JP4986490B2 - Pre-discharge device - Google Patents

Description

  The present invention relates to a preliminary discharge apparatus and a preliminary discharge method for a slit coater for applying a coating liquid such as a resist onto a substrate surface such as a glass substrate or a semiconductor wafer.

When coating the coating liquid on the substrate surface using a slit coater, the coating liquid at the tip of the slit nozzle comes into contact with air during the waiting period until the coating is performed on the next substrate after the coating operation is completed. The concentration of the liquid partially increases, and the viscosity of the coating liquid partially increases.
When the coating operation is performed in such a state, uneven coating such as vertical stripes or film breakage occurs due to partial viscosity unevenness.
In order to eliminate such problems, a preliminary discharge process is performed in which a small amount of coating liquid existing near the opening of the slit nozzle is discharged prior to the supply of the coating liquid to the substrate.

As a preliminary ejection device that performs such preliminary ejection processing, a roller-type preliminary ejection device that uses a priming roller and ejects a small amount of coating liquid from a slit nozzle onto the priming roller is known (see, for example, Patent Document 1).
In this preliminary discharge device, a priming roller is immersed in a cleaning tank in which a cleaning liquid is stored, and the coating liquid discharged from the slit nozzle is scraped off by a squeegee as the priming roller rotates.

JP 2005-329340 A

By the way, the roller-type preliminary discharge device as described above requires a cleaning tank that accommodates the roller itself, so that the volume of the device itself increases and the size of the device itself increases. Further, since the roller is also enlarged with the increase in the size of the substrate to be coated, there has been a drawback that it is difficult to maintain the processing accuracy of the roller. Further, in the case of the roller method, it has been pointed out that the consumption of the cleaning liquid is large because the priming roller is immersed in the cleaning liquid, and the running cost is also expensive.
In addition, in order to keep the entire roller clean, a squeegee longer than the slit length of the slit nozzle (for scraping the coating liquid on the roller surface) is required. It is difficult to maintain, and furthermore, it is difficult to maintain accuracy with respect to providing such a large squeegee at a predetermined angle with respect to the roller.
Further, when a defect occurs in the cleaning of the roller, there is a drawback that the defect tends to adversely affect the coating itself.

In view of the above, the present invention realizes a preliminary discharge device and a preliminary discharge method in which the apparatus itself does not increase in size and does not require high processing accuracy in the roller itself.
Furthermore, another object of the present invention is to realize a preliminary discharge apparatus and a preliminary discharge method in which the consumption of the cleaning liquid is relatively small and the running cost is low.

  The preliminary ejection device of the present invention is a preliminary ejection device for ejecting the coating liquid from the slit nozzle prior to application to the surface of the substrate, and is disposed opposite to the slit nozzle, and has a slit opening of the slit nozzle. A pre-discharge surface extending in the same direction as the extending direction and a removal mechanism for removing the coating liquid existing on the surface of the pre-discharge surface are provided in the vicinity of the pre-discharge surface.

  According to the preliminary discharge device of the present invention, the preliminary discharge surface that is arranged to face the slit nozzle and extends in the same direction as the extension direction of the slit opening of the slit nozzle, and the preliminary discharge in the vicinity of the preliminary discharge surface Since the removal mechanism for removing the coating liquid existing on the surface of the surface is provided, it is possible to perform the actual preliminary discharge processing by discharging the coating liquid onto the preliminary discharge surface (virtual substrate). Accordingly, for example, it is not necessary to provide a driving device as compared with a roller type preliminary discharge device, and a simple structure can be obtained and an increase in size of the device can be suppressed. In addition, manufacturing costs can be reduced. Furthermore, since a roller system is not used, high machining accuracy is not required.

  The preliminary ejection method of the present invention is a preliminary ejection method for ejecting a coating liquid from a slit nozzle prior to application to the substrate surface, and the slit nozzle is configured to supply the coating liquid to the substrate surface while the slit is being supplied. By moving the removing mechanism on the preliminary discharge surface extending in the same direction as the extension direction of the slit opening of the nozzle, the coating liquid remaining on the preliminary discharge surface is removed.

  According to the preliminary discharge method of the present invention, while the slit nozzle supplies the coating liquid to the substrate surface, the removal mechanism is moved on the preliminary discharge surface extending in the same direction as the slit opening extending direction of the slit nozzle. By doing so, the coating liquid remaining on the preliminary discharge surface is removed, so that the preliminary discharge process can be easily performed as compared with, for example, the roller-type preliminary discharge method, and the processing efficiency can be improved. Further, during the preliminary ejection process, for example, it is only necessary to supply a small amount of cleaning liquid to the preliminary ejection surface, and the coating liquid can be removed by the subsequent movement of the removal mechanism. The consumption of cleaning liquid can be greatly reduced.

According to the preliminary discharge device of the present invention, it is possible to obtain a preliminary discharge device that is structurally simple and inexpensive.
In addition, according to the preliminary discharge method of the present invention, it is possible to improve the processing efficiency of the preliminary discharge process and reduce the cleaning liquid.

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2 show a schematic configuration diagram of a slit coater including the preliminary ejection device of the present invention, FIG. 1 is a plan view, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. 3 and 4 are schematic configuration diagrams of the preliminary ejection device, and FIG. 5 is a side view showing details of the removal mechanism of the preliminary ejection device.
As shown in FIGS. 1 and 2, the slit coater includes a base 1, and the base 1 is provided with a pair of rails (2 a and 2 b). A moving device 4 on which the slit nozzle 3 is mounted is movably disposed on the rails (2a, 2b), and a substrate placement stage 5 is disposed substantially at the center of the rails (2a, 2b). Then, a substrate W such as a glass substrate or a semiconductor wafer is disposed on the substrate mounting stage 5, and a coating liquid such as a resist is applied to the surface of the substrate W. The moving device 4 includes driving units (6a, 6b) that engage with the rails (2a, 2b) and beams (7a, 7b) installed between these driving units.

  The slit nozzle 3 is supported so as to be movable up and down between two drive devices (6a, 6b), and has a slit opening extending in a direction perpendicular to the extending direction of the rails (2a, 2b). The coating liquid is applied to the surface of the substrate W through this slit opening. The slit nozzle 3 communicates with a syringe pump (not shown) and communicates with a coating liquid supply tube (not shown) to supply one coating liquid. And after one application | coating is complete | finished, an excess coating liquid is collect | recovered via a discharge tube.

  When applying to the surface of the substrate W, for example, a gap sensor is used to measure the distance between the slit nozzle and the surface of the substrate W, and a lifting device (not shown) is driven to set a predetermined distance between the slit nozzle 3 and the surface of the substrate W. Adjust so that the interval is maintained.

In the present embodiment, in particular, in the preliminary discharge unit 10 provided at a position away from the substrate mounting stage 5, the preliminary discharge device is configured as follows.
That is, as shown in FIGS. 3 and 4, the preliminary ejection device is disposed so as to face the slit nozzle 3, and the preliminary ejection surface 20 extends in the same direction as the extension direction of the slit opening of the slit nozzle 3. And a removal mechanism 21 that removes the coating liquid present on the surface of the preliminary ejection surface 20.

The preliminary discharge surface 20 is formed of a plate-like plate, and the plate 20 is fixed to the drain pan 22 and extends in the same direction as the extension direction of the slit opening of the slit nozzle 3. Although not shown, the drain pan 22 has a unique cleaning liquid supply mechanism for cleaning the drain pan 22 itself. An exhaust mechanism for exhausting the drain pan 22 is also provided.
Both ends (20a, 20b) of the plate 20 are chamfered. By chamfering in this way, as will be described later, when the squeegee 22 moves on the plate 20, the squeegee 22 is prevented from being affected (broken by contact, etc.) by both ends (20 a, 20 b) of the plate 20. be able to.

  As shown in FIG. 5, the removing mechanism 21 includes a main body 24 to which the squeegee 23 is attached, and a cleaning liquid supply mechanism 25, a drying mechanism 26, and a suction mechanism 27 attached to the main body 24.

When the removal mechanism 21 is arranged on the plate 20 as shown in the drawing, the drying mechanism 26 is provided at the rear stage of the main body 24 and the cleaning liquid supply mechanism 25 is provided at the front stage of the main body 24 based on the movable direction (see arrow A). Installed to be placed. The suction mechanism 27 is attached to the main body 24 on the side opposite to the side on which the squeegee 23 is attached. The body 30 is mounted for rotation fulcrum X as a reference.
Note that the attachment positions of the cleaning liquid supply mechanism 25, the drying mechanism 26, and the suction mechanism 27, the orientation of the main body 24 with respect to the plate 20, and the like are not limited to the illustrated case, and various forms are conceivable depending on the situation.

  In the removing mechanism 21 having such a configuration, the pressing mechanism 20 is pressed against the plate 20 by a pressing spring provided in a driving mechanism (not shown) and the squeegee 23 is also pressed against the plate 20. And it moves integrally in the same direction (longitudinal direction) as the extending direction of the opening of the slit nozzle 3, and performs preliminary discharge processing as described later. When the coating liquid is not discharged onto the plate 20, the removal mechanism 21 temporarily moves upward from the plate 20, moves in a direction perpendicular to the plate 20 (see arrow B), and returns to the standby position. That is, it moves to the side of the plate 20.

  As described above, the end portion (lower end) of the squeegee 23 is pressed against the surface of the plate 20, and an elastic pressing force acts between the squeegee 23 and the surface of the plate 20. The abutting angle of the squeegee 23 with respect to the plate 20 can be adjusted within a range of, for example, 30 to 75 degrees (preferably 45 to 60 degrees). By scraping the squeegee 23 against the plate 20 at such an angle, the effect of scraping off the coating liquid can be enhanced.

  The squeegee 23 is preferably made of a material having lower hardness than the plate 20, solvent resistance, and elasticity. In this embodiment, polyester is used, but other than this, for example, a material made of a rubber material that can be elastically deformed can also be used.

  The cleaning liquid supply mechanism 25 is provided with a cleaning liquid supply hole 29 for supplying a cleaning liquid. The cleaning liquid supply mechanism 25 may have any configuration as long as it can supply the cleaning liquid onto the plate 20. Various forms of supply pipes, nozzles, and the like are conceivable. For example, different types of nozzles may be provided on the plate 20 by providing a plurality of nozzles. A cleaning liquid can also be supplied. In addition, the cleaning liquid can be supplied not only to the plate 20 but also to the squeegee 23 by changing the direction of the nozzle or the supply angle of the cleaning liquid from the nozzle. In this case, it is not necessary to separately provide a cleaning liquid supply mechanism for the squeegee 23, and the configuration can be simplified.

  The drying mechanism 26 is provided with an air supply hole 28 for supplying air. The drying mechanism 26 is similar to the cleaning liquid supply mechanism 25 as long as it can supply air onto the plate 20, and various forms such as a supply pipe and a nozzle shape are conceivable. For example, air can be supplied not only to the plate 20 but also to the squeegee 23 by changing the direction of the nozzle or the air supply angle from the nozzle. In this case, there is no need to provide a separate drying mechanism for the squeegee 23 and the configuration is simplified. Can be

  When a cleaning liquid supply mechanism or a drying mechanism for the squeegee 23 is separately provided, it is provided in the vicinity of the plate 20 (upper side, lower side, lateral side, etc.), in the vicinity of the movement end point position of the removal mechanism 21, in the vicinity of the standby position of the removal mechanism 21. Can be provided. Moreover, it can also be integrated in the removal mechanism 21 integrally.

  Although not shown, the suction mechanism 27 includes a suction nozzle that communicates with the squeegee 23 through the body 24.

According to such a preliminary discharge device of the present embodiment, the plate 20 extending in the same direction as the extending direction of the slit opening of the slit nozzle 3, and present on the surface of the plate 20 in the vicinity of the plate 20. Since the removing mechanism 21 for removing the coating liquid to be removed is provided, when the plate 20 is actually moved on the plate 20 as will be described later, the coating liquid is applied to the plate (virtual substrate) 20 in the same manner as the regular coating process. It is possible to perform an easy preliminary discharge process of discharging and removing the coating liquid on the plate 20 by the removing mechanism 21 (for example, as compared with a roller type preliminary discharge device).
That is, in the case of the present embodiment, since the squeegee 23 having a width substantially equal to the width of the plate-like plate 20 is simply moved in the direction in which the opening of the slit nozzle 3 extends, The drive mechanism and the squeegee longer than the slit length are not required, and high accuracy is not required for the roller itself and how to attach the squeegee. In this way, since a high machining accuracy is not required and a large drive device is not required, a simple device structure with reduced manufacturing cost can be obtained.

  Further, since the removing mechanism 21 is composed of the squeegee 23 and the cleaning liquid supply mechanism 25, and further, the drying mechanism 26 and the suction mechanism 27, when moved on the plate 20 as will be described later, The coating solution can be softened with a cleaning solution and scraped off with a squeegee 23. Furthermore, the coating liquid scraped off by the suction mechanism can be directly sucked, and the plate 20 after scraping can be dried in a clean state.

  Next, an embodiment of an actual preliminary discharge method (preliminary discharge process) using the above-described preliminary discharge device will be described. In the present embodiment, the pre-ejection unit 10 is set as a start position during application.

When the regular coating process on the substrate W is completed, the slit nozzle 3 returns to the preliminary ejection unit 10 which is the start position as shown in FIG. Then, a predetermined amount of coating liquid is discharged (supplied) from the slit nozzle 3 to the plate 20 by the same operation as in the regular coating process.
At this time, the slit nozzle 3 descends so as to approach the plate 20 and descends to form a bead, for example, until the distance between the tip of the slit nozzle 3 and the surface of the plate 20 becomes, for example, 30 μm. Thereafter, the slit nozzle 3 is raised to, for example, about 150 to 200 μm, and during that time, the coating liquid supply speed from the pump is increased to the coating speed on the substrate W, and the slit nozzle 3 is moved to discharge a predetermined amount of coating liquid.

After the coating liquid is discharged onto the plate 20, the slit nozzle 3 moves onto the substrate W and returns to the regular coating process on the substrate W again.
Specifically, when the linear motor is driven, the moving device 5 moves toward the right side of the drawing, and a coating liquid such as a resist is supplied from the slit nozzle 3 to the surface of the substrate W. When the regular coating process on the surface of the substrate W is completed, the slit nozzle 3 moves up and down and returns to the start position.

Thus, when the regular application process on the next substrate W starts to be performed again, the removal mechanism 21 operates in the preliminary ejection unit 10 to start removing the coating liquid on the plate 20.
That is, the removal mechanism 21 moves from the standby position onto the plate 20 and is disposed opposite to the plate 20 as shown in FIGS. Then, a cleaning liquid is supplied onto the plate 20 from the cleaning liquid supply mechanism 25.

Next, the removal mechanism 21 is moved from one end on the plate 20 to the other end (arrow A in FIGS. 4 and 5) to scrape the coating solution on the plate 20 with the squeegee 23. At this time, the viscosity of the coating liquid is reduced by the cleaning liquid, and the coating liquid can be scraped cleanly from the plate 20. In accordance with this scraping operation, the application liquid attached to the squeegee 23 is directly sucked by driving the suction mechanism 27.
The suction may not be synchronized with the scraping operation, and can be performed when the squeegee 23 reaches the movement end point. In addition, the movement of the removal mechanism 21 may be performed multiple times instead of once.

Next, air is supplied onto the plate 20 from the drying mechanism 26 to dry the plate 20. After that, the removal mechanism 21 is once moved upward from the plate 20 and moved in a direction perpendicular to the plate 20 (see arrow B in FIG. 4) to return to the standby position.
For example, when the squeegee 23 is also cleaned and dried with the cleaning liquid, depending on the location where the cleaning liquid supply mechanism and the drying mechanism are provided (whether they are provided integrally with the removal mechanism 21 or separately), This is performed before returning to the standby position (after the plate 20 is dried) or after returning to the standby position.

According to the preliminary discharge method of the present embodiment as described above, since the coating liquid is discharged onto the plate 20 and the cleaning liquid is supplied, the simple method is simply scraped with the squeegee 23. The processing efficiency can be improved compared to the method. Further, during the preliminary discharge process, it is only necessary to supply a small amount of the cleaning liquid from the cleaning liquid supply mechanism 25 onto the plate 20, and for example, the consumption of the cleaning liquid can be greatly reduced as compared with the roller-type preliminary discharge system.
Further, since the coating liquid attached to the squeegee 23 is directly sucked by the suction mechanism 27, the squeegee 23 can always be brought into a close state after cleaning, and the maximum scraping effect can be maintained during the processing. Further, since the scraped plate 20 is dried by the drying mechanism 26, the plate 20 can always be kept clean.
In the case where not only the plate 20 but also the squeegee 23 is cleaned and dried, the preliminary ejection process can be performed in a cleaner environment.

In the preliminary discharge device of the above-described embodiment, a plate-like plate is used as the preliminary discharge surface 20, but a belt-like plate can also be used.
For example, if the belt is configured to be able to rotate and move in the form of a roller, the coating liquid can be applied in the same manner as in the configuration of the present embodiment (FIGS. 3 and 4) by bringing a fixed squeegee into contact with the rotating belt. Can be scraped off. In this case, since the squeegee only needs to abut on the belt, the arrangement position of the squeegee is not particularly limited.

Further, in the preliminary ejection device of the above-described embodiment, the case where the removal mechanism 21 includes the squeegee 23 and the cleaning liquid supply mechanism 25, and further the drying mechanism 26 and the suction mechanism 27 has been described. Not. That is, when the viscosity of the coating solution is low and it is not necessary to make the cleaning solution softer, it is sufficient to have at least the squeegee 23 in that the coating solution on the plate 20 is simply scraped, and a mechanism for removing only the squeegee 23 is also provided. Conceivable. In addition, a removal mechanism including a squeegee 23 and a cleaning liquid supply mechanism 25 is also conceivable.
Thus, it goes without saying that the configuration of the removal mechanism 21 can be further simplified depending on the situation. Of course, the removing mechanism 21 has the above-described configuration, and it is also possible to exclude a process that is not necessary during actual processing (the process is not performed).

In the preliminary ejection device according to the above-described embodiment, the case where the squeegee 23 is used in the removing mechanism 21 has been described. However, for example, a brush, an air knife, or a sponge can be used.
In the preliminary ejection device according to the above-described embodiment, the case where one squeegee 23 is provided in the removal mechanism 21 has been described, but a configuration in which a plurality of squeegees are provided may be employed. In this case, each squeegee may be formed of the same material or different materials. With such a configuration, the scraping effect can be greatly improved as compared with the case of only one.
Also, a squeegee and a brush or an air knife can be combined, or a brush and an air knife can be combined.
In addition to this, by combining squeegee and sponge, brush and sponge, or air knife and sponge, for example, the coating liquid can be scraped off and the plate can be cleaned (wiped off) at the same time, and a synergistic effect can be expected.

  In the preliminary ejection device according to the above-described embodiment, the plate 20 is inverted 90 degrees (vertical), for example, and the coating liquid on the plate 20 is scraped off by the removing mechanism 21 attached to the lateral surface, or a slit nozzle 3, after discharging the coating liquid onto the plate 20, the plate 20 can be inverted 180 degrees, and the coating liquid can be scraped off by the removing mechanism 21 attached to the lower surface of the plate 20.

In the preliminary discharge device of the above-described embodiment, for example, the tip of the squeegee 23 may be configured to be separated from the plate 20 at the end portion of the plate 20 (so as to be separated upward from the plate 20). For example, when the movable stop is stopped during processing, the tip of the squeegee 23 is separated from the plate 20 at the end of the plate 20, thereby eliminating the problem that the coating liquid that does not adhere to the squeegee 22 remains on the plate 20 and the surface of the plate 20 is clean. There is an advantage of being maintained in a proper state.
In addition to this, a driving mechanism may be provided on the plate 20 so that the plate 20 is separated from the removal mechanism 21 (squeegee 22).

  Further, in the preliminary ejection device of the above-described embodiment, the removing mechanism 21 is required to supply at least the cleaning liquid onto the plate 20 and to remove the coating liquid from the plate 20. It is not limited to the structure located on the upper side, and can be installed on the lateral side with respect to the plate 20, for example, depending on the arrangement position of the plate 20 or the like. In other words, the installation position of the removal mechanism 24 may be any of the upper side, the lower side, and the lateral side with respect to the plate 20.

  In the preliminary discharge method of the above-described embodiment, after the coating liquid is discharged onto the plate 20 from the slit nozzle 3, the cleaning liquid is sprayed onto the plate 20 before scraping with the squeegee 22, but if the viscosity is low, the cleaning liquid is discharged. It is also possible to simply scrape off the coating solution with the squeegee 22 without spraying.

  In the preliminary discharge device of the above-described embodiment, the slit coater having only one gantry that accommodates the slit nozzle has been described. However, it can also be applied to a double gantry method having two pairs of gantry on the base. it can.

The present invention is not limited to the above-described embodiment, and various other configurations can be taken without departing from the gist of the present invention.

It is a top view which shows an example of a slit coater. It is sectional drawing on the AA line of the slit coater shown in FIG. It is a schematic block diagram (the 1) which shows one Embodiment of the preliminary discharge apparatus which concerns on this invention. It is a schematic block diagram (the 2) which shows one Embodiment of the preliminary discharge apparatus which concerns on this invention. It is a side view which shows the detail of the removal mechanism of the preliminary discharge apparatus shown in FIG.3 and FIG.4.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Base, 2a, 2b ... Rail, 3 ... Slit nozzle, 4 ... Moving device, 5 ... Substrate mounting stage, 6a, 6b ... Drive part, 7a, 7b・ ・ ・ Beam, 10 ・ ・ ・ Preliminary ejection part, 20 ・ ・ ・ Preliminary ejection surface (plate), 21 ... Removal mechanism, 22 ... Drain pan, 23 ... Squeegee, 24 ... Main body, 25 ... Cleaning liquid supply mechanism, 26 ... Drying mechanism, 27 ... Suction mechanism, 28 ... Air supply hole, 29 ... Cleaning liquid supply hole

Claims (4)

Prior to the application to the substrate, in the preliminary discharge device for discharging the coating liquid from the slit nozzle,
A pre-ejection surface that is arranged facing the slit nozzle and extends in the same direction as the direction of extension of the slit opening of the slit nozzle;
In the vicinity of the preliminary discharge surface, a removal mechanism for removing the coating liquid present on the surface of the preliminary discharge surface is provided,
The preliminary discharge surface comprises a plate-like plate fixed to the drain pan,
The removal mechanism includes a main body to which a squeegee is attached, a cleaning liquid supply mechanism, a drying mechanism, and a suction mechanism attached to the main body, and the main body is rotatable about a fulcrum. Pre-discharge device. 2. The preliminary ejection device according to claim 1 , wherein the squeegee is made of polyester. 2. The preliminary ejection device according to claim 1 , wherein a plurality of the squeegees are provided. 2. The preliminary ejection device according to claim 1, wherein one or both ends of the plate-like plate are chamfered.