CN114377891A

CN114377891A - Nozzle position adjusting method and liquid processing apparatus

Info

Publication number: CN114377891A
Application number: CN202111109907.8A
Authority: CN
Inventors: 松浦和宏; 羽山隆史; 桾本裕一朗
Original assignee: Tokyo Electron Ltd
Current assignee: Tokyo Electron Ltd
Priority date: 2020-10-02
Filing date: 2021-09-18
Publication date: 2022-04-22
Also published as: CN217527991U; JP7478639B2; KR20220044659A; JP2022059723A

Abstract

The present invention relates to a method for adjusting the position of a nozzle and a liquid processing apparatus. The position of the discharge nozzle with respect to the rotary holding unit is accurately adjusted using the low-resolution captured image. A method for adjusting the position of a nozzle in a liquid processing apparatus, comprising the steps of: while rotating a rotation holding portion for holding and rotating a substrate in a state where the substrate is not held, performing a plurality of times of imaging by an imaging portion arranged so as to include the rotation holding portion in an imaging region; synthesizing the multiple camera shooting results and acquiring a synthesized image; determining a position of the rotation holding portion on the captured image from the synthesized image by using pattern matching; performing imaging by an imaging unit in a state where the adjustment nozzle is moved to the reference position; determining the position of the adjusting nozzle on the shot image according to the shooting result; and correcting the reference position based on a difference between the target position determined based on the position of the rotation holding portion on the captured image and the position of the adjustment nozzle on the captured image.

Description

Nozzle position adjusting method and liquid processing apparatus

Technical Field

The present disclosure relates to a method of adjusting a position of a nozzle and a liquid processing apparatus.

Background

Patent document 1 discloses a method of adjusting the position of a nozzle in a coating apparatus that applies a coating process to a substrate by supplying a coating liquid from the nozzle onto the substrate held by a spin holding member and rotating the spin holding member. In this method, the nozzle is moved upward from the center of the rotation holding member in a state where the substrate is not held, the center of the rotation holding member and the distal end portion of the nozzle are then imaged by the imaging means, and the position of the nozzle is adjusted so that the position in the horizontal direction of the center of the distal end portion of the nozzle and the position in the horizontal direction of the center of the rotation holding member coincide with each other in the imaged image.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5314657

Disclosure of Invention

Problems to be solved by the invention

With the technique of the present disclosure, the position of the discharge nozzle with respect to the rotation holding portion is accurately adjusted using the captured image, regardless of the resolution of the captured image.

Means for solving the problems

A method for adjusting a position of a nozzle in a liquid processing apparatus for processing a substrate with a processing liquid discharged from a discharge nozzle according to an aspect of the present disclosure includes: while rotating a rotation holding portion for holding and rotating a substrate in a state where the substrate is not held, performing a plurality of times of imaging by an imaging portion arranged so as to include the rotation holding portion in an imaging region; synthesizing the multiple shooting results and acquiring a synthesized image; determining a position of the rotation holding portion on the captured image from the composite image by pattern matching; performing imaging by the imaging unit in a state where the adjustment nozzle is moved to a reference position; determining a position of the adjusting nozzle on the captured image based on the imaging result in a state where the adjusting nozzle is moved to the reference position; and correcting the reference position based on a difference between a target position determined based on a position of the rotation holding portion on the captured image and a position of the adjustment nozzle on the captured image.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, the position of the discharge nozzle with respect to the rotary holding portion can be accurately adjusted using the captured image regardless of the resolution of the captured image.

Drawings

Fig. 1 is a schematic vertical sectional view showing the structure of a resist film forming apparatus as a liquid processing apparatus according to embodiment 1.

Fig. 2 is a schematic cross-sectional view showing the structure of a resist film forming apparatus as a liquid processing apparatus according to embodiment 1.

Fig. 3 is a top view of the spin chuck.

Fig. 4 is a flowchart showing an example of the position adjustment processing.

Fig. 5 is a diagram showing an example of an image used for the above-described position adjustment processing.

Fig. 6 is a diagram showing an example of an image used for the above-described position adjustment processing.

Fig. 7 is a side view showing an example of a jig nozzle.

Fig. 8 is a diagram for explaining a method of determining the position of the adjustment nozzle on the captured image according to embodiment 3.

Fig. 9 is a diagram for explaining a method of adjusting the position of the discharge nozzle according to embodiment 2.

Detailed Description

In a manufacturing process of a semiconductor device or the like, a resist coating process of coating a resist liquid on a semiconductor wafer (hereinafter, referred to as "wafer") to form a resist film, an exposure process of exposing the resist film to light, a development process of developing the exposed resist film, and the like are sequentially performed to form a resist pattern on the wafer. These processes are performed by a coating and developing system equipped with various processing apparatuses, a transport apparatus for transporting wafers, and the like.

In the coating and developing treatment system, a liquid treatment apparatus for treating a wafer with a treatment liquid such as a resist liquid or a developing liquid in the treatment apparatus includes a spin chuck for holding and rotating the wafer and a discharge nozzle for discharging the treatment liquid to the wafer held by the spin chuck. In this liquid processing apparatus, for example, a spin coating process is performed in which a processing liquid is discharged from a discharge nozzle toward the center of a wafer held by a spin chuck, and the spin chuck is rotated to spread the processing liquid over the entire wafer.

In the spin coating process, for example, the position of the discharge nozzle at the time of discharging the processing liquid needs to be accurately adjusted with respect to the center portion of the spin chuck corresponding to the center portion of the wafer. This is because the coating of the process liquid with respect to the wafer is not uniform.

In this regard, patent document 1 discloses a method of adjusting the position of the discharge nozzle as described below. In the position adjustment method disclosed in patent document 1, the discharge nozzle is moved upward from the center portion of the spin chuck in a state where the wafer is not held, and then the center portion of the spin chuck and the tip end portion of the discharge nozzle are imaged by the imaging section. Then, in the captured image, the position of the discharge nozzle is adjusted so that the horizontal position of the center of the distal end portion of the discharge nozzle matches the horizontal position of the center portion of the spin chuck.

However, in the method disclosed in patent document 1, there is room for improvement in terms of accurate position adjustment of the discharge nozzle with respect to the spin chuck when the image captured by the imaging unit has a low resolution.

Therefore, with the technique of the present disclosure, the position of the ejection nozzle with respect to the spin chuck is accurately adjusted using the captured image, regardless of the resolution of the captured image.

Hereinafter, a method for adjusting the position of a nozzle and a liquid treatment apparatus according to the present embodiment will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description thereof is omitted.

(embodiment 1)

Fig. 1 and 2 are a longitudinal sectional view and a transverse sectional view schematically showing the structure of a resist film forming apparatus 1 as a liquid processing apparatus according to embodiment 1. Fig. 3 is a plan view of a spin chuck described later.

As shown in fig. 1, the resist film forming apparatus 1 includes a processing container 10 capable of sealing the inside. A loading/unloading port (not shown) for wafers W as substrates is formed in a side surface of the processing container 10.

A spin chuck 20 as a spin holding portion for holding and rotating the wafer W about a vertical axis is provided in the processing chamber 10. The spin chuck 20 has a horizontal upper surface. For example, as shown in fig. 3, a suction port 20a for sucking the wafer W is provided in the upper surface of the spin chuck 20. The wafer W can be sucked and held by the spin chuck 20 by suction from the suction port 20 a. Further, an annular projection 20b and an arcuate projection 20c are formed on the upper surface of the spin chuck 20, and the annular projection 20b and the arcuate projection 20c form a gas flow path leading to the suction port 20a between the upper surface and the back surface (lower surface) of the wafer W so as to suck the wafer W over the entire upper surface. The annular projection 20b is formed in an annular shape centering on the center axis of the upper surface of the spin chuck 20 in a plan view, and the arcuate projection 20c is formed in an arcuate shape centering on the center axis of the upper surface of the spin chuck 20 in a plan view.

As shown in fig. 1, the spin chuck 20 can be rotated at a desired speed by a chuck driving unit 21 including an actuator such as a motor. The chuck driving unit 21 is provided with a lifting/lowering driving mechanism (not shown) such as a cylinder, for example, to lift and lower the spin chuck 20. The chuck driving unit 21 is controlled by a control unit 100 described later.

Further, a cup 22 is provided in the processing vessel 10 so as to surround the wafer W held by the spin chuck 20 with respect to the spin chuck 20. The cup 22 receives and collects liquid scattered or dropped from the wafer W.

As shown in fig. 2, a guide rail 30 extending in the Y direction (the left-right direction in fig. 2) is formed on the negative X direction (the lower direction in fig. 2) side of the cup 22. The guide rail 30 is formed, for example, from the outside of the cup 22 on the negative Y-direction (left direction in fig. 2) side to the outside on the positive Y-direction (right direction in fig. 2) side. The guide rail 30 is provided with an arm 31.

A discharge nozzle 32 for discharging a resist solution as a processing solution is supported on the distal end side of the arm 31. The discharge nozzle 32 may be provided in plural, and in this case, for example, it is provided so as to be aligned in the direction (Y direction) in which the guide rail 30 extends. The arm 31 is movable along the guide rail 30 by a nozzle driving unit 33 connected to the base end side thereof. Thus, the discharge nozzle 32 can move from the standby portion 34 provided outside the cup 22 in the positive Y-direction side to above the center portion of the wafer W in the cup 22. The arm 31 is movable up and down by the nozzle driving unit 33, and the height of the discharge nozzle 32 can be adjusted. The discharge nozzle 32 is connected to a resist liquid supply device M for supplying a resist liquid. The nozzle driving unit 33 is controlled by a control unit 100 described later.

Further, a camera 40 as an imaging unit is provided in the processing container 10. The camera 40 is provided to monitor the entire inside of the processing container 10, particularly the entire surface of the wafer W when the resist film is formed. In the present embodiment, the camera 40 is also used for adjusting the position of the discharge nozzle 32. The camera 40 is arranged so as to include the following (a) to (c) in its imaging region.

(a) The entire surface (upper surface) of the wafer W held by the spin chuck 20;

(b) the entire upper surface of the spin chuck 20 in a state where the wafer W is not held;

(c) the tip end side of the discharge nozzle 32 moved to the reference position.

The camera 40 is fixed to the ceiling wall of the processing container 10 by a fixing member (not shown), for example, so as not to interfere with the feeding and discharging of the wafer W and the movement of the discharge nozzle 32. For the camera 40, for example, a CCD camera can be used.

Further, a light source 50 is provided in the processing container 10. The light source 50 irradiates light (visible light in this example) to the imaging region of the camera 40, and illuminates the imaging region of the camera 40. The light source 50 is fixed to the ceiling wall of the processing container 10 by a fixing member (not shown), for example, so as not to interfere with the feeding and discharging of the wafer W and the movement of the discharge nozzle 32.

The camera 40 and the light source 50 are controlled by a control unit 100 described later, and the result of imaging by the camera 40 is output to the control unit 100.

The resist film forming apparatus 1 configured as described above is provided with the control section 100. The control unit 100 is a computer provided with, for example, a CPU, a memory, and the like, and includes a program storage unit (not shown). The program storage unit also stores a program for controlling the nozzle drive unit 33 and the like to realize a resist film formation process described later. Further, a program for realizing the position adjustment process of the discharge nozzle 32 described later is stored in the program storage unit. The program may be stored in a computer-readable storage medium and loaded from the storage medium to the control unit 100. Part or all of the program may be realized by dedicated hardware (circuit board).

Here, an example of the resist film forming process of the resist film forming apparatus 1 will be described.

First, the controller 100 places and adsorbs the wafer W loaded into the processing container 10 onto the spin chuck 20.

Next, the control unit 100 moves the discharge nozzle 32 to a processing position (for example, a position above the center of the wafer W) where the discharge is performed. The processing position is determined based on the reference position corrected at the time of the position adjustment processing of the ejection nozzle 32. Next, the wafer W is rotated by rotating the spin chuck 20, and the resist solution is continuously discharged from the discharge nozzle 32 toward the wafer W during the rotation. The resist sprayed out spreads over the entire surface of the wafer W due to the rotation of the wafer W.

Thereafter, the control unit 100 stops the discharge of the resist solution and retracts the discharge nozzle 32 toward the standby unit 34. Further, the control unit 100 continues to rotate the spin chuck 20 and the wafer W, thereby drying the resist solution on the wafer W. Thereby, a resist film is formed on the wafer W.

Thereafter, the wafer W with the resist film formed thereon is sent out from the processing container 10. Thereby completing a series of resist film formation processes.

Next, a position adjustment process of the discharge nozzle 32 of the resist film forming apparatus 1 will be described. Fig. 4 is a flowchart showing an example of the position adjustment processing. Fig. 5 and 6 are diagrams showing an example of an image used for the above-described position adjustment processing. In fig. 5 and 6, only the main part of each image is shown.

(image pickup of image pickup region including spin chuck 20)

In the adjustment of the position of the discharge nozzle 32, first, as shown in fig. 4, the control unit 100 controls the chuck drive unit 21, the camera 40, and the light source 50 to perform a plurality of (e.g., 60) times of image pickup by the camera 40 including the entire upper surface of the spin chuck 20 in the image pickup region while rotating the spin chuck 20 without holding the wafer W (step S1). The number of rotations of the spin chuck 20 and the number of times of image capture by the camera 40 per second are adjusted so that captured images having mutually different orientations of the spin chuck 20 are included in a plurality of captured images obtained by the image capture. At this time, the discharge nozzle 32 is located at the standby portion 34.

(acquisition of composite image)

Next, the control unit 100 synthesizes the imaging results of the plurality of times by the camera 40, and acquires a synthesized image (step S2). The composite image includes a trajectory described by an outline of a characteristic shape of the upper surface of the spin chuck 20. Specifically, as shown in fig. 5, the composite image Is includes a trajectory C1 drawn by the contour of the suction port 20a, a trajectory C2 drawn by the contour of the arcuate projection 20C, and a trajectory C3 drawn by the contour of the annular projection 20b during rotation of the spin chuck 20. In the acquisition of the composite image, the trajectory drawn by the outline of the suction port 20a and the like may be emphasized, and then the composite image may be synthesized after the emphasis process.

(determination of the position of the spin chuck 20 on the image taken by the camera 40)

After the acquisition of the composite image Is, the control section 100 determines the position Ps of the spin chuck 20 on the captured image of the camera 40 from the composite image Is by pattern matching (step S3). Specifically, the control unit 100 detects a region (hereinafter, sometimes referred to as a "chuck feature region") including a trajectory drawn by the outlines of the suction port 20a, the annular projection 20b, and the arcuate projection 20c in the composite image Is by pattern matching. Then, the control unit 100 determines a predetermined position of the chuck feature region (for example, a center position of the chuck feature region) in the composite image as a position Ps of the spin chuck 20 on the captured image of the camera 40. In addition, hereinafter, the "position on the captured image of the camera 40" may be abbreviated as "position on the captured image".

(imaging of imaging region including discharge nozzle 32 at reference position)

The control unit 100 controls the nozzle driving unit 33, the camera 40, and the light source 50 to move the discharge nozzle 32 to a reference position above the spin chuck 20, and then to perform imaging using the camera 40 including the discharge nozzle 32 in this state (i.e., the discharge nozzle 32 at the reference position) in the imaging region (step S4). The number of times of imaging in this step may be multiple (for example, 10 times). In step S2 and step S4, the imaging region of the camera 40 is the same.

(determination of the position of the discharge nozzle 32 on the picked-up image by the camera 40)

Next, the control section 100 specifies the position Pn of the discharge nozzle 32 at the reference position on the captured image based on the imaging result of the camera 40 in the state where the discharge nozzle 32 has moved to the reference position (step S5). Specifically, the control unit 100 detects a region (hereinafter, sometimes referred to as a "nozzle region") including the discharge nozzle 32 In the image In for specifying the position of the discharge nozzle 32 In fig. 6 by pattern matching, for example, based on the imaging result In step S4. Then, the control unit 100 determines a predetermined position of the nozzle region (for example, the center position of the nozzle region) in the captured image as a position Pn of the discharge nozzle 32 on the captured image at the reference position.

In step S4, when the number of times of image capturing by the camera 40 including the discharge nozzle 32 at the reference position in the image capturing region is plural, the control unit 100 synthesizes the plural image capturing results and acquires a synthesized image for the nozzle. Then, the control unit 100 may specify the position Pn of the discharge nozzle 32 at the reference position on the captured image by using the synthesized image for the nozzle as the image In for specifying the position of the discharge nozzle 32.

(correction of reference position)

Then, the control unit 100 corrects the reference position based on the difference between the target position Pt determined based on the position Ps of the spin chuck 20 on the captured image and the position Pn of the discharge nozzle 32 on the captured image at the reference position (step S6). That is, the target position Pt is determined by the following equation (1) based on the position Ps of the spin chuck 20 on the captured image and the ideal relative positional relationship Poff of the spin chuck 20 and the ejection nozzle 32 on the captured image.

Pt＝Ps+Poff…(1)

The correction amount Δ P of the reference position in step S6 is determined based on, for example, the difference between the target position Pt and the position Pn on the captured image of the discharge nozzle 32 at the reference position (i.e., the offset amount of the position Pn from the target position) (Pt — Pn). More specifically, the correction amount Δ P of the reference position is determined based on, for example, the following equation (2).

ΔP＝0.8×(Pt－Pn)…(2)

Then, step S4 to step S6 are repeated until the offset amount (Pt-Pn) becomes equal to or less than the required value.

As described above, by correcting the reference position of the discharge nozzle 32, the position of the discharge nozzle 32 with respect to the spin chuck 20 can be adjusted, and the resist liquid is discharged from the discharge nozzle 32 to a desired position of the wafer W held by the spin chuck 20 (for example, the center of the wafer W).

The ideal relative positional relationship Poff, the model used for pattern matching for determining the position of the spin chuck 20, and the model used for pattern matching for determining the position of the discharge nozzle 32 are acquired in advance using, for example, another apparatus having the same configuration as the resist film forming apparatus 1, and are stored in a storage unit (not shown). In the following description, the same reference numerals as those used for the structure of the resist film forming apparatus 1 are used for the structure of another apparatus having the same structure as that of the resist film forming apparatus 1. For example, a camera similar to the camera 40 of the resist film forming apparatus 1, which is provided in the other apparatus, will be described as "camera 40".

A model used for pattern matching for determining the position of the spin chuck 20 (hereinafter, may be referred to as a "chuck model") is created and acquired as follows, for example. First, the other device uses the camera 40 to perform image capturing in the same manner as step S1, and acquires a composite image in the same manner as step S2. In the composite image, a region including a trajectory drawn by the outlines of the suction port 20a, the annular projection 20b, and the arcuate projection 20c is designated as a region for modeling. Then, a chuck model is created from the image of the designated area in the composite image.

A model used for pattern matching for specifying the position of the discharge nozzle 32 (hereinafter, may be referred to as "nozzle model") is created and acquired as follows, for example. First, in the other apparatus, the position of the discharge nozzle 32 is adjusted by the same method as in the conventional art. Thereafter, the other device uses the camera 40 to take an image in the same manner as in step S4, and acquires an image for determining the position of the discharge nozzle 32. In addition, with respect to the image, a region including the discharge nozzle 32 is designated as a region for modeling. Then, a nozzle model is created from an image of a designated area in the image for specifying the position of the discharge nozzle 32.

The ideal relative positional relationship Poff is obtained as follows, for example. First, the position Psref of the spin chuck 20 in the other apparatus on the captured image is determined from the composite image used for the creation of the chuck model by pattern matching using the chuck model created as described above. Further, the position Pnref of the discharge nozzle 32 in the other apparatus on the captured image is determined from the image for determining the position of the discharge nozzle 32 used for the creation of the nozzle model by pattern matching using the nozzle model created as described above. The ideal relative positional relationship Poff is determined based on the following equation (3).

Poff＝Pnref－Psref…(3)。

As described above, in the present embodiment, the control unit 100 performs a plurality of times of imaging by the camera 40 disposed so as to include the spin chuck 20 in the imaging region while rotating the spin chuck 20 in a state where the wafer W is not held. The control unit 100 synthesizes the plurality of imaging results and acquires a synthesized image. Then, the control unit 100 specifies the position Ps of the spin chuck 20 on the captured image from the composite image by pattern matching. As a method for specifying the position Ps, which is different from the present embodiment, for example, the following method is considered. That is, the method (hereinafter, referred to as "comparative method") is: the image is captured once by the camera 40 without rotating the spin chuck 20, and based on the result of the image capture, the feature of the upper surface of the spin chuck 20 (for example, a part of the suction port 20 a) is detected, and the position Ps is determined based on the result of the detection. However, the imaging result obtained by the camera 40 for the determination of the position Ps changes depending on the orientation (rotation angle, i.e., rotation position) of the spin chuck 20 at the time of imaging. The reasons for this include the processing accuracy of the spin chuck 20, the mounting orientation of the camera 40, the focusing state of the camera, the mounting orientation of the light source 50, and the influence of disturbance light. Further, it is difficult to precisely adjust the orientation of the spin chuck 20 by the chuck driving section 21 when the spin chuck 20 is imaged. As described above, although there is no particular problem in that the imaging result of the camera 40 changes depending on the orientation of the spin chuck 20, the imaging image of the camera 40 has a high resolution, but the imaging image of the camera 40 has a low resolution including the entire upper surface of the spin chuck 20 in the imaging region. If the imaging result obtained by the camera 40 for specifying the position Ps changes depending on the orientation of the spin chuck 20 at the time of imaging, if the image captured by the camera 40 has a low resolution, the position Ps cannot be specified accurately in the comparison method. In the comparative method, the number of times the camera 40 takes an image of the rotary chuck 20 is one, and therefore, if noise is included in the taken image, the noise is affected.

In contrast, in the present embodiment, the composite image used for specifying the position Ps is obtained by combining the results of a plurality of times of image pickup by the camera 40 while rotating the spin chuck 20, and therefore, the feature of the shape of the upper surface of the spin chuck 20 is included in the composite image in a state of being converted into a form that is independent of the orientation of the spin chuck 20 (specifically, a trajectory drawn by the outlines of the suction port 20a, the annular protrusion 20b, and the circular arc protrusion 20c during rotation of the spin chuck 20). In the present embodiment, the pattern matching is used to recognize the feature of the shape of the upper surface of the spin chuck 20 in a state in which the shape is converted from the composite image to a form that is not related to the orientation of the spin chuck 20, and the position Ps of the spin chuck 20 on the captured image is determined from the recognition result. Therefore, even if the captured image of the camera 40 has a low resolution, the position Ps of the spin chuck 20 on the captured image can be accurately determined.

In the comparative method described above, the camera 40 takes an image of the rotating chuck 20 once, and therefore, if the taken image includes noise, the taken image is affected by the noise. In contrast, in the present embodiment, the position Ps of the spin chuck 20 on the captured image is determined based on the composite image obtained by combining the results of the multiple times of imaging by the camera 40, and therefore, the determination is not affected by the above-described noise.

In the present embodiment, the control unit 100 corrects the reference position of the discharge nozzle 32 based on the difference between the target position Pt determined from the position Ps of the spin chuck 20 on the captured image accurately determined as described above and the position Pn of the discharge nozzle 32 on the captured image. Therefore, even if a low-resolution captured image is used, the position of the discharge nozzle 32 with respect to the spin chuck 20 can be accurately adjusted.

Further, according to the present embodiment, the position of the discharge nozzle 32 with respect to the spin chuck 20 can be automatically adjusted only by the control and arithmetic processing of the control unit 100.

In the present embodiment, as described above, the control unit 100 may perform a plurality of times of imaging by the camera 40 including the discharge nozzle 32 at the reference position in the imaging region, then combine the imaging results of the plurality of times of imaging, acquire a composite image for the nozzle, and specify the position Pn of the discharge nozzle 32 at the reference position on the captured image based on the composite image for the nozzle. In this case, the position Pn can be accurately determined regardless of the presence or absence of noise in the captured image of the camera 40, and as a result, the position of the discharge nozzle 32 can be accurately adjusted.

In addition, when the position Ps of the spin chuck 20 on the captured image is determined by pattern matching in step S3, the position Ps may be determined in sub-pixel units. For example, the position Ps of the spin chuck 20 on the captured image can be determined in units of sub-pixels by performing the pattern matching while performing sub-pixel processing. By performing the determination in units of sub-pixels in this manner, the position Ps of the spin chuck 20 on the captured image can be determined with high accuracy, and as a result, the position of the discharge nozzle 32 with respect to the spin chuck 20 can be adjusted more accurately.

In addition, when the position Pn of the discharge nozzle 32 on the captured image is specified in step S5, the position Pn may be specified in sub-pixel units. For example, the position Pn of the discharge nozzle 32 on the captured image can be specified in units of sub-pixels by performing sub-pixel processing when pattern matching is performed to specify the position Pn. By performing the determination in units of sub-pixels in this manner, the position Pn of the discharge nozzle 32 on the captured image can be determined with high accuracy, and as a result, the position of the discharge nozzle 32 with respect to the spin chuck 20 can be adjusted more accurately.

In step S3, the control unit 100 may determine the tilt of the camera 40 with respect to the spin chuck 20 (in other words, the tilt of the spin chuck 20 in the captured image) θ based on the pattern matching result of the spin chuck 20. Then, based on the determined inclination θ, the position Ps and the position Pn may be determined after the captured image is corrected in steps S3 and S4 so that the inclination of the spin chuck 20 in the captured image is substantially equal to the inclination when the ideal relative positional relationship Poff is acquired. This enables the position of the discharge nozzle 32 with respect to the spin chuck 20 to be adjusted more accurately.

(embodiment 2)

In embodiment 1, the actual discharge nozzle 32 is used to adjust the position of the discharge nozzle 32. Alternatively, as in the present embodiment, a jig nozzle different from the discharge nozzle 32 may be attached and used to adjust the position of the discharge nozzle 32. That is, in embodiment 1, the actual discharge nozzle 32 is used as an adjustment nozzle for adjusting the position of the discharge nozzle 32, but a jig nozzle different from the discharge nozzle 32 may be attached and used as in the present embodiment. The jig nozzle is attached to the arm 31 in place of the discharge nozzle 32 when the position of the discharge nozzle 32 is adjusted, and after the position adjustment, the jig nozzle is detached and the discharge nozzle 32 is attached.

Fig. 7 is a side view showing an example of a jig nozzle.

The jig nozzle 200 of fig. 7 is attached to the arm 31 so as to extend in the vertical direction, similarly to the discharge nozzle 32. The fixture nozzle 200 has a proximal end-side attachment portion 201 attached to the arm 31 (see fig. 2). The jig nozzle 200 further includes a nozzle shape portion 202 extending downward of the mounting portion 201.

For the purpose of monitoring the height of the liquid surface at the tip of the discharge nozzle 32, the discharge nozzle 32 may be formed using a material that is transparent or translucent to visible light. In this case, the jig nozzle 200 is formed using a material having transparency at least lower than that of the discharge nozzle 32, specifically, a material opaque to visible light.

By using such a jig nozzle 200 having low transparency as an adjustment nozzle, the contrast of the portion of the adjustment nozzle can be increased in the image for determining the position of the adjustment nozzle. Therefore, the position of the adjustment nozzle on the captured image can be determined with high accuracy, and as a result, the position of the adjustment nozzle with respect to the spin chuck 20 can be adjusted more accurately.

Further, the rigidity of the mounting portion 201 is higher than that of the discharge nozzle 32. The rigidity of the portion of the discharge nozzle 32 attached to the arm 31, that is, the portion on the proximal end side thereof, is relatively low, and therefore, the discharge nozzle may not be attached to the arm 31 at a desired angle. If the reference position is corrected using the discharge nozzle 32 that is not mounted at a desired angle, an appropriate result may not be obtained. In contrast, since the rigidity of the attachment portion of the jig nozzle 200 is high, the attachment portion can be more reliably attached to the arm 31 at a desired angle (for example, an angle at which the jig nozzle 200 extends in the vertical direction). Therefore, by using the jig nozzle 200 as an adjustment nozzle to correct the reference position, an appropriate result can be obtained.

In particular, when a plurality of discharge nozzles 32 are provided, and one of the discharge nozzles is used as an adjustment nozzle to correct the reference position, the reference position cannot be appropriately corrected when the one discharge nozzle 32 is not attached at a desired angle to the arm 31. The processing positions of the discharge nozzles 32 other than the discharge nozzles 32 serving as the adjustment nozzles are also determined based on the reference positions, and therefore, may be displaced from the appropriate positions by the influence of the discharge nozzles 32 serving as the adjustment nozzles. This problem can be avoided by using the jig nozzle 200 having a higher rigidity with respect to the mounting portion 201 on the base end side, which is the mounting portion of the arm 31, than the discharge nozzle 32.

(embodiment 3)

As shown in fig. 8, another camera 301 and another light source 302 may be provided on an arm 300 supporting the discharge nozzle 32. The camera 301 includes only the tip side of the discharge nozzle 32 in the imaging region. The light source 302 irradiates light (for example, infrared light) to the imaging region of the camera 301, and illuminates the imaging region of the camera 301 including the discharge nozzle 32. As described above, the camera 301 and the light source 302 are provided on the arm 300 supporting the discharge nozzle 32, and therefore can move together with the discharge nozzle 32.

The light source 302 may be provided at a position where light from the light source 50 (see fig. 1 and 2) is blocked by the light source 302 when the adjustment nozzle (the discharge nozzle 32 or the jig nozzle 200 attached in place of the discharge nozzle) is moved to the reference position. In this case, the adjustment nozzle at the reference position may be imaged by the camera 40 to be dark. Therefore, in the above case, when the adjustment nozzle at the reference position is imaged by the camera 40, both the light source 50 and the light source 302 may be turned on. Thus, even if the light from the light source 50 is blocked by the light source 302, the contrast of the portion of the adjustment nozzle can be increased in the image for determining the position of the adjustment nozzle, and the position of the adjustment nozzle on the captured image can be determined with high accuracy.

(reference embodiment 1)

In the above embodiment, while the spin chuck 20 is rotated in a state not holding the wafer W, a plurality of times of image capturing are performed by the camera 40 disposed so as to include the spin chuck 20 in the image capturing region, and the results of the plurality of times of image capturing are synthesized to acquire a synthesized image for specifying the position Ps of the spin chuck 20 on the captured image.

In contrast, in the present embodiment, while the wafer W having a pattern formed thereon is held by the spin chuck 20, the spin chuck 20 is rotated to perform a plurality of times of image capturing by the camera, and the results of the plurality of times of image capturing are combined to obtain a combined image. In the present embodiment, the position Ps of the spin chuck 20 on the captured image is determined from the composite image by pattern matching. Specifically, in the composite image, a region including a locus drawn by the outline of the pattern on the wafer W during rotation of the spin chuck 20 is detected by pattern matching, and a predetermined position of the region is determined as a position Ps of the spin chuck 20 on the captured image.

Instead of the position Ps of the spin chuck 20 on the captured image, the position Pw of the wafer W held by the spin chuck 20 on the captured image may be determined. In this case, the reference position of the discharge nozzle 32 is corrected based on the difference between the target position Pt determined from the position Pw of the wafer W held by the spin chuck 20 on the captured image and the position Pn of the discharge nozzle 32 on the captured image.

In the present embodiment, the camera 40 is disposed so as to include the entire surface (upper surface) of the wafer W held by the spin chuck 20 in the imaging region thereof.

(reference embodiment 2)

In embodiment 1 and embodiment 2, the adjustment nozzle is moved to the reference position, and in this state, an image is taken by the camera 40, and the position of the adjustment nozzle on the taken image is specified based on the result of the image taking. Then, the reference position of the discharge nozzle 32 is corrected based on the difference between the target position Pt determined from the position Ps of the spin chuck 20 on the captured image and the position Pn of the adjustment nozzle on the captured image.

In contrast, in the present embodiment, as shown in fig. 9, a target mark 401 is formed on an arm 400 supporting the discharge nozzle 32, and when the position of the discharge nozzle 32 is adjusted, the discharge nozzle 32 is moved to a reference position, and in this state, an image is taken by the camera 40, and based on the result of the image taking, the position Pm of the target mark 401 on the taken image is specified. For the determination of the position Pm described above, pattern matching is used, for example. In the present embodiment, the reference position of the discharge nozzle 32 is corrected based on the difference between the target position Pt' determined from the position Ps of the spin chuck 20 on the captured image and the position Pm of the target mark 401 on the captured image.

In the image for specifying the position Pm of the target mark 401 on the captured image, the contrast of the portion of the target mark 401 is higher than the contrast of the portion of the discharge nozzle 32, and therefore the position Pm of the target mark 401 on the captured image can be specified with high accuracy, and as a result, the position of the discharge nozzle 32 with respect to the spin chuck 20 can be adjusted more accurately.

In the present embodiment, the camera 40 is arranged so that the target mark 401 is included in the imaging region of the camera 40 when the discharge nozzle 32 is moved to the reference position.

As described above, the position of the discharge nozzle 32 that discharges the resist liquid is adjusted, but the discharge nozzle 32 that is the object of adjustment is not limited to this, and may be a discharge nozzle that discharges the developer liquid, for example.

The embodiments disclosed herein are illustrative in all respects and should not be construed as being limiting. The above-described embodiments may be omitted, replaced, or modified in various ways without departing from the scope of the appended claims and the gist thereof.

Claims

1. A method for adjusting the position of a nozzle in a liquid processing apparatus for processing a substrate with a processing liquid discharged from a discharge nozzle,

the method for adjusting the position of the nozzle comprises the following steps:

while rotating a rotation holding portion for holding and rotating a substrate in a state where the substrate is not held, performing a plurality of times of imaging by an imaging portion arranged so as to include the rotation holding portion in an imaging region;

synthesizing the multiple shooting results and acquiring a synthesized image;

determining a position of the rotation holding portion on the captured image from the composite image by pattern matching;

performing imaging by the imaging unit in a state where the adjustment nozzle is moved to a reference position;

determining a position of the adjusting nozzle on the captured image based on the imaging result in a state where the adjusting nozzle is moved to the reference position; and

the reference position is corrected based on a difference between a target position determined based on a position of the rotation holding portion on the captured image and a position of the adjustment nozzle on the captured image.

2. The method of adjusting a position of a nozzle according to claim 1,

a step of performing imaging by the imaging unit while the adjustment nozzle is moved to the reference position, the imaging unit performing imaging a plurality of times,

the step of determining the position of the adjustment nozzle on the captured image is performed based on a synthesized image obtained by synthesizing the results of the plurality of times of imaging performed by the imaging unit while the adjustment nozzle is moved to the reference position.

3. The position adjustment method of a nozzle according to claim 1 or 2,

the adjusting nozzle is a jig nozzle that is installed at the time of position adjustment in place of the discharge nozzle used in actual processing, and has lower transparency than the discharge nozzle used in actual processing.

4. The position adjustment method of a nozzle according to claim 3,

the rigidity of the mounting portion of the adjustment nozzle is higher than that of the discharge nozzle.

5. The method of adjusting a position of a nozzle according to claim 1,

the step of determining the position of the adjustment nozzle on the captured image determines the position of the adjustment nozzle on the captured image in units of sub-pixels.

6. The method of adjusting a position of a nozzle according to claim 1,

the step of determining the position of the rotary holding unit on the captured image determines the position of the rotary holding unit on the captured image in units of sub-pixels.

7. A liquid processing apparatus for processing a substrate with a processing liquid,

the liquid treatment apparatus includes:

a rotation holding unit that holds and rotates the substrate;

an adjustment nozzle for adjusting a position of a discharge nozzle that discharges the processing liquid to the substrate held by the spin holding unit;

a rotation mechanism that rotates the rotation holding portion;

a moving mechanism that moves the adjusting nozzle;

an imaging unit arranged so as to include the rotation holding unit and the adjustment nozzle moved to a reference position in an imaging region; and

a control part for controlling the operation of the display device,

the control unit performs the following control:

performing a plurality of times of imaging by the imaging unit while rotating the rotation holding unit in a state where the substrate is not held;

synthesizing the multiple shooting results and acquiring a synthesized image;

performing imaging by the imaging unit in a state where the adjustment nozzle is moved to the reference position;