JP7165019B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

The present invention relates to a substrate processing method and a substrate processing apparatus.

2. Description of the Related Art As an apparatus for processing a substrate, a substrate processing apparatus is used that discharges a processing liquid from a discharge nozzle onto the surface of the substrate while rotating the substrate in a horizontal plane. The processing liquid that has landed on the substantially center of the substrate from the ejection nozzle spreads over the entire surface due to the centrifugal force accompanying the rotation of the substrate, and scatters outward from the periphery. By spreading the processing liquid over the entire surface of the substrate, the processing liquid can act on the entire surface of the substrate. As the processing liquid, a chemical liquid, a cleaning liquid, or the like is used according to the processing to be performed on the substrate.

In such a substrate processing apparatus, there has been proposed a technique of providing a camera in order to monitor whether or not the processing liquid is properly discharged (Patent Documents 1 to 5).

Moreover, in the manufacturing process of a semiconductor substrate, various films remaining on the peripheral edges of the substrate may adversely affect the device surface of the substrate.

Therefore, conventionally, bevel processing has been proposed for removing the film from the peripheral edge of the substrate. In the bevel process, while the substrate is rotated in a horizontal plane, a removal processing liquid is discharged from a discharge nozzle onto the edge of the substrate, thereby removing the film on the peripheral edge of the substrate with the processing liquid.

JP 2015-173148 A JP 2017-29883 A JP 2015-18848 A JP 2016-122681 A JP 2008-135679 A

In the bevel process, the processing liquid needs to be supplied only to the edges of the substrate, so the flow rate of the processing liquid is reduced. In other words, the liquid columnar treatment liquid ejected from the ejection nozzle becomes thinner. Therefore, the liquid column-shaped processing liquid is easily affected by factors such as an air current accompanying the rotation of the substrate and static electricity generated in the surroundings, and the ejection state thereof is likely to fluctuate. Specifically, the landing position of the processing liquid on the substrate may shift due to these factors. Since displacement of the liquid landing position adversely affects the process, it is desirable to be able to monitor the ejection state of the treatment liquid.

However, in the bevel process, since the distance between the ejection nozzle and the substrate is narrow, it is necessary to devise an image of the liquid column-shaped treatment liquid ejected from the ejection nozzle.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present application to provide a substrate processing method and a substrate processing apparatus capable of monitoring the landing position of a liquid column-shaped processing liquid discharged onto the edge of a substrate.

A first aspect of a substrate processing method includes a holding step of holding a substrate in a substrate holding portion, a rotating step of rotating the substrate holding portion to rotate the substrate, and a cup member surrounding the outer circumference of the substrate holding portion. to position the upper end of the cup member at an upper end position higher than the upper surface of the substrate held by the substrate holding portion; a bevel processing step of discharging a processing liquid onto an end portion of the upper surface of the substrate held by the substrate holding portion; an imaging step of obtaining a captured image by causing a camera to capture an imaging region including a mirror image of a liquid, the imaging region viewed from an imaging position above the substrate held by the substrate holding part; a monitoring step of monitoring the landing position of the processing liquid based on the processing liquid and the mirror image in the captured image.

A second aspect of the substrate processing method is the substrate processing method according to the first aspect, wherein in the captured image, an entire image including the processing liquid and the mirror image is bent at a boundary between the processing liquid and the mirror image. In the monitoring step, the liquid landing position is obtained based on the curved position of the overall image of the processing liquid.

A third aspect of the substrate processing method is the substrate processing method according to the second aspect, wherein in the monitoring step, a binary value obtained by performing edge detection processing and binarization processing on the captured image detecting a first straight line component extending along the discharge direction of the treatment liquid and a second straight line component extending along the discharge direction of the mirror image from the converted image, and determining the first straight line component and the second straight line component; is obtained as the bending position.

A fourth aspect of the substrate processing method is the substrate processing method according to any one of the first to third aspects, wherein the exposure time of the camera is set to be longer than the time required for the substrate to rotate once. .

A fifth aspect of the substrate processing method is the substrate processing method according to the second or third aspect, wherein a plurality of captured images are captured by the camera within a time period equal to or longer than the time required for the substrate to rotate once. The liquid landing position is determined based on the overall image in the captured image obtained by integrating or averaging the .

A sixth aspect of the substrate processing method is the substrate processing method according to any one of the first to fifth aspects, wherein in the monitoring step, the position of the peripheral edge of the substrate in the captured image is specified, The liquid landing position of the processing liquid is obtained with reference to the position of the peripheral edge of the substrate.

A seventh aspect of the substrate processing method is the substrate processing method according to any one of the first to sixth aspects, wherein the monitoring step is performed when the obtained liquid landing position is not within a predetermined range. , and the step of notifying the notification unit to that effect.

An eighth aspect of the substrate processing method is the substrate processing method according to any one of the first to seventh aspects, wherein in the monitoring step, a machine-learned classifier classifies the captured image into It is classified into either the category without positional anomaly or the category with liquid landing positional anomaly.

A ninth aspect of the substrate processing method is the substrate processing method according to the eighth aspect, wherein, in the monitoring step, from the captured image, the image is located directly below the nozzle and includes the processing liquid and the mirror image. A region is clipped and an image of the clipped region is input to the classifier.

A mode of the substrate processing apparatus includes a substrate holding part that holds a substrate and rotates the substrate, a cup member that surrounds the outer circumference of the substrate holding part, and a cup member that is lifted so that the upper end of the cup member It has an elevating mechanism positioned at an upper end position higher than the upper surface of the substrate held by the substrate holding part, and an ejection port positioned lower than the upper end position, and is held by the substrate holding part from the ejection port. an imaging region including a nozzle for ejecting a treatment liquid, a treatment liquid ejected from the ejection port of the nozzle, and a mirror image of the treatment liquid reflected on the upper surface of the substrate; a camera that captures an image of an imaging region viewed from an imaging position above the substrate held by the substrate holding unit, and obtains a captured image; and a mirror image of the treatment liquid in the captured image. and an image processing unit that monitors the landing position of the treatment liquid based on.

According to the first aspect of the substrate processing method and the aspect of the substrate processing apparatus, it is possible to monitor the landing position of the liquid column-shaped processing liquid discharged onto the edge of the substrate.

According to the second aspect of the substrate processing method, the bending position is located above the upper surface of the substrate W, so the liquid landing position can be obtained with higher accuracy.

According to the third aspect of the substrate processing method, the bending position can be determined appropriately.

According to the fourth aspect of the substrate processing method, since the pattern on the upper surface of the substrate is averaged and made uniform, noise contained in the mirror image of the processing liquid in the captured image can be reduced.

According to the fifth aspect of the substrate processing method, since the pattern on the upper surface of the substrate is averaged and made uniform, noise contained in the mirror image of the processing liquid in the captured image can be reduced.

According to the sixth aspect of the substrate processing method, since the liquid landing position with respect to the peripheral edge of the substrate is obtained, the liquid landing position can be monitored more appropriately.

According to the seventh aspect of the substrate processing method, the operator can recognize the liquid landing position abnormality.

According to the eighth aspect of the substrate processing method, an abnormality can be detected with high accuracy.

According to the ninth aspect of the substrate processing method, the classification can be performed by removing the influence of the region with low relevance to the processing liquid, so that the classification accuracy can be improved.

It is a figure which shows a schematic example of a structure of a substrate processing apparatus. FIG. 2 is a plan view showing a schematic example of the configuration of a processing unit; FIG. 3 is a cross-sectional view showing a schematic example of the configuration of a processing unit; It is a figure which shows roughly an example of the captured image acquired by the camera. FIG. 2 is a perspective view schematically showing an example of a configuration of a camera and a camera holding section; 4 is a flowchart showing an example of substrate processing; 6 is a flowchart illustrating an example of monitoring processing; It is the figure which expanded a part of picked-up image. FIG. 4 is a diagram schematically showing an example of a binarized image; FIG. 2 is a plan view showing a schematic example of the configuration of a processing unit; FIG. 2 is a plan view showing a schematic example of the configuration of a processing unit; 3 is a functional block diagram schematically showing an example of the internal configuration of a control unit; FIG.

Embodiments will be described below with reference to the attached drawings. It should be noted that the drawings are shown schematically, and for the convenience of explanation, the configuration may be omitted or simplified as appropriate. Also, the mutual relationship of sizes and positions of the configurations shown in the drawings are not necessarily described accurately, and may be changed as appropriate.

In addition, in the description given below, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, a detailed description thereof may be omitted to avoid duplication.

<Overview of substrate processing equipment>
FIG. 1 is a diagram showing the overall configuration of a substrate processing apparatus 100. As shown in FIG. The substrate processing apparatus 100 is an apparatus that processes the substrate W by supplying a processing liquid to the substrate W. As shown in FIG. The substrate W is, for example, a semiconductor substrate. This substrate W has a substantially disk shape.

This substrate processing apparatus 100 can remove unnecessary substances adhering to the peripheral edge of the substrate W by supplying the processing liquid to the edge of the substrate W while rotating the substrate W in the horizontal plane. The width of this peripheral edge portion (the width along the radial direction) is, for example, about 0.5 to 3 [mm]. The undesired substances include, for example, films such as _SiO2 films, SiN films and polysilicon films, particles, and the like. Examples of processing liquids for removing such unnecessary substances include hydrofluoric acid (HF), phosphoric acid (H ₃ PO ₄ ), a mixed solution of ammonia (NH ₃ ) and hydrogen peroxide (H ₂ O ₂ ) (SC- 1), and fluoronitric acid (a mixture of hydrofluoric acid and nitric acid (HNO ₃ )). The substrate processing apparatus 100 removes unnecessary substances by supplying the processing liquid to the edge of the substrate W while rotating the substrate W. FIG. Such processing is also called bevel processing.

A substrate processing apparatus 100 includes an indexer 102 , a plurality of processing units 1 and a main transfer robot 103 . The indexer 102 has a function of loading unprocessed substrates W received from outside the apparatus into the apparatus and unloading processed substrates W from the apparatus. The indexer 102 mounts a plurality of carriers and has a transfer robot (not shown). As a carrier, adopt a FOUP (front opening unified pod) or SMIF (Standard Mechanical Interface) pod that stores the substrate W in a sealed space, or an OC (open cassette) that exposes the substrate W to the outside while stored. can be done. The transfer robot transfers the substrate W between the carrier and the main transfer robot 103 .

Twelve processing units 1 are arranged in the substrate processing apparatus 100 . The detailed arrangement configuration is such that four towers in which three processing units 1 are stacked are arranged so as to surround the main transfer robot 103 . In other words, the four processing units 1 arranged around the main transfer robot 103 are stacked in three layers, and FIG. 1 shows one of them. The number of processing units 1 mounted on the substrate processing apparatus 100 is not limited to twelve, and may be, for example, eight or four.

The main transfer robot 103 is installed in the center of four towers in which the processing units 1 are stacked. The main transport robot 103 loads unprocessed substrates W received from the indexer 102 into the respective processing units 1 and unloads the processed substrates W from the respective processing units 1 to deliver them to the indexer 102 .

<Processing unit>
Next, the processing unit 1 will be explained. One of the 12 processing units 1 mounted on the substrate processing apparatus 100 will be described below, but the other processing units 1 are also the same. FIG. 2 is a plan view of the processing unit 1. FIG. 3 is a longitudinal sectional view of the processing unit 1. FIG.

In the chamber 10, the processing unit 1 includes, as main elements, a substrate holding part 20 that holds the substrate W in a horizontal posture (a posture in which the normal line of the substrate W is along the vertical direction), and a substrate held by the substrate holding part 20. It comprises three processing liquid supply units 30 , 60 , 65 for supplying processing liquid to the upper surface of W, a processing cup (cup member) 40 surrounding the substrate holding unit 20 , and a camera 70 . A partition plate 15 is provided around the processing cup 40 in the chamber 10 to partition the inner space of the chamber 10 into upper and lower parts. The processing unit 1 is also provided with a control section 9 and a notification section 93 .

<Chamber>
The chamber 10 includes side walls 11 extending in the vertical direction, a ceiling wall 12 that closes the upper side of the space surrounded by the side walls 11, and a floor wall 13 that closes the lower side. A space surrounded by the side walls 11, the ceiling wall 12, and the floor wall 13 serves as a processing space for the substrates W. As shown in FIG. A loading/unloading port for loading/unloading the substrate W by the main transfer robot 103 into/from the chamber 10 and a shutter for opening/closing the loading/unloading port are provided on a part of the side wall 11 of the chamber 10 (both are shown in the figure). omit).

A fan filter unit (FFU) 14 is attached to the ceiling wall 12 of the chamber 10 for further purifying the air in the clean room in which the substrate processing apparatus 100 is installed and supplying it to the processing space in the chamber 10 . . The fan filter unit 14 is equipped with a fan and a filter (for example, a HEPA filter) for taking in air in the clean room and sending it out into the chamber 10 , and forms clean air downflow in the processing space inside the chamber 10 . In order to uniformly disperse the clean air supplied from the fan filter unit 14 , a punching plate having a large number of blowout holes may be provided immediately below the ceiling wall 12 .

<Board holder>
The substrate holder 20 is, for example, a spin chuck. The substrate holding unit 20 includes a disk-shaped spin base 21 fixed in a horizontal posture to the upper end of a rotating shaft 24 extending along the vertical direction. A spin motor 22 that rotates a rotating shaft 24 is provided below the spin base 21 . The spin motor 22 rotates the spin base 21 in the horizontal plane via the rotation shaft 24 . A tubular cover member 23 is provided to surround the spin motor 22 and the rotating shaft 24 .

The outer diameter of the disk-shaped spin base 21 is slightly larger than the diameter of the circular substrate W held by the substrate holder 20 . Therefore, the spin base 21 has a holding surface 21a facing the entire lower surface of the substrate W to be held.

A plurality of (four in this embodiment) chuck pins 26 are erected on the periphery of the holding surface 21 a of the spin base 21 . The plurality of chuck pins 26 are spaced evenly along the circumference corresponding to the outer circumference of the circular substrate W (in the case of four chuck pins 26 as in this embodiment, they are spaced at 90° intervals). ) are placed. A plurality of chuck pins 26 are interlocked and driven by a link mechanism (not shown) housed in the spin base 21 . The substrate holding unit 20 holds the substrate W in a horizontal position above the spin base 21 and close to the holding surface 21a by holding the substrate W with each of the plurality of chuck pins 26 in contact with the outer peripheral edge of the substrate W. (see FIG. 3), and each of the plurality of chuck pins 26 can be separated from the outer peripheral edge of the substrate W to release the grip.

In a state where the substrate holding unit 20 holds the substrate W by gripping with a plurality of chuck pins 26, the spin motor 22 rotates the rotation shaft 24, thereby rotating the rotation axis CX along the vertical direction passing through the center of the substrate W. substrate W can be rotated. Here, it is assumed that the substrate holder 20 rotates counterclockwise in FIG.

<Processing liquid supply unit>
The processing liquid supply unit 30 includes an ejection nozzle 31 , a fixing member 32 and a moving mechanism 33 . The fixing member 32 is a member that fixes the ejection nozzle 31 and includes, for example, a nozzle arm 321 and a nozzle base 322 . A discharge nozzle 31 is attached to the tip of the nozzle arm 321 . The base end side of the nozzle arm 321 is fixedly connected to the nozzle base 322 . The moving mechanism 33 moves the ejection nozzle 31 by displacing the fixing member 32 . For example, the moving mechanism 33 is a motor, and rotates the nozzle base 322 around an axis along the vertical direction. As the nozzle base 322 rotates, the discharge nozzle 31 moves between the processing position above the edge of the substrate W and the standby position outside the processing cup 40 as indicated by the arrow AR34 in FIG. to move in an arc along the horizontal direction.

The processing liquid supply section 30 may have a plurality of ejection nozzles 31 . In the examples of FIGS. 2 and 3, three ejection nozzles 31 are shown as the ejection nozzles 31 . The three discharge nozzles 31 are fixed to a nozzle base 322 via nozzle arms 321 . Therefore, the three ejection nozzles 31 move in synchronization with each other. The three discharge nozzles 31 are provided at positions aligned along the circumferential direction of the substrate W at the processing position. The distance between the three discharge nozzles 31 in the circumferential direction is, for example, about ten mm.

As illustrated in FIG. 3, the discharge nozzle 31 is connected to a processing liquid supply source 37 via a pipe 34 . An on-off valve 35 is provided in the middle of the pipe 34 . A discharge port (not shown) is formed on the lower surface of the tip of the discharge nozzle 31 . By opening the on-off valve 35 , the processing liquid from the processing liquid supply source 37 flows inside the pipe 34 and is discharged from the discharge port of the discharge nozzle 31 . The processing liquid discharged while the discharge nozzle 31 is stopped at the processing position lands on the edge of the upper surface of the substrate W held by the substrate holder 20 . As the substrate W rotates, the processing liquid from the discharge nozzles 31 is supplied to the entire peripheral edge portion of the substrate W, thereby removing unnecessary substances from the peripheral edge portion (bevel processing).

A suck back valve 36 may be provided in each of the pipes 34 . The suck-back valve 36 draws in the processing liquid from the tip of the discharge nozzle 31 by sucking the processing liquid in the pipe 34 when the discharge of the processing liquid is stopped. As a result, when the ejection is stopped, the treatment liquid is less likely to drop from the tip of the ejection nozzle 31 as a relatively large lump (droplet).

When a plurality of ejection nozzles 31 are provided, the ejection nozzles 31 may be connected to different treatment liquid supply sources 37 . That is, the processing liquid supply unit 30 may be configured to supply a plurality of types of processing liquids. Alternatively, at least two of the plurality of ejection nozzles 31 may supply the same processing liquid.

The processing unit 1 of the present embodiment is further provided with two processing liquid supply units 60 and 65 in addition to the processing liquid supply unit 30 described above. The processing liquid supply units 60 and 65 of this embodiment have the same configuration as the processing liquid supply unit 30 described above. That is, the treatment liquid supply section 60 has a discharge nozzle 61 , a fixing member 62 and a moving mechanism 63 . The fixed member 62 has a nozzle arm 621 and a nozzle base 622 like the fixed member 32 . A discharge nozzle 61 is attached to the tip of the nozzle arm 621, and a nozzle base 622 is connected to the base end thereof. The moving mechanism 63 is, for example, a motor, and rotates the nozzle base 622 to move the discharge nozzle 61 to a processing position above the edge of the substrate W and outside the processing cup 40 as indicated by an arrow AR64. in an arc between the standby position of This discharge nozzle 61 also supplies the processing liquid to the edge of the substrate W. As shown in FIG. As the substrate W rotates, the processing liquid from the discharge nozzles 61 is supplied to the entire area of the peripheral edge of the substrate W, and unnecessary substances on the peripheral edge are removed (bevel processing).

The processing liquid supply unit 65 has a discharge nozzle 66 , a fixing member 67 and a moving mechanism 68 . The fixed member 67 has a nozzle arm 671 and a nozzle base 672 . A discharge nozzle 66 is attached to the tip of the nozzle arm 671, and a nozzle base 672 is connected to the base end thereof. The moving mechanism 68 is, for example, a motor, and rotates the nozzle base 672 to move the discharge nozzle 66 to a processing position substantially above the center of the substrate W and outside the processing cup 40 as indicated by an arrow AR69. in an arc between the standby position of This ejection nozzle 66 supplies the processing liquid to the approximate center of the substrate W. As shown in FIG. As the substrate W rotates, the processing liquid from the discharge nozzle 66 spreads from the center of the substrate W and scatters outward from the periphery. As a result, the entire upper surface of the substrate W can be acted upon by the processing liquid.

Each of the processing liquid supply units 60 and 65 may also be configured to supply a plurality of types of processing liquids. Alternatively, each of the processing liquid supply units 60 and 65 may be configured to supply a single processing liquid.

The processing liquid supply units 60 and 65 discharge the processing liquid onto the upper surface of the substrate W held by the substrate holding unit 20 with the discharge nozzles 61 and 66 positioned at the processing positions. At least one of the processing liquid supply units 60 and 65 mixes a cleaning liquid such as pure water with a pressurized gas to generate droplets, and jets a mixed fluid of the droplets and the gas onto the substrate W. A two-fluid nozzle may be used. Further, the number of processing liquid supply units provided in the processing unit 1 is not limited to three, and may be one or more. Each of the discharge nozzles of the processing liquid supply units 60 and 65 is also connected to the processing liquid supply source through a pipe in the same manner as the processing liquid supply unit 30, and an on-off valve is provided in the middle of the pipe, and a suckback valve is provided in the middle of the pipe. may be provided. Bevel processing using the processing liquid supply unit 30 will be representatively described below.

<Processing cup>
The processing cup 40 is provided so as to surround the substrate holder 20 . The processing cup 40 has an inner cup 41 , a middle cup 42 and an outer cup 43 . The inner cup 41, the middle cup 42 and the outer cup 43 are provided so as to be able to move up and down. Specifically, a lifting mechanism 44 is provided in the processing unit 1, and the lifting mechanism 44 can lift and lower the inner cup 41, the middle cup 42, and the outer cup 43 individually. The lifting mechanism 44 has, for example, a ball screw mechanism.

The upper end of the processing cup 40 (here, the upper end of the outer cup 43) is located above the upper surface of the substrate W when the inner cup 41, the middle cup 42, and the outer cup 43 are raised. Hereinafter, the height position of the upper end of the outer cup 43 when the outer cup 43 is raised is also referred to as the upper end position of the processing cup 40 . The vertical distance between the upper end position of the processing cup 40 and the substrate W can be set to, for example, about 2 [mm] to about 10 [mm].

When the inner cup 41 , the middle cup 42 and the outer cup 43 are raised, the processing liquid scattered from the peripheral edge of the substrate W hits the inner peripheral surface of the inner cup 41 and drops. The dropped treatment liquid is appropriately recovered by a first recovery mechanism (not shown). In a state where the inner cup 41 is lowered and the middle cup 42 and the outer cup 43 are raised, the processing liquid scattered from the peripheral edge of the substrate W hits the inner peripheral surface of the middle cup 42 and falls. The dropped treatment liquid is appropriately recovered by a second recovery mechanism (not shown). In a state where the inner cup 41 and the middle cup 42 are lowered and the outer cup 43 is raised, the processing liquid scattered from the peripheral edge of the substrate W hits the inner peripheral surface of the outer cup 43 and falls. The dropped treatment liquid is appropriately recovered by a third recovery mechanism (not shown). According to this, different processing liquids can be recovered appropriately.

Hereinafter, the state in which the outer cup 43 is lifted will be described as the state in which the processing cup 40 is lifted. That is, the states in which the processing cup 40 is raised include a state in which the inner cup 41, the middle cup 42, and the outer cup 43 are all raised, a state in which only the inner cup 42 and the outer cup 43 are raised, and a state in which only the outer cup 43 is raised. including the state of

<Partition plate>
The partition plate 15 is provided around the processing cup 40 so as to vertically partition the inner space of the chamber 10 . The partition plate 15 may be a single plate-like member surrounding the processing cup 40, or may be a plurality of plate-like members joined together. Further, the partition plate 15 may be formed with a through hole or a notch that penetrates in the thickness direction. A through hole (not shown) is formed for passing a support shaft for support.

The outer peripheral edge of the partition plate 15 is connected to the side wall 11 of the chamber 10 . Further, the edge portion of the partition plate 15 surrounding the processing cup 40 is formed in a circular shape with a diameter larger than the outer diameter of the outer cup 43 . Therefore, the partition plate 15 does not hinder the lifting of the outer cup 43 .

Also, an exhaust duct 18 is provided in the vicinity of the floor wall 13 at a portion of the side wall 11 of the chamber 10 . The exhaust duct 18 is communicatively connected to an exhaust mechanism (not shown). Of the clean air supplied from the fan filter unit 14 and flowing down inside the chamber 10 , the air that has passed between the processing cup 40 and the partition plate 15 is discharged from the exhaust duct 18 to the outside of the apparatus.

<Camera>
The camera 70 is installed inside the chamber 10 above the partition plate 15 . The camera 70 includes, for example, an imaging device (such as a CCD (Charge Coupled Device)) and an optical system such as an electronic shutter and a lens. The camera 70 can capture an image of an imaging area described below. That is, the imaging area is an area viewed from an imaging position above the substrate W, and the processing liquid Lq1 flowing down toward the substrate W from the ejection nozzle 31 and the processing liquid Lq1 reflected on the upper surface of the substrate W are defined. is the containing region.

FIG. 4 is a diagram schematically showing an example of image data (hereinafter referred to as a captured image) IM1 acquired by the camera 70. As shown in FIG. In the example of FIG. 4 , the captured image IM1 includes the tips of three ejection nozzles 31 . This captured image IM1 includes the substantially liquid columnar treatment liquid Lq1 ejected from the ejection nozzle 31 located in the center among the three ejection nozzles 31 . The processing liquid Lq<b>1 having a substantially liquid columnar shape here refers to the processing liquid Lq<b>1 that flows down from the tip of the discharge nozzle 31 toward the upper surface of the substrate W. As shown in FIG.

In the captured image IM1, the upper surface of the substrate W includes the tip of the ejection nozzle 31 and the treatment liquid Lq1 in a substantially liquid columnar shape. This is because the light from the illumination unit 71 is specularly reflected by the upper surface of the substrate W after being reflected by the discharge nozzle 31 and the treatment liquid Lq1 and is received by the light receiving surface of the camera 70 . In other words, the upper surface of the substrate W functions as a mirror, and the outer appearance of the discharge nozzle 31 is reflected on the upper surface. Camera 70 outputs this captured image IM<b>1 to control unit 9 .

Hereinafter, the substantially liquid columnar processing liquid Lq1 reflected on the upper surface of the substrate W in the captured image IM1 is referred to as a mirror image Lqm1 of the processing liquid Lq1. An image including the treatment liquid Lq1 and its mirror image Lqm1 in the captured image IM1 is also called a whole image.

As illustrated in FIG. 2, the camera 70 may be movably provided. In the example of FIG. 2 , the camera 70 is fixed to the fixing member 62 of the processing liquid supply section 60 . As a more specific example, a camera holding portion 73 that holds the camera 70 is provided, and the camera holding portion 73 is connected to the nozzle arm 621 of the fixing member 62 . For example, the camera holding part 73 is fixed to the distal end of the nozzle arm 621 by a fastening member (for example, a screw) at its proximal end, and fixes and holds the camera 70 with a fastening member at its distal end. The camera holding portion 73 is made of, for example, metal (for example, stainless steel). The moving mechanism 63 moves the camera 70 to an imaging position above the substrate W by displacing the fixing member 62 . Specifically, the moving mechanism 63 rotates the nozzle base 622 to reciprocate the camera 70 between an imaging position above the substrate W and a standby position outside the processing cup 40 . can.

In the example of FIG. 2, the standby position of the ejection nozzle 31 is shifted clockwise by approximately 90 degrees from the standby position of the camera 70 . The ejection nozzle 31 and the camera 70 move from their standby positions toward each other and stop at the processing position and imaging position, respectively. At its imaging position, the camera 70 is held by the camera holding portion 73 in a posture capable of imaging an imaging region including the tip of the ejection nozzle 31 and the substantially liquid columnar treatment liquid Lq1 ejected from the tip. In the example of FIG. 2, the camera holding portion 73 obliquely protrudes clockwise with respect to the nozzle arm 621, and holds the camera 70 on the tip side thereof.

Here, an example of the positional relationship between the camera 70 and the ejection nozzle 31 in a state where the ejection nozzle 31 is stopped at the processing position and the camera 70 is stopped at the imaging position will be described. Below, the positional relationship will be described using the ejection nozzle 31 located in the center among the three ejection nozzles 31 .

In the example of FIG. 2, the camera 70 is located on the center side of the substrate W with respect to the discharge nozzle 31 in plan view. That is, the radial position of the camera 70 with respect to the substrate W is located closer to the center of the substrate W than the radial position of the discharge nozzle 31 .

In the example of FIG. 2, the camera 70 images the tips of the three discharge nozzles 31 from a direction closer to the circumferential direction than the radial direction of the substrate W in plan view. That is, the position of the camera 70 in the circumferential direction with respect to the substrate W is shifted to one side with respect to the position of the discharge nozzle 31 in the circumferential direction. In other words, in plan view, the angle θ1 (0<θ1<90) formed between the virtual straight line L1 connecting the center of the substrate W and the ejection nozzle 31 and the optical axis of the camera 70 is an imaginary angle perpendicular to the straight line L1. is larger than the angle .theta.2 (0<.theta.2<90) formed by the straight line L2 and the optical axis of the camera 70. According to this, it is possible to easily see the radial position of the liquid landing position of the treatment liquid Lq1 on the substrate W in the captured image IM1. However, if the angle θ2 is too small, the three ejection nozzles 31 may overlap in the depth direction when viewed from the imaging position. In this case, it is difficult to include all three ejection nozzles 31 in the captured image IM1, so the angle θ2 should be set so that the three ejection nozzles 31 are appropriately laterally displaced from the imaging position.

Further, when the camera 70 captures an image of the imaging area from a direction closer to the circumferential direction, the three ejection nozzles 31 are shifted in the depth direction from each other when viewed from the imaging position. The distance between the three discharge nozzles 31 in the depth direction is, for example, about several [mm] to ten-odd [mm]. The depth of field of the camera 70 is set large enough to clearly define the contours of these three ejection nozzles 31 . Also, the distance between the camera 70 and the ejection nozzle 31 is, for example, about 100 [mm].

In the example of FIG. 2 , the camera 70 is positioned upstream of the discharge nozzle 31 in the rotation direction of the substrate holder 20 . On the upstream side with respect to the discharge nozzle 31, the amount of the processing liquid Lq1 on the peripheral edge of the substrate W can be smaller than on the downstream side. This is because the processing liquid Lq1 can splash outward from the peripheral edge of the substrate W as the substrate W rotates. Therefore, if the camera 70 is positioned upstream with respect to the ejection nozzle 31, the processing liquid Lq1 will not adhere to the camera 70, or the vaporized component of the processing liquid Lq1 will affect the camera 70. Hateful. In other words, positioning the camera 70 on the upstream side with respect to the ejection nozzle 31 is preferable from the viewpoint of protecting the camera 70 .

Now, when the ejection nozzle 31 ejects the processing liquid Lq1, the processing cup 40 is in an elevated state. This is because the processing cup 40 receives the processing liquid Lq1 that scatters from the periphery of the substrate W. FIG. In this state, the tip (discharge port) of the discharge nozzle 31 is positioned lower than the upper end position of the processing cup 40 . For example, the vertical distance between the upper end position of the processing cup 40 and the upper surface of the substrate W is set to about 2 mm to about 10 mm, and the distance between the discharge nozzle 31 and the substrate W is It is set to about 2 [mm] or less (for example, about 1 [mm]).

Here, for comparison, a case where the imaging position of the camera 70 is set outside the processing cup 40 will be described. For example, the imaging position is set on the side closer to the ejection nozzle 31 in the space outside the processing cup 40 (the upper right region in the chamber 10 in FIG. 3). Since the upper end position of the processing cup 40 is higher than the tip of the ejection nozzle 31, the processing cup 40 may interfere with imaging. That is, even if an attempt is made to capture an image of the substantially liquid-column-shaped processing liquid Lq<b>1 from an imaging position outside the processing cup 40 , the processing liquid Lq<b>1 may be blocked by the processing cup 40 . If the imaging position is set to a higher position to avoid the processing cup 40, the ejection nozzle 31 is imaged obliquely from above. Since the distance between the tip of the discharge nozzle 31 and the substrate W is narrow, when the processing liquid Lq1 in a substantially liquid columnar shape is to be imaged from obliquely above, the processing liquid Lq1 may be blocked by the discharge nozzle 31 this time.

Therefore, it is conceivable to set the imaging position in the space outside the processing cup 40 on the side opposite to the discharge nozzle 31 with respect to the center of the substrate W (upper left region in the chamber 10 in FIG. 3). With this, it may be possible to capture an image of the treatment liquid Lq<b>1 in a substantially liquid column shape ejected from the ejection nozzle 31 . However, since the distance between the tip of the discharge nozzle 31 and the imaging position of the camera 70 is long, the camera 70 with high resolution or the camera 70 for telephoto is required.

On the other hand, in the present embodiment, since the imaging position is above the substrate W, it is easy to bring the imaging position close to the upper surface of the substrate W in the height direction, and the optical axis of the camera 70 is set horizontally. Easy to follow directions. Therefore, the camera 70 can image the substantially liquid columnar treatment liquid Lq<b>1 ejected from the ejection nozzle 31 without being blocked by the treatment cup 40 and the ejection nozzle 31 . The angle formed by the optical axis of the camera 70 and the horizontal plane can be set to, for example, about 10 degrees [degrees] or less.

It is also possible to bring the camera 70 closer to the ejection nozzle 31 in plan view. Therefore, a lower resolution camera or a less expensive camera that does not require telephoto can be employed. The small size of such cameras is preferred. In the example of FIG. 4, since the distance between the camera 70 and the ejection nozzle 31 is short, only part of the peripheral edge of the substrate W is included in the captured image IM1.

Here, an example of the imaging position in the height direction of the camera 70 will be described. The imaging position of the camera 70 may be set such that the lower end of the light receiving surface of the imaging element of the camera 70 is the same as or lower than the upper end position of the processing cup 40 . For example, the distance between the camera 70 and the upper surface of the substrate W can be set to about 1 [mm] to 5 [mm]. As a result, the camera 70 can be brought closer to the upper surface of the substrate W, and the optical axis of the camera 70 can be made more horizontal.

Alternatively, the imaging position of the camera 70 may be set such that the lower end of the housing of the camera 70 is the same as or lower than the upper end position of the processing cup 40 .

Also, the camera holding portion 73 may support the lower surface of the camera 70 . FIG. 5 is a perspective view schematically showing an example of the camera 70 and the camera holding section 73. In FIG. 5, the substrate W and the discharge nozzle 31 are also shown. In the example of FIG. 5, the camera holding portion 73 includes an L-shaped connecting member 731, an upper surface member 732 positioned on the upper surface side of the camera 70, a side surface member 733 positioned on the side surface side of the camera 70, and a and a lower surface member 734 located on the lower surface side. The connecting member 731 has a first rod-shaped member extending horizontally from the nozzle arm 621 and a second rod-shaped member extending vertically downward from the tip of the rod-shaped member. The tip of the second rod-shaped member is connected to the top member 732 . In the example of FIG. 5, the upper surface member 732, the side surface member 733 and the lower surface member 734 have plate-like shapes. The upper surface member 732 and the lower surface member 734 are arranged with their thickness direction along the vertical direction, and the side member 733 is arranged with their thickness direction along the horizontal direction. A side member 733 connects the top member 732 and the bottom member 734 . The lower surface member 734 also functions as a support member that supports the camera 70 .

In such a structure, the imaging position of the camera 70 may be set such that the lower end of the lower surface member 734 is the same as or lower than the upper end position of the processing cup 40 . This also allows the camera 70 to be brought closer to the upper surface of the substrate W, and the optical axis of the camera 70 can be made more horizontal.

<Lighting section>
As shown in FIG. 3, an illumination unit 71 is provided inside the chamber 10 and above the partition plate 15 . The lighting unit 71 includes a light source such as an LED (Light Emitting Diode). Although the wavelength of the light emitted by the illumination unit 71 is not particularly limited, visible light or near-infrared light, for example, can be used. In the example of FIG. 3, the lighting section 71 is arranged above the camera 70 . For example, the illumination unit 71 is arranged at a position overlapping the camera 70 in plan view (see FIG. 2). The lighting section 71 may be held by a camera holding section 73 . For example, the lighting section 71 may be fixed to the upper surface of the upper surface member 732 of the camera holding section 73 . Since the interior of the chamber 10 is normally a dark room, the illumination unit 71 irradiates the imaging area with light when the camera 70 performs imaging.

<Control part>
The control unit 9 controls various components of the substrate processing apparatus 100 to proceed with the processing of the substrate W. FIG. Also, the control unit 9 performs image processing on the captured image IM1 acquired by the camera 70 . Therefore, the control section 9 functions as an image processing section. Since the camera 70 captures an image of the tip of the ejection nozzle 31 from an imaging position above the substrate W, the captured image IM1 acquired by the camera 70 is the treatment liquid Lq1 in the substantially liquid column shape ejected from the ejection nozzle 31. include. The control unit 9 monitors the landing position of the treatment liquid Lq1 ejected from the ejection nozzle 31 (bevel monitoring) by performing image processing on the captured image IM1. An example of this monitoring process will be detailed later.

The hardware configuration of the control unit 9 is similar to that of a general computer. That is, the control unit 9 stores a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable and writable memory that stores various information, control software, data, and the like. It is configured with a magnetic disk or the like to store. Each operation mechanism of the substrate processing apparatus 100 is controlled by the control unit 9 by the CPU of the control unit 9 executing a predetermined processing program, and processing in the substrate processing apparatus 100 proceeds. Further, image processing is performed by the CPU of the control unit 9 executing a predetermined processing program. Part or all of the functions of the control unit 9 may be realized by dedicated hardware.

<Notification part>
The notification unit 93 is, for example, an audio output unit (for example, a speaker) or a display. The notification unit 93 can give various notifications to the operator. For example, the audio output unit outputs notification sound (buzzer or voice), or the display displays notification information, so that various notifications can be given to the operator. Notification by the notification unit 93 is controlled by the control unit 9 .

<Operation of the control unit>
FIG. 6 is a flow chart showing an example of substrate processing. First, in step S<b>1 , the main transfer robot 103 transfers the substrate W onto the substrate holder 20 . The substrate holding part 20 holds the substrate W that has been transported.

Next, in step S2, the controller 9 controls the moving mechanism 33 to move the discharge nozzle 31 to the processing position, and controls the moving mechanism 63 to move the camera 70 to the imaging position. Next, in step S<b>3 , the control unit 9 controls the lifting mechanism 44 to lift the processing cup 40 and controls the spin motor 22 to rotate the spin base 21 . The rotation speed of the spin base 21 is set to, for example, about 1000 [rpm] or more.

Next, in step S4, the control unit 9 controls the camera 70 to start imaging. The camera 70 captures an image of the imaging area at a predetermined frame rate (for example, 60 frames/second) and sequentially outputs the acquired captured images IM1 to the control unit 9 . The control unit 9 monitors the ejection state of the treatment liquid Lq1 based on the image processing of the captured image IM1, as will be described in detail later.

Next, in step S<b>5 , the controller 9 starts ejecting the treatment liquid Lq<b>1 from the ejection nozzle 31 . Specifically, the controller 9 outputs an open signal to the on-off valve 35 . The on-off valve 35 performs an opening operation based on this open signal to open the pipe 34 . As a result, the processing liquid Lq1 from the processing liquid supply source 37 is discharged from the discharge nozzle 31 and lands on the edge of the upper surface of the substrate W. As shown in FIG. The flow rate of the processing liquid Lq1 is set to, for example, several to several tens [ml/min]. This flow rate is smaller than the flow rate of the processing liquid when the entire surface of the substrate W is processed (for example, the flow rate of the processing liquid discharged from the discharge nozzle 66 of the processing liquid supply section 65).

The treatment liquid Lq1 is discharged onto the edge of the substrate W while rotating the substrate W, so that the treatment liquid Lq1 acts on the entire peripheral edge of the substrate W. FIG. This processing liquid Lq1 can remove unnecessary substances adhering to the edge of the substrate W (bevel processing). From the ejection openings of the three ejection nozzles 31, the treatment liquid Lq1 corresponding to the type of the unnecessary matter (for example, film) can be sequentially ejected. At least two ejection openings of the three ejection nozzles 31 may eject the treatment liquid at the same time.

In this bevel process, it is desirable to control the flow rate of the processing liquid Lq1 with high accuracy in order to properly remove the unnecessary substances adhering to the edge of the substrate W. FIG.

A device is formed in a device region on the upper surface of the substrate W other than the peripheral edge portion. It is undesirable for the processing liquid Lq1 to enter this device region as it removes the film. This is because necessary films in the device region can be removed. On the other hand, it is necessary to remove unnecessary films present at the peripheral edges. In order to satisfy this requirement, it is desirable to control the landing position of the treatment liquid Lq1 with high accuracy in the bevel process. The required accuracy of the landing position of the processing liquid Lq1 on the substrate W is, for example, about several tens (eg, 50) [μm].

Since the flow rate of the treatment liquid Lq1 is small in the bevel process, the treatment liquid Lq1 is easily affected by the air current accompanying the rotation of the substrate W or static electricity in the surroundings, and the liquid landing position and the like may fluctuate.

The control unit 9 monitors the discharge state of the treatment liquid Lq1 in the monitoring process. A detailed operation of the monitoring process will be described later.

The controller 9 stops the ejection of the treatment liquid Lq1 from the ejection nozzle 31 in step S6 when the conditions for ending the bevel processing are satisfied. Although the condition for ending the bevel process is not particularly limited, it is possible to adopt, for example, a condition that the elapsed time from step S5 reaches a predetermined time. The control unit 9 outputs a close signal to the on-off valve 35 in response to the establishment of the termination condition. The on-off valve 35 performs a closing operation based on this closing signal to close the pipe 34 . This completes the ejection of the treatment liquid Lq1. When the suck back valve 36 is provided, the controller 9 outputs a suction signal to the suck back valve 36 .

A step of drying the substrate W may be performed as appropriate after the discharge of the treatment liquid Lq1 is stopped. Next, in step S7, the control unit 9 causes the camera 70 to finish imaging. That is, the monitoring process ends. Next, in step S8, the control section 9 controls the spin motor 22 to finish the rotation of the spin base 21, and controls the elevating mechanism 44 to lower the processing cup 40. As shown in FIG. Next, in step S9, the controller 9 controls the moving mechanism 33 and the moving mechanism 63 to move the discharge nozzle 31 and the camera 70 to their standby positions.

FIG. 7 is a flowchart illustrating an example of the operation of monitoring processing. The processing flow shown in FIG. 7 is executed each time the captured image IM1 is input to the control unit 9 . First, in step S11, the control unit 9 specifies a determination region R2 described below in the captured image IM1.

FIG. 8 is a diagram schematically showing an example of an enlarged view of the captured image IM1. In the example of FIG. 8, an enlarged view of a region R1 near the tip of one discharge nozzle 31 is shown. The determination region R2 is a region directly below the discharge nozzle 31 in the captured image IM1, and includes at least a portion of the substantially liquid columnar processing liquid Lq1 discharged from the discharge nozzle 31 onto the substrate W and the processing reflected on the upper surface of the substrate W. It is a region including at least part of the mirror image Lqm1 of the liquid Lq1. This determination region R2 includes a boundary B1 between the treatment liquid Lq1 and its mirror image Lqm1.

This determination region R2 is set at a position away from the ejection nozzles 31 in the captured image IM1. The lateral width of the determination region R2 is set to be wider than the liquid filling width of the treatment liquid Lq1 discharged from the discharge nozzles 31 . The lateral position of the determination region R2 is set so that both ends in the width direction of the treatment liquid Lq1 are included in the determination region R2. The width of the determination region R2 in the vertical direction is set so that the determination region R2 includes the treatment liquid Lq1 and its mirror image Lqm1.

A determination region R2 in the captured image IM1 is set in advance with respect to the ejection nozzles 31 . That is, the relative positional relationship between the ejection nozzles 31 and the determination region R2 is set in advance. Information indicating this positional relationship may be stored in the storage medium of the control unit 9 .

By the way, since the relative position of the camera 70 with respect to the ejection nozzle 31 can vary depending on the accuracy of the moving mechanisms 33 and 63, the position of the ejection nozzle 31 within the captured image IM1 can also vary. Therefore, the control unit 9 may specify the positions of the ejection nozzles 31 in the captured image IM1 and specify the determination region R2 having a predetermined positional relationship with respect to the specified ejection nozzles 31 . A reference image including the appearance of the tip of the ejection nozzle 31 is also stored in advance in the storage medium of the control unit 9 in order to specify the position of the ejection nozzle 31 in the captured image IM1. The control unit 9 specifies the positions of the ejection nozzles 31 in the captured image IM1 by pattern matching based on the reference image, and determines the determination region R2 based on a predetermined relative positional relationship with respect to the specified ejection nozzles 31. Identify. Accordingly, even if the position of the ejection nozzle 31 changes in the captured image IM1, it is possible to appropriately specify the determination region R2 corresponding to the position of the ejection nozzle 31 .

When the ejection nozzle 31 is ejecting the treatment liquid Lq1, the determination region R2 includes part of the substantially liquid columnar treatment liquid Lq1. Since the light emitted by the illumination unit 71 is reflected by the treatment liquid Lq1 and received by the camera 70, the luminance value of the pixels reflecting the treatment liquid Lq1 is higher than the luminance values of the other pixels. When the camera 70 is a grayscale monochrome camera, it can be said that the pixel value of the pixel indicates the luminance value. Here, as an example, the camera 70 is assumed to be a monochrome camera.

Next, in step S12, the control unit 9 identifies the landing position of the treatment liquid Lq1 based on the overall image of the treatment liquid Lq1 within the determination region R2. An example of a method for specifying the liquid landing position will be described below.

As illustrated in FIG. 8, the overall image is curved at the surface of the substrate W (that is, at the boundary B1 between the processing liquid Lq1 and its mirror image Lqm1). This is because in the bevel process, the ejection direction of the processing liquid Lq1 from the ejection nozzle 31 is not perpendicular to the substrate W, but is slightly oblique due to various factors such as air currents accompanying the rotation of the substrate W. be. In addition, since the degree of this bending (the angle formed by the ejection direction of the treatment liquid Lq1 and the ejection direction of its mirror image Lqm1) depends on the imaging direction of the camera 70 (specifically, the angle θ2), this bending becomes clear. It is preferable that the imaging direction of the camera 70 is set as follows.

Since this bending position indicates the landing position of the treatment liquid Lq1 on the upper surface of the substrate W, the control unit 9 identifies this bending position in the captured image IM1. Specifically, for example, the control unit 9 performs edge detection processing and binarization processing on the determination region R2 to obtain a binarized image IM2. FIG. 9 is a diagram schematically showing an example of the binarized image IM2. In FIG. 9, pixels with high pixel values (here, "1") are shown in white, and pixels with low pixel values (here, "0") are shown with sanded hatching. That is, the white area indicates a region where the brightness value changes steeply in the determination region R2 of the captured image IM1, and the sandy region indicates a region where the brightness value changes slowly in the determination region R2 of the captured image IM1. is shown. In the following, the region indicated by white is also referred to as a high pixel value region R4.

As illustrated in FIG. 9, in the high pixel value region R4 of the binarized image IM2, a linear component LC1 extending along the ejection direction of the treatment liquid Lq1 and a linear component LC2 extending along the ejection direction of the mirror image Lqm1 of the treatment liquid Lq1 are formed. and are included. A lower end of the linear component LC1 and an upper end of the linear component LC2 are connected to each other at a connection angle corresponding to the ejection direction at a boundary B1 between the treatment liquid Lq1 and its mirror image Lqm1.

The control unit 9 identifies the straight line component LC1 and the straight line component LC2 based on this binarized image IM2. Although this identification may employ a known method, it may be performed, for example, as follows.

In the example of FIG. 9, in the binarized image IM2, since the high pixel value region R4 includes the region R41 indicating the tip of the discharge nozzle 31 and the peripheral edge of the substrate W, first, in the binarized image IM2 This region R41 may be removed. For example, the region R41 can be removed by masking.

A region R42 other than the region R41 in the high pixel value region R4 shows the treatment liquid Lq1 and its mirror image Lqm1. Therefore, edge detection processing is further performed on this binarized image IM2, and straight line components whose edges extend for a predetermined length or more are specified. Since the range of the discharge direction of the treatment liquid Lq1 can be presumed through experiments, simulations, or the like, the range of the extending direction of each of the linear component LC1 and the linear component LC2 can also be set in advance. Therefore, the control unit 9 identifies a linear component whose extending direction is within a preset range in the region R41.

Further, as illustrated in FIG. 9, the linear component LC1 extends from the upper right to the lower left, and the linear component LC2 extends from the upper left to the lower right. Therefore, the control unit 9 identifies the linear component extending from the upper right to the lower left as the linear component LC1, and identifies the linear component extending from the upper right to the lower left as the linear component LC2.

Next, the control unit 9 obtains the intersection of the straight line component LC1 and the straight line component LC2 as the bending position. The control unit 9 obtains the landing position of the treatment liquid Lq1 based on this bent position. For example, the bending position may be obtained as the liquid landing position.

Note that although the example of FIG. 9 shows a set of one linear component LC1 and one linear component LC2, a plurality of sets can be specified in practice. Therefore, the liquid landing position may be obtained based on the bending position of each of the plurality of sets. For example, the average of a plurality of bending positions may be obtained as the liquid landing position.

Next, in step S13, the control unit 9 determines whether or not the difference (absolute value) between the obtained liquid landing position and the position reference value is equal to or greater than a predetermined position tolerance. In other words, the controller 9 determines whether or not the liquid landing position is within an appropriate range. As the position reference value, a value that indicates an appropriate liquid landing position can be used. For example, an average value of normal liquid landing positions may be calculated based on a plurality of captured images IM1 captured while the treatment liquid Lq1 is normally discharged, and the average value may be used as the position reference value. A position tolerance is also preset. The position reference value and the position allowable value may be stored in the storage medium of the control section 9, for example.

When the difference is equal to or greater than the positional allowable value, in step S14, the control section 9 causes the notification section 93 to notify that effect (that is, liquid landing abnormality), and the process ends. On the other hand, when the difference is less than the allowable value, the process ends without executing step S14.

As described above, the controller 9 obtains the liquid landing position based on the overall image including the processing liquid Lq1 and its mirror image Lqm1 in the captured image IM1. This overall image includes a boundary B1 between the processing liquid Lq1 and its mirror image Lqm1, and the boundary B1 reflects the liquid landing position on the substrate W of the processing liquid Lq1. In other words, the liquid landing position can be obtained appropriately based on the overall image including information on the liquid landing position.

Further, in the above example, the flexion point of the entire image is obtained, and the liquid landing position is specified based on the flexion point. Since the inflection point is located on the boundary B1 between the treatment liquid Lq1 and its mirror image Lqm1, the liquid landing position can be determined appropriately.

<Mirror image Lqm1 of treatment liquid Lq1>
Various patterns such as metal patterns, semiconductor patterns, insulating layer patterns and resist patterns can be formed on the upper surface of the substrate W. FIG. Therefore, the processing liquid Lq1 reflected on the upper surface of the substrate W (that is, the mirror image Lqm1) is affected by these patterns. That is, noise is included in the mirror image Lqm1 of the treatment liquid Lq1.

Therefore, it is preferable to set the exposure time of the camera 70 to be longer than the rotation time required for the substrate W to make one rotation. According to this, the pattern of the substrate W in the captured image IM1 is averaged and made uniform, so the mirror image Lqm1 of the treatment liquid Lq1 in the captured image IM1 can be made a more accurate image. In other words, noise contained in the mirror image Lqm1 of the treatment liquid Lq1 can be reduced. Therefore, it is easy to determine the ejection direction (that is, the linear component LC2) of the mirror image Lqm1 of the treatment liquid Lq1.

Alternatively, the exposure time may be shorter than the rotation time. The control unit 9 may integrate or average a plurality of captured images IM1 captured within a predetermined time longer than the rotation time to generate a processed image every predetermined time. Since the pattern of the upper surface of the substrate W is averaged and made uniform in the processed images at predetermined time intervals, the mirror image Lqm1 of the processing liquid Lq1 can be made a more accurate image.

<Fixing the camera>
Also, in the above example, the camera 70 is fixed to the fixing member 62 in the same manner as the ejection nozzle 61 . That is, the mechanism for moving the camera 70 and the mechanism for moving the ejection nozzle 61 are used together. Therefore, the manufacturing cost and size can be reduced as compared with the case where a dedicated mechanism is provided for each.

FIG. 10 is a plan view schematically showing an example of the configuration of the processing unit 1A. The processing unit 1A has the same configuration as the processing unit 1 except that the camera 70 is fixed. In this processing unit 1A, the camera 70 is fixed to the fixing member 32 in the same manner as the ejection nozzle 31 to be imaged. More specifically, the camera holding portion 73 is connected to the nozzle arm 321 on the side of the nozzle arm 321 . The camera holding section 73 holds the camera 70 . The camera 70 is fixed to the fixing member 32 via this camera holding portion 73 . The camera 70 and the camera holder 73 are arranged on the counterclockwise side of the nozzle arm 321 (that is, on the side from the waiting position of the discharge nozzle 31 toward the processing position). The camera 70 is held by the camera holding portion 73 in a posture capable of imaging the tip of the ejection nozzle 31 and the treatment liquid Lq1 ejected from the ejection nozzle 31 .

By rotating the nozzle base 322 by the moving mechanism 33, the ejection nozzle 31 and the camera 70 can be moved to the processing position and the imaging position, respectively, while maintaining their positional relationship. The positional relationship between the imaging position of the camera 70 and the processing position of the discharge nozzle 31 is the same as that of the processing unit 1 .

In this processing unit 1A, similarly to the processing unit 1, the camera 70 can appropriately capture an image of the substantially liquid columnar processing liquid Lq1 ejected from the ejection nozzle 31. FIG.

Further, since the camera 70 is fixed to the same fixing member 32 as the discharge nozzle 31, the camera 70 can be positioned with respect to the discharge nozzle 31 with high accuracy. That is, in the processing unit 1, the ejection nozzle 31 and the camera 70 are fixed to different nozzle arms 321 and 621. Therefore, in consideration of the accuracy of the moving mechanisms 33 and 63, there is a gap between the camera 70 and the nozzle arm 321. While it is necessary to provide a relatively wide margin, in the processing unit 1A, the ejection nozzle 31 and the camera 70 are fixed to the same nozzle arm 321, so the margin between the camera 70 and the nozzle arm 321 is narrower. Can be set. That is, the camera 70 can be brought closer to the nozzle arm 321 . According to this, the camera 70 can image the ejection nozzles 31 from a direction closer to the circumferential direction. Therefore, it is easy to specify the radial ejection position of the treatment liquid Lq1 in the captured image IM1.

<Camera protection>
When the treatment liquid Lq1 contains hydrofluoric acid, the lower surface of the housing of the camera 70 or the lower end surface of the lower surface member 734 of the camera holding portion 73 is preferably made of a chemical-resistant material. In short, it is preferable that the protective member 74 for protecting the camera 70 is provided on the lower surface side of the camera 70 . As the protective member 74, a fluorine resin such as polytetrafluoroethylene, a chemical resistant resin such as vinyl chloride resin, or a metal such as stainless steel, which has high chemical resistance to hydrofluoric acid, can be used.

According to this, it is possible to reduce the possibility that the camera 70 positioned above the substrate W is corroded by the vaporized component of the processing liquid Lq1. Therefore, the reliability of camera 70 can be improved.

<Liquid landing position on substrate>
In the above example, the control unit 9 obtains the landing position of the treatment liquid Lq1 based on the pixels within the determination region R2 with the position of the ejection nozzle 31 as a reference. In other words, the liquid landing position was monitored by determining the liquid landing position with reference to the position of the discharge nozzle 31 . This is particularly effective, for example, when the positional accuracy of the ejection nozzles 31 by the moving mechanism 33 is high. However, there are cases where the positional accuracy is relatively low. Therefore, the control unit 9 may monitor the liquid landing position of the processing liquid Lq1 with the position of the peripheral edge of the substrate W as a reference.

The control unit 9 specifies the position of the peripheral edge of the substrate W in the captured image IM1 (hereinafter referred to as the substrate peripheral edge position) in order to obtain the liquid landing position with reference to the position of the peripheral edge of the substrate W. FIG. First, the control unit 9 specifies a peripheral region R3 described below in the captured image IM1 (see also FIG. 8).

The peripheral region R3 is a region including part of the peripheral edge of the substrate W in the captured image IM1. In the example of FIG. 8, the peripheral region R3 has a rectangular shape. The position of the peripheral region R3 is set in advance corresponding to the position of the ejection nozzle 31, similarly to the determination region R2. That is, the relative positional relationship between the ejection nozzles 31 and the peripheral region R3 is set in advance. Information indicating this positional relationship may be stored in the storage medium of the control unit 9 .

The control unit 9 identifies the positions of the discharge nozzles 31 in the captured image IM1 by pattern matching, and identifies the peripheral region R3 based on the identified positions of the discharge nozzles 31 . Then, the control unit 9 specifies the substrate peripheral position of the substrate W within the peripheral region R3. For example, the control unit 9 identifies the peripheral edge of the substrate W based on image processing such as edge detection processing. Thereby, the substrate peripheral edge position of the substrate W can be identified with reference to the position of the discharge nozzle 31 .

As described above, the control unit 9 can specify the liquid landing position and the substrate edge position both based on the position of the discharge nozzle 31 . Therefore, based on these positions, the control unit 9 can specify the liquid landing position with reference to the substrate peripheral edge position. For example, table information that serves as a reference is generated in advance through experiments or the like. Specifically, the processing position of the discharge nozzle 31 is changed as appropriate under the control of the control unit 9 in advance, and the processing liquid Lq1 is discharged from the discharge nozzle 31 each time, and the captured image IM1 is obtained. Then, at each processing position of the discharge nozzle 31, the distance between the liquid landing position of the processing liquid Lq1 and the peripheral edge of the substrate W is measured, and the distance between the substrate edge position and the discharge position in the captured image IM1 at that time is measured. Identify positional relationships. Then, the measured distance and the specified positional relationship are associated with each other and stored in advance in the storage medium of the control unit 9 as table information.

The control unit 9 specifies the positional relationship between the substrate peripheral edge position and the ejection position in the captured image IM1, and determines the peripheral edge of the substrate W and the liquid landing position of the treatment liquid Lq1 based on the specified positional relationship and the table information. (that is, the liquid landing position with reference to the peripheral edge of the substrate W) is calculated.

Since the controller 9 can obtain the liquid landing position based on the position of the peripheral edge of the substrate W, the liquid landing position can be monitored more appropriately.

<Specification of liquid landing position>
In the above example, the controller 9 obtains the liquid landing position based on the curved position of the straight line component LC1 and the straight line component LC2. However, it is not necessarily limited to this.

As illustrated in FIG. 9, a region R42 (a region corresponding to the treatment liquid Lq1 and its mirror image Lqm1) in the high pixel value region R4 of the binarized image IM2 is located at the boundary B1 between the treatment liquid Lq1 and its mirror image Lqm1. , which extends laterally. It can be considered that this is because when the processing liquid Lq1 lands on the upper surface of the substrate W, it slightly spreads around. In other words, it can be said that this spreading portion reflects the boundary between the treatment liquid Lq1 and its mirror image Lqm1, and thus the liquid landing position.

Therefore, the control unit 9 may specify the portion where the region R42 spreads in the binarized image IM2, and obtain the liquid landing position based on the position of the spread portion. Specifically, the control unit 9 may specify the two points located at the ends in the horizontal direction (that is, both ends of the spread portion) in the region R42, and obtain the center positions of the both ends as the liquid landing positions.

<Imaging optical system>
FIG. 11 is a diagram schematically showing an example of the configuration of the processing unit 1B. The processing unit 1B has the same configuration as the processing unit 1, except for the imaging optical system. A mirror 75 is provided in the processing unit 1B. The mirror 75 is arranged at an imaging position above the substrate W, and the camera 70 is arranged in a region other than above the substrate W. As shown in FIG. As illustrated in FIG. 11, the camera 70 may be positioned above the processing cup 40 in plan view. Mirror 75 reflects light from the imaging area toward the light receiving surface of camera 70 . Therefore, the camera 70 can image the imaging area seen from the imaging position above the substrate W. FIG.

As illustrated in FIG. 11, the mirror 75 is preferably provided movably. In the example of FIG. 11, the mirror 75 is fixed to the fixing member 62 of the processing liquid supply section 60 . As a more specific example, a mirror holding portion 76 that holds the mirror 75 is provided, and this mirror holding portion 76 is connected to the nozzle arm 621 of the fixed member 62 . For example, the mirror holding part 76 is fixed to the distal end of the nozzle arm 621 with a fastening member (for example, a screw) at its proximal end, and fixes and holds the mirror 75 with the fastening member at its distal end. The mirror holding portion 76 is made of, for example, metal (for example, stainless steel). By rotating the nozzle base 622 , the moving mechanism 63 can reciprocate the mirror 75 between an imaging position above the substrate W and a standby position outside the processing cup 40 . The moving mechanism 63 moves the mirror 75 to the imaging position, so that the light from the imaging area can be reflected from the mirror 75 to the camera 70 .

The positional relationship between the position of the mirror 75 (imaging position) and the ejection nozzle 31 in plan view is the same as the positional relationship between the position of the camera 70 (imaging position) and the ejection nozzle 31 in the processing unit 1 . The imaging position is preferably close to the substrate W. For example, the imaging position may be set so that the lower end of the reflecting surface of the mirror 75 is the same as or lower than the upper end position of the processing cup 40. . Alternatively, when the mirror holding part 76 has a lower surface member arranged on the lower side of the mirror 75, the lower end of the lower surface member is at the same position as the upper end position of the processing cup 40 or at a lower position than the upper end position. You may set an imaging position so that it may become. Thereby, the camera 70 can capture an image of the imaging area viewed from the imaging position along a direction closer to the horizontal. In other words, it is easier to make the imaging direction from the imaging position more horizontal.

According to the processing unit 1B, the camera 70 can be arranged in a region other than above the substrate W, so the influence of the processing liquid Lq1 on the camera 70 can be reduced. For example, it is possible to reduce the possibility that the treatment liquid Lq1 adheres to the camera 70 or the vaporized component of the treatment liquid Lq1 adheres to the camera 70. FIG. Therefore, even if the processing liquid Lq1 contains hydrofluoric acid, corrosion of the camera 70 is unlikely to occur.

Note that the camera 70 may be fixed substantially immovably within the processing unit 1B, or may be fixed movably.

Also, the mirror 75 does not necessarily need to be fixed to the fixing member 62 of the processing liquid supply section 60, and may be fixed to the fixing member 32 of the processing liquid supply section 30, similarly to the camera 70 of the processing unit 1A. According to this, the mirror 75 can be brought closer to the nozzle arm 321, so that the imaging direction from the imaging position can be more easily along the circumferential direction.

<Machine learning>
In the above example, the control unit 9 performs image processing on the captured image IM1 to obtain the landing position of the treatment liquid Lq1, and determines whether or not it is within an appropriate range. However, the control unit 9 may make the determination using machine learning.

FIG. 12 is a diagram schematically showing an example of the internal configuration of the control section 9. As shown in FIG. The control unit 9 has a classifier 91 and a machine learning unit 92 . The captured images IM1 from the camera 70 are sequentially input to the classifier 91 . The classifier 91 classifies each input captured image IM1 into categories related to the discharge state quantity (flow rate or discharge position) of the discharge nozzles 31 . Categories may also be called classes. As a category, a category with abnormality and a category with no abnormality can be adopted for the discharge state quantity. More specifically, a first category indicating that there is no abnormality in the liquid landing position and a second category indicating that there is an abnormality in the liquid landing position can be adopted.

This classifier 91 is generated by the machine learning section 92 using a plurality of teacher data. In other words, it can be said that this classifier 91 is a machine-learned classifier. The machine learning unit 92 uses, for example, a neighborhood method, a support vector machine, a random forest, or a neural network (including deep learning) as a machine learning algorithm. Since neural networks automatically generate feature values, designers do not need to determine feature vectors.

The training data includes image data and a label indicating to which category the image data is classified. The image data is a captured image captured by the camera 70 and is generated in advance. Each image data is labeled with the correct category. This application can be performed by an operator. The machine learning unit 92 performs machine learning based on these teacher data to generate the classifier 91 .

As an example, the classifier 91 that classifies frames by the neighborhood method will be described. The classifier 91 includes a feature vector extraction unit 911, a determination unit 912, and a storage medium in which a determination database 913 is stored. Each frame of the captured image from the camera 70 is sequentially input to the feature vector extraction unit 911 . A feature vector extraction unit 911 extracts a feature vector of the captured image IM1 according to a predetermined algorithm. This feature vector is a vector indicating a feature quantity corresponding to the ejection state of the ejection nozzle 31 . A known algorithm can be adopted as the algorithm. Feature vector extraction section 911 outputs the feature vector to determination section 912 .

A determination database 913 stores a plurality of feature vectors (hereinafter referred to as reference vectors) generated from a plurality of teacher data by the machine learning unit 92, and the reference vectors are classified into categories. Specifically, the machine learning unit 92 applies the same algorithm as the feature vector extraction unit 911 to multiple teacher data to generate multiple reference vectors. Then, the machine learning unit 92 assigns a teacher data label (correct category) to the reference vector.

The determination unit 912 classifies the captured image IM1 based on the feature vector input from the feature vector extraction unit 911 and a plurality of reference vectors stored in the determination database 913 . For example, the determination unit 912 may specify the reference vector whose feature vector is the closest, and classify the captured image IM1 into the category of the specified reference vector (nearest neighbor method). Accordingly, the determination unit 912 can classify the captured image input to the classifier 91 (feature vector extraction unit 911) into categories.

The control unit 9 uses the classifier 91 to classify each captured image IM1 into either one of the first category and the second category. This classification means that it is determined whether or not the landing position of the processing liquid Lq1 is within an appropriate range. Since classification is performed by machine learning, anomalies can be detected with high accuracy.

<Input to classifier>
In the above example, the input data to the classifier 91 is the entire area of the captured image IM1, but it is not necessarily limited to this. For example, the control unit 9 may cut out the image of the determination region R2 from the captured image IM1 and input the image to the classifier 91 . In this case, the image showing the determination region R2 is also used as learning data input to the machine learning unit 92 .

According to this, the classifier 91 can classify by removing the influence of the region with low relevance to the discharge state, so that the classification accuracy can be improved.

In addition, in order to monitor the liquid landing position with reference to the periphery of the substrate W, not only the determination region R2 but also the peripheral region R3 may be input to the classifier 91. FIG. In this case, an image showing the determination region R2 and the peripheral region R3 is also used as the learning data input to the machine learning unit 92 . Alternatively, a rectangular region including the determination region R2 and the peripheral region R3 may be cut out from the captured image IM1 and this image may be input to the classifier 91. FIG.

<server>
In the above example, the control unit 9 provided in the substrate processing apparatus 100 generated the classifier 91 by machine learning, and the classifier 91 classified the frames. However, at least a part of the machine learning function (the classifier 91 and the machine learning section 92) by the control section 9 may be provided in the server.

Although the embodiment of the present substrate processing apparatus has been described above, it is possible to make various modifications other than those described above without departing from the gist of the embodiment. The various embodiments and modifications described above can be implemented in appropriate combinations.

Also, as the substrate W, a semiconductor substrate was used in the description, but the substrate W is not limited to this. For example, substrates such as photomask glass substrates, liquid crystal display glass substrates, plasma display glass substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, or magneto-optical disk substrates may be used. good.

9 Image processing unit (control unit)
20 substrate holder 31 nozzle (ejection nozzle)
33 moving mechanism 40 cup member (processing cup)
44 lifting mechanism 70 camera 91 classifier 93 reporting unit 100 substrate processing apparatus W substrate

Claims (10)

a holding step of holding the substrate in the substrate holding portion;
a rotating step of rotating the substrate holding part to rotate the substrate;
a lifting step of raising the cup member surrounding the outer periphery of the substrate holding portion to position the upper end of the cup member at an upper end position higher than the upper surface of the substrate held by the substrate holding portion;
a bevel processing step of discharging a processing liquid from a discharge port of a nozzle located at a position lower than the upper end position onto an end portion of the upper surface of the substrate held by the substrate holding portion;
An imaging position above the substrate held by the substrate holding unit, an imaging region including the processing liquid ejected from the ejection port of the nozzle and a mirror image of the processing liquid reflected on the upper surface of the substrate. an imaging step of acquiring an imaged image by causing a camera to image an imaging area viewed from
and a monitoring step of monitoring a landing position of the processing liquid based on the processing liquid and the mirror image in the captured image. The substrate processing method according to claim 1,
In the captured image, an entire image including the treatment liquid and the mirror image is bent at a boundary between the treatment liquid and the mirror image;
The substrate processing method, wherein in the monitoring step, the liquid landing position is determined based on a curved position of the entire image of the processing liquid. The substrate processing method according to claim 2,
In the monitoring step,
From the binarized image obtained by performing edge detection processing and binarization processing on the captured image, a first straight line component extending along the ejection direction of the treatment liquid and a mirror image along the ejection direction detecting an extending second straight line component, and obtaining an intersection of the first straight line component and the second straight line component as the bent position. The substrate processing method according to any one of claims 1 to 3,
The substrate processing method, wherein the exposure time of the camera is set to be longer than the time required for the substrate to rotate once. The substrate processing method according to claim 2 or 3 ,
Obtaining the liquid landing position based on the overall image in a captured image obtained by integrating or averaging a plurality of captured images acquired by the camera within a time longer than the time required for one rotation of the substrate; Substrate processing method. The substrate processing method according to any one of claims 1 to 5,
In the monitoring step,
Identifying the position of the peripheral edge of the substrate in the captured image;
A substrate processing method, wherein the liquid landing position of the processing liquid is determined with reference to the position of the peripheral edge of the substrate. The substrate processing method according to any one of claims 1 to 6,
The monitoring step includes
A substrate processing method, comprising a step of notifying a notification unit when the obtained liquid landing position is not within a predetermined range. The substrate processing method according to any one of claims 1 to 7,
In the monitoring step,
A substrate processing method, wherein a machine-learned classifier classifies the captured image into either a category of no liquid landing position abnormality or a liquid landing position abnormality. The substrate processing method according to claim 8,
In the monitoring step,
A substrate processing method, wherein a region located directly below the nozzle and containing the processing liquid and the mirror image is cut out from the captured image, and an image of the cut out region is input to the classifier. a substrate holder that holds a substrate and rotates the substrate;
a cup member surrounding the outer periphery of the substrate holding portion;
an elevating mechanism that elevates the cup member and positions the upper end of the cup member at an upper end position higher than the upper surface of the substrate held by the substrate holding portion;
a nozzle having an ejection port located at a position lower than the upper end position, and ejecting the processing liquid from the ejection port to an end portion of the upper surface of the substrate held by the substrate holding portion;
An imaging position above the substrate held by the substrate holding unit, an imaging region including the processing liquid ejected from the ejection port of the nozzle and a mirror image of the processing liquid reflected on the upper surface of the substrate. a camera that acquires a captured image by causing the camera to capture an image of an imaging area viewed from
A substrate processing apparatus comprising: an image processing unit that monitors a landing position of the processing liquid based on the processing liquid and the mirror image in the captured image.

Images