JP3653688B2 - Slit coat type coating device and slit coat type coating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slit coat type coating apparatus and a slit coat type coating method, and in particular, a resist solution, a slurry or the like on a flat coating object (hereinafter referred to as a substrate W) such as plasma or a liquid crystal display or a semiconductor wafer. The present invention relates to a technique for applying various liquid coating solutions in a uniform thin film state.
[0002]
[Prior art]
As a method for applying various coating fluids such as a photoresist solution, an insulating material, and a solder resist onto a glass flat substrate used for a display unit of a display device of various electronic devices or a semiconductor manufacturing wafer, Using a coating head having a slit-shaped opening having a short side or a full length corresponding to the diameter of the wafer, a predetermined amount of a predetermined coating solution is discharged from the slit-shaped slit opening, and the coating head In recent years, a slit coat type coating apparatus that forms a uniform thin film by relatively moving the substrate side or the substrate side at a constant speed has been widely employed.
[0003]
According to this slit coat type coating apparatus, the amount of ejected fluid required for forming a desired coating surface (for example, a film thickness of 1.5 μm ± 5%) can be suppressed to 1.1 times or less of the required forming amount. Therefore, it is possible to greatly reduce the consumption of the application fluid that is wasted in comparison with the spin coating type coating apparatus.
[0004]
However, since this slit coat type coating apparatus is designed to obtain a uniform thin film only by coating in a single relative movement, the conditions for discharging the discharge fluid with a uniform film thickness over the entire length of the slit opening Further, it is necessary to have a condition for forming a uniform thin film while increasing the film thickness of the discharge fluid discharged from the slit opening, and further a condition for minimizing the unstable region at the start and end of application.
[0005]
On the other hand, according to “Die coater coating method” disclosed in Japanese Patent Application Laid-Open No. 10-421, a non-contact distance measuring sensor is fixed to the coating head, and the sensor between the coating effective surface and the coating head opening in advance. After measuring the gap and calculating the deviation from the reference value, coating is performed while moving the coating head relatively based on the calculation result, and uniform coating is performed so as to deal with substrate waviness, warpage, and thickness unevenness. It is described.
[0006]
In addition, the applicant of the present application detects foreign matter having a size of 100 to 200 microns by performing a step of detecting foreign matter by scanning the effective coating surface in a non-contact manner with a laser scanning type detection device before the coating step. ing.
[0007]
[Problems to be solved by the invention]
However, according to the laser scanning type detection device, the presence or absence of a foreign object is detected by an interference waveform generated by irradiating the foreign object with laser light. For this reason, in order to increase the detection accuracy of minute foreign matter, more scanning time is required, and there is a problem that a considerable time is required for the foreign matter detection step before coating. In this method, the size of foreign matter that can be detected is limited, and a small foreign substance of about several tens of microns cannot be detected.
[0008]
In addition, the state in which the height of the substrate gradually changes due to foreign substances existing between the holding plate that holds the substrate and the substrate is difficult to detect because an interference waveform cannot be obtained. For this reason, in many cases, no abnormality is detected, the process proceeds to the coating process as it is, and when coating is performed, the tip portion of the coating head opening first comes into contact with the gradually increasing substrate surface, and further coating is performed. When the head is relatively moved, the coating head opening strongly presses the substrate, resulting in damage to the substrate.
[0009]
In this way, since the substrate is damaged, it will be known for the first time that foreign matter is interposed between the substrate and the holding plate, so that the operator can resume the coating process by removing the damaged substrate together with the foreign matter. However, at this time, the tip of the coating head opening is also damaged. Since the breakage of the tip of the coating head opening causes the application fluid to be drawn, for example, the coating head must be replaced and adjusted. As a result, there is a problem that the slit coat type coating apparatus, and thus the entire substrate production line, is forced to stop for a long time. Furthermore, since the tip of the coating head requires a precision process and is quite expensive, it is desirable to avoid damage to the tip as much as possible.
[0010]
Therefore, the present invention has been made in view of the above-described problems, and in the slit coat type coating apparatus, the cycle time can be shortened by eliminating the foreign matter detection step before coating, and exists on the substrate. The cost burden due to the coating head being damaged by the foreign matter or the foreign matter existing between the substrate holding plate and the substrate can be avoided, the possibility of long-term operation stoppage is eliminated, and the fineness is as small as several tens of microns. An object of the present invention is to provide a slit coat type coating apparatus and a slit coat type coating method capable of handling foreign substances.
[0011]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, according to the present invention, the coating fluid flows out from the slit-shaped opening onto the coating effective surface of the planar substrate to be coated held on the substrate holding plate. A slit coat-type coating apparatus comprising: a coating head that performs a predetermined gap separation from the coating effective surface; and a relative movement unit that moves the substrate relative to the coating head. A plate-like member having a linear protective tip along the coating effective surface and fixed to the plate-like member so as to move along with the relative movement. A collision detecting means for detecting that the unit collides with a foreign substance existing on the substrate or a collision with a surface of the substrate when a foreign substance exists between the substrate holding plate and the substrate; Said phase It is characterized by comprising a control means for forcibly stopping the movement means.
[0012]
In addition, the plate-like member is disposed on both sides of the head front end portion, thereby enabling collision detection in the reciprocal relative movement and protecting the head front end portion.
[0013]
A step of holding a flat substrate to be coated on a substrate holding plate; a step of flowing a coating fluid from a coating head having a slit-shaped opening on the coating effective surface of the substrate; and the coating effective surface And a step of moving the substrate relative to the coating head with a predetermined gap separation between the substrate and the coating portion, and a slit coating type coating method provided alongside the head end of the opening. And a plate-like member having a linear protective tip along the effective coating surface, and the protective tip collides with a foreign substance on the substrate with the relative movement by being fixed to the plate-like member. Or detecting a collision with the surface of the substrate when there is a foreign object between the substrate holding plate and the substrate , forcibly stopping the relative movement step when detected, Status It is characterized by comprising a step of informing.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0015]
First, FIG. 1 is an operation principle diagram schematically showing a state in which application fluid T flows out with a predetermined thickness onto an effective application surface of a flat substrate W to be applied by the application head 1. .
[0016]
In this figure, a supply pipe 2 and a discharge pipe 3 are connected to the coating head 1, and a coating fluid is supplied through the supply pipe 2 and discharged into a substantially sheet shape through a slit-shaped opening 1a. Thus, it is configured to discharge the coating fluid immediately after coating through the discharge pipe 3, and is configured to be lifted and lowered by a lifting mechanism described later.
[0017]
The coating head 1 is lifted to a standby position (P1) for waiting for the transfer of the substrate W and is in a standby state, and is sucked by the negative pressure supplied to the suction hole 13a on the suction holding plate 13 after the substrate W is transported. Then, it waits for being positioned and held by a positioning device (not shown). As shown in the drawing, when the substrate W is held, the coating head 1 descends to a certain position (P2) and performs coating from a straight coating start line determined by the slit-like opening 1a of the coating head 1. A constant pressure is always applied to the coating fluid T supplied to the film to obtain a uniform film having a predetermined film thickness. At this time, the application fluid stored in the coating head 1 is slit by moving relative to the direction of the arrow while stably supplying the coating fluid to which the pressure is applied by opening and closing each valve described later. The liquid is ejected through the opening 1a to form a constant amount of discharge up to the position (P3) to form a coating end line, and then rises again to the standby position (P4).
[0018]
In this way, in order to provide reproducibility so that the coating start line is in the same position in a straight line and to perform uniform coating between the starting line and the position (P3), the coating head 1 The inside is filled with the stored coating liquid, and the traveling speed on the coating start line needs to reach a predetermined constant speed. Further, as shown in FIG. 1, the fluid supply on / off valve is closed at an appropriate position slightly before the coating end line, the supply to the coating head 1 is stopped, and the amount discharged by the residual pressure of the coating head 1 Apply with. Thereafter, when the coating head 1 arrives at the position indicated by P3, when the coating head 1 is lifted, the suction head mechanism provided on the coating head 1 is operated at the same time, so that the coating head tip, the applied liquid drain and the head tip are applied The liquid adhering to is drawn into the slit opening 1a by a fixed amount (fixed time) to complete the coating operation.
[0019]
Then, the coating head 1 that has been waiting at the position P1 in FIG. 1 is lowered to the position P2 so that the distance to the tip of the coating head reaches a predetermined set value, and the valve is opened with respect to the coating head 1. When the supply is started, the movement of the substrate W is accelerated from the P1 position to the P2 position, and when the coating head reaches the P2a position, the traveling speed reaches the maximum coating speed, and the uniform coating is performed at that speed. I try to do it. In this manner, the reproducibility (quality) of the coating film from the coating start line is influenced by bringing the coating head close to the substrate W. Further, at the position P3, the state changes each time due to the mutual pulling of the coating liquid applied to the substrate W and the coating liquid in the coating head 1 at the completion of coating. Further, when returning from the standby position of P4 to the standby position of P1 again, it is possible to perform coating continuously by applying the substrate W while relatively moving in the opposite direction.
[0020]
The coating head 1 that performs the coating operation as described above is provided with plate-like members 6 and 7 as shown in the figure before and after the moving direction. These plate-like members 6 and 7 are precisely processed so that the linear protective tip portions 6 a and 7 a along the coating effective surface of the substrate W are linear, and the linear opening 1 a of the coating head 1. The head is accurately fixed and fixed so as to be parallel to the tip of the head. Among these plate-like members 6, 7, a vibration sensor 5 that detects weak vibration is fixed on the plate-like member 6 that is the leading side of the movement of application. Although the drawing shows a state in which the coating head 1 moves relative to the substrate in both directions, it may be applied by relative movement in only one direction. In this case, a plate-like shape is formed only on the front side in the traveling direction. The member 6 and the vibration sensor 5 may be attached.
[0021]
Further, in order to make the gap between the opening 1a and the substrate surface constant, the distance sensor 8 is fixed on the plate-like members 6 and 7 without suppressing vibration. The distance sensor is preferably a non-contact type sensor that optically or electrically measures the distance, but is not particularly limited.
[0022]
FIG. 2 is an external perspective view showing a slit coat type coating apparatus 10 in which two coating heads 1 based on the operation principle described above are arranged, partially broken.
[0023]
In this figure, an elevating air cylinder 12 is disposed on a frame 11 which is a base portion of the apparatus 10. A motor 15 is fixed on the frame 11. The screw shaft 15a of the output shaft of the motor 15 is driven to rotate, and the linear guide 14 that is screwed to the screw shaft 15a is driven to reciprocate. Has been. Further, each coating head 1 is fixed to the lifting member 4 provided with the lifting air cylinder 12 at both ends, and the coating of the substrate W sucked and held on the suction holding plate 13 by driving each air cylinder 12 is performed. It is configured to be driven up and down relative to the surface. A servo motor 120 for fine adjustment is fixed on the lift air cylinder. The linear guide 14 is fixed to the bottom surface of the suction holding plate 13 so as to reciprocate in the direction of the arrow as the motor 15 is energized so that the coating can be performed with the relative movement.
[0024]
The substrate W placed on the robot arm 18 is transported while the suction holding board 13 is waiting at the position shown in the drawing. An alarm light 20 is provided on the upper right of the apparatus 10 and is configured to notify an operator together with an alarm when any trouble is detected by a foreign object. In addition, an operation panel 19 is provided on the front side of the apparatus so that adjustment knobs can be adjusted.
[0025]
FIG. 3 is a piping diagram of the coating head 1. Components already described in FIG. 1 are denoted by the same reference numerals and description thereof is omitted. In this figure, the coating fluid T is stored in a tank 24 which is a supply unit, and the coating fluid T is placed in the flow path 25 by the gas supply pressure supplied from the aeroelectric unit 23 controlled by the control unit 22. At a predetermined supply pressure. The flow path 25 is connected to a degassing device 26 that is connected to a vacuum pump 29 via an electromagnetic valve 28 so that the inside is brought close to a vacuum state. By applying a vacuum to 27, the gas mixed in the coating fluid T is removed, thereby making it possible to realize coating without streaking due to the influence of the gas. Thereafter, the coating fluid T is sent to the on / off valve 31 and sent to the supply pipe 2 via the suck back valve 30. Further, the ON / OFF valve 31 is further connected as shown in the figure by branching from the flow path between the ON / OFF valve 31 and the suck back valve 30, and this ON / OFF valve 31 is connected to the flow path 25 and the residual pressure in the supply pipe 2. It functions as a residual pressure release valve that opens the flow path 25 and the supply pipe 2 to the atmosphere by opening a plug that is driven with a predetermined stroke to release the valve.
[0026]
This residual pressure release valve opens the flow path to the atmosphere for a certain period of time at the end of application and rapidly reduces the pressure, thereby rapidly reducing the supply of application fluid compared to the case where this residual pressure release valve is not provided. Is for. The coating fluid discharged to the outside from the residual pressure release valve is collected in the container 32.
[0027]
Further, the discharge pipe 3 of the coating head 1 is fixed to the left and right ends as shown in the figure, and is discharged from the collected discharge pipe. Further, the suck back valve 30 connected to the supply pipe 2 of the coating head 1 has a plug that is driven with a predetermined stroke in order to temporarily reduce the volume in the supply pipe 2. The on / off valve 31 connected between the suck-back valve 30 and the supply unit also has a built-in plug body that is driven with a predetermined stroke, and is configured to open and close the flow path by the plug body. Yes.
[0028]
On the other hand, a control device 22 to which a vibration detection signal is input is connected to the vibration sensor 5. The control device 22 is connected with the alarm light 20 described above.
[0029]
4 is an enlarged view of a main part for explaining the operation of the slit coat type coating apparatus configured as described above, and FIG. 4A shows a foreign substance G fixed on the coating surface of the substrate W. FIG. FIG. 4B shows a case where the foreign matter G is fixed on the back surface of the coated surface of the substrate W and is sucked and held on the suction holding platen 13.
[0030]
First, in the case shown in FIG. 4A, when the substrate W is applied while being moved relative to the application head 1, and the foreign object G collides against the protective tip 6 a of the plate-like member 6, this state is obtained. Is detected by the vibration sensor 5 and a collision detection signal is sent to the control unit 22 to forcibly stop the subsequent coating operation. In the case shown in FIG. 4B, application is performed while the substrate W is moved relative to the application head 1 indicated by the solid line, and when the application head 1 is moved relative to the position shown by the broken line, the plate-like member 6 is moved. The surface of the substrate W collides with the protective tip 6a. The vibration sensor 5 captures this state and sends a collision detection signal to the control unit 22 to forcibly stop the subsequent coating operation, thereby preventing the substrate W from being damaged and opening the opening 1a of the coating head 1. To prevent damage to the tip of the.
[0031]
FIG. 5 is a flowchart relating to the operation of FIG. 4 and shows a control example. In this figure, when the operation is started, the distance from the substrate surface is measured by the distance sensor 8 in step S1, and based on the measurement result, the movement from the P1 position to the P2 position in FIG. It is. Then the process proceeds to step S2, are performed coated with relative movement to the position P3, collision detection is initiated by the vibration sensor 5 in step S3, it is determined the presence or absence of collision detection in step S4, when there is detected a collision In step S5-1, the power supply to the motor 15 is forcibly stopped. Immediately after that, in step S6, the alarm light 20 is activated to notify the operator of the occurrence of an abnormality, and the process returns. If no collision is detected in step S4, the coating operation is continued to the position P3 in S5-2, the head is raised to the position P4, and preparation for starting the coating of the next substrate is performed in S8.
[0032]
In the above description, only the case of a rectangular substrate has been described. However, the present invention is not limited to this, and is a coated substrate by a slit coat type coating method, and can be applied to a flat rectangular substrate and a circular flat semiconductor wafer. It is.
[0033]
It should be noted that the present invention is not limited to the above-described embodiments, and it is a matter of course that the present invention is included even if there is a design change or the like without departing from the gist of the present invention.
[0034]
【The invention's effect 】
As described above, according to the present invention, in the slit coat type coating apparatus, the cycle time can be shortened by eliminating the foreign matter detection step before coating, and foreign matter existing on the substrate or the substrate holding plate. A slit coat type coating apparatus and a slit coat type coating method can be provided in which the coating head is damaged by foreign matters existing between the substrate and the substrate, thereby eliminating the possibility of long-term shutdown.
[0035]
[Brief description of the drawings]
FIG. 1 is an operation principle diagram showing a state in which coating fluid T flows out with a predetermined thickness onto a coating effective surface of a flat substrate W to be coated by a coating head 1;
FIG. 2 is an external perspective view showing a part of the slit coat type coating apparatus in a broken state.
FIG. 3 is a piping diagram of a coating head.
FIG. 4 is an explanatory diagram of an operation of foreign object detection by a vibration sensor.
FIG. 5 is a flowchart for explaining the operation of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Coating head 2 Supply pipe 3 Discharge pipe 4 Elevating member 5 Vibration sensor 10 Coating device 12 Air cylinder 13 Adsorption holding board 15 Motor 18 Robot arm 20 Alarm light 22 Control part 24 Tank 25 Flow path 26 Degassing device T Coating fluid W Substrate

Claims (3)

A coating head for flowing a coating fluid from a slit-shaped opening onto a coating effective surface of a flat substrate to be coated held on a substrate holding plate, and the opening from the coating effective surface is separated by a predetermined gap. A slit coat type coating apparatus including a relative moving means for relatively moving the substrate with respect to the coating head, and is provided along the head end portion of the opening and along the coating effective surface. A plate-shaped member having a linear protective tip, and the protective tip collides with a foreign substance on the substrate with the relative movement by being fixed to the plate-shaped member, or the substrate holding plate, And a collision detection means for detecting a collision with the surface of the substrate when a foreign substance is present between the substrates, and a control means for forcibly stopping the relative movement means when detected. You Slit coating type application apparatus.  2. The plate-like member is disposed on both sides of the head tip, thereby enabling collision detection in the reciprocal relative movement and protecting the head tip. Slit coat type coating device. A step of holding a planar substrate to be coated on a substrate holder, a step of flowing a coating fluid from a coating head having a slit-shaped opening on the coating effective surface of the substrate, and the coating effective surface from the coating effective surface A slit coat type coating method comprising a step of separating the opening relative to the coating head with a predetermined gap separation, and being provided alongside the head tip of the opening, A plate-like member having a linear protective tip along the effective coating surface, and being fixed to the plate-like member, the protective tip collides with a foreign substance on the substrate with the relative movement, or Detecting a collision with the surface of the substrate when foreign matter is present between the substrate holding plate and the substrate; forcibly stopping the relative movement step when detected; and an abnormal state. News Slit coating type coating method characterized by comprising the steps.

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