JP4145110B2 - Slit nozzle cleaning device and cleaning method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a cleaning method for cleaning a slit nozzle for applying a coating liquid to a surface of a plate-like workpiece such as a semiconductor wafer or a glass substrate with a certain width.
[0002]
[Prior art]
Conventionally, in order to apply a resist solution or the like to the surface of a plate-like object to be processed such as a semiconductor wafer or a glass substrate, the application liquid is dropped from a nozzle onto the center of the object to be processed placed on the spinner, and the spinner The coating liquid is diffused outward by centrifugal force generated by rotating the object to be processed. This method is wasteful because only a small amount of the coating liquid remains on the surface of the object to be processed and most of the liquid is scattered.
[0003]
Therefore, a slit nozzle that applies a coating liquid with a predetermined width to the surface of the object to be processed by opening a coating liquid discharge port with a predetermined width in the nozzle itself instead of spinner application and moving the nozzle relative to the object to be processed. It has been known.
[0004]
If the slit nozzle having the coating liquid discharge port of the predetermined width described above is used, the coating liquid is not wasted and the coating can be performed efficiently. If this is dried, a large amount of foreign matter is generated. Therefore, the coating liquid at the nozzle tip and its peripheral part must be removed by washing after application.
[0005]
As a method of cleaning the tip of the nozzle, a method of removing the foreign matter at the tip of the nozzle with a roller to which the cleaning liquid is attached, or a method of cleaning the entire nozzle tip once with a cleaning device having a cleaning liquid discharge hole is used.
[0006]
However, cleaning with a roller may cause cleaning liquid that has dissolved foreign substances to return to the cleaning liquid pool and contaminate the cleaning liquid. Cleaning using a device having cleaning liquid discharge holes is performed with uniform pressure in all the discharge holes. It was difficult to supply the cleaning liquid, and there was a possibility that uniform cleaning could not be performed.
[0007]
In view of this, Japanese Patent Application Laid-Open No. 2001-252603 discloses a method of cleaning the nozzle tip while moving a cleaning device shorter than the width of the nozzle along the nozzle.
[0008]
JP-A-2001-252603 discloses a solvent discharge means for bringing a solvent that dissolves the coating liquid into contact with the periphery of the discharge port of the coating head while moving the cleaning unit along the longitudinal direction of the coating head (slit nozzle). A method of cleaning the coating head by providing a gas discharge means for removing the remaining deposits and solvent by collision with gas is disclosed.
[0009]
[Problems to be solved by the invention]
However, in the above prior art, “In the solvent discharge means, the solvent discharge from the lower solvent nozzle is performed at a discharge speed at which the discharged solvent reaches not only the lower surface of the slit die but also the inclined surface. The cleaning unit is moved toward the end of the slit die (the left end of FIG. 9) ”(see paragraph [0061] of the publication). In this case, a larger amount of cleaning liquid is required as the width of the coating head becomes longer, and further, the cleaning liquid blows up during cleaning, so that the entire slit die including the coating head is contaminated with the cleaning liquid in which foreign matters are dissolved. is there.
[0010]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an apparatus and a cleaning method for cleaning the tip of a slit nozzle with a small amount of cleaning liquid without contaminating the peripheral portion of the slit nozzle. To do.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the apparatus for cleaning the slit nozzle tip having the coating liquid discharge port of a predetermined width opened according to the present invention while moving along the longitudinal direction of the slit nozzle is provided along the longitudinal direction of the slit nozzle. A cleaning liquid discharge means for generating a mist-like cleaning liquid and a cleaning liquid jet outlet for spraying the generated mist-like cleaning liquid against the inclined portion of the tip of the slit nozzle, and an upper portion of the cleaning liquid jet outlet. A gas ejection port and a gas ejection means for ejecting the gas are provided.
[0012]
Further, the cleaning liquid discharge means includes a liquid passage having one end serving as the cleaning liquid outlet, a cleaning liquid supply passage that opens to the liquid passage in the vicinity of the cleaning liquid outlet, and the cleaning liquid jet more than the opening of the cleaning liquid supply passage. A gas supply passage that opens to the liquid passage at a position away from the outlet, and the gas ejection means includes a gas passage having one end serving as the gas ejection port, and a gas supply passage that opens to the gas passage. Have.
[0013]
Therefore, by adding gas to the cleaning liquid, the cleaning liquid becomes a mist, increases the surface area of the cleaning liquid, and comes into contact with the deposit attached to the tip of the slit nozzle, improving the cleaning effect of dissolving and removing the deposit. In addition, the amount of cleaning liquid used can be saved. Furthermore, by providing the gas ejection port above the cleaning fluid ejection port, it is possible to suppress the cleaning liquid from being blown up.
[0014]
In addition, with the slit nozzle tip stopped at a predetermined position, the gap between the slit nozzle cleaning device and the inclined portion of the slit nozzle tip is uniform from the root to the tip of the slit nozzle. Alternatively, the slit nozzle gradually becomes wider from the base to the tip. By adopting such a configuration, it is possible to efficiently prevent the mist cleaning liquid from being blown up.
[0015]
Furthermore, the cleaning method using the slit nozzle cleaning device described above performs cleaning of the tip of the slit nozzle by simultaneously supplying a mist-like cleaning liquid and gas, and further, after the cleaning of the slit nozzle is completed. The gas is supplied to dry the tip of the slit nozzle.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of an embodiment of a slit nozzle cleaning apparatus according to the present invention. In the figure, a pair of cleaning blocks 2 are provided on a support 1 and a discharge block 3 is provided below the support 1. Is provided. In addition, a slit nozzle 4 is mounted above the cleaning block 2 so as to freely move up and down.
[0017]
In the slit nozzle 4, inclined portions 7 and 8 are formed from the roots 5 and 6 in accordance with the shape of the pair of cleaning blocks 2, forming a tapered shape, and a discharge portion for coating liquid is formed in the lower portion 9. Yes.
[0018]
The pair of cleaning blocks 2 is provided with a liquid passage 10 that forms an angle θ (θ: 1 to 20 °) in the horizontal direction with respect to the inclined portions 7 and 8 of the slit nozzle 4. A liquid jet 11 is formed at one end of the liquid passage 10 facing the inclined portions 7 and 8. A cleaning liquid supply passage 12 is opened near the liquid jet port 11 of the liquid passage 10, and a gas supply passage 13 is opened at a position farther from the liquid jet port 11 than this opening.
[0019]
The liquid passage 10, the liquid jet port 11, the cleaning liquid supply passage 12, and the gas supply passage 13 constitute a cleaning liquid discharge means. FIG. 2 is a simplified view in the direction A of FIG. 1. As shown in FIG. 2, the liquid ejection port 11 has a single long hole (FIG. 2A) or a plurality of round holes (FIG. 2). (B)).
[0020]
Further, in the pair of cleaning blocks 2, a gas passage 14 that forms an angle θ (θ: 1 to 20 °) in the horizontal direction with respect to the inclined portions 7 and 8 of the slit nozzle 4 is formed above the liquid passage 10. It has been drilled. One end of the gas passage 14 directed toward the inclined portions 7 and 8 is formed with a gas (for example, air, nitrogen, argon, etc.) jet port 15 at a position away from the gas jet port 15 of the gas channel 11. The supply passage 16 is open.
[0021]
The gas passage 14, the gas ejection port 15, and the gas supply passage 16 constitute a gas ejection means. Moreover, as shown in FIG. 2, the gas jet nozzle 15 is comprised by one long hole (FIG. 2 (A)) or a some round hole (FIG. 2 (B)). Further, a combination of the long hole liquid jet 11 and the plurality of round hole gas jets 15 or a combination of the plurality of round hole liquid jets 11 and the long hole gas jet 15 is also possible.
[0022]
A method for cleaning the slit nozzle 4 using the cleaning apparatus as described above will be described. FIG. 3 is an operation diagram of the cleaning device in which the support 1 is omitted. The cleaning device (or the cleaning block 2) has a width W1 shorter than a width W2 along the longitudinal direction of the slit nozzle 4 and The tip of the slit nozzle 4 is cleaned and dried by reciprocating along. Further, the slit nozzle can move up and down with respect to the cleaning device.
[0023]
First, the slit nozzle 4 is lowered with respect to the cleaning device so that the gap between the inclined portion at the tip of the slit nozzle 4 and the cleaning block 2 is 1.5 mm. In this case, the gradient of the inclined surface with respect to the inclined portions 7 and 8 of the slit nozzle 4 of the cleaning block 2 is the same as that of the inclined portions 7 and 8.
[0024]
Next, the cleaning process is started while moving the cleaning device along the slit nozzle 4 at a speed of 250 mm / s. Simultaneously with the movement of the cleaning device, the mist-like cleaning liquid and air are simultaneously jetted to the inclined portions 7 and 8 of the slit nozzle 4 for cleaning.
[0025]
Specifically, the liquid outlet 11 and the gas outlet 15 are both long holes and have an opening width of 0.3 mm. While supplying the cleaning liquid supply passage 12 at a speed of 0.2 to 0.6 l / min, air is supplied to the gas supply passage 13 at a pressure of 200 to 500 kPa and a speed of 80 to 150 l / min. By doing so, a mist-like cleaning liquid is ejected from the cleaning liquid outlet 11 and the tip of the slit nozzle is cleaned. At this time, the mist-like cleaning liquid supplied to the inclined portions 7 and 8 at the tip of the slit nozzle 4 and the washed-out deposits are not ejected from the gap between the inclined portions 7 and 8 of the slit nozzle 4 and the cleaning block 2. The air is supplied to the gas supply passage 16 at a pressure of 200 to 500 kPa at a speed of 80 to 150 l / min, and the air is ejected from the gas outlet 15, and the cleaning block 2 for the cleaning liquid and the inclined portions 7 of the slit nozzle 4, Prevents ejection from outside through the gap with 8.
[0026]
Further, when the cleaning block 2 moves, the discharge block 3 is always exhausted to 250 to 500 kPa, so that the cleaning liquid and the washed-off deposits are discharged from the exhaust block 3.
[0027]
Further, when the cleaning device (or cleaning block 2) arrives at the end of the slit nozzle 4, it stops supplying the mist-like cleaning liquid and air, operates only the exhaust block 3, and returns to the start end of the slit nozzle 4 while drying. Come. When the cleaning device returns to the starting end of the slit nozzle 4 and exhausts with the exhaust block 3 and also operates the gas ejection means, drying can be further promoted. Moreover, drying can be promoted by making the moving speed of the nozzle in the drying process slower than the moving speed of the nozzle in the cleaning process. The cleaning block 2 can perform cleaning by reciprocating a plurality of times.
[0028]
FIG. 4 shows another embodiment of the slit nozzle cleaning device. In the above embodiment, the gap between the inclined portion of the tip of the slit nozzle 4 and the cleaning block 2 is made constant, but in this embodiment, as shown by the shaded portion in FIG. 4, the inclined portion of the slit nozzle 4 '. It is structured such that it gradually expands from the bases 5 ', 6' of 7 ', 8' to the lower part 9 'of the slit nozzle 4. At this time, the closest distance between the bases 5 'and 6' of the inclined portions 7 'and 8' and the cleaning block 2 'is set to 1.5 mm.
[0029]
【The invention's effect】
As described above, according to the slit nozzle cleaning device and the cleaning method according to the present invention, the amount of cleaning liquid used can be reduced by using a mist-like cleaning liquid to clean the tip of the slit nozzle. In addition, the surface area of the cleaning liquid is increased so that the deposits come into contact with the deposits, so that the deposits can be easily dissolved and removed. Furthermore, by providing the gas jet port above the liquid jet port, it is possible to suppress the cleaning liquid from being blown up.
[Brief description of the drawings]
1 is a longitudinal sectional view of a cleaning apparatus according to the present invention. FIG. 2 is a simplified view from the direction A in FIG. 1. FIG. 3 is an operation diagram of the cleaning apparatus in FIG. Simplified side view [FIG. 4] Longitudinal sectional view of another embodiment of the cleaning apparatus according to the present invention [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 1 '... Support body, 2, 2' ... Cleaning block, 3, 3 '... Discharge block, 4, 4' ... Slit nozzle, 5, 6 ... Base of slit nozzle, 7, 8 ... Slant part of slit nozzle 9, lower part of slit nozzle, 10, 10 '... liquid passage, 11, 11' ... liquid ejection port, 12, 12 '... cleaning liquid supply passage, 13, 13' ... gas supply passage, 14, 14 '... gas passage 15, 15 ′ gas outlet, 16, 16 ′ gas supply passage.

Claims (6)

In the apparatus for cleaning the slit nozzle tip with the coating liquid discharge port having a predetermined width opened while moving along the longitudinal direction of the slit nozzle, this apparatus is set shorter than the width along the longitudinal direction of the slit nozzle, And a cleaning liquid discharge means for generating a mist-like cleaning liquid, a cleaning liquid outlet for spraying the generated mist-like cleaning liquid to the inclined portion of the tip of the slit nozzle, a gas outlet located above the cleaning liquid outlet, and the gas The cleaning liquid discharging means includes a liquid passage having one end serving as the cleaning liquid jet outlet, a cleaning liquid supply passage opening to the liquid passage in the vicinity of the cleaning liquid jet outlet, and the cleaning liquid. characterized in that it is composed of a gas supply passage than the opening of the supply passage opening into said liquid passage at a location remote from said cleaning liquid ejection port Cleaning device of a slit nozzle for.   2. The slit nozzle cleaning device according to claim 1, wherein the gas ejection means includes a gas passage having one end serving as the gas ejection port, and a gas supply passage that opens to the gas passage. A slit nozzle cleaning device. The slit nozzle cleaning device according to any one of claims 1 and 2 , wherein the slit nozzle cleaning device and the inclined portion of the slit nozzle tip are in a state where the slit nozzle tip is stopped at a predetermined position. The slit nozzle cleaning device is characterized in that the gap is uniform from the base to the tip of the slit nozzle. The slit nozzle cleaning device according to any one of claims 1 and 2 , wherein the slit nozzle cleaning device and the inclined portion of the slit nozzle tip are in a state where the slit nozzle tip is stopped at a predetermined position. The slit nozzle cleaning device is characterized in that the gap is gradually widened from the base to the tip of the slit nozzle.   2. A cleaning method using the slit nozzle cleaning device according to claim 1, wherein the tip of the slit nozzle is cleaned by simultaneously supplying a mist-like cleaning liquid and a gas. Method. 6. The method of cleaning a slit nozzle according to claim 5 , wherein after the cleaning of the slit nozzle is finished, gas is supplied to dry the tip of the slit nozzle.

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