Method for adjusting position of nozzle and liquid processing apparatus

Abstract

The present invention relates to a method of adjusting the position of a nozzle and a liquid processing apparatus. The position of an ejection nozzle with respect to a rotary holding section is accurately adjusted using a low-resolution camera image. A method of adjusting the position of a nozzle in a liquid processing apparatus includes the following steps: while a rotary holding section for holding and rotating a substrate is rotated in a state in which the substrate is not held, a plurality of camera images are captured using a camera section arranged to include the rotary holding section in a camera region; a composite image is acquired by synthesizing the plurality of camera images; the position of the rotary holding section on the camera image is determined from the composite image using pattern matching; a camera image is captured using the camera section in a state in which an adjustment nozzle is moved to a reference position; the position of the adjustment nozzle on the camera image is determined from the camera image; and the reference position is corrected based on the difference between the target position determined from the position of the rotary holding section on the camera image and the position of the adjustment nozzle on the camera image.

Description

Technical Field

[0001] This disclosure relates to a method for adjusting the position of a nozzle and a liquid treatment apparatus. Background Technology

[0002] Patent Document 1 discloses a method for adjusting the position of a nozzle in a coating process apparatus. In this apparatus, coating liquid is supplied from a nozzle to a substrate held by a rotating holding member, causing the rotating holding member to rotate, thereby coating the substrate. In this method, the nozzle is moved above the center of the rotating holding member when the substrate is not held. Then, an imaging unit captures images of the center of the rotating holding member and the tip of the nozzle. In the captured image, the nozzle position is adjusted so that the horizontal position of the center of the nozzle tip matches the horizontal position of the center of the rotating holding member.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 5314657 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] With respect to the technology disclosed herein, the position of the ejector nozzle relative to the rotating retainer is accurately adjusted using the camera image, regardless of the resolution of the image.

[0008] Solution for solving the problem

[0009] The nozzle position adjustment method disclosed herein is a method for adjusting the nozzle position in a liquid treatment apparatus that uses a processing liquid sprayed from an ejector nozzle to treat a substrate. The method includes the following steps: rotating a rotating holding part used to hold and rotate the substrate in a state where the substrate is not held; taking multiple images using an imaging unit arranged to include the rotating holding part in an imaging area; combining the multiple imaging results to obtain a composite image; determining the position of the rotating holding part on the image from the composite image using pattern matching; taking an image using the imaging unit while the adjustment nozzle is moved to a reference position; determining the position of the adjustment nozzle on the image based on the imaging results while the adjustment nozzle is moved to the reference position; and correcting the reference position based on the difference between a target position determined according to the position of the rotating holding part on the image and the position of the adjustment nozzle on the image.

[0010] The effects of the invention

[0011] According to this disclosure, the position of the ejector nozzle relative to the rotating retainer can be accurately adjusted using the camera image, regardless of the resolution of the camera image. Attached Figure Description

[0012] Figure 1 This is a schematic longitudinal sectional view showing the structure of the resist film forming apparatus as a liquid treatment apparatus according to the first embodiment.

[0013] Figure 2 This is a schematic cross-sectional view showing the structure of the resist film forming apparatus as a liquid treatment apparatus according to the first embodiment.

[0014] Figure 3 This is a top view of the rotating chuck.

[0015] Figure 4 This is a flowchart illustrating an example of the aforementioned position adjustment process.

[0016] Figure 5 This is a diagram showing an example of an image used for the aforementioned position adjustment process.

[0017] Figure 6 This is a diagram showing an example of an image used for the aforementioned position adjustment process.

[0018] Figure 7 This is a side view showing an example of a fixture nozzle.

[0019] Figure 8 This is a diagram illustrating the method for determining the position of the adjustment nozzle on the photographic image according to the third embodiment.

[0020] Figure 9 This is a diagram illustrating the method for adjusting the position of the ejector nozzle in Embodiment 2. Detailed Implementation

[0021] In the manufacturing process of semiconductor devices, etc., the following processes are performed sequentially: resist coating process, in which a resist is applied to a semiconductor wafer (hereinafter referred to as "wafer") to form a resist film; exposure process, in which the resist film is exposed; and development process, in which the exposed resist film is developed, thereby forming a resist pattern on the wafer. These processes are performed using a coating and development process system equipped with various processing devices and wafer transport devices.

[0022] In this coating and developing system, the liquid treatment apparatus of the aforementioned processing device, which uses processing liquids such as resist and developer to process the wafer, includes a rotary chuck that holds and rotates the wafer and an ejection nozzle that ejects the processing liquid onto the wafer held in the rotary chuck. In this liquid treatment apparatus, for example, the processing liquid is ejected from the ejection nozzle toward the center of the wafer held in the rotary chuck, and the rotary chuck is rotated, thereby performing a spin coating process that diffuses the processing liquid throughout the entire wafer.

[0023] During spin coating, for example, it is necessary to precisely adjust the position of the nozzle when spraying the coating solution relative to the center of the rotating chuck, which corresponds to the center of the wafer. This is because uneven coating of the coating solution relative to the wafer can occur.

[0024] Regarding this, Patent Document 1 discloses a method for adjusting the position of the ejector nozzle as follows. In the position adjustment method disclosed in Patent Document 1, the ejector nozzle is moved above the center of a rotating chuck in a state where the wafer is not held. Then, an image is captured of the center of the rotating chuck and the tip of the ejector nozzle using an imaging unit. Then, in the captured image, the position of the ejector nozzle is adjusted so that the horizontal position of the center of the tip of the ejector nozzle is aligned with the horizontal position of the center of the rotating chuck.

[0025] However, in the method disclosed in Patent Document 1, there is room for improvement in the accurate position adjustment of the ejector nozzle relative to the rotating chuck when the image captured by the camera unit is of low resolution.

[0026] Therefore, with respect to the technology of this disclosure, the position of the ejector nozzle relative to the rotary chuck is accurately adjusted using the camera image, regardless of the resolution of the camera image.

[0027] Hereinafter, the nozzle position adjustment method and liquid treatment apparatus of this embodiment will be described with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, elements having substantially the same functional structure are labeled with the same reference numerals, and repeated descriptions are omitted.

[0028] (First Embodiment)

[0029] Figure 1 and Figure 2 These are schematic longitudinal and transverse sectional views showing the structure of the resist film forming apparatus 1, which is a liquid treatment apparatus according to the first embodiment. Figure 3 This is a top view of the rotary chuck, which will be described later.

[0030] like Figure 1As shown, the resist forming apparatus 1 has a processing container 10 capable of sealing its interior. An inlet / outlet (not shown) for a wafer W serving as a substrate is formed on the side of the processing container 10.

[0031] A rotary chuck 20, serving as a rotation holding part, is provided within the processing container 10 to hold the wafer W and rotate it about a vertical axis. This rotary chuck 20 has a horizontal upper surface. For example, as... Figure 3 As shown, a suction port 20a for suctioning the wafer W is provided on the upper surface of the rotary chuck 20. The wafer W can be held on the rotary chuck 20 by suction from this suction port 20a. Furthermore, annular protrusions 20b and arcuate protrusions 20c are formed on the upper surface of the rotary chuck 20. These protrusions form a gas flow path to the suction port 20a between the upper surface and the back surface (lower surface) of the wafer W, thereby utilizing the entire upper surface to hold the wafer W. The annular protrusion 20b is formed in annular shape centered on the central axis of the upper surface of the rotary chuck 20 when viewed from above, and the arcuate protrusion 20c is formed in arcuate shape centered on the central axis of the upper surface of the rotary chuck 20 when viewed from above.

[0032] like Figure 1 As shown, the rotary chuck 20 can rotate at a desired speed using a chuck drive unit 21 equipped with an actuator such as a motor. Furthermore, the chuck drive unit 21 is provided with a lifting drive mechanism (not shown), such as a cylinder, to allow the rotary chuck 20 to be raised and lowered freely. The chuck drive unit 21 is controlled by the control unit 100, which will be described later.

[0033] Furthermore, within the processing container 10, a cup 22 is provided relative to the rotating chuck 20 in a manner that surrounds the wafer W held in the rotating chuck 20. The cup 22 receives and recovers liquids that spill or fall from the wafer W.

[0034] like Figure 2 As shown, in the negative X direction of cup 22 ( Figure 2 On the lower side, a shape is formed along the Y direction ( Figure 2 The guide rail 30 extends in the left-right direction. For example, the guide rail 30 extends from the negative Y direction of the cup 22 (…). Figure 2 The outer side of the left direction forms to the positive direction of the Y direction. Figure 2 (To the right) on the outer side. An arm 31 is provided on the guide rail 30.

[0035] A nozzle 32 for ejecting resist as a processing fluid is supported at the top end of the arm 31. Multiple nozzles 32 may be provided, for example, arranged in the direction (Y direction) in which the guide rail 30 extends. The arm 31 is movable along the guide rail 30 via a nozzle drive unit 33 connected to its base end. Thus, the nozzle 32 can be moved from a standby unit 34 located outside the positive Y direction side of the cup 22 to above the center of the wafer W within the cup 22. Furthermore, the arm 31 is freely raised and lowered via the nozzle drive unit 33, allowing adjustment of the height of the nozzle 32. The nozzle 32 is connected to a resist supply device M for supplying resist. The nozzle drive unit 33 is controlled by a control unit 100, described later.

[0036] Furthermore, a camera 40, serving as an imaging unit, is provided inside the processing container 10. The camera 40 is provided to monitor the entire processing container 10, particularly the entire surface of the wafer W during resist film formation. In this embodiment, the camera 40 is also used for adjusting the position of the ejection nozzle 32. The camera 40 is configured to include the following (a) to (c) within its imaging area.

[0037] (a) The entire surface (upper surface) of the wafer W held in the rotating chuck 20;

[0038] (b) The entire upper surface of the rotating chuck 20 in a state where the wafer W is not held;

[0039] (c) The top side of the ejection nozzle 32 is moved to the reference position.

[0040] The camera 40 is fixed to the top wall of the processing container 10 in a manner that does not obstruct the feeding and ejection of the wafer W and the movement of the ejection nozzle 32, for example by means of a fixing member (not shown). For example, a CCD camera can be used for the camera 40.

[0041] Furthermore, a light source 50 is provided inside the processing container 10. The light source 50 illuminates the imaging area of ​​the camera 40 with light (visible light in this example). The light source 50 is fixed to the top wall of the processing container 10 in a manner that does not obstruct the feeding and ejection of the wafer W and the movement of the ejection nozzle 32, for example by means of a fixing member (not shown).

[0042] The camera 40 and the light source 50 are controlled by the control unit 100, which will be described later. In addition, the imaging results of the camera 40 are output to the control unit 100.

[0043] The resist film forming apparatus 1 configured as described above includes a control unit 100. The control unit 100 is, for example, a computer equipped with a CPU, memory, etc., and has a program storage unit (not shown). The program storage unit also stores programs for controlling the nozzle drive unit 33 and the like to implement the resist film forming process described later. Furthermore, the program storage unit stores programs for implementing the position adjustment process of the ejection nozzle 32 described later. Alternatively, the aforementioned programs can be stored on a storage medium readable by a computer and loaded from that storage medium into the control unit 100. Part or all of the program can also be implemented using dedicated hardware (circuit board).

[0044] Here, an example of the resist film formation process of the resist film forming apparatus 1 will be described.

[0045] First, the control unit 100 loads and attaches the wafer W, which is fed into the processing container 10, onto the rotary chuck 20.

[0046] Next, the control unit 100 moves the ejection nozzle 32 towards the processing position for ejection (e.g., above the center of the wafer W). The processing position is determined based on a reference position corrected during the position adjustment process of the ejection nozzle 32. Then, the wafer W is rotated by rotating the rotary chuck 20, and during this rotation, resist is continuously ejected from the ejection nozzle 32 onto the wafer W. The ejected resist diffuses across the entire surface of the wafer W due to its rotation.

[0047] Subsequently, the control unit 100 stops the spraying of the resist and retracts the spray nozzle 32 towards the standby unit 34. Furthermore, the control unit 100 continues to rotate the rotary chuck 20, causing the wafer W to continue rotating, thus drying the resist on the wafer W. As a result, a resist film is formed on the wafer W.

[0048] The wafer W with the resist film formed is then sent out from the processing container 10. This completes a series of resist film formation processes.

[0049] Next, the position adjustment process of the ejection nozzle 32 of the anti-corrosion film forming apparatus 1 will be explained. Figure 4 This is a flowchart illustrating an example of the aforementioned position adjustment process. Figure 5 and Figure 6 This is an example diagram showing an image used for the aforementioned position adjustment process. Additionally, in Figure 5 and Figure 6 Only the main parts of each image are shown in the image.

[0050] (Video recording of the camera area, including the rotating chuck 20)

[0051] When adjusting the position of the nozzle 32, firstly, as follows: Figure 4As shown, the control unit 100 controls the chuck drive unit 21, the camera 40, and the light source 50, rotating the rotating chuck 20 without holding the wafer W, while simultaneously taking multiple (e.g., 60) images using the camera 40, which includes the entire upper surface of the rotating chuck 20 within the imaging area (step S1). The rotational speed of the rotating chuck 20 and the number of images taken per second by the camera 40 are adjusted so that the multiple images obtained from this imaging include images of the rotating chuck 20 with different orientations. Meanwhile, the ejector nozzle 32 is in the standby position of the standby unit 34 at this time.

[0052] (Acquisition of composite images)

[0053] Next, the control unit 100 synthesizes the multiple images captured by the camera 40 and acquires a composite image (step S2). This composite image includes the trajectory depicted by the contour of the characteristic shape of the upper surface of the rotating chuck 20. Specifically, as... Figure 5 As shown, the composite image Is includes the trajectory C1 drawn by the outline of the suction port 20a during the rotation of the rotating chuck 20, the trajectory C2 drawn by the outline of the arc-shaped protrusion 20c, and the trajectory C3 drawn by the outline of the annular protrusion 20b. Alternatively, the composite image may be obtained by emphasizing the trajectories drawn by the outlines of the suction port 20a, etc., during the acquisition of the composite image, and then composited after such emphasis processing.

[0054] (Determining the position of the rotating chuck 20 on the captured image of the camera 40)

[0055] After acquiring the composite image Is, the control unit 100 uses pattern matching to determine the position Ps of the rotating chuck 20 on the captured image of the camera 40 (step S3). Specifically, the control unit 100 uses pattern matching to detect a region in the composite image Is that includes the trajectory drawn by the outlines of the suction port 20a, the annular protrusion 20b, and the arc-shaped protrusion 20c (hereinafter, sometimes referred to as the "chuck feature region"). Then, the control unit 100 determines the predetermined position of the chuck feature region in the composite image (e.g., the center position of the chuck feature region) as the position Ps of the rotating chuck 20 on the captured image of the camera 40. Additionally, hereafter, "position on the captured image of the camera 40" is sometimes abbreviated to "position on the captured image".

[0056] (The video recording includes the area covered by the nozzle 32 at the reference position)

[0057] Furthermore, the control unit 100 controls the nozzle drive unit 33, camera 40, and light source 50. After moving the ejector nozzle 32 to a reference position above the rotating chuck 20, the camera 40 captures an image within its imaging area, including the ejector nozzle 32 in this state (i.e., the ejector nozzle 32 at the reference position) (step S4). The number of times this process captures an image can be multiple times (e.g., 10 times). Additionally, the imaging area of ​​the camera 40 is the same in steps S2 and S4.

[0058] (Determining the position of the nozzle 32 on the captured image of the camera 40)

[0059] Next, the control unit 100 determines the position Pn of the nozzle 32 at the reference position on the image based on the image captured by the camera 40 when the nozzle 32 is moved to the reference position (step S5). Specifically, the control unit 100, for example, determines the position Pn of the nozzle 32 at the reference position on the image based on the image captured in step S4. Figure 6 In the image In used for determining the position of the ejector nozzle 32, pattern matching is used to detect the region including the ejector nozzle 32 (hereinafter, sometimes referred to as the "nozzle region"). Then, the control unit 100 determines the position of the ejector nozzle 32 on the image at a predetermined position (e.g., the center position of the nozzle region) in the image as the position Pn of the ejector nozzle 32 at the reference position.

[0060] Furthermore, in step S4, if the camera 40 takes multiple images within the imaging area, including the nozzle 32 at the reference position, the control unit 100 synthesizes these multiple imaging results and acquires a composite image for the nozzle. Therefore, the control unit 100 can also use this composite image for the nozzle as image In for determining the position of the nozzle 32, and determine the position Pn of the nozzle 32 at the reference position on the imaging image.

[0061] (Correction of reference position)

[0062] Then, the control unit 100 corrects the reference position based on the difference between the target position Pt determined according to the position Ps of the rotating chuck 20 on the camera image and the position Pn of the ejector nozzle 32 at the reference position on the camera image (step S6). That is, the target position Pt is determined by the following formula (1) based on the position Ps of the rotating chuck 20 on the camera image and the ideal relative position relationship Poff between the rotating chuck 20 and the ejector nozzle 32 on the camera image.

[0063] Pt=Ps+Poff…(1)

[0064] The correction amount ΔP of the reference position in step S6 is determined, for example, based on the difference between the target position Pt and the position Pn of the ejector nozzle 32 at the reference position on the camera image (i.e., the offset of the position Pn from the target position) (Pt - Pn). More specifically, the correction amount ΔP of the reference position is determined, for example, based on the following equation (2).

[0065] ΔP=0.8×(Pt-Pn)…(2)

[0066] Then, repeat steps S4 to S6 until the offset (Pt - Pn) becomes below the required value.

[0067] As described above, by correcting the reference position of the ejector nozzle 32, the position of the ejector nozzle 32 relative to the rotary chuck 20 can be adjusted, and the resist can be ejected from the ejector nozzle 32 to the desired position (e.g., the center of the wafer W) held in the rotary chuck 20.

[0068] The ideal relative positional relationship Poff, the pattern matching used for determining the position of the rotating chuck 20, and the pattern matching used for determining the position of the ejection nozzle 32 are, for example, obtained in advance using another device having the same structure as the resist film forming apparatus 1, and stored in a storage unit (not shown). Furthermore, in the following description, for each structure in the other device having the same structure as the resist film forming apparatus 1, the reference numerals used to indicate the same structure as those in the resist film forming apparatus 1 are used. For example, the camera in the other device that is the same as the camera 40 in the resist film forming apparatus 1 is referred to as "camera 40".

[0069] The model used for pattern matching to determine the position of the rotating chuck 20 (hereinafter, sometimes referred to as the "chuck model") is made and obtained, for example, as follows. First, a camera 40 is used in the other device described above to take a picture, similar to step S1, and a composite image is obtained, similar to step S2. Furthermore, for this composite image, the area including the trajectory drawn by the outlines of the suction port 20a, the annular protrusion 20b, and the arcuate protrusion 20c is designated as the area for model making. Then, the chuck model is made based on the image of the designated area in the composite image.

[0070] The model used for pattern matching to determine the position of the nozzle 32 (hereinafter sometimes referred to as the "nozzle model") is made and obtained as follows: First, the position of the nozzle 32 is adjusted in the other device described above using the same method as before. Then, using the camera 40 in the other device described above, an image for determining the position of the nozzle 32 is captured, similar to step S4. Furthermore, for this image, the area including the nozzle 32 is designated as the area for model making. Then, the nozzle model is made based on the image of the designated area in the image for determining the position of the nozzle 32.

[0071] The ideal relative position relationship Poff described above is obtained, for example, as follows. First, using pattern matching of a chuck model manufactured as described above, the position Psref of the rotating chuck 20 in the other device on the camera image is determined based on the composite image used in the manufacture of the chuck model. Furthermore, using pattern matching of a nozzle model manufactured as described above, the position Pnref of the ejector nozzle 32 in the other device on the camera image is determined based on the image used in the manufacture of the nozzle model to determine the position of the ejector nozzle 32. The ideal relative position relationship Poff described above is determined based on the following equation (3).

[0072] Poff = Pnref - Psref…(3).

[0073] As described above, in this embodiment, the control unit 100 rotates the rotary chuck 20 without holding the wafer W while taking multiple images using a camera 40 arranged to include the rotary chuck 20 in the imaging area. Furthermore, the control unit 100 synthesizes the results of these multiple images and acquires a composite image. Then, the control unit 100 determines the position Ps of the rotary chuck 20 on the image from the composite image using pattern matching. As a method for determining the position Ps differently from this embodiment, consider the following method (hereinafter referred to as the "comparison method"): without rotating the rotary chuck 20, take one image using the camera 40; based on this image result, detect features on the upper surface of the rotary chuck 20 (e.g., a portion of the suction port 20a); and determine the position Ps based on this detection result. However, depending on the orientation (rotation angle, i.e., rotation position) of the rotary chuck 20 during imaging, the image result obtained using the camera 40 for determining the position Ps will change. The reasons for this include the machining accuracy of the rotary chuck 20, the mounting orientation of the camera 40, the camera's focusing state, the mounting orientation of the light source 50, and the influence of interfering light. Furthermore, it is difficult to precisely adjust the orientation of the rotary chuck 20 when taking a picture using the chuck drive unit 21. Regarding the fact that the image captured by the camera 40 changes depending on the orientation of the rotary chuck 20, there is no particular problem if the image captured by the camera 40 is high resolution, but the image captured by the camera 40 is low resolution, including the entire upper surface of the rotary chuck 20 in the image area. When the image obtained by the camera 40 for determining the aforementioned position Ps changes depending on the orientation of the rotary chuck 20 during image capture, if the image captured by the camera 40 is low resolution, the aforementioned position Ps cannot be accurately determined in the comparison method. Furthermore, in the comparison method, the camera 40 takes a picture of the rotary chuck 20 only once; therefore, if the image contains noise, it will be affected by that noise.

[0074] In contrast, in this embodiment, the composite image used to determine the position Ps is obtained by combining the results of multiple images taken by the camera 40 while rotating the rotary chuck 20. Therefore, the shape features of the upper surface of the rotary chuck 20 are included in the composite image in a state that is independent of the orientation of the rotary chuck 20 (specifically, the trajectory depicted by the outlines of the suction port 20a, the annular protrusion 20b, and the arcuate protrusion 20c during the rotation of the rotary chuck 20). Furthermore, in this embodiment, pattern matching is used to identify the shape features of the upper surface of the rotary chuck 20 in its state of being independent of the orientation of the rotary chuck 20 from the composite image, and the position Ps of the rotary chuck 20 on the captured image is determined from the identification result. Therefore, even if the captured image from the camera 40 is low resolution, the position Ps of the rotary chuck 20 on the captured image can be accurately determined.

[0075] Furthermore, in the comparison method described above, the camera 40 takes one image of the rotating chuck 20. Therefore, if the image contains noise, it will be affected by that noise. In contrast, in this embodiment, the position Ps of the rotating chuck 20 on the image is determined based on a composite image obtained by combining the results of multiple images taken by the camera 40. Therefore, this determination is not affected by the aforementioned noise.

[0076] Furthermore, in this embodiment, the control unit 100 corrects the reference position of the ejector nozzle 32 based on the difference between the target position Pt determined according to the position Ps of the rotating chuck 20 on the camera image as accurately determined as described above and the position Pn of the ejector nozzle 32 on the camera image. Therefore, even when using a low-resolution camera image, the position of the ejector nozzle 32 relative to the rotating chuck 20 can be accurately adjusted.

[0077] Furthermore, according to this embodiment, the position of the ejector nozzle 32 relative to the rotary chuck 20 can be automatically adjusted solely through the control and calculation processing of the control unit 100.

[0078] In this embodiment, as described above, the control unit 100 may also take multiple images using a camera 40 that includes the ejector nozzle 32 at the reference position within the imaging area. Then, it may synthesize these multiple imaging results to obtain a composite image of the nozzle. Based on this composite image, the position Pn of the ejector nozzle 32 at the reference position on the imaging image is determined. In this case, the position Pn can be accurately determined regardless of the presence or absence of noise in the imaging image from the camera 40, resulting in accurate adjustment of the position of the ejector nozzle 32.

[0079] Alternatively, when determining the position Ps of the rotating chuck 20 on the camera image using pattern matching in step S3, the position Ps can be determined using sub-pixel units. For example, by performing sub-pixel processing while simultaneously performing pattern matching, the position Ps of the rotating chuck 20 on the camera image can be determined using sub-pixel units. By determining the position Ps of the rotating chuck 20 on the camera image using sub-pixel units in this way, the position Ps of the rotating chuck 20 can be determined with high precision, resulting in a more accurate adjustment of the position of the ejector nozzle 32 relative to the rotating chuck 20.

[0080] Alternatively, when determining the position Pn of the ejector nozzle 32 on the camera image in step S5, the position Pn can be determined using sub-pixel units. For example, sub-pixel processing can be performed during pattern matching to determine the position Pn, thereby enabling the position Pn of the ejector nozzle 32 on the camera image to be determined using sub-pixel units. By determining the position Pn using sub-pixel units in this way, the position Pn of the ejector nozzle 32 on the camera image can be determined with high precision, resulting in a more accurate adjustment of the position of the ejector nozzle 32 relative to the rotating chuck 20.

[0081] Alternatively, in step S3, the control unit 100 determines the tilt angle θ of the camera 40 relative to the rotating chuck 20 (in other words, the tilt angle of the rotating chuck 20 within the captured image) based on the pattern matching result of the rotating chuck 20. Then, based on the determined tilt angle θ, in steps S3 and S4, after correcting the captured image, the positions Ps and Pn can be determined in a manner that makes the tilt angle of the rotating chuck 20 within the captured image approximately equal to the tilt angle when obtaining the ideal relative position relationship Poff. This allows for more accurate adjustment of the position of the ejector nozzle 32 relative to the rotating chuck 20.

[0082] (Second Implementation)

[0083] In the first embodiment, an actual ejector nozzle 32 is used to adjust the position of the ejector nozzle 32. Alternatively, as in this embodiment, a fixture nozzle different from the ejector nozzle 32 may be installed and used to adjust the position of the ejector nozzle 32. That is, in the first embodiment, an actual ejector nozzle 32 is used as an adjustment nozzle for adjusting the position of the ejector nozzle 32, but it is also possible, as in this embodiment, to install and use a fixture nozzle different from the ejector nozzle 32. For example, the fixture nozzle is installed on the arm 31 in place of the ejector nozzle 32 during the position adjustment of the ejector nozzle 32, and after the position adjustment, the fixture nozzle is removed and the ejector nozzle 32 is installed.

[0084] Figure 7 This is a side view showing an example of a fixture nozzle.

[0085] Figure 7 The fixture nozzle 200, like the ejection nozzle 32, is mounted on the arm 31 in a vertically extending manner. The mounting portion 201 on the base end side of the fixture nozzle 200 is mounted on the arm 31 (see reference). Figure 2 The fixture nozzle 200 also includes a nozzle-shaped portion 202 extending downward toward the mounting portion 201.

[0086] For purposes such as monitoring the height of the liquid level at the tip of the ejection nozzle 32, the ejection nozzle 32 may be formed using a material that is transparent or translucent relative to visible light. In this case, the fixture nozzle 200 is formed using a material whose transparency is at least lower than that of the ejection nozzle 32; specifically, it is formed using a material that is opaque relative to visible light.

[0087] By using a fixture nozzle 200 with low transparency as the adjustment nozzle, the contrast of the portion of the adjustment nozzle in the image used to determine the position of the adjustment nozzle can be increased. Therefore, the position of the adjustment nozzle on the captured image can be determined with high precision, resulting in more accurate adjustment of the position of the adjustment nozzle relative to the rotary chuck 20.

[0088] Furthermore, the rigidity of the mounting portion 201 is higher than that of the ejector nozzle 32. The rigidity of the mounting portion of the ejector nozzle 32 relative to the arm 31, i.e., its base end side, is relatively low. Therefore, it is sometimes impossible to mount it at the desired angle relative to the arm 31. If the reference position is corrected using an ejector nozzle 32 that is not mounted at the desired angle, proper results may not be obtained. In contrast, the mounting portion of the jig nozzle 200 has higher rigidity, and therefore, it can be mounted more reliably at the desired angle relative to the arm 31 (e.g., the angle at which the jig nozzle 200 extends in the vertical direction). Therefore, by using this jig nozzle 200 as an adjustment nozzle to correct the reference position, proper results can be obtained.

[0089] In particular, since there are multiple ejector nozzles 32, when using one of them as an adjustment nozzle to correct the reference position, the reference position cannot be properly corrected if that ejector nozzle 32 is not installed at the desired angle relative to the arm 31. The processing position of the ejector nozzles 32 other than the one used as an adjustment nozzle is also determined based on the aforementioned reference position; therefore, they will be affected by the ejector nozzle 32 used as an adjustment nozzle and deviate from the appropriate position. This problem can be avoided by using a jig nozzle 200 whose rigidity relative to the mounting portion 201 on the base end side of the arm 31 is higher than that of the ejector nozzle 32.

[0090] (Third Implementation)

[0091] Figure 8This is a diagram illustrating the method for determining the position of the adjustment nozzle on the photographic image according to the third embodiment.

[0092] like Figure 8 As shown, sometimes another camera 301 and another light source 302 are provided on the arm 300 supporting the nozzle 32. The camera 301 only includes the top side of the nozzle 32 in the imaging area. The light source 302 illuminates the imaging area of ​​the camera 301 with light (e.g., infrared light), illuminating the imaging area of ​​the camera 301 including the nozzle 32. As described above, the camera 301 and the light source 302 are provided on the arm 300 supporting the nozzle 32, and therefore can move together with the nozzle 32.

[0093] Sometimes, the light source 302 is positioned so that when the adjusting nozzle (ejector nozzle 32 or fixture nozzle 200 installed instead) is moved to the reference position, it originates from the light source 50 (see reference). Figure 1 and Figure 2 The position where the light from the light source 50 is blocked by the light source 302. In this case, the adjustment nozzle at the reference position may appear darker when captured by the camera 40. Therefore, in the above-described case, when capturing the adjustment nozzle at the reference position using the camera 40, both the light source 50 and the light source 302 can be illuminated. 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 in the image used for determining the position of the adjustment nozzle can be increased, and the position of the adjustment nozzle on the captured image can be determined with high accuracy.

[0094] (Refer to Implementation Method 1)

[0095] In the above embodiments, while rotating the chuck 20 in a state where the wafer W is not held, multiple images are taken using a camera 40 that is configured to include the chuck 20 in the imaging area, and the multiple imaging results are combined to obtain a composite image for determining the position Ps of the chuck 20 on the imaging image.

[0096] In contrast, in this embodiment, while the patterned wafer W is held in the rotating chuck 20, the rotating chuck 20 is rotated while multiple images are captured using a camera. These multiple images are then combined to obtain a composite image. In this embodiment, pattern matching is used to determine the position Ps of the rotating chuck 20 on the captured image from the composite image. Specifically, in the composite image, pattern matching is used to detect the region including the trajectory traced by the outline of the pattern on the wafer W during the rotation of the rotating chuck 20, and the predetermined position of this region is determined as the position Ps of the rotating chuck 20 on the captured image.

[0097] Alternatively, the position Pw of the wafer W held in the rotating chuck 20 on the camera image can be determined instead of the position Ps of the rotating chuck 20 on the camera image. In this case, the reference position of the ejector nozzle 32 is corrected based on the difference between the target position Pt determined according to the position Pw of the wafer W held in the rotating chuck 20 on the camera image and the position Pn of the ejector nozzle 32 on the camera image.

[0098] In addition, in this embodiment, the camera 40 is configured to include the entire surface (upper surface) of the wafer W held in the rotating chuck 20 in its imaging area.

[0099] (Refer to Implementation Method 2)

[0100] Figure 9 This is a diagram illustrating the method for adjusting the position of the ejector nozzle in Embodiment 2.

[0101] In the first and second embodiments, the adjustment nozzle is moved to a reference position, and an image is captured by the camera 40 in this state. Based on the image capture result, the position of the adjustment nozzle on the image is determined. Then, the reference position of the ejection nozzle 32 is corrected based on the difference between the target position Pt determined according to the position Ps of the rotating chuck 20 on the image and the position Pn of the adjustment nozzle on the image.

[0102] In contrast, in this embodiment, such as Figure 9 As shown, a target mark 401 is formed on the arm 400 supporting the ejector nozzle 32. When adjusting the position of the ejector nozzle 32, the ejector nozzle 32 is moved to a reference position, and an image is captured by the camera 40 in this state. Based on the image capture result, the position Pm of the target mark 401 on the captured image is determined. For example, pattern matching is used to determine the position Pm. Then, in this embodiment, the reference position of the ejector nozzle 32 is corrected based on the difference between the target position Pt' determined according to the position Ps of the rotating chuck 20 on the captured image and the position Pm of the target mark 401 on the captured image.

[0103] In the image used to determine the position Pm of the target mark 401 on the camera image, the contrast of the portion of the target mark 401 is higher than that of the portion of the nozzle 32. Therefore, the position Pm of the target mark 401 on the camera image can be determined with high precision. As a result, the position of the nozzle 32 relative to the rotary chuck 20 can be adjusted more accurately.

[0104] In addition, in this embodiment, the camera 40 is configured to include a target mark 401 in the imaging area of ​​the camera 40 when the ejection nozzle 32 is moved to a reference position.

[0105] The position of the nozzle 32 for spraying the resist solution has been adjusted as described above. However, the nozzle 32 to be adjusted is not limited to this. For example, it could also be a nozzle for spraying the developer solution.

[0106] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The above embodiments may also be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

Claims

1. A method of adjusting a position of a nozzle, which is a method of adjusting a position of a nozzle in a liquid processing apparatus that processes a substrate using a processing liquid sprayed from a spray nozzle, wherein the method of adjusting a position of a nozzle includes the following steps of: rotating a rotation holding portion that holds and rotates a substrate in a state where the substrate is not held, while performing imaging a plurality of times using an imaging portion that is disposed so as to include the rotation holding portion in an imaging region; synthesizing the results of the plurality of times of imaging and acquiring a synthesized image; determining a position of the rotation holding portion on an imaged image from the synthesized image using pattern matching; performing imaging using the imaging portion in a state where an adjustment nozzle is moved to a reference position; determining a position of the adjustment nozzle on an imaged image from a result of imaging in a state where the adjustment nozzle is moved to the reference position; and correcting the reference position based on a difference between a target position determined from the position of the rotation holding portion on the imaged image and the position of the adjustment nozzle on the imaged image.

2. The method of adjusting a position of a nozzle according to claim 1, wherein the step of performing imaging using the imaging portion in a state where the adjustment nozzle is moved to the reference position performs imaging a plurality of times using the imaging portion, and the step of determining a position of the adjustment nozzle on an imaged image is performed based on a synthesized image obtained by synthesizing results of the plurality of times of imaging performed using the imaging portion in a state where the adjustment nozzle is moved to the reference position.

3. The method of adjusting a position of a nozzle according to claim 1 or 2, wherein the adjustment nozzle is a jig nozzle that is installed in place of the spray nozzle used in actual processing at the time of position adjustment, and has lower transparency than the spray nozzle used in the actual processing.

4. The method of adjusting a position of a nozzle according to claim 3, wherein a rigidity of a mounting portion of the adjustment nozzle is higher than that of the spray nozzle.

5. The method of adjusting a position of a nozzle according to claim 1, wherein the step of determining a position of the adjustment nozzle on an imaged image determines the position of the adjustment nozzle on the imaged image using a sub-pixel unit.

6. The method of adjusting a position of a nozzle according to claim 1, wherein the step of determining a position of the rotation holding portion on an imaged image determines the position of the rotation holding portion on the imaged image using a sub-pixel unit.

7. A liquid processing apparatus that processes a substrate using a processing liquid, wherein the liquid processing apparatus includes: a rotation holding portion that holds and rotates a substrate; an adjustment nozzle that is used for position adjustment of a spray nozzle that sprays the processing liquid toward a substrate held by the rotation holding portion; a rotation mechanism that rotates the rotation holding portion; a moving mechanism that moves the adjustment nozzle; an imaging portion that is disposed so as to include the rotation holding portion and the adjustment nozzle moved to a reference position in an imaging region; and a control portion, the control portion performs the following control: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ rotating the rotation holding portion in a state where the substrate is not held, and performing imaging by the imaging section a plurality of times; synthesizing the plurality of imaging results and acquiring a synthesized image; determining a position of the rotation holding portion on an imaging image from the synthesized image using pattern matching; performing imaging by the imaging section in a state where the adjustment nozzle is moved to the reference position; determining a position of the adjustment nozzle on an imaging image from an imaging result in a state where the adjustment nozzle is moved to the reference position; and correcting the reference position based on a difference between a target position determined from the position of the rotation holding portion on the imaging image and the position of the adjustment nozzle on the imaging image.

Images