Liquid processing apparatus

Abstract

The utility model relates to a liquid treatment device. The state of a plurality of nozzles is monitored in a suitable manner according to the situation. The liquid processing apparatus includes: a plurality of stages on which substrates are placed; a plurality of nozzles which are shared by the plurality of stages and are used for supplying a processing liquid to the substrate; a camera commonly used for the plurality of nozzles and used for monitoring the states of the plurality of nozzles; and an imaging condition changing unit that changes the imaging condition of the camera in accordance with the monitoring condition.

Description

Technical Field

[0001] The utility model relates to a liquid processing device. Background Art

[0002] When manufacturing semiconductor devices, a liquid processing apparatus includes a nozzle that discharges a processing liquid such as a resist onto a semiconductor wafer (hereinafter referred to as a wafer) to form a resist film on the wafer. For example, Patent Document 1 discloses using a CCD camera to monitor the discharge state of a photoresist liquid from a processing liquid supply nozzle onto a substrate and detect abnormalities in the discharge state.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-318079 Utility Model Content

[0006] Problems to be solved by utility models

[0007] The utility model provides a technology capable of monitoring the states of a plurality of nozzles in an appropriate manner according to the situation.

[0008] Solutions for solving problems

[0009] The liquid processing device of the present invention comprises: a plurality of stages, each of which carries a substrate; a plurality of nozzles, which are shared by the plurality of stages and are used to supply processing liquid to the substrate; a camera, which is shared by the plurality of nozzles and is used to monitor the status of the plurality of nozzles; and a shooting condition changing unit, which changes the shooting conditions of the camera according to the monitoring conditions.

[0010] Alternatively, the liquid processing device includes: a movable body provided with the plurality of nozzles, which moves relative to each stage in order to supply the processing liquid to the substrate on each stage; an illumination unit provided on the movable body, which irradiates light in a direction different from the direction toward each nozzle; and a reflecting member, whose relative position relative to the stage is fixed, which reflects the irradiated light from the illumination unit and irradiates it toward each nozzle.

[0011] The reflecting member may reflect the irradiation light from the illuminating unit toward the substrate on the stage, and the light reflected by the substrate may be irradiated toward each of the nozzles.

[0012] Alternatively, the reflective member may be provided for each of the stages.

[0013] The camera may include a liquid lens configured to bring the plurality of nozzles within an imaging range of the camera, and the imaging condition changing unit may monitor the states of the plurality of nozzles by changing a focus according to a nozzle to be monitored.

[0014] By changing the focus, monitoring of a discharge state of the processing liquid from one of the nozzles and monitoring of a state different from the discharge state with respect to the other nozzles may be performed alternately.

[0015] Alternatively, the liquid processing device may be provided with an arm having the plurality of nozzles, and may move relative to each stage in order to supply the processing liquid to the substrate on each stage, and the camera may be provided on the arm in such a manner that the optical axis is oriented in a direction different from the extension direction of the arm when viewed from above.

[0016] Effect of utility model

[0017] According to the present invention, the states of a plurality of nozzles can be monitored in an appropriate manner according to the situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a plan view showing a liquid processing apparatus according to an embodiment.

[0019] Figure 2 It is a longitudinal sectional side view showing the liquid processing device.

[0020] Figure 3 It is a longitudinal sectional side view showing the liquid processing device.

[0021] Figure 4 It is a plan view showing a state where the diluent nozzle has moved to the discharge position.

[0022] Figure 5 It is a plan view showing a state where the resist nozzle has moved to the ejection position.

[0023] Figure 6 It is an explanatory diagram schematically showing a focusing state.

[0024] Figure 7 It is an explanatory diagram schematically showing a focusing state.

[0025] Figure 8 The image is focused on the diluent nozzle.

[0026] Figure 9 is an image focused on the resist nozzle.

[0027] Figure 10 This is a flowchart showing the operation of the liquid processing apparatus.

[0028] Figure 11 This is a graph showing the ratio of the focus time of the nozzles that do not discharge the processing liquid.

[0029] Figure 12 It is a top view showing a liquid processing apparatus according to a first modification.

[0030] Figure 13 It is a top view showing a liquid processing apparatus according to a second modified example.

[0031] Figure 14 It is a top view showing a liquid processing apparatus according to a third modified example.

[0032] Description of Reference Numerals

[0033] 11r, resist nozzle; 11t, diluent nozzle; 25A, 25B, rotating holding plate; 31, camera; 6, control unit; W, wafer. DETAILED DESCRIPTION

[0034] Figure 1 This is a top view of a resist coating apparatus, one embodiment of a liquid processing apparatus according to the present invention, showing a nozzle 11, described later, specifically a resist nozzle 11r, positioned at a discharge position, described later. In this embodiment, an XYZ orthogonal coordinate system is used for explanation. The resist coating apparatus includes processing sections 21A and 21B, which serve as locations for performing various processes on wafers W. Figure 2 is a longitudinal sectional side view of the treatment portion 21A along the Y direction, Figure 3 This is a longitudinal cross-sectional side view of the processing unit 21A along the X direction. Hereinafter, the X direction may be referred to as the lateral direction, and the Y direction may be referred to as the front-back direction. Furthermore, the side where the processing liquid supply mechanism 10 including the nozzle 11 is located may be referred to as the front, and the side where the processing units 21A and 21B are located on the opposite side may be referred to as the rear.

[0035] The resist coating apparatus includes a processing liquid supply mechanism 10 that supplies a diluent and a resist as processing liquid to a wafer W to form a resist film on the wafer W. The diluent is supplied to the wafer W before the resist is supplied, and is a processing liquid for processing (pre-wetting) to improve the wettability of the wafer W surface with respect to the resist.

[0036] Furthermore, the diluent is also used in EBR (Edge Bead Removal). In this EBR, the diluent is sprayed toward the periphery of the wafer W after the resist film is formed, thereby removing unwanted portions of the resist film in a circular pattern. The diluent for EBR is supplied from EBR mechanisms 4A and 4B, which are independently provided from the processing liquid supply mechanism 10. Thus, in the resist coating apparatus 1, the wafers W are processed in the processing sections 21A and 21B in the order of pre-wetting, resist coating, and EBR.

[0037] The processing liquid supply mechanism 10 for performing pre-wetting and resist coating is commonly used by the processing units 21A and 21B. In addition, the resist coating device is provided with a camera 31 for photographing the nozzle 11, a plurality of lighting units, and a reflecting member 34 for reflecting the irradiation light from a part of the plurality of lighting units, so that the control unit 6 described later can monitor the status of each nozzle 11 constituting the processing liquid supply mechanism 10. The plurality of lighting units and the reflecting member 34 illuminate the nozzle 11 and its surroundings, that is, the photographing area of ​​the camera 31. In addition, as described in detail later, the irradiation of light from each lighting unit to the nozzle 11 is performed with the aid of the surface of the wafer W. That is, the irradiation light from the lighting unit is reflected on the surface of the wafer W and irradiates the nozzle 11. The above-mentioned reflecting member 34 reflects the light from the lighting unit toward the wafer W.

[0038] The processing units 21A and 21B are described below. The processing units 21A and 21B are arranged side by side along the X direction and are sometimes collectively referred to as the processing unit 21. The processing units 21A and 21B have the same structure, so the processing unit 21A will be described as a representative.

[0039] like Figure 2 As shown, the processing portion 21A includes a cup 22A that is open at the top and accommodates the wafer W in a holding area therein. Figure 2 Reference numeral 23A in the figure is a drain port provided in the cup 22A, and reference numeral 24A is an exhaust port for exhausting the inside of the cup 22A during the processing of the wafer W. A rotating holding disk 25A serving as a stage for placing the wafer W is provided in the cup 22A. The rotating holding disk 25A adsorbs the central portion of the back side of the wafer W to keep the wafer W horizontal. The lower side of the rotating holding disk 25A is connected to a rotating drive unit 26. The rotating holding disk 25A rotates around the vertical axis (Z axis) together with the wafer W held therein by the rotating drive unit 26. Three pins (in Figure 2 Only two are shown in the figure) 28, which transfers the wafer W between a transport mechanism (not shown) for transporting the wafer W and the rotating holding plate 25A.

[0040] A reflective member 34A and an EBR mechanism 4A for performing EBR are provided in the processing section 21A. The EBR mechanism 4A is arranged in the area to the left of the cup 22A. In addition, the EBR mechanism 4A includes a guide 41, a moving portion 42, an arm 43, a peripheral nozzle 44A, and a cup-shaped standby portion 45A. The moving portion 42 moves linearly in the left and right directions (X direction) along the guide 41 on the front side of the cup 22A. In addition, an arm 43 that can be raised and lowered extends rearward from the moving portion 42, and a peripheral nozzle 44A is provided at the rear end of the arm 43.

[0041] The peripheral nozzle 44A is connected to a diluent supply mechanism (not shown) via piping. The diluent supply mechanism supplies diluent to the peripheral nozzle 44A, which has moved to a predetermined discharge position within the cup 22A, and discharges the diluent downward. This diluent is discharged toward the peripheral edge of the wafer W, which is rotated by the rotating holding disk 25A, thereby performing EBR.

[0042] The standby portion 45A is provided outside the cup 22A, and is located to the left of the center of the front and rear of the cup 22A. The peripheral nozzle 44A is moved between a standby position and a discharge position within the standby portion 45A by the moving portion 42. When not in use, the peripheral nozzle 44A is on standby at the aforementioned standby position. The standby portion 45A is configured to store and discharge diluent therein, and the stored diluent can be used to clean the peripheral nozzle 44A while on standby at any time.

[0043] like Figure 1 、 Figure 2 As shown, the reflective member 34A is arranged between the cup 22A and the EBR standby part 45A. The reflective member 34A is a vertical plate with two main surfaces facing the X direction when viewed from above. The main surface on the right side (the side facing the cup 22A) of the two main surfaces constitutes the reflective surface 35A. The reflective surface 35A is located above the cup 22A and can be horizontally opposite to the first lighting unit 32 that can be raised and lowered, which will be described later. The reflective surface 35A is configured to face slightly downward relative to the horizontal direction. As a result, the irradiation light from the first lighting unit 32 can be reflected toward the surface of the wafer W placed on the rotating holding disk 25A. As described above, the reflective surface 35A is located on the opposite side to the side where the EBR standby part 45A is located. Therefore, even if the diluent splashes at the standby part 45A, the diluent can be suppressed from adhering to the reflective surface 35A. Therefore, since the contamination of the reflective surface 35A is prevented, the clarity of the acquired imaging data is ensured.

[0044] As described above, the processing unit 21B is constructed in the same manner as the processing unit 21A. Among the components of the processing unit 21B, components identical to those of the processing unit 21A are indicated by reference numerals having the same numbers as those used in the processing unit 21A. However, the English letters following the numbers are indicated by different English letters between the processing units, and the English letters used as the reference numerals of the processing unit 21B are indicated by B. In addition, for components identical to those of the processing units 21A and 21B, the English letters are omitted and the components are collectively referred to. For example, they are sometimes indicated as the EBR mechanism 4, the processing unit 21, the cup 22, the rotating holding disk 25, the reflecting member 34, the reflecting surface 35, etc.

[0045] Between the processing section 21A and the processing section 21B and in front of them, a standby section 48 for each nozzle 11 constituting the processing liquid supply mechanism 10 is provided. The standby section 48 is arranged in front of the cups 22A and 22B. Figure 1 As shown by the dotted line, the detailed shape of the standby portion 48 is omitted from illustration. The standby portion 48 is configured, for example, as a platform with multiple recessed portions (not shown) open upward. The nozzle 11 is accommodated and waits in the recessed portions. Furthermore, the standby portion 48 is configured to allow the supply and discharge of diluent from the recessed portions. Thus, the diluent is supplied to the outer surface of the nozzle 11 during standby, thereby cleaning it.

[0046] The processing liquid supply mechanism 10 includes a plurality of nozzles 11 and a nozzle transport mechanism 15 . The nozzle transport mechanism 15 is a movable body for transporting the nozzles 11 onto each wafer W placed on each processing unit 21 , and the processing liquid supply mechanism 10 supplies the processing liquid onto the wafer W. The nozzle transport mechanism 15 includes a guide 16 extending left and right in front of the standby unit 48 , and an arm mechanism 17 for positioning the nozzles 11 at a discharge position on each wafer W placed on the rotary holding plate 25 .

[0047] like Figure 1 、 Figure 2 As shown, the arm mechanism 17 includes a base end 18 and an arm 19. The base end 18 includes a lifting mechanism 18a that can move left and right along the guide 16, and a lifting unit 18b that is connected to the lifting mechanism 18a and is raised and lowered. The base end of the lifting unit 18b is located on the left side of the lifting mechanism 18a, and the top end extends rearward. The base end of the arm 19, which extends horizontally, for example linearly, is connected to the top end of the lifting unit 18b so as to rotate freely about a rotation axis extending along the Z axis. In other words, the arm 19 rotates along the horizontal plane with the base end as the center.

[0048] Three nozzles 11 extending downward are installed at the lower part of the top side of the arm 19. Among these nozzles 11, one resist nozzle 11r that sprays resist is arranged at the top side of the arm 19, and two diluent nozzles 11t that spray diluent are arranged at the base side of the arm 19. In this way, the resist nozzle 11r and the diluent nozzle 11t are staggered in the extension direction from the base side to the top side of the arm 19. The two diluent nozzles 11t are arranged in a direction that intersects with the extension direction of the arm 19, specifically, is orthogonal. In addition, any one of the two diluent nozzles 11t is selected for use, and the focusing of the diluent nozzle 11t described later is performed in a manner that focuses on these two diluent nozzles 11t.

[0049] The resist nozzle 11r is connected to a resist supply mechanism 12 equipped with a valve and a pump, and the resist supply mechanism 12 adjusts the amount of resist supplied to the resist nozzle 11r. In other words, the amount of resist ejected from the resist nozzle 11r is adjusted by the resist supply mechanism 12. The diluent nozzle 11t is connected to a diluent supply mechanism 13 equipped with a valve and a pump, and the diluent supply mechanism 13 adjusts the amount of diluent supplied to the diluent nozzle 11t. In other words, the amount of diluent ejected from the diluent nozzle 11t is adjusted by the diluent supply mechanism 13. The resist nozzle 11r and the diluent nozzle 11t described above eject the resist and the diluent downward at the ejection position in the cup 22 on the center portion of the wafer W held on the rotating holding disk 25.

[0050] Figure 1 FIG. 1 shows a state where the resist nozzle 11r has moved to the ejection position of the processing unit 21A. Figure 4 The thinner nozzle 11t is shown as being moved to the ejection position of the processing unit 21A. At this time, the arm 19 is extended toward the right rear. The positional relationship between the arm 19 and the processing unit 21B is shown as follows: Figure 1 、 Figure 4 The positional relationship between the arm 19 and the treatment portion 21A shown is the same.

[0051] The resist coating apparatus 1 includes a camera 31 for monitoring the state of the nozzle 11, a first lighting unit 32, a second lighting unit 33, and the aforementioned reflecting member 34. Figure 1 、 Figure 2As shown, the first lighting unit 32 is provided at the lower portion of the arm 19, closer to the base end than the nozzle 11. As shown by the dot-dash line indicating the optical axis, the first lighting unit 32 irradiates light from the left side of the arm 19 (the left side when facing from the base end side toward the top end side of the arm 19). The first lighting unit 32 is arranged at approximately the same height as the reflecting surface 35A of the reflecting member 34 so that light can be irradiated toward the left rear when each nozzle 11 is in the ejection position. The irradiation light from the first lighting unit 32 along the optical axis is reflected by the reflecting surface 35A and the surface of the wafer W, and illuminates each nozzle 11 from the lower left.

[0052] The second illumination unit 33 is located in front of the right side of the lifting mechanism 18a, positioned higher than the cup 22. As indicated by the dashed line indicating the optical axis, the second illumination unit 33 is positioned to irradiate light slightly downward and rearward. This allows the second illumination unit 33 to illuminate the surface of the wafer W placed on the rotating holding plate 25 from above the cup 22. When viewed from above, the second illumination unit 33 is positioned in front of each nozzle 11 in the ejection position. Light from the second illumination unit 33 directed toward the surface of the wafer W is reflected by the wafer W and illuminates each nozzle 11 from below and in front.

[0053] Next, the camera 31 will be described. The camera 31 is mounted on the arm 19 in a position and orientation such that the resist nozzle 11r and the two thinner nozzles 11t are within its imaging range. More specifically, the camera 31 is supported by a connecting portion 31d, which is provided to protrude from the distal end of the arm 19 toward the distal end of the arm 19. This allows the camera 31 to be positioned in an area extending from the arm 19 when viewed from above, capturing images from the distal end toward the proximal end of the arm 19.

[0054] Figure 5 This is a top view illustrating the camera's optical axis, etc. The optical axes of the light irradiating the nozzles 11 from the reflective member 34A and the second illumination unit 33, respectively, are positioned to the left and right of the optical axis L1 of the camera 31. This means that when the camera 31 images each nozzle 11 and its surroundings, light is irradiated from the left and right of the imaging area, preventing the nozzles 11 from casting shadows. Furthermore, when viewed from above, the orientation of the optical axis L1 of the camera 31 is offset relative to the direction of the straight line L2 representing the extension direction of the arm 19. In other words, when viewed from above, the extension of the optical axis L1 intersects the straight line L2. This is intended to prevent components such as the lifting unit 18b connected to the base end of the arm 19 and the first illumination unit 32 located below the arm 19 from being reflected within the camera 31's imaging range, thereby improving the accuracy of abnormality detection based on the imaging data D1. Furthermore, the optical axis L1 is tilted slightly downward relative to the horizontal plane to bring the lower side of the nozzle 11 within the imaging range.

[0055] As described above, the camera 31 is provided on the arm 19, so the distances between the resist nozzle 11r and the thinner nozzle 11t are different from each other. The camera 31 is configured to be able to change the focal length and focus on the resist nozzle 11r and the thinner nozzle 11t respectively. Figure 3 and schematically showing the focusing situation Figure 6 、 Figure 7 The camera 31 includes a housing 31a, an image sensor 31b housed therein, and a focus-variable lens 31c. The camera 31 is connected to an external power source 30. Light passing through the focus-variable lens 31c forms an image on the image sensor 31b. The image sensor 31b then photoelectrically converts the received light to generate image data D1, which is then transmitted to the control unit 6, described below.

[0056] The focus variable lens 31c is the interface between two liquids 30a and 30b that are sealed in the lens unit 31g and separated from each other. Figure 6 、 Figure 7 As shown, the shape of the interface between the liquids 30a and 30b changes, thereby changing the focal length of the camera 31. That is, the lens unit 31g is configured as a liquid lens. In the figure, reference numeral 31f is an insulating member that insulates the electrodes 31e from each other.

[0057] exist Figure 6 、 Figure 7 In the figure, the solid line indicates the focused nozzles of the resist nozzle 11r and the thinner nozzle 11t, and the dotted line indicates the unfocused nozzles of the resist nozzle 11r and the thinner nozzle 11t. Figure 6 The state focused on the diluent nozzle 11t is described as the first focusing state. Figure 7 The state in which the resist nozzle 11 r is focused in this manner is referred to as a second focused state.

[0058] Furthermore, the camera 31 captures not only the nozzle 11 but also the area surrounding it. Specifically, this area includes the area below the nozzle 11. Therefore, the liquid column P1 of the treatment liquid formed by the focused nozzle 11 and the droplets P2 of the treatment liquid dripping from the nozzle 11 can also be captured in a focused state. These liquid columns P1 and droplets P2 will be described further later.

[0059] The camera 31 constructed as described above alternately focuses on the resist nozzle 11r and the thinner nozzle 11t within the imaging range and repeatedly images them without moving the imaging range. In other words, while the relative positions of the resist nozzle 11r, the thinner nozzle 11t and the camera 31 are fixed, the camera 31 repeatedly switches between the first focus state and the second focus state to acquire the imaging data D1 of each nozzle 11, thereby monitoring these nozzles 11. Figure 4 、 Figure 6 The following shows how each nozzle 11 is monitored when the wafer W is processed using the diluent nozzle 11 t in step S2 described later.

[0060] Figure 8 The camera focuses on the diluent nozzle and takes the picture ( Figure 6 An example of the shooting data of the first focus state of Figure 9 This is the state of focusing on the resist nozzle and photographing ( Figure 7 The example of captured data (in a second focus state) is shown. Switching between the first and second focus states can be performed in, for example, 100 milliseconds or less. Furthermore, the camera 31 is configured with a liquid lens so that the shape of the lens can be instantly changed (i.e., focus adjustment) by applying a voltage. More specifically, compared to a configuration in which focus is adjusted by changing the positional relationship of the components that make up the optical system, focus switching can be performed in an extremely short time, as illustrated.

[0061] Hereinafter, the imaging data obtained by focusing on the resist nozzle 11r and the imaging data obtained by focusing on the thinner nozzle 11t may be simply recorded as imaging data of the resist nozzle 11r and imaging data of the thinner nozzle 11t. In addition, the nozzle 11 that is the imaging object in the imaging data refers to the resist nozzle 11r or the thinner nozzle 11t that is captured relatively clearly by adjusting the focus.

[0062] The resist coating apparatus 1 includes a control unit 6 (see Figure 1 ). The control unit 6 includes a program storage unit, a memory, and an alarm output unit for controlling the operation of each part of the resist coating apparatus 1. The program storage unit stores a program that includes instructions (a set of steps) for causing each part of the apparatus to operate and form a resist film on the wafer W, as described later. The program storage unit is, for example, a storage medium such as a hard disk, an optical disk, a magneto-optical disk, a memory card, or a DVD. Using this program, control signals are output from the control unit 6 to each part of the resist coating apparatus 1, thereby performing the above-mentioned formation of the resist film.

[0063] This program also switches the lighting units used between the processing units 21A and 21B, acquires imaging data D1 from the camera 31, switches the focus of the camera 31, and determines whether the resist nozzle 11r and the thinner nozzle 11t are abnormal based on the imaging data D1. In other words, this program constitutes an imaging condition changing unit that monitors the nozzles 11 and changes the imaging conditions based on the monitored conditions. Furthermore, this program controls response actions such as alarm output in conjunction with this monitoring.

[0064] The monitoring of the nozzle 11 is further described in detail. When one of the resist nozzle 11r and the diluent nozzle 11t moves to the ejection position on the center of the wafer W and ejects the processing liquid (resist or diluent), the other also moves to a position slightly deviated from the ejection position (for convenience of explanation, it is set as a retreat position) (see Figure 1 、 Figure 4 ) The imaging data D1 is acquired when any one of the nozzles 11 is located at the ejection position. At this time, both the resist nozzle 11r and the thinner nozzle 11t are repeatedly imaged by switching the focus.

[0065] The nozzle 11 ejecting the treatment liquid at the ejection position is judged to determine whether the treatment liquid is properly ejected and whether any abnormalities are present based on the image data D1. The ejection of the treatment liquid forms a liquid column P1 beneath the nozzle 11. The proper ejection of the treatment liquid includes determining whether the liquid column P1 is formed at the appropriate time and whether the shape of the liquid column P1 is appropriate (whether it is of appropriate thickness or whether it is skewed).

[0066] For the nozzle 11 in the retreat position, the presence or absence of abnormalities other than the ejection state of the processing liquid is determined based on the imaging data D1. Specifically, for example, the falling (dripping) of the droplets P2 from the nozzle 11 and the amount of diluent used for cleaning the nozzle 11 attached to the outer surface of the nozzle 11 are determined based on the image. In addition, the dripping droplets P2 are the processing liquid and the diluent used for cleaning and attached to the nozzle 11. In addition, for the nozzle 11 in the retreat position, when managing the liquid level position of the processing liquid in the nozzle 11, it is also possible to determine whether the position of the liquid level is within the allowable range based on the imaging data D1.

[0067] Because they are located on the same arm 19, the resist nozzle 11r and the diluent nozzle 11t are positioned close to each other. While one nozzle 11 is in the ejection position, the other nozzle 11 is in the retreat position. However, this retreat position, like the ejection position, is also located above the wafer W. Therefore, if processing liquid or the diluent used for cleaning drips from the nozzle 11 as described above, it could potentially be supplied onto the wafer W, causing an abnormality. Furthermore, if there is an abnormality in the ejection state of the processing liquid from the nozzle 11 at the ejection position, an appropriate amount of processing liquid may not be supplied to the wafer W, or the processing liquid may splash onto the wafer W and become foreign matter. Thus, abnormalities in each nozzle 11 at the ejection position or the retreat position could potentially cause problems in the processing of the wafer W. Therefore, the focus of the camera 31 is repeatedly switched at high speed to repeatedly acquire image data D1 of each nozzle 11 at the ejection position and the retreat position, and abnormality determination is performed based on each image data D1.

[0068] The presence or absence of an abnormality is determined, for example, by pre-storing reference data of the nozzle 11, captured in a normal state, in the memory of the control unit 6, and then comparing this reference data with the acquired captured data D1 using a program. If an abnormality is determined, a predetermined sound or visual alarm is output from the alarm output unit 65.

[0069] Reference Figure 10 The operation of the resist coating apparatus is described in order. First, for example, a wafer W is transported to the processing unit 21A of the processing units 21A and 21B and held by suction on the rotating holding disk 25. The thinner nozzle 11t and the resist nozzle 11r, which are on standby in the standby unit 48, are moved to the ejection position and the retreat position on the wafer W, respectively, and light is irradiated from the first lighting unit 32 and the second lighting unit 33 of the processing unit 21A to illuminate the thinner nozzle 11t and the resist nozzle 11r (step S1). Then, the camera 31 is repeatedly photographed and the focus is repeatedly switched, repeatedly acquiring photographic data D1 of the thinner nozzle 11t and the resist nozzle 11r.

[0070] In parallel with the acquisition of the imaging data D1 of the nozzle 11, diluent is ejected from the diluent nozzle 11t to form a liquid column P1. The presence of any abnormality in the diluent ejection state of the diluent nozzle 11t is determined based on the acquired imaging data. Furthermore, the presence of any abnormality other than the ejection state of the resist nozzle 11r (such as the dripping of liquid droplets P2 or the amount of cleaning diluent adhering to the outer surface of the nozzle) is determined based on the acquired imaging data D1 (step S2).

[0071] The discharge of diluent from the diluent nozzle 11t is stopped, and the acquisition of imaging data D1, focus switching, and determination of abnormalities are temporarily suspended. The diluent supplied to the center of the wafer W is applied to the entire surface by rotating the wafer W, thereby pre-wetting the wafer. Meanwhile, the arm 19 is moved left and right and in a swiveling motion to move the resist nozzle 11r to the discharge position on the wafer W pre-wetted in step S1, and the diluent nozzle 11t is moved to a retracted position (step S3).

[0072] The acquisition of imaging data and the switching of focus are restarted, and imaging data of the diluent nozzle 11t and imaging data D1 of the resist nozzle 11r are repeatedly acquired. In parallel with the acquisition of imaging data of the nozzle 11, resist is ejected from the resist nozzle 11r to form a liquid column P1. For the resist nozzle 11r, based on the acquired imaging data, it is determined whether there is any abnormality in the ejection state of the resist from the resist nozzle 11r. In addition, for the diluent nozzle 11t, based on the acquired imaging data, it is determined whether there is any abnormality other than the ejection state of the diluent (drip of liquid droplets P2, the amount of cleaning diluent adhering to the outer surface of the nozzle) from the diluent nozzle 11t (step S4). Therefore, the abnormality is determined in the same way as in step S2.

[0073] The resist nozzle 11r stops discharging resist, and the acquisition of imaging data D1, focus switching, determination of abnormalities, and irradiation of light from the first and second illumination units 32 and 33 are all stopped. As the wafer W rotates, the resist supplied to the center of the wafer W is applied to the entire surface, forming a resist film. The peripheral nozzle 44 moves from the standby unit 45A to the discharging position, discharging a diluent to perform EBR, and then the wafer W is transported from the processing unit 21A.

[0074] While the wafer W is being processed by the processing unit 21A, the wafer W is transported to the processing unit 21B. When the ejection of the resist in the processing unit 21A is completed, the resist nozzle 11r and the diluent nozzle 11t are moved to the processing unit 21B, and the wafer W is processed in the same order as the processing in the processing unit 21A. During this processing, the presence or absence of an abnormality in the nozzle 11 is determined. Afterwards, the wafer W is also repeatedly transported alternately to the processing units 21A and 21B to be processed and abnormalities are determined. Furthermore, when it is determined that an abnormality exists in steps S2 and S4 of the processing units 21A and 21B, an alarm is output. Alternatively, in addition to the output of the alarm, the processing of the wafer W may be stopped at the time when an abnormality is determined, and the resist nozzle 11r and the diluent nozzle 11t may be returned to the standby unit 48 to clean each nozzle 11.

[0075] Furthermore, in each of steps S2 and S4, the start time of ejection of the processing liquid (resist or diluent) onto the wafer W is set to t1, the end time of ejection is set to t3, and the period from time t1 to t3 is set to the processing liquid ejection period T1. When switching the focus as described above, the ratio of the focus time per unit time for each nozzle 11 may be changed during the processing liquid ejection period T1.

[0076] Referring to the focus time ratio of the nozzle 11 that does not eject the processing liquid (i.e., the resist nozzle 11r in step S2 for detecting abnormality such as dripping, and the thinner nozzle 11t in step S4), Figure 11 This is explained using the graph. From time t1, when the treatment liquid begins to be ejected, to the time immediately thereafter (denoted as time t2 in the graph), the movement of the treatment liquid toward the nozzle 11 is less stable than after time t2, and thus the shape of the liquid column P1 formed below the nozzle 11 may also be unstable. Therefore, from time t1 to t2, the proportion of the focus time per unit time for the nozzle 11 ejecting the treatment liquid and forming the liquid column P1 is greater than that for the nozzle 11 not ejecting the treatment liquid, and the proportion of the focus time per unit time for the nozzle 11 not ejecting the treatment liquid is smaller.

[0077] To give a more specific example, when the focus is repeatedly changed in step S2, the resist nozzle 11r, after being focused, remains focused until time t11 has passed. Furthermore, the thinner nozzle 11t, after being focused between time t1 and t2, remains focused until time t11+α has passed. And after being focused between time t2 and t3, remains focused until time t11 has passed. In this way, the thinner liquid column P1 is imaged and monitored for a longer period of time between time t1 and t2 than between time t2 and t3, improving the accuracy of detecting abnormalities in the liquid column P1.

[0078] Furthermore, the camera 31 transmits the imaging data D1 to the control unit 6 at regular intervals. Therefore, the fact that the ratio of the focus time per unit time of the nozzle 11 that is not ejecting the processing liquid between time points t1 and t2 is small means that the frequency of acquiring the imaging data D1 per unit time of the nozzle 11 is small.

[0079] As described above, in the resist coating apparatus, the camera 31 performs imaging under a shooting condition selected from a plurality of imaging conditions based on the monitoring conditions of the nozzle 11. Specifically, the imaging condition is selected based on which of the thinner nozzle 11t and the resist nozzle 11r is being monitored, selecting between the first focus state for the thinner nozzle 11t and the second focus state for the resist nozzle 11r. Furthermore, based on which of the monitoring conditions is being used, namely, monitoring the nozzle 11 during wafer processing W in the processing unit 21A or monitoring the nozzle 11 during wafer processing W in the processing unit 21B, the camera 31 switches between using the first illumination unit 32, the second illumination unit 33, and the reflective member 34A and using the first illumination unit 32, the second illumination unit 33, and the reflective member 34B. In other words, the selection of the member to be used is performed based on the imaging conditions. Therefore, in the resist coating apparatus, each nozzle 11 can be monitored with high precision, improving the accuracy of determining the presence or absence of abnormalities.

[0080] In addition, as already mentioned, both the nozzle 11 in the ejection position and the nozzle 11 in the retreat position may cause abnormalities in the processing of the wafer W. Therefore, monitoring both of the above-mentioned nozzles 11 and detecting abnormalities is effective in preventing a reduction in the yield of semiconductor products. In this way, when monitoring both the diluent nozzle 11t and the resist nozzle 11r, a common camera 31 is used by switching the focus. Since the number of cameras 31 installed is reduced, it is preferable in terms of suppressing the size and cost of the device. In addition, as already mentioned, for the reason of the focus switching speed, the camera 31 is preferably equipped with a liquid lens, but a structure without a liquid lens is also possible.

[0081] Furthermore, when imaging conditions are changed based on monitoring conditions, the imaging conditions may also be the illumination of the first and second illumination units 32, 33, or a threshold value used to determine abnormalities in the imaging data D1. For example, the device may include an illumination unit in addition to the first and second illumination units 32, 33, and this illumination unit may cause a difference in illumination between the processing units 21A and 21B. In this case, for example, a difference may be created between the illumination of the light directed toward the wafer W from the first and second illumination units 32, 33 in the processing unit 21A and the illumination of the light directed toward the wafer W from the first and second illumination units 32, 33 in the processing unit 21B to compensate for the difference in illumination caused by this illumination unit.

[0082] Changing the threshold used for abnormality determination in image data D1 is also described. Image data D1 acquired by camera 31, for example, includes information on the brightness of each pixel. When determining the presence or absence of the aforementioned dripping of droplet P2, the position of nozzle 11 is determined in image data D1. Then, if a cluster of pixels whose brightness exceeds a predetermined threshold appears below nozzle 11, and this cluster consists of a predetermined number of pixels, it is determined that droplet P2 has dripped. This brightness threshold can be different when wafers W are processed by processing unit 21A and when wafers W are processed by processing unit 21B. For example, consider the case where the device structures reflected in the area outside nozzle 11 differ between when imaging nozzle 11 in processing unit 21A and when imaging nozzle 11 in processing unit 21B. By setting the brightness threshold differently when determining an abnormality based on image data captured by processing unit 21A and when determining an abnormality based on image data captured by processing unit 21B, the influence of these different reflected structures on the abnormality determination can be suppressed.

[0083] In this embodiment, the focus is repeatedly switched during the period T1 during which the treatment liquid is ejected from the nozzle 11, and imaging data D1 is acquired each time the focus is switched. However, the focus may be repeatedly switched and imaging data D1 acquired during only a portion of the period T1. Furthermore, the presence or absence of an abnormality based on the imaging data D1 may be determined at any time.

[0084] Machine learning can also be used to determine whether the nozzle 11 is abnormal. For example, before processing the wafer W, a large amount of image data captured by the camera 31 for each nozzle 11r and 11t is stored in the memory of the control unit 6. This large amount of image data includes image data acquired when dripping occurs and image data acquired when no abnormality occurs. Each image data is associated with information indicating whether dripping occurs or is normal, and then stored. In other words, learning about dripping is performed.

[0085] Then, in steps S2 and S4 when processing the wafer W as described above, when acquiring the imaging data D1 of the nozzle 11 that does not eject the processing liquid, the most similar imaging data is selected from a large amount of imaging data stored in the memory of the control unit 6 relative to the imaging data D1 acquired during the processing. Then, based on the information associated with the selected imaging data, a judgment is made as to whether dripping has occurred or there is no abnormality. By using this machine learning judgment, for example, even when the amount of light irradiated from each lighting unit to the nozzle 11 is relatively small, or when the components of the device are reflected in the outer area of ​​the nozzle 11 in the imaging data D1, a high-precision judgment of the presence or absence of an abnormality can be made. In addition, it is also possible to generate imaging data of predicted dripping occurrence based on the stored imaging data of dripping occurrence by a predetermined algorithm. In this case, when the actual imaging data D1 is consistent with the predicted imaging data, it can also be judged that dripping has occurred.

[0086] Furthermore, the present invention can also be used for the management of the liquid level position of the processing liquid in the nozzle 11 as described above, and for the detection of defects in the nozzle 11 itself. In this case, machine learning can also be used to determine the background object located behind the nozzle 11 in the shooting data as an object different from the nozzle 11 or its liquid level in the area near the outline of the nozzle 11 in the shooting data and the liquid level in the nozzle 11. Examples of background objects include the pattern of the coating formed on the surface of the substrate and the structures constituting the processing device. When the background object is near the nozzle 11, it is difficult to determine and detect the nozzle shape and liquid level. By such determination, the posture and liquid level of the nozzle 11 can be accurately identified in the shooting data, and therefore, it is easy to determine whether there is nozzle damage such as contamination, cracks, and deformation of the nozzle 11, or abnormalities such as dripping.

[0087] Furthermore, nozzle damage including the top portion of the nozzle 11 can also be judged or detected based on both the state of the area corresponding to the nozzle 11 in the shooting data and the width of the liquid column of the processing liquid ejected from the nozzle 11. In the case where the shooting data is obtained by shooting the nozzle 11 from the side, due to the shooting direction (optical axis L1), the top surface and the side surface of the nozzle 11 are in an overlapping area in the shooting data D1, and it is difficult to determine the location of the nozzle damage to be detected in this area. At this time, for example, in the case where the width of the liquid column of the processing liquid ejected from the nozzle 11 is abnormal, it is considered that the nozzle damage at the top of the nozzle 11 including the ejection port of the processing liquid is associated with the abnormality in the width of the liquid column, and it can be judged that the nozzle damage is located at the top of the nozzle 11. That is, even in the case where the nozzle 11 is shot from the side, where it is difficult to identify the top of the nozzle 11, it is possible to judge whether there is nozzle damage at the top of the nozzle 11.

[0088] For abnormalities other than dripping, learning can be performed in the same manner as described above, and based on this learning, the presence or absence of abnormalities can be determined during the processing of wafer W. For example, the shape of the liquid column formed by the ejection of the processing liquid can also be determined using machine learning to determine the presence or absence of abnormalities. Considering that the scattering of light irradiating wafer W makes it difficult to grasp the shape of the liquid column from the image data D1 of nozzle 11 when the liquid column is formed, even in such cases, the use of machine learning can accurately determine abnormalities in the shape of the liquid column. Furthermore, deep learning can also be used to determine the presence or absence of abnormalities based on this machine learning.

[0089] Machine learning is not limited to being used only to determine the presence or absence of abnormalities, but can also be used to adjust the focus of the camera 31. When the camera 31 and the nozzle 11 are removed from the arm 19 for maintenance and then reinstalled, the focus shifts due to slight errors in each component, so the user of the device manually adjusts the focus. This adjustment is performed by changing the applied voltage applied to the electrode 31e of the lens unit 31g from the external power supply 30 for changing the shape of the focus variable lens 31c while acquiring the captured data. After the focus is adjusted, for example, the maximum and minimum values ​​of the brightness of the captured data of the nozzle 11 acquired before the focus correction (when the components are reinstalled) are associated with the applied voltage after the focus adjustment and stored in the control unit 6. If a large amount of corresponding data of the maximum and minimum values ​​of the brightness and the applied voltage is stored, the focus is automatically adjusted based on the corresponding data. Specifically, if the shooting data of the nozzle 11 is obtained after each component is installed again, the control unit 6 calculates the maximum value-minimum value of the brightness of the shooting data, selects the value closest to the calculated value from the stored corresponding data, and corrects the applied voltage in a manner that becomes the applied voltage of the corresponding data.

[0090] In addition, the presence of dripping droplets P2 is determined by whether the brightness of a set of pixels exceeds a specified threshold value, and this threshold value is further explained. Before processing wafer W, the shooting data of the nozzle 11 is acquired in advance, and the average brightness of each pixel is calculated. The average brightness value is associated with the above-mentioned threshold value and stored. For the setting of the threshold value relative to the average value, a relatively low value is set within the range that can be judged as a droplet. In addition, the average brightness value of the shooting data is changed by irradiating light or configuring a structure around the nozzle 11. A relatively low threshold value is also set relative to the average brightness value thus changed, and the values ​​are associated with each other and stored. In this way, the corresponding data of the average brightness value and the threshold value are repeatedly acquired. When processing wafer W, the average brightness value is acquired from the acquired shooting data, and the threshold value of the corresponding data that is closest to the average value in the stored corresponding data is used for the judgment of dripping.

[0091] The presence or absence of liquid column P1 is determined similarly to the presence or absence of falling droplets P2. Therefore, as with falling droplets P2, the threshold can be set to a relatively low value based on the actual captured image data. If other structures are reflected in the image data around nozzle 11, the average brightness may be relatively high, and if the threshold is low, these other structures may be mistakenly detected as droplets P2 or liquid column P1. However, if the average brightness is low, meaning that the reflection of other structures is suppressed, this false detection is suppressed. Therefore, as described above, a relatively low threshold is set based on pre-stored corresponding data. This improves the detection sensitivity of falling droplets P2 and liquid column P1.

[0092] Modifications of the lighting unit and the reflecting member will be described below. Figure 12 This is a top view showing a first modification. As a first modification, the reflective members 34A and 34B may be positioned on the right side of each cup 22, the first lighting unit 32 may be positioned on the right side of the arm 19, and the second lighting unit 33 may be positioned on the left side of the lifting mechanism 18a. In this case, the first lighting unit 32 and the second lighting unit 33 illuminate the nozzle 11 from opposite sides relative to the left and right sides of the embodiment.

[0093] In this first modified example and the present embodiment, the first lighting unit 32 is provided on the arm 19, and the second lighting unit 33 is provided on the lifting mechanism 18a. However, this is not a required element. For example, the first lighting unit 32 and the second lighting unit 33 may be arranged outside and above each cup 22, respectively. Furthermore, for example, the second lighting unit 33 may be provided on the arm 19, and two sets of reflective members 34 may be provided for each treatment unit 21. In either case, it is preferred that the first lighting unit 32 and the second lighting unit 33 be arranged so as to illuminate the nozzle 11 from both the left and right sides.

[0094] And, in Figure 13 In the second modified example shown, the first lighting unit 32 is not provided on the arm 19, and the reflective member 34 is not provided. In this modified example, the fourth lighting unit 37 and the fifth lighting unit 38 are provided corresponding to each cup 22. Specifically, the fourth lighting unit 37 and the fifth lighting unit 38 are arranged on the left side of the cup 22A, and are arranged to irradiate light from the left side to the nozzle 11 on the wafer W located in each cup 22. In addition, the fourth lighting unit 37 is arranged to illuminate the nozzle 11 in the cup 22A during discharge from the side. The fifth lighting unit 38 is arranged to illuminate the nozzle 11 in the cup 22B during discharge from slightly behind, and the optical axis is arranged so as not to pass through the center of the cup 22A and the cup 22B when viewed from above.

[0095] In such Figure 14In the third modified example shown, the fourth and fifth lighting units 37 and 38 of the second modified example are arranged in a reversed manner. Therefore, the fourth and fifth lighting units 37 and 38 are arranged on the right side of the cup 22B, illuminating the nozzles 11 of each cup 22 from the right side. As illustrated above, the lighting units of the present invention can be configured and arranged in any desired manner.

[0096] The number of treatment units 21 is not limited to two; more than two can be provided. For example, in addition to treatment units 21A and 21B, treatment unit 21C can be provided, thereby providing a configuration with three treatment units 21. These treatment units 21A to 21C can be arranged in a straight line in the left-right direction, and the treatment liquid supply mechanism 10 can be configured to be common to these three treatment units 21. When treatment unit 21C is provided in this manner, the configuration of the reflective member 34 and the lighting unit can also be applied in the same manner as in the above-described examples. In other words, when a reflective member 34 and a first lighting unit 32 are provided for each treatment unit 21, the cup 22, reflective member 34, and first lighting unit 32 can be arranged in treatment unit 21C in the same layout as the cup 22, reflective member 34, and first lighting unit 32 in treatment units 21A and 21B. While an example of a lighting unit configuration common to treatment units 21 is shown, it can be common to treatment units 21A to 21C.

[0097] The liquid processing device to which this technology is applied is not limited to the resist coating device. For example, it can also be a structure in which a liquid for forming an anti-reflective film or a liquid for forming an insulating film is sprayed from the nozzle 11r instead of the resist. In addition, the present technology can also be applied to a liquid processing device in which an arm 19 is provided with a nozzle for supplying a developer to the exposed resist film and developing it, and a nozzle for supplying a cleaning liquid such as pure water to clean the surface of the wafer W after supplying the developer. Moreover, in each embodiment, the substrate to be processed is not limited to a wafer, and can also be, for example, a substrate for manufacturing a flat panel display or a mask substrate for manufacturing a mask for exposure. Therefore, square substrates can also be processed.

[0098] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive, and the embodiments described above may be omitted, replaced, modified, and combined in various forms without departing from the scope of the appended claims and their spirit.

Claims

1. A liquid processing device, characterized in that: The liquid treatment device has: a plurality of stages for placing substrates respectively; a plurality of nozzles, which are shared by the plurality of stages and are used to supply a processing liquid to the substrate; a camera, which is common to the plurality of nozzles and is used to monitor the status of the plurality of nozzles; as well as The imaging condition changing unit changes the imaging condition of the camera according to the monitoring condition.

2. The liquid processing device according to claim 1, characterized in that The liquid treatment device has: a movable body provided with the plurality of nozzles and moving relative to each stage in order to supply the processing liquid to the substrate on each stage; an illumination unit provided on the movable body and irradiating light in a direction different from a direction toward each of the nozzles; as well as The reflecting member is fixed in position relative to the stage and reflects the irradiation light from the illuminating unit to irradiate the nozzles.

3. The liquid processing device according to claim 2, characterized in that The reflecting member reflects the irradiation light from the illumination unit toward the substrate on the stage, and the light reflected by the substrate is irradiated toward the nozzles.

4. The liquid processing device according to claim 2 or 3, characterized in that: The reflecting member is provided for each of the stages.

5. The liquid processing device according to claim 1, characterized in that The camera has a liquid lens configured to bring the plurality of nozzles into the photographing range of the camera. The imaging condition changing unit monitors the states of the plurality of nozzles by changing a focus according to a nozzle to be monitored.

6. The liquid processing device according to claim 5, characterized in that By changing the focus, monitoring of the discharge state of the processing liquid from one of the nozzles and monitoring of a state different from the discharge state with respect to the other nozzles are performed alternately.

7. The liquid processing device according to claim 1, characterized in that The liquid processing device includes an arm provided with the plurality of nozzles, and moves relative to each stage in order to supply the processing liquid to the substrate on each stage. The camera is provided on the arm so that the optical axis thereof is oriented in a direction different from the extension direction of the arm in a plan view.

Images