KR100775086B1 - Apparatus and method for detecting foreign substance - Google Patents

Abstract

An apparatus and a method for detecting foreign substances are provided to detect the foreign substances existing on a substrate when a photoresist is coated on a substrate by using a slit cotter. An apparatus for detecting foreign substances detects foreign substances existing at the upper or lower part of a substrate of a slit cotter. The apparatus includes a first light emitting unit(232), a first light receiving unit(234), a second light emitting unit(242), and a second light receiving unit(244). The first light emitting unit and the first light receiving unit are disposed on opposite sides of the substrate. The second light emitting unit and the second light receiving unit are disposed on both sides of the substrate on the front side of the first light emitting unit and the first receiving unit. The first light emitting unit and the second light emitting unit are located on opposite sides of the substrate.

Description

Foreign object detection device and method {APPARATUS AND METHOD FOR DETECTING FOREIGN SUBSTANCE}

1 is a perspective view illustrating a structure of a slit coater in which a general foreign matter sensing device is installed.

FIG. 2 is a side cross-sectional view illustrating a state in which photoresist is applied to a substrate by the slit coater shown in FIG. 1.

FIG. 3 is a front view for explaining a state of sensing foreign matter on a substrate in the slit coater shown in FIGS. 1 and 2.

Figure 4 is a perspective view showing the structure of the slit coater is installed foreign matter detection apparatus according to the present invention.

5 and 6 are side cross-sectional and top views of the slit coater shown in FIG. 4.

7 and 8 are front views for explaining a state in which a foreign material on the substrate is detected in the slit coater is installed foreign matter detection apparatus according to the present invention.

<Explanation of symbols for the main parts of the drawings>

102: substrate chuck 104: foreign matter

110: slit nozzle 120: nozzle transfer unit

200: slit coater 232: first light emitting unit

233: First light 234: First light receiver

242: second light emitting unit 233: second light

244: second light receiving unit GS: substrate

PR: Photoresist

The present invention relates to a foreign matter detection apparatus and method for detecting a foreign matter present on a substrate loaded in a slit coater, and more particularly, when the photoresist is applied on a substrate using a slit coater. The present invention relates to a foreign matter sensing device and method for detecting a foreign matter and measuring its exact position.

In general, when manufacturing a liquid crystal display device, a process error occurs mainly in a photo process using a photoresist. If the photoresist is not uniformly applied, a difference in resolution and circuit line width may occur in a later process, and a difference in reflectance may also occur, causing a defect to appear on a screen as it is.

Recently, there is a need to reduce the process time required to coat photoresist on a substrate. There is a need for a method of uniformly applying and drying the photoresist in a short time.

The method of coating the photoresist uniformly by loading the photoresist on the outside of the round roll and rolling the roll in a predetermined direction on the substrate to apply a photoresist, a roll coating method, and placing the substrate on the support of the disc A spin coating method in which the photoresist is dropped on the center of the substrate and then rotated to apply the photoresist to the substrate by centrifugal force, and a slit coating which is scanned and applied in a predetermined direction while discharging the photoresist to the substrate through a slit nozzle. There is a way.

Among the above coating methods, the roll coating method is difficult to precisely perform uniformity and film thickness adjustment of the photoresist film, and a spin coating method is used for forming a high precision pattern. However, the spin coating method is suitable for coating a photosensitive material on a substrate having a small size, such as a wafer, and is not suitable for a substrate having a large size and a heavy weight, such as a glass substrate for a liquid crystal display panel. This is because the larger and heavier the substrate is, the more difficult it is to rotate the substrate at high speed, and there is a problem in that breakage or energy consumption of the substrate is increased at high speed. For this reason, the slit coating method is mainly used as a method of coating a photoresist on a large glass substrate.

1 is a perspective view illustrating a structure of a slit coater in which a general foreign matter sensing device is installed, FIG. 2 is a side cross-sectional view illustrating a state in which photoresist is applied to a substrate by the slit coater shown in FIG. 1, and FIG. 3 is FIG. 1. And a front view for explaining a state of sensing a foreign matter on the substrate in the slit coater shown in FIG. 2.

Referring to FIG. 1, a general slit coater 100 includes a substrate chuck 102 on which a substrate GS is fixedly seated, a slit nozzle 110 to apply a photoresist PR onto a substrate GS, and With a pair of nozzle transfer unit 120 supporting both sides of the slit nozzle 110 and advancing it in the longitudinal direction, and a light emitting portion 132 and a light receiving portion 134 provided in front of each of the nozzle transfer unit 120. The foreign matter detection device 130, the photoresist supply unit 115 is attached to one side of the nozzle transfer unit, and the photoresist (PR) to transfer the photoresist (PR) from the photoresist supply unit 115 to the slit nozzle 110 A first photoresist supply line 116 and a second photoresist supply line 117 supplying the photoresist PR to the photoresist supply unit 115 are included.

The slit nozzle 110 is a long bar-shaped nozzle, and a fine slit-shaped outlet 112 is formed at the center of the lower end of the slit nozzle facing the substrate GS, and a predetermined amount through the outlet 112. Photoresist PR is discharged to the substrate. The photoresist supply unit 115 is a means for supplying the photoresist PR to the slit nozzle 110 and applying a predetermined pressure to the supplied photoresist PR to eject the photoresist PR. In general, the photoresist supply unit 115 includes a pump to apply a constant pressure to the slit nozzle 110 and the photoresist PR stored in the slit nozzle is discharged onto the substrate by the pressure.

Referring to FIG. 2, the slit coater configured as described above is configured to discharge photoresist PR onto the substrate GS while the slit nozzle 110 moves in the longitudinal direction at a constant speed at one end of the substrate. PR is uniformly coated on the substrate GS.

As described above, when the slit nozzle 110 moves forward and the photoresist PR is applied onto the substrate GS, the foreign matter sensing device 130 installed in front of the slit nozzle 110 is disposed on the upper or lower portion of the substrate GS. Detects the presence of foreign objects. That is, referring to FIG. 3, which shows a state of detecting a foreign substance on a substrate, the light receiving unit 134 receives a light 133 such as a laser emitted from the light emitting unit 132 of the foreign material detecting apparatus 130. Measure If there is no foreign matter 132 between the light emitting unit 132 and the light receiving unit 134, all of the light 133 emitted from the light emitting unit 132 is incident on the light receiving unit 134. If the foreign matter 132 exists between the light receiving unit 134 and the light receiving unit 134, a part of the light 133 emitted from the light emitting unit 132 is obscured by the foreign material 104, and only a part of the light 133 is incident on the light receiving unit 134. As such, when the amount of light measured by the light receiver 134 decreases from the normal state, it is determined that the foreign matter 104 exists between the light emitter 132 and the light receiver 134.

However, in this case, it is possible to determine the presence of foreign matter and the position of the foreign matter in the longitudinal direction, but the exact position of the foreign matter, that is, the position of the foreign matter in the transverse direction of the slit nozzle 110 is unknown.

The location of the foreign matter not only facilitates the removal of the foreign matter, but also checks the location of the foreign matter, and if the foreign matter is found intensively at a certain position, it helps to determine the cause of the foreign matter. That is, the position of the foreign matter is detected and the change of the environment around the slit coater is accumulated and stored over a predetermined time period to monitor the occurrence position of the foreign matter. If the location where the foreign matter is detected is concentrated on either side, the cause of the foreign matter can be identified by identifying the flow of air inside the space where the slit coater is installed or the influence of other equipment around the slit coater.

Therefore, there is a growing demand for detecting the foreign matter present on the substrate and confirming its position.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and when detecting a photoresist on a substrate by using a slit coater, detecting a foreign substance present on the substrate and detecting a foreign substance that can be measured up to its position. It is to provide an apparatus and method.

The foreign matter detection device according to an aspect of the present invention for achieving the above object is a foreign matter detection device for detecting the foreign matter present on the upper or lower substrate of the slit coater, the first disposed facing the opposite sides of the substrate A light emitting portion and a light receiving portion, and a second light emitting portion and a light receiving portion disposed to face opposite sides of the substrate in front of the first light emitting portion and the light receiving portion, wherein the first light emitting portion and the second light emitting portion are opposed to the substrate. It is located on one side and the other side.

Preferably, the second light emitting portion and the light receiving portion are disposed adjacent to the first light receiving portion and the light emitting portion, respectively.

Preferably, the first light emitting portion and the light receiving portion and the second light emitting portion and the light receiving portion move with the front of the slit nozzle of the slit coater.

The foreign matter detection method according to another aspect of the present invention is a foreign matter detection method for detecting a foreign matter present on the upper or lower substrate of the slit coater, and emits light from one side of the substrate and receives the light from the other side of the substrate A first metering step of measuring the amount of light, a second metering step of emitting light from the other side of the substrate, and receiving the light from the one side of the substrate to measure the amount of light; and the first and second metering steps Comparing the amount of light measured in the step of calculating the location of the foreign matter.

Hereinafter, exemplary embodiments of a foreign substance sensing apparatus and method according to the present invention will be described with reference to the accompanying drawings.

Figure 4 is a perspective view showing the structure of the slit coater is installed foreign matter detection apparatus according to the present invention, Figures 5 and 6 are a side cross-sectional view and a plan view of the slit coater shown in Figure 4, Figures 7 and 8 in the present invention The front view for explaining the state of detecting the foreign matter on the substrate in the slit coater is installed according to the foreign matter detection device.

4 to 6, the slit coater 200 in which the foreign matter detection apparatus according to the present invention is installed includes a substrate chuck 102 on which the substrate GS is fixedly seated, and a photoresist PR on the substrate GS. A slit nozzle 110 to be applied to the nozzle, a pair of nozzle transfer units 120 for supporting both sides of the slit nozzle 110 and advancing them in the longitudinal direction, and first and second nozzles provided in the nozzle transfer unit 120. It includes a foreign matter detection device consisting of the second optical sensor (230, 240), the photoresist supply unit 115, and the first and second photoresist supply line (116, 117), the configuration described in the prior art It is the same as the slit coater 100, but the configuration of the foreign matter detection device mounted thereon is only different. Moreover, the operation of the slit coater 200 itself to apply the photoresist PR on the substrate is also the same as the slit coater 100 described in the prior art. Therefore, hereinafter, the configuration and operation of the foreign matter detection apparatus according to the present invention will be described mainly.

The foreign matter detection apparatus according to the present invention is installed in front of the nozzle transfer unit 120 and comprises a first optical sensor 230 and a first light emitting unit and a light receiving unit (232, 234), and the first optical sensor 230 It is installed in front of the second light sensor and a second light sensor 240 composed of the light receiving portion (242,244). That is, the first light emitting part 232 and the second light receiving part 244 are disposed in front of any one of the nozzle transfer unit 120 in a longitudinal direction to be spaced apart from each other, and the other of the nozzle transfer unit 120 is disposed. The first light receiving part 234 and the second light emitting part 242 are disposed to be spaced apart from each other in the longitudinal direction by one front. In this case, the first light emitter 232 and the first light receiver 234 face each other, and the second light receiver 244 and the second light emitter 242 are disposed to face each other.

That is, light emitted from the first light emitting part 232 disposed on one side in the lateral direction of the substrate GS is received by the first light receiving part 234 disposed on the other side in the lateral direction of the substrate GS. The light emitted from the second light emitting part 242 disposed on the other side of the substrate GS at a position spaced apart from the light emitting part and the light receiving parts 232 and 234 by a predetermined distance in the longitudinal direction is the substrate GS. Is arranged to receive light from the second light receiving unit 244 disposed on one side of the lateral direction.

These first and second light emitting units and light receiving units 232, 234, 242, and 244 are both positioned in front of the slit nozzle 110 and move together with the slit nozzle 110. To this end, in the illustrated embodiment, the light emitting portion and the light receiving portion 232, 234, 242, and 244 all have a pair of nozzle transfer units 120 for advancing the slit nozzle 110 in the longitudinal direction of the substrate GS. Although it is fixedly installed on the other hand, it may be provided in a separate moving means to advance these light emitting parts and the light receiving parts 232, 234, 242, 244 in the longitudinal direction in front of the slit nozzle 110.

Next, with reference to Figures 7 and 8, it will be described the operation of the foreign matter detection apparatus according to the present invention. Hereinafter, a case in which the foreign matter 104 existing on the substrate GS fixedly seated on the slit coater 200 is positioned to be oriented on one side in the lateral direction of the substrate GS as shown in FIGS. 6 to 8. It will be described by way of example.

Although a lot of lasers having excellent straightness are used as the light emitted from the light emitting parts 232 and 242, in general, light has a characteristic of spreading according to a traveling distance, so that the cross-sectional diameter of the light emitted from the light emitting part is the light emitting part and the light receiving part. It increases with the distance between them. Furthermore, due to the enlargement of the current substrate, the width of the substrate GS increases in lateral width, thereby increasing the distance between the light emitting portion and the light receiving portion, and thus, a large distance between the cross section of the light emitted from the light emitting portion and the cross section of the light incident on the light receiving portion. The difference occurs.

First, after the substrate GS is seated on the substrate chuck 102 of the slit coater 200, the photoresist supply unit 115 operates to slit the photoresist PR on the substrate through the slit nozzle 110. Is discharged to. At the same time, the photoresist PR is applied onto the substrate GS while the nozzle transfer unit 120 is advanced in the longitudinal direction. At this time, the second light emitting unit and the light receiving unit 242, 244 disposed at the foremost of the light emitting unit and the light receiving unit installed in the moving nozzle transfer unit 120 detect the foreign matter 104. Referring to FIG. 7 where the state in which the second light emitting unit and the light receiving units 242 and 244 detect the foreign matter 104 is illustrated, the light 243 emitted from the second light emitting unit 242 is the foreign matter 104. A portion of the light is obstructed by the foreign material 104 while only the remaining part of the light is incident on the second light receiving part 244, and the amount of light incident on the second light receiving part 244 is indicated as S1 in FIG. 7. .

After the presence of the foreign matter 104 is sensed by the second light emitting part and the light receiving parts 242 and 244, the first light emitting part and the light receiving part are further moved while the nozzle transfer unit 120 moves further in the longitudinal direction. 232 and 234 detect the foreign matter 104. Referring to FIG. 8, in which the first light emitting unit and the light receiving units 232 and 234 detect the foreign matter 104, the first light 233 emitted from the first light emitting unit 232 may be a foreign matter ( While passing through 104, a part of the light is blocked by the foreign material 104, so that only the remaining part of the light is incident on the first light receiving unit 234. In this case, the amount of light incident on the first light receiving unit 234 is represented as S2 in FIG. 8. have.

Since the foreign matter 104 is located close to the second light emitting portion 242 and far from the first light emitting portion 242, considering the fact that the diameter of the cross section of light increases in proportion to the traveling distance of the second light emitting portion, A part of the second light 243 emitted from the unit 242 is obscured by the foreign matter 104 in a slightly diffused state, and the first light 233 emitted from the first light emitting unit 232 is the second light 243. After being diffused more than two lights 243, a portion of it is obscured by the same foreign matter 104. Accordingly, the amount of light S1 received by the second light receiver 244 after the second light 243 (emitted from the second light emitter 242) after passing through the foreign matter 104 may cause the foreign matter 104 to pass through. The first light 233 (emitted from the first light emitting part 232) after passing through is smaller than the light amount S2 received by the first light receiving part 234.

At this time, the difference in the amount of light measured by the first and second light receiving units 234 and 244 corresponds to the distance where the foreign matter 104 is located. That is, when the light amount S1 measured by the second light receiving unit 244 is greater than the light amount S2 measured by the first light receiving unit 234, the foreign matter 104 may have the second light receiving unit 244 rather than the first light receiving unit 234. If it is located closer to and the amount of light measured by the first and second light receiving units 234 and 244 is the same, it can be seen that the foreign matter 104 is located at the transverse center of the substrate GS. The position of the foreign matter 104 due to the difference in the amount of light is automatically calculated by a controller (not shown) that calculates the amount of light measured by the first and second light receiving units 234 and 244.

As such, two pairs of light emitting parts and a light receiving part are disposed to face both sides in the transverse direction of the substrate, and two light emitting parts are disposed at positions facing each other to emit and receive light in different directions to detect the same foreign matter. In addition to the presence of the foreign matter can also know the position in the transverse direction of the foreign matter.

In the above-described embodiment, the foreign material 104 is described in the case where the upper portion of the substrate GS, but the foreign matter 104 is lower than the substrate GS, that is, the substrate GS and the substrate chuck 102. The same applies to the case where it exists in between. That is, when foreign matter is present under the substrate GS, that is, between the substrate GS and the substrate chuck 102, the corresponding portion of the substrate protrudes upward due to the foreign matter 104 to emit light 232 and 242. A portion of the light emitted from) is covered by the protruding portion of the substrate GS, so that the foreign matter can be detected in the same manner as the light is covered by the foreign matter as described above.

Although described above with reference to the drawings and embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit of the invention described in the claims below You will understand.

The foreign matter sensing device according to the present invention having the above-described configuration has a simple structure and can measure not only whether foreign matter is present on the upper and / or lower portions of the substrate in a short time but also the exact position of the foreign matter.

By measuring the position of the foreign matter in this way, it is not only easy to remove the foreign matter present on the substrate or the upper part of the substrate chuck, but also changes the environment around the slit coater in a predetermined period together with the position on the slit coater where the foreign matter is detected. By accumulating storage and monitoring the location of occurrence of foreign matters, if they are found to be concentrated on either side, the cause of foreign matters may be considered by considering the flow of air inside the space where the slit coater is installed or the influence of other equipment around the slit coater. Can be found. Accordingly, it is possible to reduce the defect rate when applying the photoresist on the substrate by eliminating the cause of the generation of foreign substances generated in the slit coater.

Claims (4)

A foreign matter detection device for detecting a foreign matter present on the upper or lower substrate of the slit coater, A first light emitting portion and a light receiving portion disposed to face opposite sides of the substrate; A second light emitting part and a light receiving part which are disposed on opposite sides of the substrate in front of the first light emitting part and the light receiving part; And the first light emitting part and the second light emitting part are positioned on opposite and opposite sides of the substrate, respectively. The foreign matter sensing apparatus of claim 1, wherein the second light emitting unit and the light receiving unit are disposed adjacent to the first light receiving unit and the light emitting unit, respectively. The foreign matter sensing device according to claim 1 or 2, wherein the first light emitting part and the light receiving part, and the second light emitting part and the light receiving part move together with the front of the slit nozzle of the slit coater. As a foreign matter detection method for detecting a foreign matter present on the upper or lower substrate of the slit coater, A first photometric step of emitting light from one side of the substrate and measuring the amount of light by receiving the light from the other side of the substrate; A second metering step of emitting light from the other side of the substrate and measuring the amount of light by receiving the light from the one side of the substrate; And detecting the position of the foreign matter by comparing the amount of light measured in the first and second photometric steps.

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