JP5859389B2 - Coating apparatus and coating liquid filling method - Google Patents

Description

  Embodiments disclosed herein relate to a coating apparatus and a coating liquid filling method.

  Conventionally, a spin coating method is known as a method of applying a coating solution to a substrate such as a semiconductor wafer or a glass substrate. In the spin coating method, the coating solution is dropped on the center of the substrate while the substrate is rotated, and the coating solution is spread on the substrate by diffusing the coating solution on the substrate by centrifugal force to form a coating film. It is a method of forming.

  In such a spin coating method, since most of the dropped coating solution is scattered outside the substrate, the usage efficiency of the coating solution is low. Therefore, in recent years, a slit coating method has been proposed as a coating method replacing the spin coating method.

  The slit coating method is a method of applying using a nozzle having a slit-like discharge port. Specifically, in the slit coating method, the coating liquid slightly exposed from the nozzle outlet is brought into contact with the substrate, and in this state, the nozzle and the substrate are moved relative to each other to apply the coating liquid onto the substrate. Spread coating to form a coating film. According to such a slit coating method, a necessary amount of the coating liquid can be applied to the substrate, so that the usage efficiency of the coating liquid can be increased (see Patent Document 1).

  Note that the nozzle described in Patent Document 1 has a storage space for storing the coating liquid, and discharges the coating liquid filled in the storage space from the discharge port through the slit-shaped passage. A coating liquid supply system is connected to the storage space, and the coating liquid is filled into the storage space by supplying the coating liquid from the coating liquid supply system.

JP-A-8-173875

  However, the above-described conventional technology has room for further improvement in terms of improving the efficiency of filling the coating liquid into the nozzle.

  For example, when the storage space of the nozzle is filled with the coating liquid, the coating liquid may be biased in the storage space. If the coating liquid in the storage space is biased, the water head pressure acting on the nozzle outlet becomes non-uniform, which may cause deterioration in film thickness uniformity. For this reason, it is preferable to wait until the coating liquid in the storage space is flattened after the nozzle is filled with the coating liquid, but it takes a long time to start the coating process.

  In particular, the higher the viscosity of the coating solution to be used, the longer the time until the coating solution is flattened. Therefore, how to improve the efficiency of filling the coating solution into the nozzle becomes a major issue.

  An object of one embodiment is to provide a coating apparatus and a coating liquid filling method capable of improving the efficiency of filling a nozzle with a coating liquid.

The coating apparatus which concerns on 1 aspect of embodiment is provided with a nozzle, a moving mechanism, a planarization part, a liquid level detection part, and a control part . The nozzle includes a storage chamber in which the coating liquid is stored and a slit-like flow path communicating with the storage chamber, and discharges the coating liquid from a discharge port formed at the tip of the flow path. The moving mechanism relatively moves the nozzle and the substrate along the surface of the substrate. The flattening unit flattens the liquid surface of the coating liquid stored in the storage chamber. The liquid level detection unit detects a plurality of liquid level heights in the longitudinal direction of the nozzle. The control unit controls the flattening unit based on the heights of the plurality of liquid levels detected by the liquid level detection unit.

The coating liquid filling method according to one aspect of the embodiment includes a supply process, a planarization process, a liquid level detection process, and a control process . The supply process includes a storage chamber in which the coating liquid is stored, and a slit-like flow path communicating with the storage chamber, and a storage chamber provided in a nozzle that discharges the coating liquid from a discharge port formed at the tip of the flow path. Supply coating solution inside. In the flattening step, the liquid surface of the coating liquid supplied into the storage chamber in the supplying step is flattened. In the liquid level detection step, a plurality of liquid level heights are detected in the longitudinal direction of the nozzle. The control process controls the flattening process based on the heights of the plurality of liquid levels detected by the liquid level detection process.

  According to one aspect of the embodiment, it is possible to improve the efficiency of filling the nozzle with the coating liquid.

FIG. 1 is a schematic side view showing the configuration of the coating apparatus according to the first embodiment. FIG. 2 is a schematic explanatory diagram of the coating process. FIG. 3A is a schematic front sectional view showing the configuration of the nozzle. 3B is a cross-sectional view taken along arrow AA in FIG. 3A. FIG. 4A is a schematic front view of a nozzle. FIG. 4B is a schematic rear view of the nozzle. FIG. 5 is a time chart showing the state change of each device in the coating process. FIG. 6A is a schematic diagram illustrating a state of the coating process. FIG. 6B is a schematic diagram illustrating a state of the coating process. FIG. 6C is a schematic diagram illustrating a state of the coating process. FIG. 7 is a flowchart showing a processing procedure executed by the coating apparatus. FIG. 8 is a schematic cross-sectional side view showing the configuration of the nozzle standby unit. FIG. 9 is a diagram illustrating the content of pressure control during the coating liquid filling process. FIG. 10 is a schematic perspective view showing the configuration of the nozzle cleaning unit. FIG. 11A is a schematic diagram illustrating another example of the liquid level detection method. FIG. 11B is a schematic diagram illustrating another example of the liquid level detection method. FIG. 12A is a schematic diagram illustrating another example of the liquid level detection method. FIG. 12B is a schematic diagram illustrating another example of the liquid level detection method. FIG. 13 is a schematic side sectional view showing another configuration of the flattening portion. FIG. 14A is a schematic side sectional view showing another configuration of the flattening portion. FIG. 14B is a diagram illustrating a state of the flattening process by the flattening unit illustrated in FIG. 14A. FIG. 15A is a schematic side cross-sectional view illustrating a configuration of a nozzle according to a third embodiment. FIG. 15B is a schematic front sectional view showing the configuration of the liquid supply port. FIG. 16 is a schematic diagram illustrating a connection relationship between a device related to the coating liquid filling process and a nozzle according to the fourth embodiment. FIG. 17 is a schematic diagram illustrating a connection relationship between a device related to the coating liquid filling process and a nozzle according to the fifth embodiment. FIG. 18 is a schematic enlarged view around the pressure adjusting tube in FIG. FIG. 19A is a schematic side cross-sectional view illustrating a configuration of a nozzle according to a sixth embodiment. FIG. 19B is a schematic enlarged view of a portion H shown in FIG. 19A.

  Hereinafter, embodiments of a coating apparatus and a coating liquid filling method disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

(First embodiment)
FIG. 1 is a schematic side view showing the configuration of the coating apparatus according to the first embodiment. In the following, in order to clarify the positional relationship, the X axis, the Y axis, and the Z axis that are orthogonal to each other are defined, and the positive direction of the Z axis is the vertically upward direction.

  As shown in FIG. 1, the coating apparatus 1 according to the first embodiment includes a mounting table 10, a first moving mechanism 20, a nozzle 30, and an elevating mechanism 40.

  The first moving mechanism 20 is a mechanism unit that moves the substrate W in the horizontal direction, and includes a substrate holding unit 21 and a driving unit 22. The substrate holding unit 21 has a horizontal upper surface on which a suction port is formed, and sucks and holds the substrate W on the horizontal upper surface by suction from the suction port. The driving unit 22 is mounted on the mounting table 10 and moves the substrate holding unit 21 in the horizontal direction (here, the X-axis direction). The first moving mechanism 20 moves the substrate holding unit 21 using the driving unit 22 to move the substrate W held by the substrate holding unit 21 in the horizontal direction.

  The nozzle 30 is a long nozzle extending in the direction (Y-axis direction) orthogonal to the moving direction (X-axis direction) of the substrate W, and is disposed above the substrate W held by the substrate holding unit 21. The The configuration of the nozzle 30 will be described later.

  The elevating mechanism 40 is a mechanism unit that elevates and lowers the nozzle 30 and includes a fixing unit 41 and a driving unit 42. The fixing portion 41 is a member that fixes the nozzle 30. The drive unit 42 moves the fixed unit 41 in the vertical direction. The elevating mechanism 40 moves the fixing unit 41 in the vertical direction by using the driving unit 42 to elevate and lower the nozzle 30 fixed to the fixing unit 41.

  In addition, the coating apparatus 1 includes a thickness measuring unit 50a, a nozzle height measuring unit 50b, a nozzle cleaning unit 60, a nozzle standby unit 80, a second moving mechanism 90, and a control device 100.

  The thickness measurement unit 50 a is a measurement unit that is disposed above the substrate W (here, the lifting mechanism 40) and measures the distance to the upper surface of the substrate W. The nozzle height measuring unit 50 b is disposed below the substrate W (here, the mounting table 10) and measures the distance to the lower end surface of the nozzle 30.

  The measurement results by the thickness measurement unit 50a and the nozzle height measurement unit 50b are transmitted to the control device 100 described later, and are used to determine the height of the nozzle 30 during the coating process. For example, a laser displacement meter can be used as the thickness measuring unit 50a and the nozzle height measuring unit 50b.

  The nozzle cleaning unit 60 is a processing unit that removes the coating liquid adhering to the tip of the nozzle 30. The configuration of the nozzle cleaning unit 60 will be described later.

  The nozzle standby unit 80 has a storage space in which the nozzle 30 can be stored. The interior of the storage space is maintained in a thinner atmosphere, and drying of the coating liquid in the nozzle 30 is prevented by allowing the nozzle 30 to stand by in the storage space. The configuration of the nozzle standby unit 80 will also be described later.

  The second moving mechanism 90 is a mechanism that moves the nozzle cleaning unit 60 and the nozzle standby unit 80 in the horizontal direction, and includes a placement unit 91, a support unit 92, and a drive unit 93.

  The placement unit 91 is a plate-like member that places the nozzle cleaning unit 60 and the nozzle standby unit 80 substantially horizontally. The placement unit 91 is supported by the support unit 92 at a predetermined height, specifically, a height at which the substrate W held by the substrate holding unit 21 can pass under the placement unit 91. The drive unit 93 moves the support unit 92 in the horizontal direction.

  The second moving mechanism 90 moves the nozzle cleaning unit 60 and the nozzle standby unit 80 mounted on the mounting unit 91 in the horizontal direction by moving the support unit 92 in the horizontal direction using the driving unit 93. Let

  The control device 100 is a device that controls the operation of the coating apparatus 1. The control device 100 is a computer, for example, and includes a control unit and a storage unit (not shown). The storage unit stores a program for controlling various processes such as a coating process. The control unit controls the operation of the coating apparatus 1 by reading and executing the program stored in the storage unit.

  Such a program may be recorded on a computer-readable recording medium and may be installed in the storage unit of the control device 100 from the recording medium. Examples of the computer-readable recording medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

  Next, an outline of the coating process performed by the coating apparatus 1 will be described with reference to FIG. FIG. 2 is a schematic explanatory diagram of the coating process. The coating process performed by the coating apparatus 1 is performed by applying the coating liquid onto the substrate W by moving the substrate W in the horizontal direction while the coating liquid exposed from the long nozzle 30 is in contact with the substrate W. This is a process of spreading and forming a coating film.

  As shown in FIG. 2, the nozzle 30 is a long member extending in a direction (Y-axis direction) orthogonal to the moving direction (X-axis direction) of the substrate W, and is formed at the lower end portion. The coating liquid R is discharged from the long discharge port D.

  First, the coating apparatus 1 exposes the coating liquid R from the discharge port D of the nozzle 30. At this time, the coating apparatus 1 can maintain the state in which the coating liquid R is exposed from the discharge port D by controlling the pressure in the nozzle 30. This point will be described later.

  Subsequently, the coating apparatus 1 moves the nozzle 30 downward using the elevating mechanism 40 (see FIG. 1) to bring the coating liquid R exposed from the discharge port D into contact with the upper surface of the substrate W. Then, the coating apparatus 1 moves the substrate W horizontally using the first moving mechanism 20 (see FIG. 1). Thereby, the coating liquid R is spread on the upper surface of the substrate W to form a coating film. Note that the coating film formed on the substrate W by the coating apparatus 1 is a thick film of 10 μm or more.

  The nozzle 30 according to the first embodiment includes a storage chamber for storing the coating liquid R, and discharges the coating liquid R filled in the storage chamber from the discharge port D through the slit-shaped channel. A coating liquid supply system is connected to the storage chamber, and the coating liquid R is filled into the storage chamber by supplying the coating liquid R from the coating liquid supply system.

  Here, when the storage chamber is filled with the coating liquid R, the coating liquid R may be biased in the storage chamber. If the coating liquid R in the storage chamber is biased, the water head pressure acting on the discharge port D of the nozzle 30 becomes non-uniform, which may deteriorate the film thickness uniformity. For this reason, after filling the nozzle 30 with the coating liquid R, it is preferable to wait until the coating liquid R in the storage chamber is flattened, but it takes time to start the coating process. In particular, since the coating liquid R handled by the coating apparatus 1 is a high-viscosity fluid having a viscosity of about several thousand cP, it takes a long time to flatten.

  Therefore, the coating apparatus 1 according to the first embodiment positively planarizes the coating liquid R by applying a physical force to the coating liquid R stored in the storage chamber. Thereby, since the time required for planarization can be shortened, the filling operation | work of the coating liquid R to the nozzle 30 can be made efficient.

  Hereinafter, the configuration of the flattening unit will be specifically described together with the configuration of the nozzle 30. 3A is a schematic front sectional view showing the configuration of the nozzle 30, and FIG. 3B is a cross-sectional view taken along the line AA in FIG. 3A. 4A is a schematic front view of the nozzle 30, and FIG. 4B is a schematic rear view of the nozzle 30.

  As shown in FIGS. 3A and 3B, the nozzle 30 includes a storage chamber S in which the coating liquid R is stored, and a slit-like flow path C that is disposed below the storage chamber S and communicates with the storage chamber S. The coating liquid R is discharged from the discharge port D formed at the tip of the flow path C (that is, the lower end surface of the nozzle 30).

  More specifically, the nozzle 30 includes a first main body portion 31 that forms a back surface portion and both side surface portions of the nozzle 30, a second main body portion 32 that forms a front surface portion, a lid portion 33 that forms a ceiling portion, The first main body 31 includes a long land portion 34 disposed on a surface facing the second main body 32. Of the space inside the nozzle 30 formed by the first main body portion 31, the second main body portion 32 and the lid portion 33, a space having a width K sandwiched between the first main body portion 31 and the second main body portion 32 is stored. A space having a width G narrower than the width K sandwiched between the land portion 34 and the second main body portion 32 becomes the flow path C. The width of the channel C is constant at the width G, and the width of the discharge port D formed at the tip of the channel C is also the width G.

  In the state where the pressure inside the storage chamber S is equal to the pressure outside the storage chamber S, the width G becomes smaller than the gravity acting on the coating liquid R, and the coating liquid is applied at a predetermined flow rate. The value is set such that R drops from the discharge port D. Specifically, the width G is obtained by changing the width G, the viscosity of the coating liquid R, and the material of the nozzle 30 in a test performed in advance, and evaluating the state of the coating liquid R in that case.

  The lid 33 adjusts the pressure in the sealed space, and a pressure measuring unit 36 that measures the pressure in the sealed space surrounded by the liquid level of the coating liquid R stored in the storage chamber S and the inner wall surface of the storage chamber S. A pressure adjustment pipe 37 connected to the pressure adjustment unit 110 is provided through the lid 33. The pressure measurement unit 36 is electrically connected to the control device 100, and the measurement result is input to the control device 100.

  The pressure measurement unit 36 may be arranged in any manner as long as it communicates with the sealed space in the nozzle 30, and may be provided through the first main body 31, for example.

  The pressure adjustment unit 110 has a configuration in which an exhaust unit 111 such as a vacuum pump and a gas supply source 112 that supplies a gas such as N 2 are connected to the pressure adjustment pipe 37 via a switching valve 113. The pressure adjusting unit 110 is also electrically connected to the control device 100, and the pressure of the exhaust unit 111 or the gas supply source 112 is adjusted by adjusting the opening of the switching valve 113 according to a command from the control device 100. By connecting to the adjustment pipe 37, the exhaust amount from the inside of the storage chamber S can be adjusted, or the amount of gas supplied into the storage chamber S can be adjusted. Thereby, the coating device 1 can adjust so that the measurement result of the pressure measurement part 36, ie, the pressure in the storage chamber S, may become a predetermined value.

  In such a case, the inside of the storage chamber S is evacuated so that the pressure in the storage chamber S is lower than the pressure outside the storage chamber S, whereby the coating liquid R in the storage chamber S is pulled upward and applied from the discharge port D. The liquid R can be prevented from dripping. Further, by supplying gas into the storage chamber S, the coating liquid R remaining in the storage chamber S after application of the coating liquid R can be pressurized and pushed out or purged.

  The coating apparatus 1 performs the coating process of the coating liquid R on the substrate W while controlling the pressure of the sealed space formed in the storage chamber S. This point will be described later.

  In addition, about the structure of the pressure adjustment part 110, if it can control the pressure in the storage chamber S, it is not limited to this embodiment, The structure can be set arbitrarily. For example, a pressure adjusting pipe 37 and a pressure adjusting valve may be provided in each of the exhaust part 111 and the gas supply source 112 and individually connected to the lid part 33.

  The nozzle 30 is connected to a coating liquid supply system including the coating liquid supply unit 120, the intermediate tank 130, the supply pump 140, and the pressurization unit 150.

  The coating liquid supply unit 120 includes a coating liquid supply source 121 and a valve 122. The coating liquid supply source 121 is connected to the intermediate tank 130 via the valve 122 and supplies the coating liquid R to the intermediate tank 130. Further, the coating liquid supply unit 120 is electrically connected to the control device 100, and the opening / closing of the valve 122 is controlled by the control device 100.

  The intermediate tank 130 is a tank interposed between the coating liquid supply unit 120 and the nozzle 30. The intermediate tank 130 includes a tank unit 131, a first supply pipe 132, a second supply pipe 133, a third supply pipe 134, and a liquid level sensor 135.

  The tank part 131 stores the coating liquid R. A first supply pipe 132 and a second supply pipe 133 are provided at the bottom of the tank portion 131. The first supply pipe 132 is connected to the coating liquid supply source 121 via the valve 122. Further, the second supply pipe 133 is connected to the side surface portion of the nozzle 30 via the supply pump 140.

  A pressurizing unit 150 is connected to the third supply pipe 134. The pressurizing unit 150 includes a gas supply source 151 that supplies a gas such as N 2 and a valve 152, and pressurizes the tank unit 131 by supplying gas into the tank unit 131. The pressurizing unit 150 is electrically connected to the control device 100, and the opening / closing of the valve 152 is controlled by the control device 100.

  The liquid level sensor 135 is a detection unit that detects the liquid level of the coating liquid R stored in the tank unit 131. The liquid level sensor 135 is electrically connected to the control device 100, and a detection result is input to the control device 100.

  The supply pump 140 is provided in the middle of the second supply pipe 133 and supplies the coating liquid R supplied from the intermediate tank 130 to the nozzle 30 by a predetermined amount. The supply pump 140 is electrically connected to the control device 100, and the supply amount of the coating liquid R to the nozzle 30 is controlled by the control device 100.

  As described above, the nozzle 30 is connected to the coating liquid supply system including the coating liquid supply unit 120, the intermediate tank 130, the supply pump 140, and the pressurization unit 150. The coating liquid R is supplied into the storage chamber S.

  Here, as described above, the coating liquid R is a highly viscous fluid. For this reason, when the coating liquid R is supplied from the coating liquid supply system into the storage chamber S, as shown in FIG. 3A, the coating liquid R is biased toward the side to which the coating liquid supply system is connected. It is stored in.

  Therefore, the coating apparatus 1 according to the first embodiment includes an ultrasonic vibrator 180 as a flattening unit for flattening the coating liquid R stored in the storage chamber S as illustrated in FIG. 3B. did.

  The ultrasonic vibrator 180 is attached to, for example, the back surface of the nozzle 30 and applies ultrasonic vibration to the coating liquid R in the storage chamber S via the back surface. Thereby, the coating liquid R can be planarized quickly. Further, the ultrasonic transducer 180 is electrically connected to the control device 100, and on / off is controlled by the control device 100.

  As shown in FIG. 4A, a plurality of ultrasonic transducers 180 (here, five) are provided along the longitudinal direction of the nozzle 30. Thereby, ultrasonic vibration can be uniformly given to the coating liquid R along the longitudinal direction of the nozzle 30. Note that the coating apparatus 1 may be configured to include one ultrasonic transducer 180 on the side to which the coating liquid supply system is connected.

  In addition, the ultrasonic vibrator 180 is as low as possible in the storage chamber S, specifically, the storage chamber S and the flow path C so that the coating liquid R does not scatter in the storage chamber S due to vibration by the ultrasonic vibrator 180. It is preferable to provide in the vicinity of the boundary part.

  Moreover, the coating device 1 is further provided with the liquid level detection part 160, as shown to FIG. 3B. The liquid level detection unit 160 is disposed in front of the nozzle 30 and detects the position of the liquid level of the coating liquid R stored in the storage chamber S (hereinafter referred to as “liquid level height”).

  Here, as shown in FIG. 4B, a part of the second main body portion 32 forming the front portion of the nozzle 30 is formed of a transparent member 32a, and the coating liquid R stored in the storage chamber S is transferred to the transparent member. It can be visually recognized through 32a. The liquid level detection unit 160 is, for example, a CCD (Charge Coupled Device) camera, and detects the position of the liquid level of the coating liquid R by photographing the inside of the storage chamber S from the front of the nozzle 30 via the transparent member 32a. . The detection result by the liquid level detection unit 160 is input to the control device 100. Thereby, the coating device 1 can detect the liquid level height of the coating liquid R easily.

  The coating apparatus 1 controls on / off of the ultrasonic transducer 180 based on the detection result by the liquid level detection unit 160. That is, the coating apparatus 1 obtains a difference between the maximum height and the minimum height of the liquid level from the detection result by the liquid level detection unit 160, and if the difference exceeds a predetermined threshold, the ultrasonic vibrator 180 is set. Turn on. And the coating device 1 turns off the ultrasonic transducer | vibrator 180, when a difference becomes below a predetermined threshold value.

  The coating apparatus 1 may change the vibration force of the ultrasonic transducer 180 based on the detection result by the liquid level detection unit 160. For example, the coating apparatus 1 may increase the vibration force of the ultrasonic vibrator 180 as the application liquid is more biased.

  Next, the operation | movement at the time of an application | coating process is demonstrated using FIG. 5 and FIG. 6A-FIG. 6C. FIG. 5 is a time chart showing the state change of each device in the coating process. 6A to 6C are schematic views showing the state of the coating process.

  Hereinafter, a pressure state lower than the pressure outside the storage chamber S is referred to as “negative pressure”. Further, when changing the negative pressure value, for example, when changing in a direction in which the absolute value increases, as in changing from “−400 Pa” to “−450 Pa”, “reducing pressure” or “ Increase the degree of vacuum.

  Further, the nozzle 30 is assumed to be filled with the coating liquid R. The amount of the coating liquid R filled in the nozzle 30 may be any amount that can apply the coating liquid R to the entire surface of the substrate W at least once.

  Further, in the coating liquid filling process (see step S101 in FIG. 8) described later, the storage is performed after the coating liquid R is filled in the nozzle 30 until the next coating process (see step S108 in FIG. 8) is started. The pressure in the chamber S is adjusted to a predetermined value P0 (see FIG. 5). Thereby, the coating liquid R is held in the nozzle 30 without dripping from the discharge port D until the coating process is started. The predetermined value P0 is a negative pressure (for example, −450 Pa) lower than the pressure outside the storage chamber S (atmospheric pressure).

  When the coating apparatus 1 starts the coating process, first, the pressure in the storage chamber S is adjusted to P1 (for example, −440 Pa) higher than P0 using the pressure adjusting unit 110 (see time t1 in FIG. 5). Thereby, the gravity acting on the coating liquid R slightly exceeds the surface tension of the coating liquid R and the negative pressure in the storage chamber S, and the coating liquid R held in the nozzle 30 is exposed from the discharge port D. As a result, the liquid level of the coating liquid R stored in the storage chamber S decreases from H0 to H1.

  Subsequently, the coating apparatus 1 lowers the nozzle 30 using the lifting mechanism 40 (see FIG. 1), and as shown in FIG. 6A, the distance between the discharge port D and the substrate W (hereinafter referred to as “nozzle gap”). Is a predetermined distance Z1 (see time t2 in FIG. 5). Thereby, the coating liquid R exposed from the discharge port D comes into contact with the upper surface of the substrate W.

  The nozzle gap Z0 is calculated based on the distance to the upper surface of the substrate W obtained by a thickness measurement process (see S107 in FIG. 8) described later. The nozzle gap Z1 is a value set in advance by a test or the like.

  Subsequently, the coating apparatus 1 raises the nozzle 30 to set the nozzle gap to Z2 (> Z1) (see time t3 in FIG. 5). As a result, the coating liquid R exposed from the discharge port D is stretched upward while in contact with the upper surface of the substrate W, as shown in FIG. 6B. Further, along with this, the liquid level of the coating liquid R stored in the storage chamber S decreases from H1 to H2. The nozzle gap Z2 is set according to the thickness of the coating film to be formed on the substrate W.

  Thereafter, the coating apparatus 1 uses the first moving mechanism 20 (see FIG. 1) to move the substrate W to a predetermined speed until the end of the substrate W on the X-axis negative direction side is disposed directly below the nozzle 30. Move with. As a result, as shown in FIG. 6C, the coating liquid R in the storage chamber S flows out from the discharge port D, and the coating liquid R is applied to the upper surface of the substrate W.

  Here, the coating apparatus 1 prevents the deterioration of the film thickness uniformity in the scanning direction by adjusting the pressure in the storage chamber S using the pressure adjusting unit 110.

  Specifically, the coating apparatus 1 adjusts the pressure in the storage chamber S from P2 (for example, −430 Pa) to P5 (for example, −430 Pa) by the pressure adjusting unit 110 in accordance with the decrease in the liquid level of the coating liquid R in the storage chamber S. , −400 Pa) (steps t5 to t8 in FIG. 5).

  When the liquid level of the coating liquid R in the storage chamber S decreases, the hydraulic head pressure due to the coating liquid R acting on the discharge port D decreases. During this time, if the pressure in the storage chamber S and the pressure outside the storage chamber S are constant and constant, the force that pushes the coating liquid R from the discharge port D is reduced by the amount that the hydraulic head pressure has decreased. The discharge amount of the coating liquid R decreases.

  Therefore, in the present embodiment, the pressure in the storage chamber S is increased stepwise to P5 (−400 Pa) by the pressure adjusting unit 110 in accordance with the decrease in the liquid level of the coating liquid R in the storage chamber S. The decrease in the water head pressure at the discharge port D due to the liquid level drop is compensated. As a result, the discharge amount of the coating liquid R from the discharge port D is kept constant, and a coating film having a uniform film thickness can be formed in the surface of the substrate W.

  The pressure in the storage chamber S can be adjusted according to the relative movement distance between the nozzle 30 and the substrate W, for example. In such a case, a correlation between the moving distance of the nozzle 30 and the pressure setting value in the storage chamber S may be obtained in advance, and the pressure in the storage chamber S may be adjusted based on this correlation. By obtaining such a correlation in advance, a decrease in the water head pressure is obtained from the consumption of the coating liquid R at a predetermined position on the substrate W of the nozzle 30, thereby adjusting the pressure in the storage chamber S. Can do.

  Further, the pressure in the storage chamber S may be adjusted according to the level of the coating liquid R in the storage chamber S. In this case, the value of the pressure in the storage chamber S to be raised by the pressure adjusting unit 110 is obtained based on, for example, the liquid level of the coating liquid R detected by the liquid level detecting unit 160.

  Specifically, the difference between the liquid level height of the coating liquid R before the start of coating and the liquid level height of the coating liquid R after the start of coating is obtained. Then, by multiplying the difference by the density of the coating liquid R, a decrease in the hydraulic head pressure applied to the discharge port D can be obtained. Therefore, the pressure adjusting unit 110 increases the pressure in the storage chamber S by the reduced amount of the water head pressure, so that the water head pressure applied to the discharge port D becomes constant. Thereby, the discharge amount of the coating liquid R from the discharge port D becomes constant, and a coating film having a uniform film thickness can be formed in the surface of the substrate W.

  Further, for example, another pressure measuring mechanism is provided in the channel C, and the head pressure acting on the coating liquid R in the channel C is directly obtained, and the pressure adjusting unit 110 causes the head pressure in the storage chamber S to be constant. It is also possible to adjust the pressure.

  In any case, the pressure adjustment unit 110 makes the discharge amount of the coating liquid R from the discharge port D constant, in other words, the hydraulic head pressure acting on the coating liquid R at the discharge port D becomes constant. In addition, since the pressure in the storage chamber S is adjusted, a coating film having a uniform film thickness can be formed in the surface of the substrate W.

  As described above, the coating apparatus 1 controls the pressure adjusting unit 110 so that the discharge amount of the coating liquid R is constant while the coating liquid R is applied to the substrate W under the control of the control apparatus 100 to store the storage chamber. Adjust the pressure inside S. Thereby, the coating device 1 can suppress the deterioration of the film thickness uniformity in the scanning direction.

  Further, the coating apparatus 1 adjusts the pressure in the storage chamber S to hold the coating liquid R against gravity acting on the coating liquid, or to control the discharge amount of the coating liquid R to the substrate W. Is possible. For this reason, even if the width of the discharge port is widened in order to handle a high-viscosity coating liquid R having a viscosity of about several thousand cP, liquid dripping from the discharge port and film thickness failure during coating are prevented. Can do. That is, the high-viscosity coating liquid can be uniformly coated on the substrate W without waste.

  When the end of the substrate W on the X-axis negative direction side moves to a position directly below the nozzle 30, the coating apparatus 1 lowers the nozzle 30 to bring the ejection port D and the substrate W closer to the distance Z1 (time t9 in FIG. 5). At the same time, the coating apparatus 1 raises the pressure in the storage chamber S to P6 (for example, −390 Pa) by the pressure adjusting unit 110, whereby the coating liquid R once applied to the substrate W is drawn into the storage chamber S side. , Preventing application defects.

  Thereafter, the coating apparatus 1 raises the nozzle 30 to the nozzle gap Z0 (time t10 in FIG. 5). Thereby, the supply of the coating liquid R from the discharge port D to the substrate W is stopped, and the coating process is completed.

  Next, a substrate processing procedure including the above-described coating treatment will be described. FIG. 7 is a flowchart showing a processing procedure of the substrate processing executed by the coating apparatus 1. Note that each processing procedure shown in FIG. 7 is executed by the coating apparatus 1 based on the control of the control apparatus 100.

  Here, the processing of steps S101 to S109 shown in FIG. 7 is repeated until the processing is completed for all of the plurality of substrates included in one lot. When the substrate processing for one lot is completed, the substrate processing for the next lot is started, but before that, nozzle cleaning processing for cleaning the tip of the nozzle 30 is performed. This nozzle cleaning process will be described later.

  As shown in FIG. 7, the coating apparatus 1 performs the processes of steps S101 to S104 and the processes of steps S105 to S107 in parallel, and after the processes of step S104 and step S107 are finished, the coating process described above is performed. Is executed (step S108). First, the processing of steps S101 to S104 will be described.

  In the processes of steps S101 to S104, the coating apparatus 1 first performs a coating liquid filling process (step S101). In the coating liquid filling process in step S <b> 101, the coating apparatus 1 first moves the nozzle standby unit 80 directly below the nozzle 30, then lowers the nozzle 30 and arranges it in the nozzle standby unit 80. Then, the nozzle 30 is filled with the coating liquid in a state where the nozzle 30 is disposed in the nozzle standby unit 80.

  Here, the configuration of the nozzle standby unit 80 will be described with reference to FIG. FIG. 8 is a schematic side sectional view showing the configuration of the nozzle standby unit 80.

  As shown in FIG. 8, the nozzle standby unit 80 has an accommodation space 81 in which the nozzle 30 can be accommodated. Thinner is stored in the storage space 81, and the thinner is volatilized to keep the interior of the storage space 81 in a thinner atmosphere.

  The accommodating space 81 is provided with a substantially flat contact member 82 extending in the longitudinal direction (Y-axis direction) of the discharge port D of the nozzle 30. The contact member 82 is formed of a resin material having chemical resistance such as rubber.

  The coating apparatus 1 causes the tip end surface of the nozzle 30 to abut against the abutting member 82 by lowering the nozzle 30 toward the accommodation space 81 of the nozzle standby unit 80. As a result, the discharge port D is closed by the contact member 82. In this state, the coating apparatus 1 can prevent the coating liquid R from leaking from the discharge port D during the filling of the coating liquid R by filling the nozzle 30 with the coating liquid R. In particular, when the coating liquid R is filled from an empty state with respect to the nozzle 30, leakage of the coating liquid R from the discharge port D can be effectively prevented.

  Next, the operation of the coating apparatus 1 during the coating liquid filling process will be described. The coating apparatus 1 determines the amount of coating liquid R to be filled into the nozzle 30 (hereinafter referred to as “target amount”) based on the detection result of the liquid level detection unit 160 (see FIG. 3B). Then, the coating apparatus 1 operates the supply pump 140 to supply a target amount of the coating liquid R from the intermediate tank 130 to the nozzle 30 (see FIG. 3A).

  At this time, the coating apparatus 1 supplies the coating liquid R to the storage chamber S while adjusting the pressure in the storage chamber S using the pressure adjusting unit 110 (see FIG. 3A). Here, the content of the pressure control during the coating liquid filling process will be described with reference to FIG. FIG. 9 is a diagram illustrating the content of pressure control during the coating liquid filling process.

  During the coating liquid filling process, the pressure in the storage chamber S is adjusted to a negative pressure. Thereby, the coating liquid R remaining in the storage chamber S can be prevented from leaking from the discharge port D.

  As shown in FIG. 9, the coating apparatus 1 gradually increases the pressure in the storage chamber S adjusted to the negative pressure according to the liquid level height of the storage chamber S detected by the liquid level detection unit 160. The coating liquid R is supplied while decreasing (that is, increasing the degree of vacuum).

  Specifically, the pressure in the storage chamber S at the start of the coating liquid filling process is P6 (for example, −390 Pa), similar to the pressure in the storage chamber S at the end of the coating process. On the other hand, the pressure in the storage chamber S at the end of the coating liquid filling process is adjusted to a pressure P0 (for example, −450 Pa) before the coating process is started. And the coating device 1 changes a pressure from P6 to P0 according to the liquid level height of the storage chamber S. FIG.

  As described above, the coating apparatus 1 controls the pressure adjusting unit 110 to make the inside of the storage chamber S have a negative pressure, and further gradually reduce the pressure inside the storage chamber S that has been set to a negative pressure. The coating liquid R is supplied into S.

  When the storage chamber S is filled with the coating liquid R and the liquid level of the coating liquid R in the storage chamber S rises, the hydraulic head pressure due to the coating liquid R acting on the discharge port D increases. During this time, if the pressure inside the storage chamber S and the pressure outside the storage chamber S do not change and are constant, the force that pushes up the coating liquid R by the amount that the hydraulic head pressure has increased is relatively weakened. The coating liquid R is likely to leak from the discharge port D.

  On the other hand, in the first embodiment, the pressure adjustment unit 110 gradually decreases the pressure in the storage chamber S in accordance with the increase in the liquid level of the coating liquid R in the storage chamber S, so that the application is performed. The force which pushes up the liquid R upward can be supplemented. For this reason, it can prevent more reliably that the coating liquid R leaks from the discharge outlet D during a coating liquid filling process.

  In addition, the coating apparatus 1 controls the pressure adjusting unit 110 from the end of the supply of the coating liquid R into the storage chamber S to the start of the coating process, and thereby applies the coating liquid R into the storage chamber S. The pressure in the storage chamber S (that is, P0) at the time when the supply of is completed is maintained. For this reason, the pressure control in the storage chamber S in a series of substrate processing can be performed efficiently.

  Here, the pressure is changed according to the liquid level, but the pressure is not limited to this, and the pressure may be changed according to a predetermined time, for example.

  Further, the coating apparatus 1 supplies the coating liquid R to the nozzle 30 not from the coating liquid supply source 121 but from an intermediate tank 130 provided between the coating liquid supply source 121 and the nozzle 30. Thereby, since the piping distance to the nozzle 30 can be shortened, for example, even when the viscosity of the coating liquid R is high and supply from the coating liquid supply source 121 is difficult, the intermediate tank 130 to the nozzle 30. The coating liquid R can be easily supplied.

  In addition, when the supply from the intermediate tank 130 to the nozzle 30 is difficult, the coating apparatus 1 applies the pressure from the intermediate tank 130 to the nozzle 30 by increasing the pressure in the tank unit 131 using the pressurizing unit 150. Liquid R can be supplied.

  In addition, based on the detection result of the liquid level sensor 135, the coating apparatus 1 controls the coating liquid supply unit 120 when determining that the amount of the coating liquid R stored in the tank unit 131 is less than a predetermined amount. Then, the coating liquid R is supplied from the coating liquid supply source 121 to the tank unit 131. Thereby, the coating liquid R is replenished to the tank part 131.

  Here, an example in which the liquid level detection unit is an imaging device such as a CCD camera has been shown, but the liquid level detection unit is not limited to the imaging device, and may be an optical sensor such as an infrared sensor. There may be.

  Returning to FIG. 7, the description of the substrate processing will be continued. When the coating liquid filling process in step S101 is completed, the coating apparatus 1 determines whether or not the liquid level of the coating liquid R filled in the storage chamber S is flat based on the detection result of the liquid level detection unit 160. (Step S102). For example, the coating apparatus 1 calculates a difference between the highest position and the lowest position of the liquid level, and determines that the liquid level is flat if the difference is within a predetermined range.

  In this process, when the liquid level is not flat (No at Step S102), the coating apparatus 1 performs the above-described flattening process (Step S103) and then performs the determination at Step S102 again. The coating apparatus 1 repeats the process of step S102 and step S103 until the liquid level becomes flat, and determines that the liquid level is flat (step S102, Yes), the process proceeds to the nozzle priming process of step S104. .

  As described above, the coating apparatus 1 determines whether the liquid level is flattened based on the detection result by the liquid level detection unit 160, and uses the nozzle 30 when determining that the liquid level is flattened. Since the coating process is started, it is possible to prevent deterioration in film thickness uniformity. That is, when the liquid level is not flat, in other words, when the coating liquid R in the storage chamber S is uneven, the water head pressure acting on the discharge port D of the nozzle 30 becomes non-uniform, and the film thickness uniformity deteriorates. There is a fear. For this reason, the deterioration of film thickness uniformity can be prevented by starting the coating process after the liquid surface is flattened as in this embodiment.

  Next, the nozzle priming process in step S104 will be described. The nozzle priming process is a process of adjusting the state of the discharge port D by wiping the tip of the nozzle 30 using the nozzle cleaning unit 60 (see FIG. 1). When the nozzle priming process is started, the coating apparatus 1 returns the substrate W to the initial position (position shown in FIG. 1) and moves the nozzle cleaning unit 60 directly below the nozzles 30 using the second moving mechanism 90. . And the coating device 1 arranges the state of the discharge outlet D by wiping off the coating liquid R exposed from the discharge outlet D using the nozzle washing | cleaning part 60. FIG.

  Here, the configuration of the nozzle cleaning unit 60 and the contents of the nozzle priming process will be described with reference to FIG. FIG. 10 is a schematic perspective view showing the configuration of the nozzle cleaning unit 60.

  As shown in FIG. 10, the nozzle cleaning unit 60 includes thinner discharge units 61 a and 61 b, pad units 62 a and 62 b, N 2 ejection units 63 a and 63 b, a mounting unit 64, and a driving unit 65.

  The thinner discharge parts 61a and 61b are connected to a thinner supply source via a pump (not shown), and the thinner supplied from the thinner supply source is directed from both sides of the nozzle 30 in the short direction toward the tip of the nozzle 30. Discharge. Thereby, the coating liquid adhering to the tip part of the nozzle 30 can be dissolved.

  The pad portions 62 a and 62 b are formed in a substantially V shape along the shape of the tip portion of the nozzle 30 and abut on both sides of the tip portion of the nozzle 30 in the short direction. When the pad portions 62a and 62b are moved by a driving portion 65 described later, the coating liquid adhering to the tip portion of the nozzle 30 is wiped off by the pad portions 62a and 62b.

  The N2 ejection parts 63a and 63b are connected to an N2 supply source via a pump (not shown) or the like, and N2 supplied from the N2 supply source is directed from both sides in the short direction of the nozzle 30 toward the tip part of the nozzle 30. Erupts. Thereby, the front-end | tip part of the nozzle 30 is dried.

  These thinner discharge parts 61a and 61b, pad parts 62a and 62b, and N2 ejection parts 63a and 63b are mounted on the mounting part 64. Specifically, in parallel with the extending direction of the nozzle 30 (Y-axis direction), the thinner discharge portion 61a, the pad portion 62a, the thinner discharge portion 61b, the pad portion 62b, the N2 discharge portion 63a, and the N2 discharge portion 63b, respectively. Placed side by side.

  The driving unit 65 moves the mounting unit 64 in a direction parallel to the extending direction (Y-axis direction) of the nozzle 30 to thereby perform thinner discharge units 61a and 61b and a pad unit 62a mounted on the mounting unit 64. , 62b and the N2 ejection parts 63a, 63b are moved in parallel with the extending direction of the nozzle 30.

  When performing the nozzle priming process, the coating apparatus 1 uses only the pad parts 62a and 62b among the thinner discharge parts 61a and 61b, the pad parts 62a and 62b, and the N2 ejection parts 63a and 63b.

  Specifically, the coating apparatus 1 lowers the nozzle 30 using the elevating mechanism 40, and places the nozzle 30 at a position where the tip of the nozzle 30 abuts against the pad portions 62a and 62b. Is used to move the mounting portion 64 in the negative Y-axis direction. Thereby, the coating liquid R exposed from the discharge port D and the coating liquid R adhering to the tip of the nozzle 30 are wiped off by the pad portions 62a and 62b, and the state of the discharge port D is adjusted.

  After finishing the nozzle priming process, the coating apparatus 1 starts the coating process (step S108). Thus, the coating apparatus 1 can improve the film thickness uniformity immediately after the start of the coating process by starting the coating process after adjusting the state of the discharge port D by the nozzle priming process. Moreover, since the coating apparatus 1 performs the nozzle priming process immediately before starting the coating process, it is possible to easily maintain the state in which the discharge ports D are arranged.

  Note that the thinner discharge portions 61a and 61b and the N2 ejection portions 63a and 63b included in the nozzle cleaning portion 60 are used during nozzle cleaning processing performed between lots. That is, in the nozzle cleaning process, the coating apparatus 1 uses the driving unit 65 to move the mounting unit 64 in the Y-axis while the thinner is ejected from the thinner discharge units 61a and 61b and N2 is ejected from the N2 ejecting units 63a and 63b. Move in the negative direction. Accordingly, the nozzle cleaning unit 60 supplies the thinner at the tip of the nozzle 30 with the thinner discharger 61a, the wiper with the pad 62a, the thinner supply with the thinner discharger 61b, the wiper with the pad 62b, and the N2 ejection part 63a. , 63b, N2 is ejected to clean the nozzle 30.

  It continues and demonstrates the process of step S105-S107. The coating apparatus 1 sucks and holds the substrate W placed on the upper surface of the substrate holding unit 21 using the substrate holding unit 21 (step S105), and then performs a nozzle height measurement process (step S106). In such a nozzle height measurement process, the coating apparatus 1 uses the nozzle height measurement unit 50b to measure the distance to the lower end surface of the nozzle 30 to determine whether the nozzle 30 is positioned at a specified height. Confirm. In such a process, when the nozzle height is deviated from the predetermined height, the coating apparatus 1 may correct the nozzle height using the drive unit 42.

  The nozzle height measurement process may be performed before step S105. Further, the nozzle height measurement process may be performed only for any one (for example, the first one) of the substrate processes repeatedly performed for each lot.

  Subsequently, the coating apparatus 1 performs a thickness measurement process (step S107). Specifically, the coating apparatus 1 moves the substrate W held by the substrate holding unit 21 to the lower side of the thickness measuring unit 50a using the driving unit 22, and then uses the thickness measuring unit 50a to move the upper surface of the substrate W. Measure the distance to. A measurement result by the thickness measuring unit 50 a is transmitted to the control device 100.

  Note that the outer edge of the substrate W may have a roughened surface due to each process until it is transferred to the coating apparatus 1. For this reason, it is preferable that a position inside a predetermined distance (for example, about 2 mm) from the outer edge of the substrate W is a measurement point of the thickness measurement unit 50a.

  In addition, the coating apparatus 1 includes a plurality of (for example, two) thickness measurement units 50a, and values (for example, average values) based on the measurement results obtained by the thickness measurement units 50a are measured up to the upper surface of the substrate W. Determine as distance.

  When the thickness measurement process is finished, the coating apparatus 1 moves the substrate W to a coating process start position (a position where the end of the substrate W on the X-axis positive direction side is disposed directly below the nozzle 30). The coating apparatus 1 performs the coating process immediately after the nozzle priming process in step S104 is completed, and immediately after the nozzle priming process is completed if the nozzle priming process is not completed (step S108). Since the content of the coating process has been described above, a description thereof is omitted here.

  When the coating process of step S108 is completed, the coating apparatus 1 returns the process to step S101 and performs the processes of steps S101 to S104. In addition, after performing the substrate carry-out process (Step S109), the coating apparatus 1 performs the processes of Steps S105 to S107 again in parallel with the processes of Steps S101 to S104. The substrate carry-out process is a process of delivering the processed substrate W to an external device after releasing the suction holding of the substrate W by the substrate holding unit 21.

  When the processing in steps S101 to S109 described above is finished for all the substrates W included in one lot, the coating apparatus 1 finishes a series of substrate processing for one lot.

  As described above, the coating apparatus according to the first embodiment includes a nozzle, a moving mechanism, and a flattening unit. The nozzle includes a storage chamber in which the coating liquid is stored and a slit-like flow path communicating with the storage chamber, and discharges the coating liquid from a discharge port formed at the tip of the flow path. The moving mechanism relatively moves the nozzle and the substrate along the surface of the substrate. The flattening unit is an ultrasonic vibrator and flattens the liquid surface of the coating liquid stored in the storage chamber by ultrasonic vibration.

  Therefore, according to the coating apparatus which concerns on 1st Embodiment, the filling operation | work of the coating liquid to a nozzle can be made efficient.

  In the first embodiment, the coating apparatus 1 flattens the coating liquid R by applying ultrasonic vibration to the coating liquid R. However, the vibration applied to the coating liquid R is ultrasonic vibration. It is not limited to. That is, the coating apparatus 1 may include another vibration generating unit instead of the ultrasonic vibrator 180.

  In the first embodiment, the inside of the storage chamber S is imaged using the liquid level detection unit 160 (see FIG. 3B). However, since the storage chamber S is long, In order to image the inside from one end to the other in the longitudinal direction, it is necessary to dispose the liquid level detection unit 160 at a position somewhat away from the nozzle 30. Therefore, a configuration for disposing the liquid level detection unit 160 in the vicinity of the nozzle 30 will be described with reference to FIGS. 11A, 11B, 12A, and 12B. FIG. 11A, FIG. 11B, FIG. 12A, and FIG. 12B are schematic views showing another example of the liquid level detection method.

  For example, as shown in FIG. 11A, the coating apparatus 1 includes a plurality of liquid level detection units (here, two liquid level detection units 160a and 160b) that detect the liquid level of the coating liquid R from the front of the nozzle 30. You may prepare. In this way, by providing a plurality of liquid level detection units, the range to be detected by each liquid level detection unit can be reduced, so that the liquid level detection unit can be disposed in the vicinity of the nozzle 30.

  As shown in FIG. 11B, the coating apparatus 1 includes one liquid level detection unit 160c, and a drive unit 161 that moves the liquid level detection unit 160c along the longitudinal direction (Y-axis direction) of the nozzle 30. May be provided. Also by this, a liquid level detection part can be arrange | positioned in the vicinity of the nozzle 30. FIG.

  Further, when it is not desired to arrange the liquid level detection unit in front of the nozzle 30, for example, as shown in FIG. 12A, the liquid level detection unit 160d is arranged downward above the nozzle 30 to reflect or refract light. The liquid level of the coating liquid R may be imaged through the prism 162 to be moved.

  In this way, the liquid level detection unit 160d is disposed at a predetermined angle with respect to the liquid level of the coating liquid R, and an image of the liquid level viewed from a direction substantially parallel to the liquid level of the coating liquid R is prism-shaped. It is good also as imaging through 162. Thereby, a liquid level detection part can be arrange | positioned in places other than the front of the nozzle 30. FIG.

  The prism may be formed integrally with the nozzle. For example, as illustrated in FIG. 12B, the nozzle 30_2 may include a transparent member 32a_2 having a prism 162_2 on the front surface portion.

(Second Embodiment)
By the way, in embodiment mentioned above, although the example in case a coating device was provided with the vibration generation part as a planarization part was shown, the planarization part with which a coating device is provided is not limited to a vibration generation part. Hereinafter, another example of the flattening portion will be described. FIG. 13 is a schematic side sectional view showing another configuration of the flattening portion. In the following description, parts that are the same as those already described are given the same reference numerals as those already described, and redundant descriptions are omitted.

  As shown in FIG. 13, the nozzle 30_1 is provided with a stirring unit 180_1 as a flattening unit instead of the ultrasonic transducer 180. The stirring unit 180_1 is disposed inside the storage chamber S and flattens the coating liquid R in the storage chamber S by stirring the coating liquid R in the storage chamber S.

  Similar to the ultrasonic transducer 180 according to the first embodiment, a plurality of the agitating units 180_1 may be provided along the longitudinal direction of the nozzle 30_1, or only one is provided on the side to which the coating liquid supply system is connected. May be. In order to prevent the coating liquid R from splashing in the storage chamber S by stirring by the stirring unit 180_1, the stirring unit 180_1 is as low as possible in the storage chamber S, specifically, a boundary portion between the storage chamber S and the flow path C. It is preferable to provide in the vicinity.

  Similarly to the first embodiment, the coating apparatus 1 controls on / off of the stirring unit 180_1 based on the detection result by the liquid level detection unit 160. That is, the coating apparatus 1 obtains the difference between the maximum height and the minimum height of the liquid level from the detection result by the liquid level detection unit 160, and turns on the stirring unit 180_1 when the difference exceeds a predetermined threshold value. . And the coating device 1 turns off the stirring part 180_1, when a difference becomes below a predetermined threshold value.

  As described above, the flattening unit may be a stirring unit that flattens the liquid surface of the coating liquid by stirring the coating liquid stored in the storage chamber. Even in such a case, as in the first embodiment, the filling operation of the coating liquid into the nozzle can be made efficient. In addition, the coating device 1 may change the stirring force of the stirring unit 180_1 based on the detection result by the liquid level detection unit 160. For example, the coating apparatus 1 may increase the stirring force of the stirring unit 180_1 as the bias of the coating liquid is larger.

  Further, the flattening unit may be a posture changing unit that flattens the liquid surface of the coating liquid stored in the storage chamber by changing the posture of the nozzle. This will be described with reference to FIGS. 14A and 14B. 14A is a schematic side cross-sectional view showing another configuration of the flattening unit, and FIG. 14B is a diagram showing a state of the flattening process by the flattening unit shown in FIG. 14A.

  As shown in FIG. 14A, the nozzle 30_2 is provided with a posture changing unit 180_2 as a flattening unit instead of the ultrasonic transducer 180. The posture changing unit 180_2 is provided, for example, on the back surface of the nozzle 30_2, and rotates the nozzle 30 around a rotation axis parallel to the X-axis direction around a horizontal axis passing through the central portion in the longitudinal direction of the nozzle 30.

  The coating apparatus 1 controls the posture changing unit 180_2 based on the detection result by the liquid level detection unit 160. That is, the coating apparatus 1 obtains a difference between the maximum height and the minimum height of the liquid level from the detection result by the liquid level detection unit 160, and controls the posture changing unit 180_2 when the difference exceeds a predetermined threshold. Then, the nozzle 30_2 is tilted in such a direction that the higher liquid level is on the upper side and the lower liquid level side is on the lower side.

  For example, as shown in FIG. 14B, it is assumed that the liquid level height on the Y axis negative direction side is higher than the liquid level height on the Y axis positive direction side. In such a case, the coating apparatus 1 controls the posture changing unit 180_2 to tilt the nozzle 30_2 so that the Y axis negative direction side of the nozzle 30_2 is on the upper side and the Y axis positive direction side is on the lower side. As a result, the coating liquid R on the Y axis negative direction side moves to the Y axis positive direction side due to gravity, and the liquid level is flattened.

  In addition, the coating device 1 may adjust the angle according to the difference between the maximum height and the minimum height of the liquid level. That is, the coating apparatus 1 may gradually relax the inclination of the nozzle 30_2 as the liquid level of the coating liquid R is flattened. Then, the coating apparatus 1 controls the posture changing unit 180_2 so that the nozzle 30_2 is horizontal when the difference is equal to or less than a predetermined threshold.

  Thus, the flattening unit may be a posture changing unit that flattens the liquid surface of the coating liquid stored in the storage chamber by tilting the nozzle. Even in such a case, as in the first embodiment, the filling operation of the coating liquid into the nozzle can be made efficient. In this example, the posture changing unit rotates the nozzle around the rotation axis parallel to the short direction of the nozzle. However, the posture changing unit does not rotate around the rotation axis parallel to the longitudinal direction of the nozzle. The nozzle may be rotated. Thereby, the unevenness of the coating liquid generated in the short direction of the nozzle can be eliminated.

(Third embodiment)
By the way, in each of the embodiments described above, the unevenness generated in the coating liquid in the storage chamber is eliminated by the flattening unit. For example, the shape or arrangement of the supply port of the coating liquid formed in the storage chamber is changed. By changing it, it is possible to make it difficult for the application liquid to be biased in the storage chamber. Hereinafter, this point will be described with reference to FIGS. 15A and 15B. FIG. 15A is a schematic side cross-sectional view illustrating a configuration of a nozzle according to a third embodiment. FIG. 15B is a schematic front sectional view showing the configuration of the liquid supply port.

  The nozzle 30_3 according to FIG. 15A includes a temporary storage unit 35 that temporarily stores the coating liquid R filled in the storage chamber S inside the first main body 31_3.

  The temporary storage unit 35 includes a temporary storage chamber 35 a that stores the coating liquid R, and a passage 35 b that allows the temporary storage chamber 35 a and the storage chamber S to communicate with each other. The temporary storage chamber 35a is a long space having the same length as the storage chamber S. The passage 35b is a passage extending obliquely upward from the upper portion of the temporary storage chamber 35a toward the storage chamber S and has a slit shape extending along the longitudinal direction of the flow path C. The nozzle 30_3 only needs to include the passage 35b and the liquid supply port 35c, and may not include the temporary storage chamber 35a.

  In the third embodiment, the second supply pipe 133 of the intermediate tank 130 is connected to the temporary storage chamber 35 a of the temporary storage unit 35 via the supply pump 140. That is, in the third embodiment, the coating liquid supply system is connected to the back surface portion of the nozzle 30_3. The coating liquid R is supplied from the intermediate tank 130 to the temporary storage chamber 35a of the nozzle 30_3, and then supplied to the storage chamber S through the passage 35b.

  As shown in FIG. 15B, a slit-like liquid supply port 35c that communicates with the storage chamber S and extends along the longitudinal direction of the flow path C is formed at the distal end of the passage 35b. Thereby, the coating liquid R is uniformly supplied into the storage chamber S along the longitudinal direction of the storage chamber S. Therefore, it is possible to make it difficult for the application liquid R to be biased in the storage chamber S.

  The liquid supply port 35c is disposed in the vicinity of the boundary portion between the land portion 34 (channel C) and the storage chamber S, specifically, slightly above the land portion 34 (channel C). Thus, by supplying the coating liquid R from the lower side of the storage chamber S as much as possible, it is possible to prevent bubbles from being mixed into the coating liquid R when the coating liquid R is filled.

  As described above, the nozzle according to the third embodiment includes a liquid supply port that communicates the inside of the storage chamber with the outside of the storage chamber and supplies the coating liquid supplied from the outside to the inside of the storage chamber. Such a liquid supply port has a slit shape extending in the longitudinal direction of the flow path. Therefore, according to the nozzle according to the third embodiment, it is possible to make it difficult for the application liquid to be biased in the storage chamber.

(Fourth embodiment)
Further, by forming a plurality of liquid supply ports for the storage chamber and individually controlling the amount of the coating liquid supplied from each liquid supply port, it is possible to make it difficult for the application liquid to be biased in the storage chamber. Hereinafter, this point will be described. FIG. 16 is a schematic diagram illustrating a connection relationship between a device related to the coating liquid filling process and a nozzle according to the fourth embodiment.

  As shown in FIG. 16, liquid supply ports 35c_1, 35c_2, and 35c_3 are formed in the nozzle 30_4 according to the fourth embodiment. These liquid supply ports 35c_1, 35c_2, and 35c_3 have a slit shape extending in the longitudinal direction of the nozzle 30_4. The liquid supply port 35c_1 and the liquid supply port 35c_3 are respectively supplied to both ends in the longitudinal direction of the nozzle 30_4. The mouth 35c_2 is provided at the center in the longitudinal direction of the nozzle 30_4. Thus, the liquid supply ports 35c_1, 35c_2, and 35c_3 are arranged side by side along the longitudinal direction of the nozzle 30_4.

  The coating liquid supply unit 120_4 is connected to the liquid supply ports 35c_1, 35c_2, and 35c_3. The coating liquid supply unit 120_4 includes a coating liquid supply source 121_4 and valves 122_4a to 122_4c. As shown in FIG. 16, the liquid supply ports 35c_1 to 35c_3 are connected to the coating liquid supply source 121_4 via valves 122_4a to 122_4c, respectively. The coating liquid supply unit 120_4 is electrically connected to the control device 100, and the control device 100 controls the opening and closing of the valves 122_4a to 122_4c.

  The control device 100 can quickly flatten the liquid surface of the coating liquid R filled in the storage chamber S by individually controlling the opening and closing of the valves 122_4a to 122_4c.

  Specifically, the control device 100 detects the liquid level in the storage chamber S during the coating liquid filling process using the liquid level detection unit 160, and the opening degree of the valves 122_4a to 122_4c according to the detection result. Alternatively, the opening / closing time is individually controlled.

  For example, when the liquid level of the coating liquid R at the central portion in the longitudinal direction of the storage chamber S is lower than the liquid level at the longitudinal end portion, the control device 100 increases the opening degree of the valve 122_4b compared to the valves 122_4a and 122_4c. Or increase the opening time. Thereby, more coating liquid R is supplied from the liquid supply port 35c_2 arranged at the center in the longitudinal direction of the nozzle 30_4, and the unevenness of the liquid level is eliminated.

  As described above, when the control device 100 individually controls the valves 122_4a to 122_4c according to the detection result of the liquid level detection unit 160, the liquid level of the coating liquid R is biased during the coating liquid filling process. Even so, such a bias can be quickly eliminated and flattened.

  Note that, here, an example in which three liquid supply ports 35c_1 to 35c_3 are formed in the nozzle 30_4 is shown, but four or more liquid supply ports may be formed in the nozzle. In such a case, the coating liquid supply unit may include a number of valves corresponding to the number of liquid supply ports formed in the nozzle. Further, the nozzle may include only one slit-shaped liquid supply port. In such a case, a plurality of valves may be connected to one liquid supply port along the longitudinal direction of the nozzle.

  In addition, here, an example in which the coating liquid supply unit 120_4 is directly connected to the liquid supply ports 35c_1, 35c_2, and 35c_3 has been shown, but an intermediate tank may be interposed as in the first embodiment. Good.

(Fifth embodiment)
The pressure control method and the coating liquid filling method in the storage chamber are not limited to the methods described in the embodiments described above. Hereinafter, another example of the pressure control method and the coating liquid filling method in the storage chamber will be described with reference to FIGS. 17 and 18. FIG. 17 is a schematic diagram illustrating a connection relationship between a device related to the coating liquid filling process and a nozzle according to the fifth embodiment. FIG. 18 is a schematic enlarged view around the pressure adjusting tube in FIG.

  As shown in FIG. 17, the storage chamber S of the nozzle 30_5 according to the fifth embodiment is fully filled with the coating liquid R. That is, the inside of the nozzle 30_5 is filled with the coating liquid R.

  The lid 33 of the nozzle 30_5 is provided with a pressure measurement unit 36_5 and a pressure adjustment pipe 37_5 through the lid 33, respectively. The pressure measurement unit 36_5 and the pressure adjustment pipe 37_5 are provided at the approximate center of the lid 33.

  The pressure measurement unit 36_5 is electrically connected to the control device 100, measures the pressure inside the storage chamber S, and outputs the measurement result to the control device 100.

  The pressure adjustment pipe 37_5 is connected to a pressure adjustment unit 110_5 that adjusts the pressure in the storage chamber S. The pressure adjustment unit 110_5 includes an exhaust unit 111_5, a gas supply source 112_5, and a switching valve 113_5. Since the configuration of the pressure adjustment unit 110_5 is the same as that of the pressure adjustment unit 110 described above, description thereof is omitted here.

  Furthermore, the pressure adjustment pipe 37_5 is also connected to a coating liquid supply unit 120_5 that supplies the coating liquid R to the storage chamber S. The coating liquid supply unit 120_5 includes a coating liquid supply source 121_5 and a valve 122_5. Since the configuration of the coating liquid supply unit 120_5 is the same as that of the coating liquid supply unit 120 described above, description thereof is omitted here.

  In the fifth embodiment, the coating liquid R is supplied from the coating liquid supply source 121_5 of the coating liquid supply unit 120_5 to the storage chamber S through the pressure adjustment pipe 37_5. Thus, the pressure adjustment pipe 37_5 according to the fifth embodiment also functions as a liquid supply pipe.

  As shown in FIG. 18, the pressure adjustment pipe 37_5 is in a state of being filled to some extent with the coating liquid R. Specifically, it is preferable that the pressure adjustment pipe 37_5 is filled with the coating liquid R up to a point above the branch point to the coating liquid supply unit 120_5. Moreover, it is preferable that the pressure adjusting tube 37_5 is filled with an amount of the coating liquid R that can be applied to the substrate W at least once.

  Further, the pressure adjustment pipe 37_5 is formed of a transparent member, and the coating liquid R existing inside the pressure adjustment pipe 37_5 is visible from the outside.

  In the fifth embodiment, the liquid level detector 160_5 detects the liquid level height of the coating liquid R in the pressure adjustment pipe 37_5. Then, the control device 100 makes the discharge amount of the coating liquid R constant according to the detection result by the liquid level detection unit 160_5, that is, according to the liquid level of the coating liquid R in the pressure adjustment pipe 37_5. In this way, the pressure adjusting unit 110_5 is controlled to adjust the pressure inside the storage chamber S.

  Thus, in the fifth embodiment, since the liquid level height in the pressure adjustment pipe 37_5 is detected, the liquid level detection unit is compared with the case where the liquid level height in the storage chamber S is detected. The detection range by 160_5 can be reduced. Therefore, according to the fifth embodiment, it is possible to facilitate liquid level monitoring.

  In the fifth embodiment, since the storage chamber S is filled with the coating liquid R, there is no possibility that the coating liquid R is biased in the storage chamber S. Therefore, it is not necessary to wait until the unevenness of the coating liquid R filled in the storage chamber S is eliminated during the coating liquid filling process or after the coating liquid filling process.

  Although an example in which the coating liquid supply unit 120_5 is directly connected to the pressure adjustment pipe 37_5 is shown here, an intermediate tank is interposed between the pressure adjustment pipe 37_5 and the coating liquid supply unit 120_5. Also good.

(Sixth embodiment)
The nozzle may further uniformize the coating liquid supplied from the liquid supply port to the storage chamber by attaching a baffle to the liquid supply port. This point will be described with reference to FIGS. 19A and 19B. FIG. 19A is a schematic side cross-sectional view illustrating a configuration of a nozzle according to a sixth embodiment. FIG. 19B is a schematic enlarged view of a portion H shown in FIG. 19A.

  As illustrated in FIG. 19A, the nozzle 30_6 according to the sixth embodiment includes a temporary storage unit 35 in the first main body 31_6, similarly to the nozzle according to the third embodiment. The nozzle 30_6 includes a baffle 38 in the storage chamber S. The nozzle 30_6 only needs to include the passage 35b and the liquid supply port 35c, and may not include the temporary storage chamber 35a.

  The baffle 38 is a long member extending in the longitudinal direction of the nozzle 30_6 and has, for example, an L shape in a side view.

  As shown in FIG. 19B, the baffle 38 is fixed to the first main body 31_6 above the liquid supply port 35c. The lowermost part of the baffle 38 is disposed below the liquid supply port 35c.

  Thereby, the flow of the coating liquid R supplied from the liquid supply port 35 c is regulated by the baffle 38, and flows into the storage chamber S substantially horizontally from between the lowermost part of the baffle 38 and the upper end part of the land part 34. .

  Thus, since the nozzle 30_6 can prevent the application liquid R from being biased in the short direction of the nozzle 30_6 by providing the baffle 38 at the liquid supply port 35c, the nozzle 30_6 is supplied to the storage chamber S from the liquid supply port 35c. The applied coating solution R can be made more uniform.

  The baffle 38 may have a shape in which the lowermost portion is disposed below the liquid supply port 35c when the baffle 38 is fixed to the first main body 31_6 above the liquid supply port 35c. It is not limited to a letter shape.

  In addition, a bimetal that deforms due to a temperature change and a functional sheet that deforms when a voltage is applied are provided in the nozzle, and the liquid level of the coating liquid R in the storage chamber S is changed using the deforming properties of the bimetal and the functional sheet. You may planarize.

  In each of the embodiments described above, an example in which the coating liquid is applied to the upper surface of the substrate by moving the substrate in the horizontal direction has been described. However, the present invention is not limited to this, and the nozzle is moved in the horizontal direction. It is good also as apply | coating the coating liquid R to the upper surface of a board | substrate by moving.

  Moreover, in each embodiment mentioned above, although the example in case a coating device was provided with one nozzle was shown (refer FIG. 1), a coating device sets multiple nozzles and raising / lowering mechanisms along the moving direction of a board | substrate. You may have.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

W substrate R coating liquid S storage chamber C flow path D discharge port 1 coating device 10 mounting table 20 first moving mechanism 21 substrate holding unit 22 drive unit 30 nozzle 31 first main body unit 32 second main body unit 33 lid unit 34 land Unit 35 Temporary storage unit 35c Liquid supply port 40 Elevating mechanism 50a Thickness measuring unit 50b Nozzle height measuring unit 60 Nozzle cleaning unit 80 Nozzle standby unit 90 Second moving mechanism 100 Controller 180 Ultrasonic vibrator 180_1 Stirrer 180_2 Attitude change Part

Claims (11)

A storage chamber in which the coating liquid is stored; and a slit-shaped flow path communicating with the storage chamber; a nozzle that discharges the coating liquid from a discharge port formed at a tip of the flow path;
A moving mechanism for relatively moving the nozzle and the substrate along the surface of the substrate;
A flattening portion for flattening the liquid surface of the coating liquid stored in the storage chamber ;
A liquid level detector for detecting a plurality of heights of the liquid level in the longitudinal direction of the nozzle;
A coating apparatus, comprising: a control unit that controls the planarization unit based on a plurality of the liquid level heights detected by the liquid level detection unit .   The controller is
  Controlling the flattening unit based on a difference between a maximum height and a minimum height of a plurality of liquid surface heights.
  The coating apparatus according to claim 1. The flattening part is
Coating apparatus according to claim 1 or 2, characterized in that the vibration generating portion to flatten the liquid level of the coating liquid by applying vibration to the coating liquid stored in the storage chamber. The flattening part is
Coating apparatus according to claim 1 or 2, characterized in that by stirring the coating liquid stored in the reservoir chamber is a stirring unit for flattening the liquid level of the coating liquid. The flattening part is
Coating apparatus according to claim 1 or 2, characterized in that a position changing unit for flattening the liquid level of the coating liquid stored in the reservoir by changing the attitude of the nozzle. The controller is
The liquid surface is determined whether the flattened based on the height of the plurality of the liquid level thus detected to the liquid surface detecting section, when it is determined that the flattened, with the nozzle coating The coating apparatus according to any one of claims 1 to 5, wherein processing is started. The storage chamber is
A part is formed of a transparent member,
The liquid level detection unit is
The coating apparatus according to any one of claims 1 to 6, wherein the liquid level is detected from the outside of the nozzle through the transparent member. A prism that reflects or refracts light,
The liquid level detection unit is
8. The liquid surface is disposed at a predetermined angle with respect to the liquid surface, and an image of the liquid surface viewed from a direction substantially parallel to the liquid surface is captured through the prism. The coating apparatus as described in. The nozzle is
A liquid supply port for communicating the inside of the storage chamber with the outside of the storage chamber and supplying the coating liquid supplied from the outside to the inside of the storage chamber;
The liquid supply port is
The coating apparatus according to claim 1, wherein the coating apparatus has a slit shape extending in a longitudinal direction of the flow path. The liquid supply port is
The coating apparatus according to claim 9, wherein the coating apparatus is disposed in the vicinity of a boundary portion between the storage chamber and the flow path. A storage chamber in which a coating liquid is stored; and a slit-shaped flow path communicating with the storage chamber; and a nozzle that discharges the coating liquid from a discharge port formed at a tip of the flow path. A supply step of supplying the coating liquid inside;
A flattening step of flattening a liquid surface of the coating liquid supplied into the storage chamber in the supply step ;
A liquid level detecting step for detecting a plurality of heights of the liquid level in the longitudinal direction of the nozzle;
And a control step of controlling the flattening step based on a plurality of the liquid level heights detected by the liquid level detecting step .

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