

[0120] Then, the control unit 102 causes the near-infrared imaging unit 150 to capture an image of an area including the tip 136a of the nozzle 136 when a first predetermined time has elapsed since the liquid return unit 160 started to pull back the processing liquid L in the nozzle 136 to the upstream side. As a result, the near-infrared imaging unit 150 generates an image as shown in FIG. 7, for example. The control unit 102 then identifies the position of the downstream edge La of the processing liquid L from the tip 136a of the nozzle 136 based on the captured image. Then, as shown in FIG. 7, the control unit 102 calculates a distance L1 from the tip 136a of the nozzle 136 to the position of the identified edge La. At this time, the control unit 102 calculates a vertical distance L1 from the tip 136a of the nozzle 136 to the position of the identified edge La. Alternatively, the control unit 102 calculates a distance L1 from the tip 136a of the nozzle 136 to the position of the identified edge La in a direction perpendicular to the tip 136a. Thereafter, the control unit 102 calculates the velocity of the treatment liquid L based on the calculated distance L1 and the first predetermined time.

[0121] 8, the control unit 102 calculates a length L2 that the edge (lower surface) La of the treatment liquid L moves along the center line M136 of the liquid flow path 136b based on the captured image. Then, the control unit 102 calculates the velocity of the treatment liquid L based on the length L2 and the first predetermined time.

[0122] Next, with reference to Figures 6, 9 and 10, a method of capturing images of the processing liquid L moving upstream inside the nozzle 136 multiple times at a second predetermined time interval and calculating the velocity of the processing liquid L based on the captured images will be described.

[0123] 6, when the control unit 102 stops the supply of the processing liquid L to the nozzle 136 by the supply unit 135, the downstream edge (lower surface) La of the processing liquid L becomes substantially flush with the tip 136a of the nozzle 136. From this state, the control unit 102 opens the valve 162. This causes the processing liquid L in the nozzle 136 to be drawn back to the upstream side. In other words, the drawing back (suck-back) of the processing liquid L begins.

[0124] Then, the control unit 102 captures an image of the processing liquid L moving upstream inside the nozzle 136 multiple times (here, twice) at a second predetermined time interval. Specifically, the second predetermined time may be the reciprocal of the frame rate or an integer multiple of the reciprocal of the frame rate. The control unit 102 captures an image of an area including the tip 136a of the nozzle 136 by the near-infrared imaging unit 150 at the second predetermined time interval. As a result, the near-infrared imaging unit 150 generates a captured image as shown in, for example, FIG. 9 and FIG. 10. Thereafter, the control unit 102 specifies the position of the downstream edge La of the processing liquid L inside the nozzle 136 based on the captured image. The position of the edge La is specified for each captured image. Then, the control unit 102 calculates the speed of the processing liquid L based on the position of the downstream edge La of the processing liquid L in the multiple captured images and the second predetermined time.

[0125] Specifically, as shown in Figures 9 and 10, the control unit 102 calculates the distance between the positions of the edges La in the two captured images. Then, as shown in Figure 10, the control unit 102 calculates the vertical distance L3 between the edges La in the two captured images. Alternatively, the control unit 102 calculates the distance L3 between the edges La in the two captured images in a direction perpendicular to the tip 136a. Then, the control unit 102 calculates the speed of the treatment liquid L based on the calculated distance L3 and a second predetermined time.

[0126] Alternatively, the control unit 102 calculates the length L4 that the edge La of the treatment liquid L moves along the center line M136 of the liquid flow path 136b based on the two captured images. Then, the control unit 102 calculates the velocity of the treatment liquid L based on the length L4 and the second predetermined time.

[0127] Next, an example in which the processing liquid L separates in the nozzle 136 during suck back will be described with reference to Fig. 11. Fig. 11 is a schematic diagram showing a state in which the processing liquid L separates in the nozzle 136 during suck back.

[0128] As shown in FIG. 11, when the processing liquid L is sucked back, the processing liquid L may separate in the nozzle 136. In this case, a cavity C is formed between the processing liquid L and the processing liquid L. Since the cavity C hardly absorbs near-infrared rays, the brightness or luminance of the captured image changes significantly at the interface between the cavity C and the processing liquid L. Therefore, the control unit 102 can determine whether or not the processing liquid L has separated based on the captured image. Separation of the processing liquid L occurs when the pull-back speed of the processing liquid L is high. Therefore, when the control unit 102 determines that separation of the processing liquid L has occurred, it executes a predetermined process. The predetermined process will be described later.

[0129] Next, the substrate processing step in the substrate processing method of the present embodiment will be described with reference to FIGS. 1 to 12. FIG. 12 is a flow diagram of the substrate processing step in the substrate processing method of the present embodiment. Step S110 is an example of the "rotating step" of the present invention. In particular, the steps from step S110 to step S200, in which the rotation of the substrate W is stopped, are an example of the "rotating step" of the present invention. Step S120 is an example of the "supplying step" of the present invention. Step S130 is an example of the "pulling back step" of the present invention. In particular, the steps from step S130 to step S190, in which the pulling back of the processing liquid L is stopped, are an example of the "pulling back step" of the present invention. Step S140 is an example of the "irradiating step" and the "step of generating a captured image" of the present invention. Step S150 is an example of the "identifying step" of the present invention. Step S160 is an example of the "calculating step" of the present invention. Step S170 is an example of the "determining step" of the present invention. Step S180 is an example of the "step of changing at least one of the timing to start pulling back and the timing to stop pulling back" of the present invention.

[0130] 12, in step S110, the substrate W is rotated in a held state. Specifically, the substrate holder 120 rotates the substrate W in a held state. For example, the rotation speed of the substrate W is 10 rpm to 1500 rpm.

[0131] Next, in step S120, the processing liquid L is supplied to the substrate W. Specifically, the control unit 102 controls the processing liquid supply unit 130 to supply the processing liquid L to the substrate W. When a predetermined time has elapsed since the control unit 102 started supplying the processing liquid L to the substrate W, the control unit 102 controls the processing liquid supply unit 130 to stop supplying the processing liquid L to the substrate W.

[0132] Next, in step S130, the control unit 102 starts pulling back the processing liquid L. Specifically, the control unit 102 opens the valve 162 of the liquid returning unit 160 to pull back the processing liquid L in the nozzle 136 to the upstream side. As a result, the processing liquid L in the nozzle 136 starts moving toward the upstream side.

[0133] Next, in step S140, the near-infrared light source 140 irradiates an area including the tip 136a of the nozzle 136 with near-infrared light, and the near-infrared image capturing unit 150 captures an image of the area including the tip 136a of the nozzle 136 that is irradiated with near-infrared light. At this time, the near-infrared image capturing unit 150 captures an image of the processing liquid L moving upstream inside the nozzle 136. The near-infrared light source 140 irradiates an area including the tip 136a with near-infrared light, and the near-infrared image capturing unit 150 captures an image of the area including the tip 136a that is irradiated with near-infrared light. The control unit 102 controls the near-infrared light source 140 and the near-infrared image capturing unit 150 so that the near-infrared light source 140 emits near-infrared light toward the area including the tip 136a, and the near-infrared image capturing unit 150 captures an image of the area including the tip 136a. The timing at which the near-infrared light source 140 starts emitting near-infrared light may be the same as or different from the timing at which the near-infrared imaging section 150 starts imaging. The timing at which the near-infrared light source 140 starts emitting near-infrared light may be earlier or later than the timing at which the near-infrared imaging section 150 starts imaging. The timing at which the near-infrared light source 140 starts emitting near-infrared light may be the same as or different from the timing at which the treatment liquid L is pulled back in step S130. The timing at which the near-infrared light source 140 starts emitting near-infrared light may be earlier or later than the timing at which the treatment liquid L is pulled back in step S130.

[0134] Next, in step S150, the position of the outer edge of the processing liquid L in the captured image is identified based on the captured image generated by the near-infrared imaging unit 150. Specifically, for example, the control unit 102 identifies the position of the downstream edge La of the processing liquid L based on the captured image. Also, for example, the control unit 102 identifies the boundary position between the processing liquid L and the cavity C based on the captured image. Also, the control unit 102 may further identify the type of processing liquid L in the captured image based on the captured image. Note that the control unit 102 may identify the position of the center line M136 of the liquid flow path 136b based on the captured image. However, the center line M136 may be identified before step S150.

[0135] For example, the control unit 102 specifies the position of the outer edge of the processing liquid L in the captured image based on the luminance value or brightness in the captured image. For example, the control unit 102 specifies the position of the outer edge of the processing liquid L in the captured image based on the luminance value or brightness in the captured image and the luminance value or brightness of a reference processing liquid stored in the storage unit 104. Alternatively, the control unit 102 specifies the position of the outer edge of the processing liquid L in the captured image based on the captured image and the reference image. Alternatively, for example, the control unit 102 may determine that an area in the captured image whose luminance value or brightness is within a predetermined range is the processing liquid L, and determine that the outer edge of the area whose luminance value or brightness is within the predetermined range is the outer edge of the processing liquid L.

[0136] Furthermore, the control unit 102 identifies the type of processing liquid L in the captured image based on the luminance value or brightness in the captured image. The control unit 102 identifies the type of processing liquid L in the captured image based on the luminance value or brightness in the captured image and the luminance value or brightness of a reference processing liquid stored in the storage unit 104. Alternatively, the control unit 102 identifies the type of processing liquid L in the captured image based on the captured image and the reference image.

[0137] Next, in step S160, the speed at which the processing liquid L moves upstream inside the nozzle 136 is calculated based on the identified position of the downstream edge La of the processing liquid L. Specifically, the control unit 102 calculates the speed of the processing liquid L by the method described with reference to FIGS.

[0138] Next, in step S170, the control unit 102 determines whether or not an abnormality has occurred based on the position of the outer edge of the treatment liquid L.

[0139] For example, the control unit 102 determines whether or not an abnormality has occurred based on the velocity of the processing liquid L calculated in step S160. In this case, the control unit 102 determines whether or not the velocity of the processing liquid L is within a predetermined range. If the velocity of the processing liquid L is within the predetermined range, the control unit 102 determines that no abnormality has occurred. On the other hand, if the velocity of the processing liquid L is outside the predetermined range, the control unit 102 determines that an abnormality has occurred. For example, if the velocity of the processing liquid L is higher than the predetermined range, the processing liquid L will be drawn back toward the pipe 132 more than necessary. On the other hand, if the velocity of the processing liquid L is lower than the predetermined range, the processing liquid L will not be drawn back sufficiently toward the pipe 132.

[0140] Alternatively, for example, the control unit 102 determines whether or not the processing liquid L has separated based on the position of the outer edge of the processing liquid L. Note that, if the control unit 102 determines whether or not the processing liquid L has separated without calculating the speed of the processing liquid L, step S160 may be omitted. For example, the control unit 102 determines whether or not a cavity C has been formed based on the position of the outer edge of the processing liquid L. If a cavity C has not been formed, the control unit 102 determines that no abnormality has occurred. On the other hand, if a cavity C has been formed, the control unit 102 determines that an abnormality has occurred.

[0141] Furthermore, the control unit 102 may compare the type of processing liquid L calculated based on the captured image with the type of processing liquid L in the recipe data to determine whether or not the type of processing liquid L being used is correct.

[0142] If control unit 102 determines in step S170 that no abnormality has occurred, the process proceeds to step S190.

[0143] On the other hand, if control unit 102 determines in step S170 that an abnormality has occurred, the process proceeds to step S180.

[0144] Next, in step S180, the control unit 102 executes a predetermined process. The predetermined process will be described below.

[0145] Specifically, when the speed of the processing liquid L is higher than a predetermined range, the control unit 102 changes at least one of the timing for starting to draw the processing liquid L back upstream (timing for opening the valve 162) and the timing for stopping the drawing of the processing liquid L back upstream (timing for closing the valve 162) based on the identified position of the outer edge of the processing liquid L.

[0146] For example, when the velocity of the processing liquid L is higher than a predetermined range, the control unit 102 may rewrite the recipe so as to delay the timing at which the processing liquid L starts to be drawn back upstream. Also, for example, when the velocity of the processing liquid L is higher than a predetermined range, the control unit 102 may rewrite the recipe so as to advance the timing at which the processing liquid L stops being drawn back upstream.

[0147] Furthermore, when the velocity of the processing liquid L is higher than a predetermined range, for example, the control unit 102 may control the speed controller and / or the needle valve of the valve 162 to slow down the opening / closing speed of the valve 162 and / or to reduce the flow rate of the processing liquid L flowing through the pipe 161. Furthermore, the control unit 102 may notify the user of notification information indicating that the velocity of the processing liquid L is higher than the predetermined range. In this case, the user may manually adjust the speed controller and / or the needle valve of the valve 162 so that the opening / closing speed of the valve 162 is slowed down and / or the flow rate of the processing liquid L flowing through the pipe 161 is reduced. The method of notifying the user of the notification information is not particularly limited, but may be, for example, a display on a display panel of the substrate processing apparatus 100, an error lamp may be turned on, or a voice may be used to notify the user.

[0148] Furthermore, for example, when the velocity of the processing liquid L is lower than a predetermined range, the control unit 102 may rewrite the recipe so that the timing to start drawing back the processing liquid L upstream is advanced. Furthermore, for example, when the velocity of the processing liquid L is lower than a predetermined range, the control unit 102 may rewrite the recipe so that the timing to stop drawing back the processing liquid L upstream is delayed.

[0149] Furthermore, when the velocity of the processing liquid L is lower than a predetermined range, for example, the control unit 102 may control a speed controller and / or a needle valve of the valve 162 to increase the opening / closing speed of the valve 162 and / or increase the flow rate of the processing liquid L flowing through the pipe 161. Furthermore, the control unit 102 may notify the user of notification information indicating that the velocity of the processing liquid L is lower than the predetermined range. In this case, the user may manually adjust the speed controller and / or the needle valve of the valve 162 so that the opening / closing speed of the valve 162 is increased and / or the flow rate of the processing liquid L flowing through the pipe 161 is increased.

[0150] Furthermore, for example, when separation of the processing liquid L occurs, the control unit 102 may control the speed controller and / or the needle valve of the valve 162 to slow down the opening / closing speed of the valve 162 and / or to reduce the flow rate of the processing liquid L flowing through the pipe 161. The control unit 102 may also notify the user of notification information indicating that the speed of the processing liquid L is higher than a predetermined range. In this case, the user may manually adjust the speed controller and / or the needle valve of the valve 162 so that the opening / closing speed of the valve 162 is slowed down and / or the flow rate of the processing liquid L flowing through the pipe 161 is reduced.

[0151] Furthermore, if the type of treatment liquid L being used (the identified treatment liquid L) is incorrect, for example, the control unit 102 may notify the user of notification information indicating that the treatment liquid L being used is incorrect.

[0152] Next, in step S190, the control unit 102 stops the pull-back of the processing liquid L. Specifically, when a predetermined time has elapsed since the start of the pull-back of the processing liquid L in step S130, the control unit 102 closes the valve 162 of the liquid return unit 160 to stop the pull-back of the processing liquid L. Note that the timing to stop the pull-back of the processing liquid L does not have to be after the execution of the predetermined process in step S180. For example, the timing to stop the pull-back of the processing liquid L may be between steps S140 and S180.

[0153] Next, in step S200, the rotation of the substrate W is stopped. Specifically, the control unit 102 controls the substrate holding unit 120 so that the substrate holding unit 120 stops rotating the substrate W.

[0154] In the present embodiment, as described above, the control unit 102 identifies the position of the downstream edge La of the processing liquid L in the nozzle 136 based on the captured image. Therefore, it is possible to easily calculate the speed of the processing liquid L and / or determine whether or not the processing liquid L has separated.

[0155] Furthermore, as described above, the control unit 102 calculates the velocity of the treatment liquid L based on the position of the edge La of the treatment liquid L. Therefore, the velocity of the treatment liquid L during suck-back can be easily calculated.

[0156] Furthermore, as described above, when the first predetermined time has elapsed since the processing liquid L started to be returned to the upstream side, the control unit 102 captures an image of the processing liquid L moving upstream inside the nozzle 136 by the near-infrared imaging unit 150, and calculates the speed of the processing liquid L based on the position of the edge La of the processing liquid L and the first predetermined time. Therefore, the speed of the processing liquid L during suck-back can be calculated more easily.

[0157] As described above, the control unit 102 captures images of the treatment liquid L moving upstream inside the nozzle 136 multiple times at second predetermined time intervals using the near-infrared imaging unit 150, and calculates the velocity of the treatment liquid L based on the positions of the edge La of the treatment liquid L in the multiple captured images and the second predetermined time. In this case as well, the velocity of the treatment liquid L during suck-back can be more easily calculated.

[0158] Furthermore, as described above, the control unit 102 calculates the velocity of the processing liquid L based on the distance L1 from the tip 136a of the nozzle 136 to the edge La of the processing liquid L. This makes it easier to calculate the velocity of the processing liquid L. The control unit 102 may also calculate the velocity of the processing liquid L based on the distance L3. In this case as well, it is easier to calculate the velocity of the processing liquid L.

[0159] Alternatively, as described above, the control unit 102 calculates the velocity of the treatment liquid L based on the length L2 or length L4 of the movement of the edge La of the treatment liquid L along the center line M136 of the liquid flow path 136b and the first predetermined time or the second predetermined time. Therefore, the velocity of the treatment liquid L can be calculated more accurately.

[0160] Furthermore, as described above, when it is determined that an abnormality has occurred, the control unit 102 changes at least one of the timing to start drawing back the treatment liquid L upstream and the timing to stop drawing back the treatment liquid L upstream, based on the position of the outer edge of the treatment liquid L. Therefore, the speed of the treatment liquid L can be easily kept within a predetermined range.

[0161] As described above, the control unit 102 identifies the type of processing liquid L based on the captured image. Therefore, by comparing the type of processing liquid L identified based on the captured image with the type of processing liquid L in the recipe data, it is possible to confirm whether the type of processing liquid L being used is correct.

[0162] Next, an example in which the near-infrared light source 140 includes a plurality of near-infrared light sources 140a and 140b will be described with reference to Fig. 13 and Fig. 14. Fig. 13 is a schematic diagram of a substrate processing unit 110 in a substrate processing apparatus 100 including a plurality of near-infrared light sources 140a and 140b.

[0163] 13, the near-infrared light source 140 includes a plurality of (here, two) near-infrared light sources 140a and 140b. The near-infrared light source 140a and the near-infrared light source 140b emit near-infrared light having different peak wavelengths from each other.

[0164] The processing liquid supply unit 130 supplies a plurality of types of processing liquid L (here, two types) to the substrate W.

[0165] The processing liquid supply unit 130 further includes a pipe 232 and a valve 234. The processing liquid L from a supply source flows through the pipe 232. The valve 234 opens and closes a flow path in the pipe 232. The pipe 232 is connected to the pipe 132. In this embodiment, the pipe 232 is connected to a position of the pipe 132 upstream of the liquid return unit 160. In this embodiment, the pipe 232 and the valve 234 configure a supply unit 235 that supplies the processing liquid L to the nozzle 136. The supply unit 235 may include a pump (not shown) that sends out the processing liquid L from the supply source. The other configurations of the supply unit 235 (pipe 232 and valve 234) are similar to those of the supply unit 135 (pipe 132 and valve 134).

[0166] The control unit 102 acquires type information indicating the type of processing liquid L. For example, the control unit 102 acquires the type of processing liquid L supplied by the supply unit 135 and the type of processing liquid L supplied by the supply unit 235 from recipe data. Also, for example, the recipe data may include information indicating the type of near-infrared light source 140 corresponding to the type of processing liquid L. Also, for example, the control unit 102 may acquire the type of processing liquid L supplied by the supply unit 135 and the type of processing liquid L supplied by the supply unit 235 from input information input by the user.

[0167] The control unit 102 changes the near-infrared light source 140 that irradiates the area including the tip 136a of the nozzle 136 according to the acquired type information. For example, when the supply unit 135 supplies the treatment liquid L, the control unit 102 irradiates the area using the near-infrared light source 140a. On the other hand, when the supply unit 235 supplies the treatment liquid L, the control unit 102 irradiates the area using the near-infrared light source 140b.

[0168] Specifically, for example, the processing liquid L supplied by the supply unit 135 is DIW, and the processing liquid L supplied by the supply unit 235 is ethanol. For example, the near-infrared light source 140a emits near-infrared light having a peak wavelength of about 1.4 μm, and the near-infrared light source 140b emits near-infrared light having a peak wavelength of about 1.6 μm or about 1.7 μm. DIW has high absorbance (also called absorptivity) for light with a wavelength of about 1.4 μm. On the other hand, ethanol has high absorbance for light with wavelengths of about 1.6 μm and about 1.7 μm. Therefore, when the supply unit 135 supplies the processing liquid L (DIW), the near-infrared light source 140a irradiates the processing liquid L, thereby increasing the contrast in brightness or luminosity between the area showing the processing liquid L in the captured image and the area showing the parts other than the processing liquid L. Therefore, the position of the edge of the processing liquid L can be more accurately identified based on the captured image. Furthermore, when the supply unit 235 supplies the processing liquid L (ethanol), the near-infrared light source 140b irradiates the processing liquid L, thereby increasing the contrast in brightness or luminance between the area in the captured image showing the processing liquid L and the area showing the portion other than the processing liquid L. Therefore, the position of the edge of the processing liquid L can be more accurately identified based on the captured image.

[0169] FIG. 14 is a flow diagram of a substrate processing step in an example in which the near-infrared light source 140 includes a plurality of near-infrared light sources 140a and 140b. In the substrate processing flow shown in FIG. 14, step S110 is an example of the "rotating step" and "acquiring step" of the present invention. Step S220 is an example of the "supplying step" of the present invention. Step S230 is an example of the "pulling back step" of the present invention. In detail, the steps from step S230 to step S290 in which the pulling back of the processing liquid L is stopped are an example of the "pulling back step" of the present invention. Step S240 is an example of the "irradiating step", "captured image generating step", and "near-infrared light source changing step" of the present invention. Step S250 is an example of the "identifying step" of the present invention. Step S260 is an example of the "calculating step" of the present invention. Step S270 is an example of the "determining step" of the present invention. Step S280 is an example of the "changing at least one of the timing to start pulling back and the timing to stop pulling back" of the present invention.

[0170] As shown in Fig. 14, steps S110 to S190 are similar to the flow shown in Fig. 12. However, here, the control unit 102 acquires recipe data, for example, in step S110. At this time, the control unit 102 acquires type information indicating the type of processing liquid L. Furthermore, in step S140, the near-infrared light source 140a irradiates.

[0171] Next, in step S220, the processing liquid L is supplied from the supply unit 235 to the substrate W. Specifically, the control unit 102 controls the supply unit 235 to supply the processing liquid L to the substrate W. When a predetermined time has elapsed since the control unit 102 started supplying the processing liquid L to the substrate W, the control unit 102 controls the supply unit 235 to stop supplying the processing liquid L to the substrate W.

[0172] Next, in step S230, the control unit 102 starts pulling back the processing liquid L. Specifically, the control unit 102 opens the valve 162 of the liquid returning unit 160 to pull back the processing liquid L in the nozzle 136 to the upstream side. As a result, the processing liquid L in the nozzle 136 starts moving toward the upstream side.

[0173] Next, in step S240, the control unit 102 changes the near-infrared light source 140 that irradiates the area including the tip 136a of the nozzle 136 from the near-infrared light source 140a to the near-infrared light source 140b. As a result, the near-infrared light source 140b irradiates the area including the tip 136a of the nozzle 136 with near-infrared light, and the near-infrared image capturing unit 150 captures an image of the area including the tip 136a of the nozzle 136 that is irradiated with near-infrared light. Other controls in step S240 are similar to those in step S140.

[0174] The subsequent steps S250 to S290 are similar to steps S150 to S190. Also, step S200 is similar to the flow shown in FIG.

[0175] However, in step S280, the control unit 102 may change at least one of the timing to start drawing back the processing liquid L upstream and the timing to stop drawing back the processing liquid L upstream, based on the type of processing liquid L identified in step S250. Furthermore, the control unit 102 may control the speed controller and / or the needle valve of the valve 162, based on the type of processing liquid L identified in step S250.

[0176] In this embodiment, as described above, the control unit 102 acquires type information indicating the type of the treatment liquid L, and based on the acquired type information, changes the near-infrared light source 140 that irradiates the area including the tip 136a of the nozzle 136. Therefore, since the near-infrared light to be irradiated can be changed depending on the absorbance of the treatment liquid L, the position of the edge of the treatment liquid L can be accurately identified even if the type of the treatment liquid L is changed.

[0177] Other control and effects of the substrate processing flow shown in FIG. 14 are similar to those of the substrate processing flow shown in FIG.

[0178] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all components shown in the embodiments. Furthermore, components across different embodiments may be appropriately combined. The drawings are mainly shown schematically for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various changes are possible within a range that does not substantially deviate from the effects of the present invention.

[0179] For example, in the above embodiment, an example in which the processing liquid L is imaged only during suck back has been described, but the present invention is not limited to this. For example, the processing liquid L may be imaged not only during suck back, but also when the processing liquid L is being supplied to the substrate W.

[0180] In the above embodiment, an example in which the type of the processing liquid L is identified based on the captured image has been described, but the present invention is not limited to this. For example, the luminance value or brightness of the processing liquid L in the captured image varies depending on the concentration of the processing liquid L. The type of processing liquid L can be obtained from recipe data. Therefore, the concentration of the processing liquid L may be identified based on the captured image and information on the type and concentration of the processing liquid L.

[0181] 13, an example in which two types of processing liquid L are supplied to the substrate W from the same nozzle 136 has been described, but the present invention is not limited to this. For example, two types of processing liquid L may be supplied to the substrate W from separate nozzles. In this case as well, the near-infrared light source 140 for irradiating the processing liquid L may be changed depending on the type of processing liquid L. [Industrial Applicability]

[0182] The present invention can be suitably used in a substrate processing apparatus and a substrate processing method. [Explanation of symbols]

[0183] 100: Substrate processing apparatus 102: Control unit 120: Board holding part 135: Supply section 136: Nozzle (processing liquid nozzle) 136a: Tip 136b:Liquid flow path 140, 140a, 140b: Near-infrared light source 150: Near-infrared imaging unit 160: Liquid return section 235: Supply section L: Processing liquid L1: distance L2, L4: Length La : Edge M136: Center line S110: Step (rotation step, acquisition step) S120, S220: Step (supply process) S130, S230: Step (pull back process) S140: Step (irradiation step, image generation step) S150, S250: Step (specifying process) S160, S260: Step (calculation process) S170, S270: Steps (judging steps) S180, S280: Steps (steps of changing at least one of the timing to start pulling back and the timing to stop pulling back) S240: Step (irradiation step, image generation step, near-infrared light source change step) SC: Step (rotating process, supply process) SD: Step (pull back process) SE: Step (irradiation step, image generation step) SF: Step (specifying process) W: Substrate Wa: Top

Claims

1. a substrate holder that holds a substrate and rotates the substrate; a processing liquid nozzle for supplying a processing liquid to an upper surface of the substrate; a supply unit that supplies the processing liquid to the processing liquid nozzle; a liquid return section that returns the processing liquid in the processing liquid nozzle to an upstream side; a near-infrared light source that irradiates an area including a tip of the treatment liquid nozzle with near-infrared light; a near-infrared image capturing unit that captures an image of the treatment liquid being irradiated with near-infrared light from the near-infrared light source; a control unit that controls the supply unit, the liquid returning unit, and the near-infrared imaging unit; Equipped with The control unit is stopping the supply of the treatment liquid by the supply unit and drawing back the treatment liquid in the treatment liquid nozzle to the upstream side by the liquid returning unit; an image of the processing liquid moving upstream inside the processing liquid nozzle is captured by the near-infrared imaging unit; The substrate processing apparatus identifies a position of an outer edge of the processing liquid in the processing liquid nozzle based on the captured image.

2. The substrate processing apparatus according to claim 1 , wherein the control unit identifies a position of a downstream edge of the processing liquid in the processing liquid nozzle based on the captured image.

3. The substrate processing apparatus according to claim 2 , wherein the control unit calculates a speed at which the processing liquid moves upstream inside the processing liquid nozzle based on the identified position of the downstream edge of the processing liquid.

4. The control unit is an image of the processing liquid moving upstream inside the processing liquid nozzle is captured by the near-infrared imaging unit at a predetermined time after the liquid returning unit starts returning the processing liquid inside the processing liquid nozzle to the upstream side; The substrate processing apparatus according to claim 3 , wherein the speed is calculated based on the specified position of the downstream edge of the processing liquid and the predetermined time.

5. The control unit is calculating a distance from a tip of the processing liquid nozzle to a downstream edge of the processing liquid based on the captured image; The substrate processing apparatus according to claim 4 , wherein the speed is calculated based on the calculated distance and the predetermined time.

6. The control unit is The near-infrared imaging unit captures an image of the processing liquid moving upstream inside the processing liquid nozzle a plurality of times at predetermined time intervals; The substrate processing apparatus according to claim 3 , wherein the speed is calculated based on a position of a downstream edge of the processing liquid in the plurality of captured images and the predetermined time.

7. the processing liquid nozzle has a liquid flow path through which the processing liquid passes, The control unit is Identifying a center line of the liquid flow path based on the captured image; 7. The substrate processing apparatus according to claim 4, wherein the speed is calculated based on a length of movement of the downstream edge of the processing liquid along a center line of the liquid flow path and the predetermined time.

8. The control unit is determining whether or not an abnormality has occurred based on the identified position of the outer edge of the processing liquid; A substrate processing apparatus as described in any one of claims 1 to 6, wherein when it is determined that an abnormality has occurred, at least one of the timing for starting to draw back the processing liquid upstream and the timing for stopping the drawing back of the processing liquid upstream is changed based on the identified position of the outer edge of the processing liquid.

9. The substrate processing apparatus according to claim 1 , wherein the control unit identifies a type of the processing liquid based on the captured image.

10. The near-infrared light source includes a plurality of near-infrared light sources emitting near-infrared rays having different peak wavelengths, The control unit is acquiring type information indicating a type of the treatment liquid; The substrate processing apparatus according to claim 1 , further comprising: a step of changing the near-infrared light source that irradiates an area including a tip of the processing liquid nozzle based on the acquired type information.

11. holding a substrate and rotating said substrate; supplying a processing liquid to a processing liquid nozzle and supplying the processing liquid from the processing liquid nozzle onto an upper surface of the substrate; after stopping the supply of the processing liquid, drawing back the processing liquid in the processing liquid nozzle to the upstream side; irradiating an area including a tip of the processing liquid nozzle with near-infrared rays; generating an image of the processing liquid irradiated with near-infrared light and moving upstream inside the processing liquid nozzle; identifying a position of an outer edge of the processing liquid in the processing liquid nozzle based on the captured image; A method for processing a substrate, comprising:

12. The substrate processing method according to claim 11 , wherein in the specifying, a position of a downstream edge of the processing liquid in the processing liquid nozzle is specified based on the captured image.

13. 13. The substrate processing method according to claim 12, further comprising the step of calculating a speed at which the processing liquid moves upstream inside the processing liquid nozzle based on the identified position of the downstream edge of the processing liquid.

14. In the step of generating the captured image, an image of the processing liquid moving upstream inside the processing liquid nozzle is captured at a predetermined time after the processing liquid inside the processing liquid nozzle starts to return upstream, The substrate processing method according to claim 13 , wherein in the calculating, the velocity is calculated based on the identified position of the downstream edge of the processing liquid and the predetermined time.

15. In the calculating step, calculating a distance from a tip of the processing liquid nozzle to a downstream edge of the processing liquid based on the captured image; The substrate processing method according to claim 14 , further comprising the step of calculating the velocity based on the calculated distance and the predetermined time period.

16. In the step of generating the captured image, an image of the processing liquid moving upstream inside the processing liquid nozzle is captured a plurality of times at predetermined time intervals; The substrate processing method according to claim 13 , wherein in the calculating, the velocity is calculated based on a position of a downstream edge of the processing liquid in the plurality of captured images and the predetermined time.

17. In the step of identifying, a center line of a liquid flow path through which the treatment liquid passes in the treatment liquid nozzle is identified based on the captured image; 17. The substrate processing method according to claim 14, wherein in the calculating step, the velocity is calculated based on a length of movement of a downstream edge of the processing liquid along a center line of the liquid flow path and the predetermined time.

18. determining whether or not an abnormality has occurred based on the identified position of the outer edge of the processing liquid; when it is determined that the abnormality has occurred, changing at least one of a timing to start drawing back the treatment liquid to the upstream side and a timing to stop drawing back the treatment liquid to the upstream side based on the identified position of the outer edge of the treatment liquid; The method for processing a substrate according to claim 11 , further comprising:

19. The substrate processing method according to claim 11 , wherein in the identifying step, the type of the processing liquid is identified based on the captured image.

20. The near-infrared light source includes a plurality of near-infrared light sources emitting near-infrared rays having different peak wavelengths, The substrate processing method includes: acquiring type information indicating a type of the treatment liquid; changing the near-infrared light source that irradiates an area including the tip of the processing liquid nozzle based on the acquired type information; The method for processing a substrate according to claim 11 , further comprising:

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