JPH0698335B2 - Coating device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating device for coating a photoresist or the like on a glass substrate or the like used in, for example, a liquid crystal display device.

2. Description of the Related Art For example, in a manufacturing process of a so-called active matrix type liquid crystal display device including a thin film transistor (TFT), it is necessary to perform fine pattern processing of a transparent conductive film, various metal films, semiconductor films, and insulating films. A photo-etching method is used for this fine pattern processing. In this photo-etching method, a photoresist is dropped onto a glass substrate, the glass substrate is rotated, and a centrifugal force generated at this time spreads the dropped photoresist onto the glass substrate to apply the coating device called a spin coater. Is used.

In such a photoresist coating operation, excess photoresist is scattered from the glass substrate into the air. The scattered photoresist becomes droplets in the storage container that stores the glass substrate and floats in the air, or collides with the inner wall surface of the storage container and scatters in the air again, and the back surface of the rotating glass substrate (the photoresist is dropped). (The surface opposite to the surface on which it is attached). In order to remove the photoresist attached to the back surface of the glass substrate, a back rinse method is used in which a cleaning liquid is sprayed toward the back surface of the glass substrate to dissolve and remove the photoresist.

A typical prior art is shown in FIG. The spin coater 1 is configured to include a container 2, a vacuum chuck 4 that adsorbs and holds a glass substrate 3, a resist ejection nozzle 5 that ejects photoresist, and a back rinse liquid ejection nozzle 6 that ejects a back rinse liquid. It The glass substrate 3 used here is used, for example, in a liquid crystal display device and has a rectangular shape as shown in FIG.

The back rinse liquid discharge nozzle 6 is disposed so as to be located between the arc l1 which is the outer periphery of the portion of the vacuum chuck 4 adsorbed to the glass substrate 3 and the virtual inscribed circle l2 of the glass substrate 3. There is. The vacuum chuck 4 is rotationally driven by a rotation motor (not shown), and thereby the glass substrate 3 is rotationally driven.

FIG. 8 is a graph showing the photoresist coating operation.
In FIG. 8, the horizontal axis represents time (second), and the vertical axis represents the number of revolutions per minute (rpm) of the substrate 3. Fig. 6 ~
The operation of the spin coater 1 will be described with reference to FIG. FIG. 8: From the time t0, the resist liquid is dropped onto the glass substrate 3 using the resist discharge nozzle 5 for a period W1.
It ends at t1. After that, the glass substrate 3 is rotated from the time t2 and rotated at the rotation speed R1 (200 rpm) to spread the resist solution on the glass substrate 3. As soon as the rotation speed of the glass substrate 3 reaches a constant rotation speed R1, the back rinse liquid is discharged from the back rinse liquid discharge nozzle 6 to the surface on the opposite side of the glass substrate 3 for a period W2 from time t3, as described above. The resist solution adhering to the opposite side of the glass substrate 3 is removed.

After this, from time t4, the rotation speed of the glass substrate 3 is changed to the rotation speed R2.
(1000 rpm) so that the excess resist solution on the glass substrate 3 is shaken off. At time t6, the rotation of the glass substrate 3 is stopped, but before the time t5, the back rinsing liquid discharge operation is performed. The rotation of the glass substrate 3 is stopped at the time t6, and the operation of applying the resist solution onto the glass substrate 3 is completed in this manner.

Problems to be Solved by the Invention In a conventional example having the above-described configuration and operation,
As shown in FIG. 7, the removal operation of the excess resist solution by the back rinse solution of the glass substrate 3 is performed by virtually inscribing the arc l1 showing the contour of the vacuum chuck 4 and the glass substrate 3 in the rectangular glass substrate 3. The area between the circles l2 works well. On the other hand, a virtual inscribed circle on the glass substrate 3
There was a problem that the back rinse liquid was not directly discharged to the portion outside l2, so that the cleaning was not sufficiently performed.

That is, although the back rinse liquid is directly discharged to the area surrounded by the arcs l1 and l2 to effectively remove the resist liquid, the back rinse liquid spreads outward due to the centrifugal force accompanying the rotation of the glass substrate 3, When the splattering first starts from the radial minimum distance portion (the middle portion of each side of the glass substrate 3) with respect to the rotation axis, the back rinse liquid adhering to the lower surface of the glass substrate 3 splatters from this portion all at once. It does not reach the outer part. Further, even when a part of the back rinse liquid reaches the outer portion, only a small part of the outer portion is covered in a streak shape, and an effective cleaning action cannot be performed. The photoresist attached to the back surface will contaminate the baking furnace and its atmosphere in the resist baking in the next step, and in the next exposure step the dried resist will peel off and float, resulting in exposure failure. The yield was remarkably reduced. Such a technical problem is a problem that does not occur in a disk-shaped silicon wafer and is a characteristic problem in the field of using a rectangular glass substrate or the like.

The object of the present invention is to solve the above-mentioned technical problems, and even if the substrate to which the coating agent is applied has a rectangular shape, the cleaning action can be performed over the entire surface of the substrate, and the usability is significantly improved. It is to provide a coating device.

Means for Solving the Problems The present invention provides a coating material discharge nozzle (15) for discharging a coating material onto a substrate (12), and a rotating member (13) for supporting and rotating the substrate (12).
And a storage container (1 for storing the substrate (12) and the rotating member (13).
4) and a first side which is provided on the side opposite to the coating agent discharge nozzle (15) with respect to the substrate (12) and is spaced apart along the radial direction of the rotation axis of the rotating section agent (13). Cleaning nozzle (1
6) and a second cleaning nozzle (17), wherein the first cleaning nozzle (16) is arranged radially inward of the minimum radial distance of the circumferential circle of the substrate (12) with respect to the rotation axis to continuously connect the cleaning agent. The second cleaning nozzle (17) is disposed outside the minimum radial distance, and a portion outside the minimum radial distance of the substrate (12) faces the second cleaning nozzle (17). The coating device is characterized in that the cleaning agent is intermittently discharged only in the inside.

Action The coating apparatus according to the present invention discharges the coating agent onto one surface of the substrate using the coating agent discharge nozzle. The substrate is rotatably driven while being supported by the rotating member, and the coating agent is spread by centrifugal force. At this time, the coating material may be scattered and adhere to the back surface of the substrate. The first cleaning nozzle and the second cleaning nozzle are provided on the back surface side, and the first cleaning nozzle serves as a substrate related to the rotation axis. The cleaning agent is continuously disposed on the inner side in the radial direction with respect to the minimum radial distance of the peripheral edge. Therefore, the cleaning is effectively performed inward of the minimum radial distance.

On the other hand, on the outer side of the minimum radial distance, the cleaning agent is intermittently discharged by the second cleaning nozzle that intermittently discharges the cleaning agent only during the period facing the second cleaning nozzle. When the outer portion is present intermittently along the circumferential direction, the cleaning action can be effectively performed.

Embodiment FIG. 1 is a simplified vertical sectional view of a spin coater 11 which is a coating apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view of a substrate 11. Referring to these drawings, the spin coater 11
The configuration of will be described. The spin coater 11 is used, for example, to apply a photoresist solution onto a transparent substrate forming a liquid crystal display device by a spin method. The spin coater 11 is provided with a vacuum chuck 13 for supporting the substrate 12 by vacuum suction and rotating the substrate 12 about a rotation axis extending in the vertical direction.
12 is stored in a storage container 14. In this embodiment, the substrate 12
The dimensions are 300 mm × 300 mm × 1.1 mm, and vacuum chuck 13
Use an outer diameter of 240 mmφ.

A resist discharge nozzle 15 for discharging a photoresist solution (for example, OFPR800-6CP manufactured by Tokyo Ohka Co., Ltd.) is arranged above the center of rotation of the substrate 12 in the storage container 14,
A back rinse liquid for cleaning the resist liquid adhering to the back surface of the substrate 12 on the side opposite to the resist discharge nozzle 15 with respect to 12 (eg, ethyl cellosolve acetate (ECA))
A first ejection nozzle 16 and a second ejection nozzle 17 for ejecting a cleaning agent referred to as “etc.” are arranged. The vacuum chuck 13
Is rotationally driven by a motor 18, and a rotation angle detector 19 for detecting the rotation angle of the vacuum chuck 13 in association with the motor 18.
Are connected. The output of the rotation angle detector 19 is input to the control device 20 including, for example, a microprocessor.

The first and second discharge nozzles 16 and 17 are connected to a pump 23 via electromagnetic valves 21 and 22, respectively, and the pump 23 supplies the cleaning agent stored in a tank 24 to the discharge nozzles 16 and 17. The solenoid valves 21 and 22 are controlled to be opened and closed by the control device 20 as described later.

Further, the first discharge nozzle 16 is a virtual inscribed circle l11 which is a locus of points having a minimum radial distance on the peripheral edge of the substrate 12 with respect to the rotation axis of the vacuum chuck 13 as shown in FIG.
Is arranged on the inner side in the radial direction of, and on the outer side of the circle l12 indicating the periphery of the vacuum chuck 13. On the other hand, the second discharge nozzle 1
Reference numeral 7 denotes a virtual circumscribed circle which is a locus of points having the maximum radial distance of the substrate 12 and which is radially outward from the virtual inscribed circle l11.
It is located radially inward of l13.

3 is a sectional view of the spin coater 11 when the substrate 11 is angularly displaced from the state shown in FIG. 1, FIG. 4 is a plan view of the substrate 12 in this case, and FIG. 5 shows the operation of the spin coater 11. It is a graph shown. The operation of the spin coater 11 will be described with reference to these drawings. For example, 20 cc of the cleaning agent is discharged onto the stopped substrate 12 from time t11 in FIG. 5 for a period W11 (for example, 7 seconds). After the discharge end time t12, the discharge is left for a period W12 (for example, 3 seconds), and the time t1
Rotate substrate 12 from 3.

The substrate 12 is rotated at a rotation speed R11 (for example, 200 rpm), and the discharged resist liquid is spread and spread on the substrate 12. From time t14 during this steady rotation period, the cleaning agent is continuously discharged using the first discharge nozzle 16 for the period W13. By the cleaning agent from the first discharge nozzle 16 as described above, the rotation speed R11
When the resist solution scattered from the substrate 12 rotated by the step adheres to the back surface of the substrate 12, it can be effectively removed. However, the range that can be removed is the area between the virtual inscribed circles l11 and l12 as shown in FIG. 2 as in the conventional example, and the radius of the first injecting nozzle 16 alone is smaller than the virtual inscribed circle l11. No effective removal is performed on the outward portion in the direction.

Next, reduce the rotation speed of the substrate 12 to R12 (for example, 30 rpm),
An intermittent ejection operation is performed using the second ejection nozzle 17 for a period W14 (for example, 6 seconds) from the time t15 after the decrease. That is, 1 on the outer side of the virtual inscribed circle l11 of the substrate 12
2 reaches a position facing the second discharge nozzle 17 as shown in FIG.
The ejection operation is performed for a second. Next, when the substrate 12 rotates to reach a position where the portion outside the virtual inscribed circle l11 does not face the second discharge nozzle 17 as shown in FIG. 4, for example, 0.3 seconds. Stop the discharge operation. Board 12
Such an intermittent operation is performed, for example, four times per one rotation.

By the action of the first and second discharge nozzles 16 and 17 as described above, the cleaning agent is spread all over the outer side in the radial direction of the circle 11 of the substrate 11, dissolves the photoresist liquid adhering to the back surface, and then is scattered in the air. It will be. Incidentally, at the rotation speed R12, the cleaning agent of the above type is held on the back surface,
The back surface is wet with the cleaning agent.

Next, the discharge operation of the second discharge nozzle 17 is finished at time t16, and from time t17 after being left for a period W15 (for example, 1 to 2 seconds), the substrate 12 is rotated at the rotational speed R13 (to obtain a uniform photoresist film thickness. For example, 1000 rpm) rotates at high speed. At this time, the splashes of the resist liquid that have scattered are attached to the back surface of the substrate 12, but the back surface is in a state of being wet with the cleaning agent as described above, and the attached resist droplets are dissolved. Further, during the period of high-speed rotation of the rotation speed R13, the cleaning agent effectively dissolves the resist droplets and scatters in the air. After that, at time t18, the ejection operation of the first ejection nozzle 16 ends, at time t19, the rotation of the substrate 12 stops, and the resist liquid coating operation ends.

As described above, in the present embodiment, even if the substrate 12 on which the photoresist is applied by the spin method is, for example, a rectangular plate-shaped glass substrate, it is possible to effectively prevent the back surface from being contaminated by the photoresist. it can. Further, the action and effect of this embodiment are more remarkable as the substrate 12 becomes larger.

The substrate to which the present invention is applied is not limited to the glass substrate used in the liquid crystal display device, but can be effectively applied to various printed wiring boards. Needless to say, the coating agent and the cleaning agent are not limited to the above materials.

In the present invention, the substrate 12 has, for example, a rectangular shape in the above-described embodiment, but the shape is not limited to such a shape, and the substrate 1 is placed on an imaginary plane perpendicular to the rotation axis of the vacuum chuck 13, which is a rotating member. The present invention can be carried out on the substrate 12 having a shape in which the outer shape of the projected figure is at different distances from the rotation axis in the circumferential direction.

Further, an application example in which the liquid material is applied to the surface of the substrate using the first and second cleaning nozzles is also included in the spirit of the present invention.

As described above, according to the present invention, the first cleaning nozzle continuously discharges the cleaning agent radially inward of the minimum radial distance of the substrate peripheral edge with respect to the rotation axis. Therefore, the inner side of the minimum radial distance is effectively cleaned. On the other hand, the outer side of the minimum radial distance is such that the cleaning agent is intermittently discharged by the second cleaning nozzle that intermittently discharges the cleaning agent only during the period facing the second cleaning nozzle. When the outer portion is present intermittently along the circumferential direction, the cleaning action can be effectively performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a spin coater 11 according to an embodiment of the present invention, FIG. 2 is a plan view of a substrate 12, FIG. 3 is a sectional view for explaining the operation of the present embodiment, and FIG. FIG. 5 is a graph for explaining the operation of the spin coater 11, FIG. 6 is a cross-sectional view of a typical conventional spin coater 1, FIG. 7 is a plan view of the substrate 3, and FIG. 6 is a graph illustrating the operation of the spin coater 1. 11 …… Spin coater, 12 …… Substrate, 13 …… Vacuum chuck, 14 …… Container, 15 …… Register discharge nozzle, 16,17…
... Discharge nozzle

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G03F 7/16 501 H01L 21/027

Claims (1)

[Claims] 1. A coating material discharge nozzle (15) for discharging a coating material onto a substrate (12), and a rotating member (13) for supporting and rotating the substrate (12).
And a storage container (1 for storing the substrate (12) and the rotating member (13).
4) and the first cleaning provided on the opposite side of the coating material discharge nozzle (15) with respect to the substrate (12) and arranged at intervals along the radial direction of the rotation axis of the rotating member (13). Nozzle (1
6) and a second cleaning nozzle (17), wherein the first cleaning nozzle (16) is arranged radially inward of the minimum radial distance of the peripheral edge of the substrate (12) with respect to the rotation axis to continuously transfer the cleaning agent. The second cleaning nozzle (17) is disposed outside the minimum radial distance, and only within a period in which the portion outside the minimum radial distance of the substrate (12) faces the second cleaning nozzle (17). A coating device which discharges the cleaning agent intermittently.