Liquid processing apparatus and monitoring method

Abstract

The invention relates to a liquid processing apparatus and a monitoring method. 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 present disclosure relates to a liquid processing device and a monitoring method. Background Art

[0002] When manufacturing semiconductor devices, a liquid processing device includes a nozzle, from which a processing liquid such as a resist is ejected toward a semiconductor wafer (hereinafter referred to as a wafer) to form a resist film on the wafer. For example, Patent Document 1 discloses that a CCD camera is used to monitor the ejection state of a photoresist liquid from a processing liquid supply nozzle toward a substrate, and detect abnormalities in the ejection state.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-318079 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The present disclosure 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 disclosed in the present invention comprises: a plurality of stages, each of which carries a substrate; a plurality of nozzles, which are commonly used for the plurality of stages and are used to supply processing liquid to the substrate; a camera, which is commonly used for 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 condition of the camera according to the monitoring condition.

[0010] Effects of the Invention

[0011] According to the present disclosure, the states of a plurality of nozzles can be monitored in an appropriate manner according to the situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a top view showing the liquid processing apparatus according to the embodiment.

[0013] Figure 2 It is a longitudinal sectional side view showing the liquid processing device.

[0014] Figure 3 It is a longitudinal sectional side view showing the liquid processing device.

[0015] Figure 4 It is a top view showing a state where the diluent nozzle has moved to the ejection position.

[0016] Figure 5 It is a plan view showing a state where the resist nozzle has moved to the ejection position.

[0017] Figure 6 It is an explanatory diagram schematically showing a focusing state.

[0018] Figure 7 It is an explanatory diagram schematically showing a focusing state.

[0019] Figure 8 The image is focused on the diluent nozzle.

[0020] Fig. 9 is an image focused on the resist nozzle.

[0021] Fig.10 1 is a flowchart showing the operation of the liquid processing apparatus.

[0022] Fig.11 This is a graph showing the focus time ratio of the nozzle that does not eject the processing liquid.

[0023] Fig.12 It is a top view showing the liquid processing apparatus according to the first modification.

[0024] Fig.13 It is a top view showing a liquid processing apparatus according to a second modified example.

[0025] Fig.14 It is a top view showing a liquid processing apparatus according to a third modified example.

[0026] Description of Reference Numerals

[0027] 11r, resist nozzle; 11t, diluent nozzle; 25A, 25B, rotating holding disk; 31, camera; 6, control unit; W, wafer. DETAILED DESCRIPTION

[0028] Figure 1 1 is a top view of a resist coating apparatus as an embodiment of a liquid processing apparatus of the present disclosure, showing a nozzle 11 described later, specifically a resist nozzle 11r, configured at a discharge position described later. In this embodiment, an XYZ orthogonal coordinate system is used for explanation. The resist coating apparatus is provided with processing units 21A and 21B as places for performing various processing on a wafer W. Figure 2 is a longitudinal sectional side view of the processing section 21A along the Y direction, Figure 3 2 is a longitudinal sectional side view of the processing unit 21A along the X direction. Hereinafter, the X direction is sometimes referred to as the lateral direction, and the Y direction is sometimes referred to as the front-rear direction. In addition, the side where the processing liquid supply mechanism 10 including the nozzle 11 is arranged is sometimes referred to as the front, and the side where the processing units 21A and 21B on the opposite side are arranged is sometimes referred to as the rear.

[0029] The resist coating apparatus includes a processing liquid supply mechanism 10 that supplies a diluent and a resist as processing liquid to the wafer W to form a resist film on the wafer W. The diluent is a processing liquid that is supplied to the wafer W before the resist is supplied to improve the wettability of the surface of the wafer W with respect to the resist (pre-wetting).

[0030] In addition, the diluent is also used in EBR (Edge Bead Removal), in which the diluent is sprayed toward the peripheral portion of the wafer W after the resist film is formed, thereby removing the unwanted portion of the resist film in a ring shape, and the diluent for EBR is supplied from the EBR mechanisms 4A and 4B independently provided with respect to the processing liquid supply mechanism 10. In this way, in the resist coating apparatus 1, in each of the processing sections 21A and 21B, the wafer W is processed in the order of pre-wetting, resist coating, and EBR.

[0031] The processing liquid supply mechanism 10 for pre-wetting and resist coating is commonly used in 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 irradiation light from a part of the plurality of lighting units, so that the control unit 6 described later can monitor the state 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 via 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.

[0032] 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 configuration, so the processing unit 21A will be described as a representative.

[0033] like Figure 2 As shown, the processing portion 21A includes a cup 22A which is open at the top and accommodates the wafer W in a holding area therein. Figure 2Reference 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 mounting 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 hold the wafer W horizontally. The lower side of the rotating holding disk 25A is connected to a rotating drive unit 26. The rotating holding disk 25A rotates around a vertical axis (Z axis) together with the held wafer W 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 conveying mechanism (not shown) for conveying the wafer W and the rotating holding plate 25A.

[0034] The processing section 21A is provided with a reflective member 34A and an EBR mechanism 4A for performing EBR. 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 section 42, an arm 43, a peripheral nozzle 44A, and a cup-shaped standby section 45A. The moving section 42 moves linearly in the left-right direction (X direction) along the guide 41 on the front side of the cup 22A. In addition, a freely liftable arm 43 extends rearward from the moving section 42, and a peripheral nozzle 44A is provided at the rear end of the arm 43.

[0035] The peripheral nozzle 44A is connected to a diluent supply mechanism (not shown) via a pipe. The diluent is supplied from the diluent supply mechanism to the peripheral nozzle 44A moved to a predetermined ejection position in the cup 22A, and ejected downward. The diluent is ejected toward the peripheral portion of the wafer W rotated by the rotating holding disk 25A, thereby performing EBR.

[0036] The standby section 45A is provided outside the cup 22A, and is located on the left side relative to the center of the front and rear of the cup 22A. The peripheral nozzle 44A is moved between the standby position and the ejection position in the standby section 45A by the moving section 42. When not in use, the peripheral nozzle 44A stands by at the above-mentioned standby position. The standby section 45A is configured to store and discharge a diluent therein, and the peripheral nozzle 44A in standby can be cleaned at any time by using the stored diluent.

[0037] like Figure 1 , Figure 2As 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 whose two main surfaces face 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 opposite to the first lighting unit 32 that can be raised and lowered later in the horizontal direction. The reflective surface 35A is configured to face slightly downward relative to the horizontal direction. As a result, the irradiated 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 it is assumed that the diluent splashes at the standby part 45A, the attachment of the diluent to the reflective surface 35A can be suppressed. Therefore, since the contamination of the reflective surface 35A is prevented, the clarity of the acquired shooting data is ensured.

[0038] 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, the components identical to those of the processing unit 21A are indicated by reference numerals with the same numbers as those used in the reference numerals in the processing unit 21A. However, the English letters attached after 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 the components identical to those of the processing units 21A and 21B, the English letters are omitted and collectively referred to, for example, they are sometimes indicated as the EBR mechanism 4, the processing unit 21, the cup 22, the rotating retaining disk 25, the reflecting member 34, the reflecting surface 35, etc.

[0039] A standby section 48 for each nozzle 11 constituting the processing liquid supply mechanism 10 is provided between the processing section 21A and the processing section 21B and on the front side thereof. The standby section 48 is arranged in front of the cups 22A and 22B. Figure 1 In the figure, as shown by the dotted line, the detailed shape of the standby portion 48 is omitted from the figure. The standby portion 48 is, for example, a table with a plurality of recessed portions (not shown) opening upward, and the nozzle 11 is accommodated and stands by in the recessed portions. In addition, the standby portion 48 is configured so that the diluent can be supplied to the recessed portions and the liquid can be discharged. Thus, the diluent is supplied to the outer surface of the nozzle 11 in the standby state to clean it.

[0040] The processing liquid supply mechanism 10 includes a plurality of nozzles 11 and a nozzle transport mechanism 15, which is a movable body for transporting the nozzles 11 onto each wafer W mounted on each processing unit 21, and the processing liquid supply mechanism 10 supplies the processing liquid to the wafer W. The nozzle transport mechanism 15 includes a guide 16 extending left and right on the front side of the standby unit 48 and an arm mechanism 17 for arranging the nozzles 11 at the ejection position on each wafer W mounted on the rotating holding disk 25.

[0041] like Figure 1 , Figure 2 As shown, the arm mechanism 17 includes a base end portion 18 and an arm 19. The base end portion 18 includes a lifting mechanism 18a that can move left and right along the guide 16 and a lifting portion 18b that is connected to the lifting mechanism 18a and is lifted and lowered. The base end side of the lifting portion 18b is arranged on the left side of the lifting mechanism 18a, and the top end side extends backward. The base end side of the arm 19 that extends in a horizontal direction, for example, linearly is connected to the top end side of the lifting portion 18b so as to be rotatable around a rotation axis extending along the Z axis. That is, the arm 19 rotates along the horizontal plane with the base end side as the center.

[0042] Three nozzles 11 extending downward are installed at the lower part of the top end side of the arm 19. Among these nozzles 11, one resist nozzle 11r that sprays resist is arranged at the top end side of the arm 19, and two diluent nozzles 11t that spray diluent are arranged at the base end side than the resist nozzle 11r. In this way, the resist nozzle 11r and the diluent nozzle 11t are arranged staggered in the extension direction from the base end side to the top end 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 focused on the two diluent nozzles 11t.

[0043] The resist nozzle 11r is connected to a resist supply mechanism 12 having a valve and a pump, and the resist supply mechanism 12 is used to adjust the supply amount of the resist supplied to the resist nozzle 11r. That is, the discharge amount of the 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 having a valve and a pump, and the diluent supply mechanism 13 is used to adjust the supply amount of the diluent supplied to the diluent nozzle 11t. That is, the discharge amount of the diluent ejected from the diluent nozzle 11t is adjusted by the diluent supply mechanism 13. The resist nozzle 11r and the diluent nozzle 11t as described above eject the resist and the diluent downward at the ejection position in the cup 22 and on the center of the wafer W held on the rotating holding disk 25.

[0044] Figure 1 FIG. 2 shows a state where the resist nozzle 11r moves to the ejection position of the processing unit 21A. Figure 4 FIG. 1 shows a state where the thinner nozzle 11t moves to the ejection position of the processing unit 21A, and at this time, the arm 19 extends toward the right rear. In addition, the positional relationship between the arm 19 and the processing unit 21B when the resist nozzle 11r and the thinner nozzle 11t move to the ejection position of the processing unit 21B is shown in FIG. Figure 1 , Figure 4The positional relationship between the arm 19 and the treatment portion 21A shown is the same.

[0045] 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 2 As shown in FIG. 1 , the first lighting unit 32 is provided at the lower part of the arm 19 closer to the base end side than the nozzle 11. As shown by the dot-dash line diagram of the optical axis, the first lighting unit 32 irradiates light from the left side of the arm 19 (the left side when facing the direction from the base end side to 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 irradiates each nozzle 11 from the lower left.

[0046] The second lighting unit 33 is provided on the front side of the right side portion of the lifting mechanism 18a, and is arranged at a position higher than the cup 22. As shown by the light axis indicated by the dashed line, the second lighting unit 33 is arranged to irradiate light slightly downward to the rear. Thus, the second lighting unit 33 can irradiate the surface of the wafer W placed on the rotating holding plate 25 from above the cup 22. The second lighting unit 33 is arranged in front of each nozzle 11 at the ejection position when viewed from above, and the irradiation light from the second lighting unit 33 toward the surface of the wafer W is reflected by the wafer W, and irradiates each nozzle 11 from the lower front.

[0047] Next, the camera 31 will be described. The camera 31 is mounted on the arm 19 in a position and posture 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 top end portion of the arm 19 toward the top end side of the arm 19, so that the camera 31 is provided in a region extending the arm 19 in a plan view, and performs imaging from the top end side of the arm 19 toward the base end side.

[0048] Figure 5This is a top view for explaining the optical axis of the camera, etc. The optical axes of the irradiated light from the reflective member 34A and the second lighting unit 33 toward the nozzle 11 are located to the left and right relative to the optical axis L1 of the camera 31. That is, when the camera 31 is used to photograph each nozzle 11 and its surroundings, light is irradiated to the photographing area from the left and right, so that no shadow is cast on the nozzle 11. In addition, when viewed from above, the direction of the optical axis L1 of the camera 31 is offset relative to the direction of the straight line L2 indicating the extension direction of the arm 19. In other words, when viewed from above, the extension line of the optical axis L1 and the straight line L2 are in a cross relationship. The purpose of this is to prevent the lifting part 18b connected to the base end of the arm 19, the first lighting unit 32 provided below the arm 19, and other components from being reflected in the photographing range of the camera 31, and to improve the judgment accuracy when abnormality is judged based on the photographing data D1. In addition, the optical axis L1 is slightly inclined downward relative to the horizontal plane to bring the lower side of the nozzle 11 into the photographing area.

[0049] As described above, the camera 31 is provided on the arm 19, so the distance between the resist nozzle 11r and the thinner nozzle 11t is 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 and a focus variable lens 31c housed in the housing 31a, and 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 performs photoelectric conversion on the received light to generate photographic data D1, and sends it to the control unit 6 described later.

[0050] The focus variable lens 31c is an interface between two liquids 30a and 30b that are sealed in the lens unit 31g and separated from each other. By changing the applied voltage applied from the external power supply 30 to the electrode 31e provided in the lens unit 31g, as shown in FIG. Figure 6 , Figure 7 As shown, the shape of the interface between the liquids 30a and 30b changes, and thus the focal length of the camera 31 changes. 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.

[0051] exist Figure 6 , Figure 7 In the figure, the solid lines indicate the focused nozzles among the resist nozzle 11r and the thinner nozzle 11t, and the dotted lines indicate the unfocused nozzles among the resist nozzle 11r and the thinner nozzle 11t. Figure 6 The state in which the diluent nozzle 11t is focused in this way is referred to 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.

[0052] In addition to the nozzle 11, the surroundings of the nozzle 11 are also included in the shooting area of ​​the camera 31. More specifically, the surroundings include the area below the nozzle 11. Therefore, the liquid column P1 of the processing liquid formed by the focused nozzle 11 and the liquid droplets P2 of the processing liquid dripping from the nozzle 11 can also be photographed in a focused state. The liquid column P1 and the liquid droplets P2 will be further described later.

[0053] The camera 31 constructed as described above alternately focuses on the resist nozzle 11r and the thinner nozzle 11t within the shooting range and repeatedly shoots without moving the shooting range. That is, in a state where the relative positions of the resist nozzle 11r, the thinner nozzle 11t and the camera 31 are fixed, the first focus state and the second focus state are repeatedly switched to obtain the shooting data D1 of each nozzle 11, thereby monitoring these nozzles 11. In addition, Figure 4 , Figure 6 The diagram shows how each nozzle 11 is monitored when the wafer W is processed using the diluent nozzle 11 t in step S2 described later.

[0054] Figure 8 The camera focuses on the diluent nozzle and takes the picture ( Figure 6 An example of the photographic data of the first focus state of Fig. 9 This is the state of focusing on the resist nozzle ( Figure 7 The example of captured data of the first focus state and the second focus state is shown in FIG. 1 . The switching between the first focus state and the second focus state can be performed in, for example, less than 100 ms. In addition, the camera 31 is configured to have a liquid lens so that the shape of the lens can be instantly changed (i.e., the focus can be adjusted) by applying a voltage. In more detail, compared with a structure in which the focus is adjusted by changing the positional relationship of each component constituting the optical system, the focus can be switched in a very short time as shown in the example.

[0055] Hereinafter, the photographic data captured by focusing on the resist nozzle 11r and the photographic data captured by focusing on the thinner nozzle 11t may be recorded as simply the photographic data of the resist nozzle 11r and the photographic data of the thinner nozzle 11t. In addition, the nozzle 11 as the photographic object in the photographic data refers to the resist nozzle 11r or the thinner nozzle 11t that is photographed relatively clearly by adjusting the focus.

[0056] 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 unit of the resist coating device 1. The program storage unit stores a program in which instructions (a step group) for causing each unit of the device to operate to form a resist film on the wafer W as described later are stored. 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, a control signal is output from the control unit 6 to each unit of the resist coating device 1, thereby performing the formation of the above-mentioned resist film.

[0057] Furthermore, the program is used to switch the lighting unit used between the processing units 21A and 21B, acquire the imaging data D1 of the camera 31, switch the focus of the camera 31, and determine whether there is an abnormality in the resist nozzle 11r and the thinner nozzle 11t based on the imaging data D1. That is, the program constitutes an imaging condition changing unit that monitors the nozzle 11 and changes the imaging condition according to the monitored condition. Moreover, the response actions such as alarm output performed in addition to the monitoring are also controlled by the program.

[0058] 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, set to a retreat position) (refer to Figure 1 , Figure 4 ). The imaging data D1 is acquired in a state where 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.

[0059] For the nozzle 11 that ejects the processing liquid at the ejection position, whether the ejection state of the processing liquid is appropriate is determined based on the captured data D1, and whether there is any abnormality. Due to the ejection of the processing liquid, a liquid column P1 of the processing liquid is formed below the nozzle 11. Whether the ejection state of the processing liquid is appropriate includes whether the liquid column P1 is formed at an appropriate time and whether the shape of the liquid column P1 is appropriate (whether the thickness is appropriate, whether there is any distortion).

[0060] For the nozzle 11 in the evacuated position, the presence or absence of abnormalities other than the ejection state of the processing liquid is determined based on the shooting data D1. Specifically, for example, the falling (dripping) of the droplets P2 from the nozzle 11 and the amount of the 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 in the cleaning and attached to the nozzle 11. In addition, for the nozzle 11 in the evacuated 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 shooting data D1.

[0061] Since they are arranged on the same arm 19, the resist nozzle 11r and the diluent nozzle 11t are arranged close to each other. While one nozzle 11 is at the ejection position, the other nozzle 11 is at the retreat position. However, the retreat position is also on the wafer W, as in the ejection position. Therefore, if the processing liquid or the diluent used for cleaning falls from the nozzle 11 as described above, it may be supplied to the wafer W and cause an abnormality. In addition, if there is an abnormality in the ejection state of the processing liquid of the nozzle 11 at the ejection position, it may not be supplied to the wafer W in an appropriate amount, or it may cause an abnormality such as the processing liquid splashing on the wafer W and becoming a foreign body. In this way, due to the abnormality of each nozzle 11 at the ejection position and the retreat position, it is possible that a bad situation will occur in the processing of the wafer W. Therefore, the focus of the camera 31 is repeatedly switched at a high speed, and the shooting data D1 of each nozzle 11 at the ejection position and the retreat position is repeatedly acquired, and the abnormality is judged based on each shooting data D1.

[0062] The determination of the presence or absence of abnormality is performed, for example, by pre-storing the reference data of the nozzle 11 photographed in a state without abnormality in the memory of the control unit 6, and comparing the reference data with the acquired photographing data D1 by a program. If it is determined that there is an abnormality, a predetermined sound or image alarm is output from the alarm output unit 65.

[0063] Reference Fig.10 The operation of the resist coating device is described in order. First, for example, a wafer W is transported to the processing unit 21A among the processing units 21A and 21B and is held by adsorption on the rotating holding disk 25. The diluent nozzle 11t and the resist nozzle 11r waiting in the standby unit 48 are moved to the ejection position and the retreat position on the wafer W, respectively, and the first lighting unit 32 and the second lighting unit 33 of the processing unit 21A are irradiated with light to irradiate the diluent nozzle 11t and the resist nozzle 11r (step S1). Then, the camera 31 is photographed and the focus is repeatedly switched, and the photographing data D1 of the diluent nozzle 11t and the resist nozzle 11r are repeatedly acquired.

[0064] In parallel with the acquisition of the shooting data D1 of the nozzle 11, a diluent is ejected from the diluent nozzle 11t to form a liquid column P1. For the diluent nozzle 11t, the presence or absence of abnormality in the diluent ejection state of the diluent nozzle 11t is determined based on the acquired shooting data. In addition, for the resist nozzle 11r, the presence or absence of abnormality other than the ejection state of the resist (drip of the droplet P2, the amount of the cleaning diluent attached to the outer surface of the nozzle) of the resist nozzle 11r is determined based on the acquired shooting data D1 (step S2).

[0065] The discharge of the diluent from the diluent nozzle 11t is stopped, and the acquisition of the imaging data D1, the switching of the focus, and the determination of the presence or absence of abnormality are temporarily stopped. The diluent supplied to the center of the wafer W is applied to the entire surface by the rotation of the wafer W to perform pre-wetting. On the other hand, the resist nozzle 11r is moved to the discharge position on the wafer W pre-wetted in step S1 by the left-right movement and the rotation movement of the arm 19, and the diluent nozzle 11t is moved to the retreat position (step S3).

[0066] The acquisition of the shooting data and the switching of the focus are started again, and the shooting data of the diluent nozzle 11t and the shooting data D1 of the resist nozzle 11r are repeatedly acquired. In parallel with the acquisition of the shooting data of the nozzle 11, the resist is ejected from the resist nozzle 11r to form a liquid column P1. For the resist nozzle 11r, the presence or absence of abnormality in the ejection state of the resist of the resist nozzle 11r is determined based on the acquired shooting data. In addition, for the diluent nozzle 11t, the presence or absence of abnormality other than the ejection state of the diluent (the dripping of the droplets P2, the amount of the diluent for cleaning attached to the outer surface of the nozzle) of the diluent nozzle 11t is determined based on the acquired shooting data (step S4). Therefore, the abnormality is determined in the same way as step S2.

[0067] The ejection of the resist from the resist nozzle 11r is stopped, and the acquisition of the imaging data D1, the switching of the focus, the determination of the presence or absence of an abnormality, and the irradiation of light from the first lighting unit 32 and the second lighting unit 33 are stopped. The resist supplied to the center of the wafer W is applied to the entire surface by the rotation of the wafer W, forming a resist film. The peripheral nozzle 44 moves from the standby unit 45A to the ejection position, ejects the diluent to perform EBR, and then the wafer W is sent out from the processing unit 21A.

[0068] While the wafer W is being processed by the processing unit 21A, the wafer W is transported to the processing unit 21B. If 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, and the presence or absence of an abnormality of the nozzle 11 is determined during the processing. After that, the wafer W is also repeatedly transported alternately to the processing units 21A and 21B, and the processing and abnormality are determined. In addition, when it is determined that there is an abnormality in steps S2 and S4 of the processing units 21A and 21B, an alarm is output. In addition, in addition to the output of the alarm, the processing of the wafer W is stopped at the time when it is determined that there is an abnormality, and the resist nozzle 11r and the diluent nozzle 11t are returned to the standby unit 48, and each nozzle 11 is cleaned.

[0069] In addition, in each of steps S2 and S4, the start time of ejection of the processing liquid (resist or diluent) to 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 the focus is switched 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.

[0070] Referring to the focusing 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), Fig.11 The diagram is used for explanation. For the period from the time point t1 when the treatment liquid starts to be ejected to the time point immediately thereafter (recorded as time point t2 in the diagram), the movement of the treatment liquid toward the nozzle 11 is unstable compared to after time point t2, and thus the shape of the liquid column P1 formed under the nozzle 11 may also be unstable. Therefore, during the time points t1 to t2, the proportion of the focusing time per unit time for the nozzle 11 that ejects the treatment liquid and forms the liquid column P1 is relatively large, and the proportion of the focusing time per unit time for the nozzle 11 that does not eject the treatment liquid is relatively small compared to the time points t2 to t3.

[0071] To give a more specific example, when the focus is repeatedly changed in step S2, the resist nozzle 11r is focused and continues to be focused until time t11 has passed. Also, the thinner nozzle 11t is focused at time t1 to t2 and continues to be focused until time t11+α has passed, and is focused at time t2 to t3 and continues to be focused until time t11 has passed. Thus, at time t1 to t2, the thinner liquid column P1 is imaged and monitored for a longer period of time than at time t2 to t3, thereby improving the accuracy of detecting abnormalities in the liquid column P1.

[0072] In addition, the camera 31 sends the imaging data D1 to the control unit 6 at regular intervals. Therefore, the smaller ratio of the focusing time per unit time of the nozzle 11 that does not eject the processing liquid between time points t1 and t2 means that the frequency of acquiring the imaging data D1 per unit time of the nozzle 11 is smaller.

[0073] As described above, according to the resist coating apparatus, the camera 31 is photographed under the photographing condition selected from a plurality of photographing conditions according to the monitoring condition of the nozzle 11. That is, the photographing condition is selected to select which of the first focus state for the thinner nozzle 11t and the second focus state for the resist nozzle 11r is used according to the monitoring condition of which of the thinner nozzle 11t and the resist nozzle 11r is monitored. Furthermore, according to the monitoring condition of which of the monitoring of the nozzle 11 when processing the wafer W in the processing unit 21A and the monitoring of the nozzle 11 when processing the wafer W in the processing unit 21B is performed, the first lighting unit 32, the second lighting unit 33, and the reflection member 34A are used and the first lighting unit 32, the second lighting unit 33, and the reflection member 34B are used. That is, the selection of the member to be used is performed as the photographing condition. Therefore, in the resist coating apparatus, each nozzle 11 can be monitored with high accuracy, and the accuracy of the judgment of the presence or absence of abnormality is improved.

[0074] In addition, as already mentioned, both the nozzle 11 at the ejection position and the nozzle 11 at the retreat position may cause abnormalities in the processing of the wafer W. Therefore, monitoring the two nozzles 11 and detecting abnormalities is effective in preventing the reduction of 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 to be installed is suppressed, it is preferred in terms of suppressing the enlargement and high cost of the device. In addition, as already mentioned, for the camera 31, it is preferably equipped with a liquid lens for the reason of the switching speed of the focus, but it can also be a structure without a liquid lens.

[0075] In addition, when the shooting condition is changed according to the monitoring condition, the shooting condition may be the illumination of the first lighting unit 32 and the second lighting unit 33, or a threshold value for abnormal judgment of the shooting data D1. For example, in addition to the first lighting unit 32 and the second lighting unit 33, the device is provided with an illumination unit, and the illumination between the processing units 21A and 21B is deviated due to the illumination unit. In this case, for example, a difference may be formed between the illumination of the light irradiated toward the wafer W from the first lighting unit 32 and the second lighting unit 33 in the processing unit 21A and the illumination of the light irradiated toward the wafer W from the first lighting unit 32 and the second lighting unit 33 in the processing unit 21B, so as to compensate for the deviation of the illumination caused by the illumination unit.

[0076] An example is also given of changing the threshold for abnormality judgment of the photographing data D1. The photographing data D1 acquired by the camera 31 is, for example, data having information on the brightness of each pixel. When judging the presence or absence of the dripping of the above-mentioned droplet P2, the position of the nozzle 11 is determined in the photographing data D1. Then, when a set of pixels whose brightness exceeds a predetermined threshold appears below the nozzle 11, and the set is formed by a number of pixels in a predetermined range, it is judged that the droplet P2 has dripped. The threshold of the brightness may be different when the wafer W is processed by the processing unit 21A and when the wafer W is processed by the processing unit 21B. For example, it is considered that the structure of the device reflected in the area outside the nozzle 11 is different when the nozzle 11 is photographed in the processing unit 21A and when the nozzle 11 is photographed in the processing unit 21B. By making the above-mentioned brightness threshold different when judging the abnormality based on the data photographed in the processing unit 21A and when judging the abnormality based on the data photographed in the processing unit 21B, the influence of the difference in the reflected structure on the judgment of the abnormality can be suppressed.

[0077] In the present embodiment, the focus is repeatedly switched during the period T1 during which the treatment liquid is ejected from the nozzle 11, and the imaging data D1 is acquired each time the focus is switched. However, the focus may be repeatedly switched and the imaging data D1 may be acquired only during a portion of the period T1. In addition, the determination of the presence or absence of abnormality based on the imaging data D1 may be performed at any time.

[0078] In addition, machine learning can also be used to determine whether there is an abnormality in the nozzle 11. For example, before processing the wafer W, a large amount of shooting data acquired by the camera 31 for each nozzle 11r, 11t is pre-stored in the memory of the control unit 6. The large amount of shooting data includes shooting data acquired when dripping occurs and shooting data acquired when there is no abnormality, and each shooting data is associated with information on the occurrence of dripping or normality and stored. In other words, learning about dripping is performed.

[0079] Then, in the above-mentioned steps S2 and S4 when processing the wafer W, when acquiring the shooting data D1 of the nozzle 11 that does not spray the processing liquid, the most similar shooting data is selected from a large amount of shooting data stored in the memory of the control unit 6 relative to the shooting data D1 acquired during the processing. Then, based on the information associated with the selected shooting data, a judgment is made as to whether dripping has occurred or there is no abnormality. By using the judgment based on machine learning, 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 in the shooting data D1 are reflected in the outer area of ​​the nozzle 11, a high-precision judgment of the presence or absence of an abnormality can be made. In addition, it is also possible to generate predicted shooting data of dripping by a prescribed algorithm based on the stored shooting data of dripping. In this case, when the actual shooting data D1 is consistent with the predicted shooting data, it can also be judged that dripping has occurred.

[0080] Furthermore, the present disclosure can also be utilized for the management of the liquid level position of the processing liquid in the nozzle 11 as described above, and 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 patterns of coatings formed on the surface of a substrate and structures constituting a 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 the presence or absence of nozzle damage such as contamination, cracks, and deformation of the nozzle 11, and abnormalities such as dripping.

[0081] In addition, 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 of 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 direction, 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.

[0082] 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 when processing 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. It is also considered that due to the scattering of light irradiated on wafer W, it is difficult to grasp the shape of the liquid column in the shooting data D1 of the nozzle 11 when the liquid column is formed, but even in such a case, the abnormality of the shape of the liquid column can be determined with high accuracy by using this machine learning. In addition, deep learning can also be used to determine the presence or absence of abnormalities based on this machine learning.

[0083] Machine learning is not limited to being used only in determining the presence or absence of abnormalities, but can also be used in adjusting 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 is shifted due to slight errors in each part, 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 shooting data. After the focus adjustment, for example, the maximum value-minimum value of the brightness of the shooting data of the nozzle 11 acquired before the focus correction (when each component is reinstalled) is associated with the applied voltage after the focus adjustment and stored in the control unit 6. If a large amount of such corresponding data of the maximum value-minimum value 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 the components are 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.

[0084] 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 the threshold value is further described. Before processing wafer W, the shooting data of 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. With respect to the average brightness value thus changed, a relatively low threshold value is also set, 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.

[0085] In addition, the presence or absence of the formation of the liquid column P1 is also determined in the same way as the presence or absence of the dripping liquid drop P2, so it is sufficient to determine the threshold value to a relatively low value based on the actually acquired shooting data, as with the dripping liquid drop P2. If other structures are reflected around the nozzle 11 in the shooting data, it is possible that the average value of the brightness becomes relatively high, and when the threshold value is low, the other structure is erroneously detected as the liquid drop P2 or the liquid column P1. However, when the average value of the brightness is low, that is, the reflection of other structures is suppressed, since the erroneous detection is suppressed, a relatively low threshold value is set based on the pre-stored corresponding data as described above. As a result, the detection sensitivity of the dripping liquid drop P2 and the liquid column P1 is improved.

[0086] Modifications of the lighting unit and the reflecting member will be described below. Fig.12 1 is a top view showing a first modification. As a first modification, each reflective member 34A, 34B may be arranged on the right side of each cup 22, the first lighting unit 32 may be arranged on the right side of the arm 19, and the second lighting unit 33 may be arranged on the left side of the lifting mechanism 18a. In this case, the first lighting unit 32 and the second lighting unit 33 irradiate light to the nozzle 11 from opposite sides of the left and right sides of the present embodiment.

[0087] In the first modification 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, but this is not an essential element. For example, the first lighting unit 32 may be arranged outside and above each cup 22 in the same manner as the second lighting unit 33. In addition, for example, the second lighting unit 33 may be provided on the arm 19, and two sets of reflecting members 34 may be provided for each treatment unit 21. In any case, it is preferred that the first lighting unit 32 and the second lighting unit 33 are arranged to illuminate the nozzle 11 from both the left and right sides.

[0088] And, in such Fig.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 respectively 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 in each cup 22. In addition, the fourth lighting unit 37 is arranged to irradiate the nozzle 11 in the cup 22A during the ejection from the side. The fifth lighting unit 38 is arranged to irradiate the nozzle 11 in the cup 22B during the ejection from slightly behind, and the optical axis is arranged not to pass through the center of the cup 22A and the cup 22B when viewed from above.

[0089] In such Fig.14In the third modification shown, the fourth lighting unit 37 and the fifth lighting unit 38 in the second modification are arranged in the opposite left and right directions. Therefore, the fourth lighting unit 37 and the fifth lighting unit 38 are arranged on the right side of the cup 22B, and are arranged to irradiate light from the right side to the nozzles 11 on each cup 22. As shown above, the lighting unit of the present disclosure can be arbitrarily set in structure and arrangement.

[0090] The number of treatment sections 21 is not limited to two, and more than two may be provided. For example, in addition to the treatment sections 21A and 21B, a treatment section 21C may be provided, so that the treatment section 21 may be provided with three treatment sections, and these treatment sections 21A to 21C may be arranged in a straight line in the left-right direction, and the treatment liquid supply mechanism 10 may be provided with a structure common to the three treatment sections 21. In the case where the treatment section 21C is provided in this way, the configuration of the reflective member 34 and the lighting section may also be applied to the configuration of the above-mentioned examples. That is, in the case where the reflective member 34 and the first lighting section 32 are provided for each treatment section 21, the cup 22, the reflective member 34, and the first lighting section 32 may be provided in the treatment section 21C in the same layout as the cup 22, the reflective member 34, and the first lighting section 32 in the treatment sections 21A and 21B. An example is shown in which the lighting section is configured to be common to the treatment section 21, and it may be common to the treatment sections 21A to 21C.

[0091] The liquid processing device to which the present technology is applied is not limited to the resist coating device. For example, it may be a structure in which a liquid for forming an anti-reflective film or a liquid for forming an insulating film is ejected 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 resist film after exposure 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 may 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.

[0092] The embodiments disclosed herein are illustrative in all aspects and should not be construed as restrictive. The embodiments described above may be omitted, replaced, modified, and combined in various forms without departing from the appended claims and the gist thereof.

Claims

1. A liquid treatment device, characterized in that: The liquid treatment device has: A plurality of stages, each of which carries a substrate; a plurality of nozzles, which are commonly used for 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 treatment 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 relative position with respect to the stage, and reflects the irradiation light from the illuminating unit to irradiate the irradiation light toward each of the nozzles.

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

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

5. The liquid treatment 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 changes a focus according to a nozzle to be monitored, thereby monitoring the states of the plurality of nozzles.

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 is provided with an arm, the arm having the plurality of nozzles, and moving 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.

8. A monitoring method, characterized in that: The monitoring method includes the following steps: placing the substrates on a plurality of stages respectively; supplying a processing liquid to the substrate using a plurality of nozzles commonly used for the plurality of stages; A monitoring step of photographing each of the nozzles using a camera common to the plurality of nozzles to monitor the status of the plurality of nozzles; as well as The imaging conditions of the camera are changed according to the monitoring conditions.

9. The monitoring method according to claim 8, characterized in that: The camera has a liquid lens, The monitoring method includes the following steps: photographing the plurality of nozzles in such a manner that the plurality of nozzles are within the photographing range of the camera; The monitoring step includes a step of changing a focus according to a nozzle to be monitored to monitor the states of the plurality of nozzles.

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