JP2008126155A - Optical foreign matter detection apparatus and treatment liquid application apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of a detection error due to an effect of temperature difference on an optical axis of an optical beam in a treatment liquid application apparatus equipped with an optical detection means for detecting an abnormal state by radiating an optical beam along the top face of a target substrate to be treated. <P>SOLUTION: The application apparatus is configured in a manner that a target substrate 1 to be treated which is horizontally set on a stage 2 and a treatment liquid supply nozzle 11 having a slit-like discharge aperture 11b extended in the width direction of the substrate 1 are moved relatively to apply a treatment liquid discharged by the treatment liquid supply nozzle 11 to the surface of the substrate 1. In the front side in the moving direction of the treatment liquid supply nozzle 11, an optical beam 4 is radiated from a light transmission part 5 to a light reception part 6. A long optical axis cover member 15 having a U-shaped cross-sectional form and surrounding the top part and both side parts of the optical beam 4 is installed and accordingly, a generation of temperature difference on the optical axis of the optical beam due to the effect of, for example, a down flow is prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a foreign matter detection device that optically detects a state in which foreign matter such as dust adheres to a substrate to be processed, and a slit coat type that mounts the foreign matter detection device and applies a processing liquid to the substrate to be processed. The present invention relates to a treatment liquid coating apparatus.

  For example, in the field of LCD manufacturing technology, a step of selectively etching a semiconductor layer, an insulator layer, an electrode layer, etc. formed on an LCD substrate into a predetermined pattern is performed. In this case, a so-called photolithography technique is applied in which a photoresist solution is applied on the LCD substrate to form a resist film, the resist film is exposed in accordance with a circuit pattern, and this is developed.

  In the case of applying a photoresist solution on the LCD substrate, a resist supply nozzle that discharges a resist solution obtained by dissolving a photosensitive resin in a solvent in a strip shape is employed, and a rectangular LCD substrate is applied to the resist by the nozzle. A method is known in which coating is performed while being relatively translated in a direction orthogonal to the liquid discharge direction. In this case, the resist supply nozzle is provided with a slit-like discharge opening having a minute interval extending in the width direction of the LCD substrate, and a resist solution discharged in a strip shape from the slit-like discharge opening is supplied to the entire surface of the substrate. Thus, a resist layer is formed.

According to this method, since the resist solution can be discharged (supplied) from one side of the substrate to the other side in a strip shape, the resist layer can be efficiently formed on the entire surface of the substrate on average. Such a slit coat type treatment liquid coating apparatus is disclosed in Patent Document 1 shown below.
Japanese Patent Laid-Open No. 10-156255

  By the way, in the treatment liquid coating apparatus having the above-described configuration, in order to obtain a uniform film thickness by a single coating operation, when the resist liquid is ejected from the slit-shaped ejection opening, the film thickness is increased. Is accompanied by the action of forming a uniform layer while stretching. For this reason, the gap (air gap) between the nozzle for discharging the resist solution and the substrate is set to be very small so as to correspond to the film thickness, and for example, both move relative to each other with a gap of about 100 μm. Made.

  When applying the treatment liquid typified by the resist liquid to the substrate, the nozzle and the substrate move relative to each other with the above-mentioned minute interval, so that foreign matters such as dust adhere to the substrate, for example. In some cases, the problem arises that the foreign matter contacts the tip of the nozzle during the coating operation. In addition, when a foreign object is interposed between the substrate and the stage for mounting and holding the substrate, a part of the substrate is deformed into a mountain shape, and therefore the nozzle is moved along with the relative movement of the nozzle and the substrate. There arises a problem that the substrate is strongly pressed against the tip of the substrate.

  Particularly when the foreign matter is interposed between the substrate and the stage as in the latter case, the substrate is naturally damaged, and the tip of the nozzle is naturally damaged, and so-called streaking is applied to the applied processing liquid. Will occur. This necessitates replacement of the nozzle and adjustment work associated therewith, leading to a problem that the substrate production line is forced to be shut down for a long time.

Therefore, a plate-shaped member is attached in front of the processing liquid discharge nozzle in the advancing direction, and before the foreign object or the substrate to be processed comes into contact with the nozzle, the foreign object or the target object is processed against the end surface of the plate-shaped member. A slit coat type coating apparatus configured to come into contact with a substrate is disclosed in Patent Document 2 shown below.
JP 2000-24571 A

  By the way, according to the slit coat type coating apparatus disclosed in Patent Document 2, a vibration sensor is attached to the plate-like member, and the vibration sensor detects that a foreign substance or a substrate contacts the end surface of the plate-like member. Thus, the relative movement between the nozzle and the substrate is stopped.

  However, in the processing liquid coating operation by the apparatus, since the processing liquid supply nozzle and the substrate to be processed are relatively moved, it is impossible to eliminate the vibration caused by the movement. Therefore, the vibration sensor is liable to generate a false detection of detecting vibration caused by these driving.

  On the other hand, in order to prevent the occurrence of the erroneous detection described above, it is necessary to suppress the detection sensitivity by the vibration sensor to some extent. In this case, the foreign matter existing on the substrate to be processed is effectively detected. It becomes difficult. In short, it is extremely difficult to set the level of abnormality detection in the vibration sensor described above, and there is a problem that false detection occurs even though it is normal, or it cannot be detected even though it is in an abnormal state. become.

  Therefore, a light beam is projected in the horizontal direction in front of the relative movement direction of the processing liquid supply nozzle with respect to the substrate to be processed, and an abnormal state in which the substrate is lifted from the stage by the foreign matter or the foreign matter is detected. It is conceivable to employ optical detection means.

  4 (A) and 4 (B) schematically show the configuration. Reference numeral 1 denotes, for example, a glass substrate as a substrate to be processed, and reference numeral 2 denotes the glass substrate 1 in a horizontal state. A mounting table (stage) for mounting and holding is shown. And (A) has shown the state in which the foreign material 3, such as dust, has adhered to the upper surface of the glass substrate 1, and (B) has the foreign material 3 interposed between the glass substrate 1 and the stage 2, An example in which a part of the substrate 1 is in a raised state as indicated by reference numeral 1a is schematically shown.

  Although not shown in FIG. 4, the processing liquid supply nozzle having a slit-like discharge opening is configured to move relative to the surface of the substrate 1 to be processed in the direction perpendicular to the paper surface. The slit-like discharge openings are moved relative to each other in a state in which the longitudinal direction is arranged in the left-right direction of the paper surface shown in FIG. In this case, the gap between the processing liquid supply nozzle and the substrate 1 is about 100 μm as described above.

  On the other hand, an optical axis (light beam) 4 is projected from the light projecting unit 5 along the longitudinal direction of the slit-like discharge opening, and is received by the light receiving unit 6. For example, a laser beam having a wavelength of about 670 nm is used as the light beam 4 projected from the light projecting unit 5. The light beam 4 is adjusted so as to pass along the upper surface of the substrate 1 as an example at a position of about 50 μm on the upper surface.

  In the state shown in FIG. 4A, the laser beam projected from the light projecting unit 3 is interrupted by the foreign matter 3 attached to the upper surface of the substrate 1 or is received by the light receiving unit 6. The amount of light received decreases. Also in the state shown in FIG. 4B, the laser beam projected from the light projecting unit 3 is affected by the raised portion 1a of the substrate, and the laser beam is similarly blocked or received by the light receiving unit 6. The amount of light received decreases. Therefore, an abnormal state of the substrate 1 can be detected by setting a threshold value for the amount of received light.

  By the way, in recent years, the size of the glass substrate 1 as the substrate to be processed has been increased, and accordingly, the distance between the light projecting unit 3 and the light receiving unit 4 shown in FIG. 4 is also 3000 mm or more. It is in a situation where it is set to a state that is separated. Under the circumstances as described above, a temperature (air temperature) difference is generated between the light projecting unit 3 and the light receiving unit 4 due to a slight air flow such as a down flow.

  As described above, when a temperature difference occurs between the light projecting unit 3 and the light receiving unit 4, a refraction phenomenon occurs in the light by changing the traveling speed of the light depending on the temperature. The same applies to the case where a laser beam having a wavelength of 670 nm is used as described above.

  FIG. 5 schematically illustrates the generation pattern of the temperature difference generated between the light projecting unit and the light receiving unit and the light refraction phenomenon. Reference numeral 1 denotes a substrate to be processed as in FIG. Reference numeral 2 denotes a stage on which the substrate 1 is placed. 5A to 5C, the left side of the drawing shows the light projecting unit side, and the right side shows the light receiving unit side.

  For example, as shown in (A), when the light projecting part side is at a high temperature and the light receiving part side is at a low temperature and the boundary line is indicated by D1 in the figure, the light beam is refracted upward on the bass part side. Is done. Further, as shown in (B), when the light projecting part side is at a high temperature and the light receiving part side is at a low temperature, and the boundary line is indicated by D2 in the figure, the light beam is refracted downward on the bass part side. Is done.

  Furthermore, as shown in (C), when the light projecting part side is at a high temperature and the light receiving part side is at a low temperature, and the boundary line is as shown by D3 in the figure, the light beam is spread on the bass part side ( Diffused).

  It has been verified that the above-described phenomenon occurs even if the temperature difference between the light projecting unit and the light receiving unit is about 1 ° C., and thus the reliability of detection accuracy in this type of light transmission type sensor unit is verified. The inventors of the present case have found through experiments and the like that this is a problem that cannot be overlooked in practice.

  The present invention has been made paying attention to the technical problems as described above, and in a light transmission type sensor unit that projects a light beam typified by laser light along the upper surface of a substrate, a light projecting unit It is an object of the present invention to provide a foreign matter detection device capable of preventing a decrease in detection accuracy caused by a temperature difference between the side and the light receiving portion side, and a treatment liquid coating device equipped with the foreign matter detection device.

  An optical foreign matter detection apparatus according to the present invention made to solve the above-described problems includes a light projecting unit that projects a light beam along the upper surface of a substrate to be processed placed on a stage, and the light beam. The light beam is scanned in parallel along the upper surface of the substrate to be processed by moving the light transmissive sensor unit including a light receiving unit that receives light and the light transmissive sensor unit relative to the substrate to be processed. The light transmission type sensor unit includes a relative moving means configured as described above, and the light transmission type sensor unit includes a cross-sectional core surrounding an upper part and both side parts of the light beam from the light projecting part to the light receiving part. It is characterized in that a long optical axis cover member formed in a letter shape is provided.

  In this case, the optical axis cover member is preferably made of a metal material, and the substrate to be processed is formed along the side surface portion on both side surface portions of the optical axis cover member positioned on both side portions of the light beam. It is desirable that protective members made of a synthetic resin material are attached so as to face each other.

  On the other hand, in the processing liquid coating apparatus according to the present invention, the processing liquid moves relative to the substrate to be processed placed on the stage and discharges the processing liquid toward the substrate to be processed. A processing liquid supply nozzle for applying a liquid to the surface of the substrate is provided, and the optical foreign matter detection device is mounted in front of the movement direction of the processing liquid supply nozzle that moves relative to the substrate to be processed. The processing liquid supply nozzle is characterized in that it is used as the relative moving means.

  In this case, the processing liquid supply nozzle is provided with a slit-like discharge opening extending in the width direction of the substrate, and the processing liquid discharged in a strip shape from the slit-like discharge opening of the processing liquid supply nozzle is applied to the surface of the substrate. The light transmission type sensor unit is arranged so as to be applied, parallel to the longitudinal direction of the slit-like discharge opening, and so that the light beam is projected along the immediate vicinity of the substrate. It is desirable.

  In a preferred embodiment, the relative movement of the processing liquid supply nozzle with respect to the substrate to be processed is stopped when the presence of the foreign matter is detected by the optical foreign matter detection device.

  According to the optical foreign object detection device described above, since the elongate optical axis cover member formed in a U-shaped cross section surrounding the upper part and both side parts of the light beam from the light projecting part to the light receiving part is provided. Between the optical axis cover member and the substrate to be processed, the light beam is surrounded in the vertical and horizontal directions.

  Thus, as described above, it acts to prevent a temperature difference from occurring on the light projecting unit side and the light receiving unit side, that is, on the optical axis of the light beam, under the influence of downflow or the like. Therefore, it is possible to effectively prevent a decrease in detection accuracy of this type of sensor unit caused by the temperature difference.

  Then, according to the processing liquid coating apparatus in which the above-described optical foreign material detection device is mounted on the processing liquid supply nozzle, the foreign material or the substrate thereby is moved forward in the moving direction according to the relative movement of the processing liquid supply nozzle with respect to the substrate to be processed. It is possible to accurately detect that a part of is raised. By controlling the relative movement of the processing liquid supply nozzle with respect to the substrate based on this detection, a problem of damaging the substrate and the processing liquid supply nozzle can be avoided.

  Hereinafter, an optical foreign object detection apparatus according to the present invention and a treatment liquid coating apparatus equipped with the same will be described with reference to the drawings. FIG. 1 and FIG. 2 are cross-sectional views showing main parts of a processing liquid coating apparatus equipped with an optical foreign matter detection apparatus. That is, FIG. 1 is a cross-sectional view as seen in the arrow direction from the line BB in FIG. 2, and FIG. 2 is a cross-sectional view as seen from the line A-A in FIG. .

  In FIG. 1 and FIG. 2, the code | symbol 1 has shown the square-shaped glass substrate as a to-be-processed substrate already demonstrated, and the code | symbol 2 mounts the said glass substrate 1 in a horizontal state, for example by negative pressure, this is attached. A mounting table (stage) to be sucked and held is shown. Reference numeral 11 denotes a processing liquid supply nozzle. The nozzle 11 has a substantially rectangular parallelepiped appearance, a processing liquid supply port 11a is formed at the upper end thereof, and a slit-shaped processing liquid is formed at the lower end thereof. A discharge opening 11b is formed.

  In the embodiment shown in FIGS. 1 and 2, the stage 2 on which the glass substrate 1 is placed in a horizontal state is fixed, and the processing liquid supply nozzle 11 extends along the upper surface of the glass substrate 1. It is configured to move in the direction indicated by the white arrow C. That is, the treatment liquid supply nozzle 11 is moved horizontally in a direction orthogonal to the longitudinal direction of the slit-shaped opening 11b. Then, the processing liquid R is discharged linearly from the slit-shaped opening 11b while moving at a distance of about 100 μm between the tip end portion (lower end portion shown in the figure) of the nozzle 11 and the glass substrate 1. Thus, the processing liquid R is applied on the glass substrate 1 in a strip shape.

  An attachment fitting 12 having an L-shaped cross section is attached in a horizontal state on the side wall of the processing liquid supply nozzle 11, that is, in front of the movement direction of the nozzle 11. A pair of left and right holder members 13a and 13b are attached so as to face each other. That is, the pair of holder members 13a and 13b are attached to both outer sides in the width direction of the nozzle 11 at both ends of the L-shaped mounting bracket 12 as shown in FIG. The light projecting unit 5 and the light receiving unit 6 constituting the light transmission type sensor unit are attached to the holder members 13a and 13b so as to face each other.

  As shown in FIG. 2, the light projecting unit 5 and the light receiving unit 6 are such that the straight line connecting them, that is, the optical axis (light beam) 4 is parallel to the longitudinal direction of the slit-like ejection opening 11 b in the processing liquid supply nozzle 11. And are attached to the holder members 13a and 13b so as to be positioned in front of the nozzle 11 in the moving direction.

  As described above, a laser beam having a wavelength of about 670 nm is used as the light beam 4 projected from the light projecting unit 5. The optical axis of the light beam 4 is set to be parallel to the upper surface of the substrate 1, that is, to pass through a position of about 50 μm on the upper surface of the substrate 1 in this embodiment. As the supply nozzle 11 moves, scanning is performed along the upper surface of the substrate 1.

  On the other hand, a long optical axis cover member 15 is attached between the pair of holder members 13a and 13b. The cover member 15 is formed in a U-shaped cross section so as to surround the upper part and both side parts of the light beam 4 from the light projecting part 5 to the light receiving part 6.

  As shown in FIG. 3, the long optical axis cover member 15 has a main portion 15a formed of a metal material, preferably SUS, having a U-shaped cross section, and is surrounded by the U-shape. In addition, the light beam 4 is attached between the pair of holder members 13a and 13b so that the light beam 4 passes through almost the center.

  Then, each side wall surface of the main body portion 15a located on both sides in the horizontal direction of the light beam 4 is strip-shaped with a synthetic resin material, preferably a flexible Teflon (registered trademark) resin, along the side wall surface. The protective member 15b formed on the base plate 15 is attached with a plurality of screws 15c so as to protrude downward from the main body portion 15a.

  In the optical axis cover member 15, the main portion 15 a having a U-shaped cross section is formed of a metal such as SUS as described above, thereby providing a mechanical steel property in the central portion. It is molded with an appropriate thickness so that bending does not occur. Further, the protective member 15b is attached to the main body portion 15a, thereby preventing the metal main body portion 15a from coming into direct contact with the substrate 1 to be processed and preventing damage to the substrate 1 to be processed. So that it is considered.

  And the clearance gap between the lower end part of the protection member 15b in the above-mentioned optical axis cover member 15 and the glass substrate 1 as a to-be-processed substrate is set to about 1-3 mm. With this configuration, the light beam 4 is surrounded vertically and horizontally between the optical axis cover member 15 and the substrate 1 to be processed.

  Thereby, as described in the column of the effect of the invention, it acts to prevent the occurrence of a temperature difference on the optical axis of the light beam due to the influence of the indoor downflow or the like. Therefore, it is possible to effectively prevent a decrease in detection accuracy of this type of sensor unit caused by the temperature difference.

  Therefore, according to the processing liquid coating apparatus including the light transmission type sensor unit having the above-described configuration, it is possible to accurately detect the abnormal state of the substrate to be processed, and based on this detection, the relative of the processing liquid supply nozzle to the substrate is detected. By controlling to stop the movement, it is possible to avoid the problem of damaging the substrate and the processing liquid supply nozzle.

  In the embodiment described above, the stage 2 on which the substrate 1 to be processed is placed is in a fixed state, and light including the processing liquid supply nozzle 11, the light projecting unit 5, the light receiving unit 6, and the optical axis cover member 15. The transmissive sensor unit is configured to move on the substrate to be processed. On the contrary, the transmissive sensor unit includes a processing liquid supply nozzle, a light projecting unit, a light receiving unit, and an optical axis cover member. Even if the stage is fixed and the stage on which the substrate to be processed is placed is configured to move in the horizontal direction, the same effect can be obtained.

  The treatment liquid coating apparatus according to the present invention is not limited to a coating apparatus for applying a resist liquid to the LCD substrate described above, for example, the manufacturing field of semiconductor wafers, printed boards, other electronic devices, or other It can employ | adopt suitably for the slit coat type coating device employ | adopted in the field | area. Further, the optical foreign matter detection apparatus according to the present invention is preferably used not only in the processing liquid coating apparatus described above, but also particularly in an automatic machine that needs to monitor a planar substrate surface. it can.

It is sectional drawing which showed the process liquid coating device concerning this invention. It is sectional drawing of the state seen from AA in FIG. It is the perspective view which showed the structure of the optical axis cover member used for the process liquid coating device shown in FIG. 1 and FIG. It is a schematic diagram explaining the effect | action which detects an abnormal state with a light transmissive sensor unit. It is a schematic diagram explaining the abnormality detection error by the conventional light transmission type sensor unit.

Explanation of symbols

1 Substrate (glass substrate)
2 Mounting table (stage)
4 Optical axis (light beam)
DESCRIPTION OF SYMBOLS 5 Light projection part 6 Light-receiving part 11 Processing liquid supply nozzle 11a Processing liquid supply port 11b Processing liquid discharge opening 12 Mounting bracket 13a, 13b Holder member 15 Optical axis cover member 15a Cover member main-body part 15b Protection member 15c Mounting screw R Processing liquid

Claims (5)

A light transmissive sensor unit including a light projecting unit that projects a light beam along an upper surface of a substrate to be processed placed on a stage; and a light receiving unit that receives the light beam; and the light transmissive sensor unit. An optical foreign matter detection device comprising: a relative movement unit configured to cause the light beam to scan in parallel along the upper surface of the substrate to be processed by moving the substrate relative to the substrate to be processed;
The light transmission type sensor unit is provided with an elongate optical axis cover member formed in a U-shaped cross section surrounding the upper part and both side parts of the light beam from the light projecting part to the light receiving part. An optical foreign object detection device characterized by the above.   The optical axis cover member is made of a metal material, and the optical axis cover member located on both sides of the light beam is opposed to the substrate to be processed along the side surface. The optical foreign object detection device according to claim 1, wherein protective members made of a synthetic resin material are respectively attached. A processing liquid supply nozzle that moves relative to the substrate to be processed placed on a stage and discharges the processing liquid toward the substrate to be processed, thereby applying the processing liquid to the surface of the substrate. Is provided,
By mounting the optical foreign matter detection device according to claim 1 or 2 in front of a moving direction of a processing liquid supply nozzle that moves relative to the substrate to be processed, the processing liquid supply nozzle is A treatment liquid coating apparatus configured to be used as a relative movement unit.   The treatment liquid supply nozzle is provided with a slit-like discharge opening extending in the width direction of the substrate, and the treatment liquid discharged in a strip shape from the slit-like discharge opening of the treatment liquid supply nozzle is applied to the surface of the substrate. The light transmission type sensor unit is arranged so as to be parallel to the longitudinal direction of the slit-like discharge opening and so that the light beam is projected along the immediate vicinity of the substrate. The treatment liquid coating apparatus according to claim 3.   5. The structure according to claim 3, wherein when the presence of the foreign matter is detected by the optical foreign matter detection device, the relative movement of the processing liquid supply nozzle with respect to the substrate to be processed is stopped. Processed liquid coating apparatus.

Images