JP4105613B2 - Substrate processing equipment - Google Patents

Description

  The present invention relates to a technique for a substrate processing apparatus that applies a processing liquid to a surface of a substrate by scanning the substrate while discharging the processing liquid from a nozzle. More specifically, the present invention relates to a technique for detecting an interference object with high accuracy in order to prevent the nozzle from interfering with a foreign object (object) in scanning with the nozzle.

  In the manufacturing process of glass square substrates for liquid crystals, semiconductor wafers, flexible substrates for film liquid crystals, photomask substrates, color filter substrates, etc., coating devices (substrate processing devices) that apply processing liquids to the surfaces of various substrates are used. It is done. As coating apparatuses, there are known a slit coater that performs slit coating using a slit nozzle having a slit-like discharge section, and a slit / spin coater that performs spin coating after the above-described slit coating is performed once.

In such a coating apparatus, the slit nozzle or the substrate is moved in a state where the tip of the slit nozzle is close to the substrate to apply the treatment liquid, so that foreign matter is adhered to the surface of the substrate or the substrate and the stage When the substrate rises due to foreign matter sandwiched between
(1) The slit nozzle is damaged. (2) The substrate is cracked or the substrate is scratched. (3) The coating is performed while dragging foreign matter, thereby causing problems such as application failure.

  Therefore, conventionally, in a coating apparatus using a slit nozzle, it is determined whether or not there is an object in contact with the slit nozzle by performing a foreign substance inspection, and collision between the slit nozzle and the object is avoided. Technology has been proposed. Such a technique is described in Patent Document 1, for example.

  The coating apparatus described in Patent Document 1 detects interference with a transmissive laser sensor, and when the laser sensor detects the interference, the coating process is forcibly terminated to Prevent contact with interference.

  14 to 17 are conceptual diagrams for explaining the principle that the transmission laser sensor 100 used in the coating apparatus described in Patent Document 1 detects an interference. The transmissive laser sensor 100 receives the laser light emitted from the light projecting unit 101 by the light receiving unit 102 disposed on the optical axis so as to face the light projecting unit 101, and the presence or absence of an interference object is determined by the amount of the received light. It is a sensor that detects

  In the laser sensor 100, as shown in FIG. 14, when any object (target object) is present on the optical path, the laser light is shielded on the optical path by the target object. Therefore, as shown in FIG. 15, the amount of laser light received by the light receiving unit 102 decreases. Therefore, the laser sensor 100 can determine that an object exists on the optical path when the amount of light received by the light receiving unit 102 is smaller than the predetermined threshold value Q.

JP 2002-001195 A

  However, as shown in FIGS. 14 and 16, the laser beam is shifted in the optical axis direction from the focused position (the position where the light beam is most focused: the irradiation start position of the light projecting unit 101 in the example shown here). As a result, there is a property that the diameter is expanded. Therefore, as shown in FIG. 16, when the interference object is at a position far from the light projecting unit 101 (a position where the diameter is widened), most of the laser light is received by the light receiving unit 102 without being blocked. It becomes. In this case, the amount of laser light received by the light receiving unit 102 is larger than the threshold value Q, as shown in FIG. 17, so that there is an object of a size that should be detected originally. A situation occurs in which the object cannot be detected. When a general transmission type laser sensor is used, the range in which the accuracy required for the coating process can be maintained is that the distance between the light projecting unit 101 and the light receiving unit 102 is up to about 500 mm.

  That is, in the coating apparatus described in Patent Document 1, for example, due to the increase in size of the substrate, in the laser sensor 100, it is necessary to dispose the light projecting unit 101 and the light receiving unit 102 relatively apart (for detection). In the case where the optical path of the laser beam becomes longer, the detection accuracy for the region on the light receiving unit 102 side is lowered.

  In addition, the moving speed of the slit nozzle in the coating apparatus is set to about 100 mm / sec in consideration of the uniformity of the processing liquid to be applied. Therefore, when the laser sensor 100 is moved along with the movement of the slit nozzle, if an object of several tens of μm is to be detected, it is required to detect it within about 1 msec. In the detection of an object by a laser sensor, a delay timer of a certain time is usually set to prevent chattering. However, when detection must be performed in a very short time, a delay timer is set. There was a problem that I could not. In other words, the coating apparatus described in Patent Document 1 has a problem that the detection accuracy of the target object is reduced due to chattering.

  The present invention has been made in view of the above problems, and an object thereof is to prevent a decrease in detection accuracy of an object.

In order to solve the above-mentioned problems, the invention of claim 1 is a substrate processing apparatus for applying a predetermined processing liquid to a substrate, the holding means for holding the substrate, and the substrate held by the holding means. A slit nozzle that discharges a predetermined processing liquid from a slit-shaped discharge unit, and a moving unit that moves the slit nozzle with respect to the substrate held by the holding unit and performs scanning by the slit nozzle with respect to the substrate. And a scanning range of the slit nozzle with respect to the substrate by irradiating each with laser light while moving integrally with the slit nozzle while maintaining a relative distance from the slit nozzle . A plurality of transmission type laser sensors for detecting an object existing in each effective detection range, and the plurality of transmission type laser sensors Based on the detection result by the a control means for controlling the moving means, the detection direction of the plurality of transmission-type laser sensor, substantially parallel to the substrate held by said holding means and, Respective laser beams that are substantially perpendicular to the scanning direction by the slit nozzles and whose effective detection ranges are arranged at different positions in the detection direction and are emitted from the plurality of transmission type laser sensors is the light flux spread in the with the light beam is focused outside the effective detection range corresponding to the laser beam area in the effective detection range corresponding to at least the laser beam, the slit during scanning by said slit nozzle characterized in that the nozzle interfering with the object, detected by sharing the effective detection range of the respective To.

According to a second aspect of the present invention, there is provided the substrate processing apparatus according to the first aspect of the invention, wherein the plurality of transmission type laser sensors are attached to the moving means.

In the invention according to claim 1 and 2, the interfering object and the slit nozzle during scanning by the slit nozzle, by detecting and shared by each of the effective detection range defined with respect to the scanning range of the slit nozzle Therefore, it is possible to prevent a decrease in detection accuracy. In the first and second aspects of the invention, the detection direction is a direction substantially parallel to the substrate and a direction substantially perpendicular to the scanning direction, and each effective detection range is arranged in the detection direction. Thus, detection by a small number of detection means is possible. In the first and second aspects of the invention, the plurality of transmission type laser sensors are attached so as to move integrally while maintaining a relative distance from the slit nozzle. Since it is not affected by the posture, the detection accuracy can be improved.

In the invention according to claim 2 , since the plurality of transmission type laser sensors are attached to the moving means, the position adjustment of the transmission type laser sensor is unnecessary even when the slit nozzle is replaced. is there.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

<1. First Embodiment>
<1.1 Description of configuration>
FIG. 1 is a front view of a substrate processing apparatus 1 according to a first embodiment of the present invention. FIG. 2 is an enlarged view of the periphery of the detection sensor 45 in the substrate processing apparatus 1. In FIG. 1 and FIG. 2, for the sake of illustration and explanation, the Z-axis direction is defined as the vertical direction and the XY plane is defined as the horizontal plane, but these are defined for convenience in order to grasp the positional relationship. However, each direction described below is not limited. The same applies to the following figures.

  The substrate processing apparatus 1 uses a rectangular glass substrate for manufacturing a screen panel of a liquid crystal display device as a substrate 90 to be processed. In the process of selectively etching an electrode layer or the like formed on the surface of the substrate 90, the substrate 90 is processed. It is comprised as a coating device which apply | coats a resist liquid to the surface of this. Therefore, in this embodiment, the slit nozzle 41 discharges the resist solution to the substrate 90. In addition, the substrate processing apparatus 1 can be modified and used not only as a glass substrate for a liquid crystal display device but also as a device for applying a processing liquid (chemical solution) to various substrates for a flat panel display.

  The substrate processing apparatus 1 includes a stage 3 that functions as a holding table for placing and holding the substrate to be processed 90 and also functions as a base for each attached mechanism. The stage 3 is made of an integral stone having a rectangular parallelepiped shape, and its upper surface (holding surface 30) and side surfaces are processed into flat surfaces.

  The upper surface of the stage 3 is a horizontal plane and serves as a holding surface 30 for the substrate 90. A large number of vacuum suction ports (not shown) are formed on the holding surface 30 in a distributed manner. While the substrate 90 is processed in the substrate processing apparatus 1, the substrate 90 is sucked to hold the substrate 90 in a predetermined horizontal direction. Hold in position.

  Above the stage 3, a bridging structure 4 is provided that extends substantially horizontally from both sides of the stage 3. The bridging structure 4 is mainly composed of a nozzle support portion 40 that uses carbon fiber resin as an aggregate, elevating mechanisms 43 and 44 that support both ends thereof, and a moving mechanism 5.

  A slit nozzle 41 and a gap sensor 42 are attached to the nozzle support portion 40.

  The slit nozzle 41 extending in the horizontal Y-axis direction is connected to a discharge mechanism (not shown) including a pipe for supplying a chemical solution (resist solution) to the slit nozzle 41 and a resist pump. The slit nozzle 41 is supplied with a resist solution by a resist pump and scans the surface of the substrate 90, thereby discharging the resist solution to a predetermined region on the surface of the substrate 90 (hereinafter referred to as “resist application region”). To do.

  The gap sensor 42 is attached to the nozzle support portion 40 of the bridging structure 4 at a position facing the surface of the substrate 90, and is located between a certain direction (−Z direction) (for example, the substrate 90 and the resist film). The distance (gap) is detected, and the detection result is transmitted to the control unit 7.

  Thereby, the control unit 7 can detect the distance between the surface of the substrate 90 and the slit nozzle 41 based on the detection result of the gap sensor 42. The substrate processing apparatus 1 according to the present embodiment includes two gap sensors 42. However, the number of gap sensors 42 is not limited to this, and more gap sensors 42 may be provided. .

  The elevating mechanisms 43 and 44 are divided on both sides of the slit nozzle 41 and are connected to the slit nozzle 41 by the nozzle support portion 40. The elevating mechanisms 43 and 44 are used for moving the slit nozzle 41 in translation and adjusting the posture of the slit nozzle 41 in the YZ plane.

  At both ends of the bridging structure 4, moving mechanisms 5 arranged separately along the edge sides on both sides of the stage 3 are fixed. The moving mechanism 5 mainly includes a pair of AC coreless linear motors (hereinafter simply referred to as “linear motors”) 50 and a pair of linear encoders 51.

  Each linear motor 50 includes a stator and a mover (not shown), and a driving force for moving the bridging structure 4 (slit nozzle 41) in the X-axis direction by electromagnetic interaction between the stator and the mover. Is a motor that generates Further, the moving amount and moving direction of the linear motor 50 can be controlled by a control signal from the control unit 7.

  The linear encoder 51 includes a scale unit and a detector (not shown), detects the relative positional relationship between the scale unit and the detector, and transmits the relative positional relationship to the control unit 7. Each detector is fixed to both ends of the bridging structure 4, and the scale portion is fixed to both sides of the stage 3. Thereby, the linear encoder 51 has a function of detecting the position of the bridging structure 4 in the X-axis direction.

  A detection sensor 45 is further attached to the moving mechanism 5 fixed on both sides of the bridging structure 4. FIG. 3 is a diagram showing the scanning range E0 of the slit nozzle 41 and the effective detection ranges E1 to E3 of the detection sensor 45. The scanning range E0 is a scanning range of the slit nozzle 41 on the substrate. More specifically, when the moving mechanism 5 moves in the X-axis direction, the substrate 90 and the slit in the trajectory area (which becomes a planar area) drawn by the lower end (end in the −Z direction) of the slit nozzle 41. This is a region that faces the lower end of the nozzle 41 in a state of being closest (gap when applying the resist solution). That is, the scanning range E0 is an area where the slit nozzle 41 may come into contact with the object during scanning by the slit nozzle 41. In the substrate processing apparatus 1, the slit nozzle 41 is moved to various positions by the moving mechanism 5. However, when the elevating mechanisms 43 and 44 are moved while maintaining the slit nozzle 41 at a sufficiently high position, When moving the position not facing the substrate 90, the slit nozzle 41 does not interfere with the object.

  The substrate processing apparatus 1 according to the present embodiment includes three detection sensors 45 (450, 451, 452). The detection direction of each detection sensor 45 is the Y-axis direction, and each detection sensor 45 is arranged in the X-axis direction. The position of each detection sensor 45 in the Z-axis direction can be adjusted by an operator.

  The detection sensor 450 includes a light projecting unit 450a and a light receiving unit 450b. The light receiving unit 450b receives the laser light emitted from the light projecting unit 450a, measures the amount of received light, and outputs the received light amount to the control unit 7. . That is, the detection sensor 450 has a function as a transmissive laser sensor that detects an object in the detection direction. The detection sensors 451 and 452 have the same structure and function, and thus description thereof is omitted.

  As shown in FIG. 3, in the detection sensors 450 and 452, the light projecting units 450 a and 452 a are disposed on the −Y side of the substrate processing apparatus 1, and the light receiving units 450 b and 452 b are disposed on the + Y side of the substrate processing apparatus 1. . On the other hand, in the detection sensor 451, the light projecting unit 451a is disposed on the + Y side of the substrate processing apparatus 1, and the light receiving unit 451b is disposed on the −Y side of the substrate processing apparatus 1.

  In the detection sensor 450, the laser light is narrowed down at a substantially central position in the Y-axis direction, and an effective detection accuracy (in this embodiment, an object having a size of about 100 μm can be detected at this position. Accuracy). In this state, the detection sensor 450 moves in the X-axis direction as the movement mechanism 5 moves, so that the detection sensor 450 can detect an object having a desired size (a range where high-precision detection is possible). (Hereinafter referred to as “effective detection range”) is an area indicated by the effective detection range E2.

  The detection sensor 451 is set so that the laser light is focused on the + Y side in the Y-axis direction, and effective detection accuracy is obtained at this position. In this state, when the detection sensor 451 moves in the X-axis direction as the movement mechanism 5 moves, the effective detection range of the detection sensor 451 becomes an area indicated by the effective detection range E1.

  The detection sensor 452 is set so that the laser beam is focused on the −Y side in the Y-axis direction, and effective detection accuracy is obtained at this position. In this state, when the detection sensor 452 moves in the X-axis direction as the movement mechanism 5 moves, the effective detection range of the detection sensor 452 becomes an area indicated by the effective detection range E3.

  Each detection sensor 45 can detect an area outside the effective detection range as long as the object is sufficiently large. In that sense, in each detection sensor 45, a region other than each effective detection range is also a detection range. However, as described with reference to FIGS. 16 and 17, each detection sensor 45 cannot detect a relatively small object even in a region outside the effective detection range even if it is larger than a desired size. The accuracy is not guaranteed.

  As described above, in each of the detection sensors 450, 451, and 452, the position where the laser beam is focused is set to be different in the Y-axis direction, so that the substrate processing apparatus 1 has the respective effective detection ranges E1. That is, E3 is arranged in the detection direction (Y-axis direction). That is, the positions of the effective detection ranges E1 to E3 in the Y-axis direction are defined with respect to the scanning range E0 of the slit nozzle 41. As a result, the scanning range E0 of the slit nozzle 41 is inspected by sharing it with the effective detection ranges E1 to E3 of each detection sensor 45, and when there is an object of a desired size or larger, any detection sensor Its presence can be detected by 45.

  Although details will be described later, when the object is detected by the detection sensor 45, the control unit 7 determines that the object is an interference object (an object in contact with the slit nozzle 41). Therefore, the substrate processing apparatus 1 in the present embodiment can detect an interference with high accuracy at any position within the scanning range E0. In addition, each effective detection range E1 thru | or E3 may be set so that a one part area | region may mutually overlap.

  Further, each detection sensor 45 is in front of the slit nozzle 41 in the scanning direction (the moving direction when the slit nozzle 41 moves in the scanning range E0, which is the (−X) direction in the present embodiment). The interfering object is detected while moving in the same direction as the slit nozzle 41 moves in the X-axis direction (see FIGS. 6 and 7). The relative distance between the detection sensor 45 and the slit nozzle 41 is set according to the speed at which the slit nozzle 41 moves by the moving mechanism 5 and the calculation speed of the control unit 7. That is, when the control unit 7 controls the moving mechanism 5 according to the detection result of the detection sensor 45, the distance between the object and the slit nozzle 41 can be sufficiently avoided.

  Returning to FIG. 1, the control unit 7 processes various data according to the program. The control unit 7 is connected to each mechanism of the substrate processing apparatus 1 by a cable (not shown), and in response to inputs from the gap sensor 42, the linear encoder 51, the detection sensor 45, and the like, the stage 3, the elevating mechanisms 43 and 44, and Each component such as the moving mechanism 5 is controlled.

  In particular, the control unit 7 calculates the amount of laser light received by each light receiving unit 450b, 451b, 452b based on the input from each detection sensor 45, and compares it with a preset threshold value Q, respectively. It is determined whether or not an object exists in the effective detection ranges E1 to E3. In the substrate processing apparatus 1 according to the present embodiment, when the control unit 7 determines that an object is present, the object is regarded as an interference object that contacts the slit nozzle 41, and the contact is avoided. The moving mechanism 5 (linear motor 50) is stopped. The control operation of the control unit 7 when an interference is detected will be described later.

  The control unit 7 is connected to an operation unit (operation panel, keyboard, etc.) and a display unit (liquid crystal display, display buttons, etc.) not shown, receives instructions from the operator via the operation unit, and displays the display unit. By displaying necessary data, the operator is notified of the state of the substrate processing apparatus 1 and the like.

  The above is the description of the configuration of the substrate processing apparatus 1 in the present embodiment.

<1.2 Adjustment work>
First, in the substrate processing apparatus 1, the position adjustment operation of each detection sensor 45 in the Z-axis direction is performed before performing a process of applying a resist solution to the substrate 90. The position adjustment of each detection sensor 45 is performed using a micro gauge having a positioning accuracy of 10 μm or less so that the respective positions in the Z-axis direction are substantially the same.

  Each detection sensor 45 is arranged such that the optical path of the laser beam is positioned in the (+ Z) direction from the surface of the substrate 90 so that the substrate 90 held in the normal state on the stage 3 is not erroneously detected as an interference. The position is adjusted. That is, the position adjustment is performed based on the holding surface 30 of the stage 3 while taking the thickness of the substrate 90 into consideration. At this time, it is preferable to adjust in consideration of the uniformity of the thickness of the substrate 90 (usually within ± 1% of the design thickness) and the flat processing accuracy of the holding surface 30. Thus, the effective detection ranges E1 to E3 are adjusted so as to be on the (+ Z) side of the surface of the substrate 90.

  Further, in the substrate processing apparatus 1, in order to prevent the contact between the slit nozzle 41 and the target object, the target object existing on the (−Z) side from the scanning range E0 must be detected. Therefore, the position of each detection sensor 45 in the Z-axis direction is adjusted so that the effective detection ranges E1 to E3 include a region on the (−Z) side of the scanning range E0.

  As described above, in the substrate processing apparatus 1, the position of each detection sensor 45 in the Z-axis direction is adjusted with respect to the scanning range E <b> 0 of the slit nozzle 41, so that an object that may come into contact with the slit nozzle 41 is detected. If it does not exist, the laser light is received by any of the detection sensors 45 without being shielded on the way. On the other hand, when there is an object that may come into contact, the laser light of any of the detection sensors 45 is shielded by the object.

  When the thickness of the substrate 90 to be processed is changed, or when the desired resist film thickness is changed, the position adjustment operation described here is performed again before executing the coating process. It is preferable.

<1.3 Explanation of operation>
Next, the operation of the substrate processing apparatus 1 will be described. 4 and 5 are flowcharts showing the operation of the substrate processing apparatus 1 in the coating process. The operation control of each unit shown below is performed by the control unit 7 unless otherwise specified.

  In the substrate processing apparatus 1, the resist solution coating process is started when the substrate 90 is transported to a predetermined position by an operator or a transport mechanism (not shown). The instruction for starting the processing may be input by operating the operation unit by the operator when the conveyance of the substrate 90 is completed.

  First, the stage 3 sucks and holds the substrate 90 at a predetermined position on the holding surface 30. Next, the gap sensor 42 is moved to the measurement start position for measuring the gap with the substrate 90 by moving the slit nozzle 41 (step S11). This operation is performed by the elevating mechanisms 43 and 44 adjusting the height position of the slit nozzle 41 to the measurement height and the linear motor 50 adjusting the bridging structure 4 in the X-axis direction.

  When the movement of the gap sensor 42 to the measurement start position is completed, the linear motor 50 moves the bridging structure 4 in the (+ X) direction. Thus, the gap sensor 42 measures the gap between the surface of the substrate 90 and the slit nozzle 41 in the coating region on the surface of the substrate 90 while maintaining a predetermined measurement height (step S12). The application region is a region on the surface of the substrate 90 where the resist solution is to be applied, and is usually a region obtained by removing a region having a predetermined width along the edge from the entire area of the substrate 90. . Further, while the measurement by the gap sensor 42 is being performed, the slit nozzle 41 and the holding surface at the measurement altitude are set in the substrate processing apparatus 1 so that the slit nozzle 41 does not come into contact with an interfering object such as the substrate 90 or foreign matter. The distance in the Z-axis direction with respect to 30 is sufficiently secured.

  The measurement result of the gap sensor 42 is transmitted to the control unit 7. The control unit 7 stores the transmitted measurement result of the gap sensor 42 in the storage unit in association with the horizontal position (position in the X-axis direction) detected by the linear encoder 51.

  When scanning (measurement) by the gap sensor 42 is completed, the linear motor 50 moves the bridging structure 4 in the X-axis direction and moves the detection sensor 45 to the end position of the substrate 90 (step S13). Note that the end position refers to the side of the substrate 90 on the (+ X) side where the optical axis of the detection sensor 45 (in the present embodiment, the detection sensor 452) that is closest to the (−X) side. It is a position that is almost along. Further, when it is determined by the measurement by the gap sensor 42 that the thickness of the substrate 90 is not within the specified range, the substrate processing apparatus 1 displays an alarm on the display unit and moves the slit nozzle 41 to the standby position. At the same time, the substrate 90 in which an abnormality is detected is discharged.

  When the detection sensor 45 moves to the end position, the control unit 7 stops the bridging structure 4 by stopping the linear motor 50. Further, based on the measurement result from the gap sensor 42, the posture of the slit nozzle 41 in the YZ plane is an appropriate posture (the interval between the slit nozzle 41 and the application region is an appropriate interval for applying the resist (this embodiment In the embodiment, the position of the nozzle support portion 40 is calculated, and the lift mechanism 43, 44 is controlled based on the calculation result to calculate the slit. The nozzle 41 is adjusted to an appropriate posture.

  Since the detection sensor 45 of the substrate processing apparatus 1 is arranged on the (−X) side of the slit nozzle 41, the slit nozzle 41 is not opposed to the substrate 90 when the detection sensor 45 is in the end position. Has moved. Therefore, even if the slit nozzle 41 is moved in the (−Z) direction and adjusted to an appropriate posture in a state where the detection sensor 45 is at the end position, there is almost no risk that the slit nozzle 41 comes into contact with an interference object.

  When the posture adjustment of the slit nozzle 41 is finished, the control unit 7 starts detecting the interference with the detection sensor 45 (step S14). Further, the linear motor 50 is driven to move the bridging structure 4 in the (−X) direction (step S21), and based on the output from each detection sensor 45, it is determined whether or not an interference is detected ( Step S22). If it is determined that any of the detection sensors 45 has detected an interference, the process from step S27 is performed to prevent the slit nozzle 41 from contacting the interference, but details will be described later.

  On the other hand, when the interference is not detected, the control unit 7 confirms the position of the slit nozzle 41 based on the output of the linear encoder 51, and continues to steps S21 to S23 until the slit nozzle 41 moves to the discharge start position. The process is repeated (step S23). The discharge start position is a position where the slit nozzle 41 substantially follows the (+ X) side of the application region.

  In this way, the control unit 7 controls the detection start position of the detection of the interference by the detection sensor 45, so that the position on the (+ X) side of each of the effective detection ranges E1 to E3 is defined with respect to the scanning range E0. .

  When the slit nozzle 41 moves to the discharge start position, a resist solution is sent to the slit nozzle 41 by a resist pump (not shown), and the slit nozzle 41 discharges the resist solution to the application region. Along with the discharging operation, the linear motor 50 moves the slit nozzle 41 in the (−X) direction (step S24). Thereby, the application region of the substrate 90 is scanned by the slit nozzle 41, and the resist solution is applied. In parallel with the moving operation in step S24, the control unit 7 determines whether or not an interfering object has been detected in the same manner as in step S22 (step S25).

  6 and 7 are diagrams illustrating how the detection sensor 45 detects an interference. FIG. 6 shows an example in which the substrate 90 becomes an interference. When a foreign substance NG having a predetermined size or more is present on the holding surface 30 of the stage 3, the substrate 90 is raised by the foreign substance NG, and the position of the substrate 90 in the Z-axis direction is in contact with the slit nozzle 41. It has become.

  In the substrate processing apparatus 1 according to the present embodiment, as shown in FIG. 3, the scanning range E0 of the slit nozzle 41 is divided into effective detection ranges E1 to E3 by a plurality of detection sensors 450, 451, and 452, respectively. Inspected. Therefore, regardless of the position of the foreign object NG in the Y-axis direction, the amount of light received by any one of the three detection sensors 450, 451, and 452 is less than or equal to the threshold value Q, The presence of an interfering object is detected.

  The plurality of detection sensors 450, 451, and 452 have required detection accuracy in the effective detection ranges E1 to E3. Therefore, when an object having a predetermined size or larger exists in the effective detection range E1, even if it is not detected by the detection sensors 450 and 452, it is detected by the detection sensor 451.

  As described above, the substrate processing apparatus 1 has a lower detection accuracy than the conventional apparatus even when the width of the scanning range E0 in the Y-axis direction is wider than the effective detection range of each detection sensor 45. Therefore, the interference can be detected with high accuracy. That is, an interference can be detected with high accuracy using the detection sensor 45 having a narrow effective detection range.

  Moreover, each detection sensor 45 is arrange | positioned ahead of the slit nozzle 41 with respect to the scanning direction, as shown in FIG. Therefore, the control unit 7 can detect the interfering object before it contacts the slit nozzle 41. In addition, as shown in FIG. 7, even if the foreign object NG forms an interference object by adhering the foreign object NG to the surface of the substrate 90, the interference object can be similarly detected with high accuracy. it can.

  If it is determined in step S25 that the control unit 7 has detected an interference (Yes in step S25), the control unit 7 stops the linear motor 50, thereby causing the slit nozzle 41 to move in the (−X) direction. The moving operation is stopped and an alarm is output to the display unit (step S27).

  As described above, in the substrate processing apparatus 1, when the interference sensor is detected by the detection sensor 45 during the movement of the slit nozzle 41, the movement of the slit nozzle 41 is immediately stopped, so that Can be prevented. Therefore, it is possible to effectively prevent the slit nozzle 41 and the substrate 90 from being damaged by contact.

  Moreover, since an abnormality can be notified to the operator by outputting an alarm, recovery work and the like can be performed efficiently. Note that any method may be used for the alarm as long as it allows the operator to know the occurrence of an abnormal situation, and an alarm sound may be output from a speaker or the like.

  After execution of step S27, the resist pump is stopped to stop the discharge of the resist solution, and the slit nozzle 41 is retracted to the standby position by the linear motor 50 and the lifting mechanisms 43 and 44 (step S28). Further, the substrate 90 is unloaded from the substrate processing apparatus 1 (step S29). Note that when an interference is detected in step S22, the discharge of the resist solution has not yet started, and thus the process of stopping the discharge of the resist solution is not performed. Further, the substrate 90 to be unloaded as a result of the execution of step S27 is distinguished from other substrates 90 and is transported to the reprocessing step by the operator or the transport mechanism. Further, as shown in FIG. 6, since the foreign matter NG may be attached to the stage 3, it is preferable to clean the stage 3 when step S27 is executed.

  On the other hand, when no interference is detected in step S25 (No in step S25), the controller 7 confirms the position of the slit nozzle 41 based on the output of the linear encoder 51, and the slit nozzle 41 finishes discharging. The processes in steps S24 to S26 are repeated until the position is moved (step S26). As described above, when there is no interference, the slit nozzle 41 scans the entire coating region, and a resist solution layer is formed on the surface of the substrate 90 in the entire coating region.

  When the slit nozzle 41 moves to the discharge end position, the controller 7 stops the resist pump to stop the discharge of the resist solution, and the linear motor 50 and the lifting mechanisms 43 and 44 retract the slit nozzle 41 to the standby position. (Step S28). In parallel with this operation, the control unit 7 stops the detection of the interference by each detection sensor 45. As described above, the control unit 7 controls the detection end position of the detection of the interference object by the detection sensor 45, so that the positions on the (−X) side of the respective effective detection ranges E1 to E3 are defined with respect to the scanning range E0. The

  Further, the stage 3 stops the suction of the substrate 90, the operator or the transport mechanism picks up the substrate 90 from the holding surface 30, and carries the substrate 90 to the next processing step (step S29).

  Note that when the coating process is completed, a resist film thickness inspection process may be performed. That is, the elevating mechanisms 43 and 44 move the gap sensor 42 to the measurement altitude by moving the nozzle support 40 in the (+ Z) direction. Further, when the linear motor 50 moves the bridging structure 4 in the (+ X) direction, the gap sensor 42 scans the coating region, measures the gap with the resist film formed on the substrate 90, and transmits it to the control unit 7. To do. The controller 7 compares the gap value (distance to the surface of the substrate 90) measured before applying the resist solution and the gap value (distance to the surface of the resist film) measured after applying the resist. Thus, the thickness of the resist film on the substrate 90 is calculated, and the calculation result is displayed on the display unit or the like.

  When the substrate 90 carry-out processing (step S29) is completed, if processing is continuously performed on a plurality of substrates 90, the processing returns to step S11 and is repeatedly executed, and there is no substrate 90 to be processed. If so, the process ends (step S30).

  As described above, in the substrate processing apparatus 1 according to the first embodiment of the present invention, an object that interferes with the slit nozzle 41 during the scanning of the slit nozzle 41 is detected by the respective effective detection ranges E1 to E3. By performing the shared detection, it is possible to prevent a decrease in detection accuracy due to the spread of the laser beam as in the conventional apparatus. Therefore, the interference sensor can be detected with high accuracy by the detection sensor 45 having a narrow effective detection range.

  The detection directions of the plurality of detection sensors 45 are substantially parallel to the substrate 90 held on the stage 3 and substantially perpendicular to the scanning direction by the slit nozzle 41, and each effective detection range E1. Further, by arranging E3 in the detection direction of the detection sensor 45, it is possible to detect the interference with a relatively small number of detection means.

  In addition, since a plurality of detection sensors 45 are attached to the moving mechanism 5, even when the slit nozzle 41 is replaced, it is not necessary to adjust the position of the detection sensor 45 again, thereby improving work efficiency. be able to.

  In the substrate processing apparatus 1 according to the present embodiment, the scanning range E0 of the slit nozzle 41 has been described as being inspected by the three detection sensors 45 (450, 451, 452). However, the number of the detection sensors 45 is not limited thereto. It is not something that can be done. The same applies to the second embodiment.

  Further, the beam shape of the laser light irradiated by the detection sensor 45 may be either a spot type or a line type. The same applies to the following embodiments.

<2. Second Embodiment>
In the first embodiment, the detection sensor 45 is configured to be attached to the moving mechanism 5. However, the attachment position of the detection sensor 45 is not limited to this, and any position that can detect an interference is provided. It can be installed anywhere.

  FIG. 8 is an enlarged view of the periphery of the detection sensor 45 of the substrate processing apparatus 1a according to the second embodiment configured based on such a principle. As shown in FIG. 8, the substrate processing apparatus 1 a has a detection sensor 45 attached to a nozzle support portion 40. The slit nozzle 41 is fixed to the nozzle support 40 as in the above embodiment, and the slit nozzle 41 moves integrally with the nozzle support 40. A slit nozzle 41 is fixed to the nozzle support portion 40. Accordingly, the plurality of detection sensors 45 move integrally while maintaining a relative distance from the slit nozzle 41.

  As described in the above embodiment, the detection sensor 45, which is a transmissive laser sensor, has a light projecting unit and a light receiving unit, and is arranged so that they face each other with the Y-axis direction as the optical axis. As a result, one sensor is configured. Therefore, in FIG. 8, only the portion (either the light projecting portion or the light receiving portion of each detection sensor 45) arranged on the −Y side of the detection sensor 45 is shown, but detection is also performed on the + Y side of the slit nozzle 41. A sensor 45 is attached.

  The substrate processing apparatus 1a has substantially the same configuration as the substrate processing apparatus 1 in the first embodiment except that the detection sensor 45 is attached to the nozzle support portion 40. The operation of the substrate processing apparatus 1a is also substantially the same as that of the substrate processing apparatus 1. However, in the substrate processing apparatus 1, the position adjustment operation of each detection sensor 45 in the Z-axis direction is performed on the basis of the position of the holding surface 30 of the stage 3, but in the substrate processing apparatus 1 a, (−Z) of the slit nozzle 41 is performed. The position adjustment operation of the detection sensor 45 in the Z-axis direction is performed with reference to the end on the side.

  As described above, even when the detection sensor 45 is attached to the nozzle support portion 40 as in the substrate processing apparatus 1a in the second embodiment, it is almost the same as the substrate processing apparatus 1 in the first embodiment. Similar effects can be obtained.

  In addition, since the plurality of detection sensors 45 are attached so as to move integrally while maintaining a relative distance from the slit nozzle 41, the relative distance between the detection sensor 45 and the slit nozzle 41 is once adjusted. Since the relative distance is constant regardless of the posture of the slit nozzle 41 (mainly the position in the Z-axis direction), the detection accuracy can be improved. Further, in the substrate processing apparatus 1a, even if the thickness of the substrate 90 to be processed is changed, it is not necessary to perform the position adjustment operation again, and the work efficiency can be improved.

  In the substrate processing apparatus 1a according to the present embodiment, the detection sensor 45 is described as being attached to the nozzle support portion 40. However, for example, the detection sensor 45 may be directly attached to the slit nozzle 41.

<3. Third Embodiment>
In the above-described embodiment, a transmission type laser sensor is used as the detection sensor 45, and laser light is irradiated in the Y-axis direction (in a direction substantially parallel to the surface of the substrate 90). However, the method of detecting an object that may come into contact with the slit nozzle 41 is not limited to this.

  FIG. 9 is a rear view showing the configuration of the substrate processing apparatus 1b according to the third embodiment configured based on such a principle.

  In the substrate processing apparatus 1b in the present embodiment, as shown in FIG. 9, a plurality of detection sensors 45a are arranged in the direction along the Y axis on the (−X) side of the nozzle support section 40. However, in FIG. 9, only some detection sensors 45a are illustrated. Thus, by arranging the plurality of detection sensors 45a, the respective effective detection ranges are arranged in a direction substantially perpendicular to the scanning direction by the slit nozzle 41. The substrate processing apparatus 1b has substantially the same configuration as the substrate processing apparatus 1 in the first embodiment except that the detection sensor 45a is used instead of the detection sensor 45.

  The detection sensor 45a is a general reflection type laser sensor, and its detection direction is a (−Z) direction (a direction substantially perpendicular to the surface of the substrate 90). Laser light emitted by a light projecting unit (not shown) of the detection sensor 45a is reflected by an object existing in the (−Z) direction and received by a light receiving unit (not shown) of the detection sensor 45a. As a result, the detection sensor 45a measures the gap (distance) to the object that reflects the laser light, and transmits it to the control unit 7. That is, each detection sensor 45a has a function as a distance measuring sensor that measures a distance from an object existing in the (−Z) direction.

  The width of the effective inspection range of each detection sensor 45a in the Y-axis direction is narrower than the effective detection ranges E1 to E3 in the first and second embodiments. However, by arranging the detection sensors 45a densely in the Y-axis direction, the scanning range E0 can be inspected by sharing the effective inspection range arranged in the Y-axis direction, and an interference with a desired size is detected. can do.

  Since the operation of the substrate processing apparatus 1 in the present embodiment is substantially the same as the operation of the substrate processing apparatus 1 in the first embodiment shown in FIGS. 4 and 5, detailed description thereof is omitted. The determination in step S25 is different as follows.

  In Steps S22 and S25, the control unit 7 first calculates the relative distance between the slit nozzle 41 and the object based on the measurement result of each detection sensor 45a. If the relative distance obtained at this time is equal to or smaller than the predetermined value L0, it is determined that an interfering object has been detected, and the processing in step S27 and subsequent steps is executed as in the first embodiment. On the other hand, when the obtained relative distance is equal to or smaller than the predetermined value L1 but larger than the predetermined value L0, the process is continued while displaying a warning to the operator.

  In this way, the substrate processing apparatus 1b can perform control according to the relative distance between the slit nozzle 41 and the target object by using the distance sensor as the detection sensor 45a. Note that the predetermined value L1 and the predetermined value L0 are set in advance as values satisfying the relationship of L1> L0.

  As described above, also in the substrate processing apparatus 1b according to the third embodiment of the present invention, the same effect as in the above embodiment can be obtained.

  The detection directions of the plurality of detection sensors 45 a are substantially perpendicular to the substrate 90 held on the stage 3, and each effective detection range is arranged in a direction substantially perpendicular to the scanning direction by the slit nozzle 41. By doing so, the plurality of detection sensors 45a can be configured by the same detection sensor (it is not necessary to set each effective detection range to be different).

  Note that the detection sensor 45a may use any principle as long as it can measure the relative distance to an object existing in the (−Z) direction. For example, an ultrasonic sensor that measures the relative distance by emitting ultrasonic waves may be used.

<4. Fourth Embodiment>
In the above embodiment, by combining the effective detection ranges of the plurality of detection sensors as the effective detection range of the substrate processing apparatus, and inspecting the scanning range of the slit nozzle by sharing the effective detection ranges of the plurality of detection sensors, A method for preventing a decrease in the accuracy of detecting an interference object has been described. However, in the case where an interference is detected by such a detection sensor, a technique for preventing a decrease in detection accuracy is not limited to this. For example, it is possible to prevent the detection accuracy of the interference object from being lowered by preventing erroneous detection due to chattering of the detection sensor.

  FIG. 10 is a diagram showing the slit nozzle 41 and the detection sensors 453 and 454 of the substrate processing apparatus 1c according to the fourth embodiment configured based on such a principle.

  The detection sensors 453 and 454 are transmissive laser sensors having the same configuration, and the light receiving unit and the light projecting unit are Y as in the substrate processing apparatus 1 (FIG. 1) in the first embodiment. It is fixed to the moving mechanism 5 so as to face in the axial direction. As shown in FIG. 10, the detection sensor 453 and the detection sensor 454 are arranged at an interval δ in the X-axis direction. In the present embodiment, the interval δ is about 50 mm. Further, the detection sensors 453 and 454 may be respectively attached to the nozzle support portion 40, similarly to the substrate processing apparatus 1a in the second embodiment.

  FIG. 11 is a diagram showing a positional relationship on the XY plane between the scanning range EL0 and the effective detection ranges EL1 and EL2 in the present embodiment. Here, the substrate 91 is narrower in the Y-axis direction than the substrate 90, and the detection sensors 453 and 454 have sufficient detection accuracy in the Y-axis direction.

  The region where the interference sensor is detected when the detection sensor 453 is moved in the (−X) direction by the moving mechanism 5 is a region of the effective detection range EL1 indicated by a bold rectangle in FIG. Further, the region where the detection sensor 454 detects the interference is the region of the effective detection range EL2 indicated by a broken-line rectangle in FIG.

  As described above, the two detection sensors 453 and 454 are arranged at the interval δ in the X-axis direction. Accordingly, as shown in FIG. 11, the effective detection range EL1 and the effective detection range EL2 are strictly positioned at an interval δ in the X-axis direction. However, since the interval δ is sufficiently smaller than the lengths of the effective detection ranges EL1 and EL2 in the X-axis direction, the effective detection range EL1 and the effective detection range EL2 are areas where most of the areas overlap. Can be regarded as almost the same region.

  Although the details will be described later, the control unit 7 in the present embodiment compares the detection results of the detection sensors 453 and 454, and when there is an interference detected in any of the detection sensors 453 and 454, “ It is determined that an interfering object has been detected. Therefore, the detection result cannot be compared for the region inspected only by one of the detection sensors 453 and 454, and thus the effective detection range of the substrate processing apparatus 1c is not achieved. That is, in the substrate processing apparatus 1c, the scanning range EL0 is inspected by detecting an object in a region where the effective detection range EL1 and the effective detection range EL2 overlap.

  Next, the operation of the substrate processing apparatus 1c in the present embodiment will be described. In the operation of the substrate processing apparatus 1c, detailed description of the operation that is substantially the same as the operation of the substrate processing apparatus 1 (the operation shown in FIGS. 4 and 5) is omitted. Since the position adjustment of the detection sensors 453 and 454 in the Z-axis direction is also performed according to the first embodiment, the description thereof is omitted.

  In the substrate processing apparatus 1c, the control unit 7 is different from the above-described embodiment in that the controller 7 determines that an interference is detected based on the detection results of the detection sensors 453 and 454 in steps S22 and S25 shown in FIG. .

  FIG. 12 is a diagram illustrating an example of a detection result of the detection sensor 453. FIG. 13 is a diagram illustrating an example of a detection result of the detection sensor 454 in the example illustrated in FIG. In the substrate processing apparatus 1c, the detection of the interference substance by the detection sensors 453 and 454 is started by executing step S14, and when step S21 or step S24 is executed, the detection sensors 453 and 454 are (−X). Interfering objects are detected while moving in the direction.

  The control unit 7 corrects the time difference ΔT for the detection result of the detection sensor 454 in order to compare the detection result of the detection sensor 453 and the detection result of the detection sensor 454. In the substrate processing apparatus 1c, the detection sensor 453 and the detection sensor 454 are arranged at an interval δ in the X-axis direction. Accordingly, there is a time difference ΔT before the inspection sensor 454 inspects the area inspected by the detection sensor 453.

  Here, using the moving speed V of the detection sensors 453 and 454 by the moving mechanism 5, the interval δ between the detection sensor 453 and the detection sensor 454, and the error α (constant) of the program scan, the control unit 7 determines this time difference. ΔT is obtained by Equation 1.

  ΔT = δ / V + α Equation 1

  The control unit 7 compares the output from the detection sensor 453 with the output from the detection sensor 454 after delaying the output by the time difference ΔT obtained by Equation 1. Thereby, the detection results at the same position of the detection sensors 453 and 454 are compared with each other.

  Since the relative position of the interfering object with respect to the substrate 91 does not change, when the interfering substance actually exists, the detection sensor 454 that performs the inspection after the time difference ΔT has passed also targets the same position in the X-axis direction. An object is detected. In this way, the control unit 7 confirms whether or not the interference detected by the detection sensor 453 is also detected by the detection sensor 454. Then, in any of the detection sensors 453 and 454, when the amount of received light is smaller than the threshold value Q at the same position, it is determined that an interfering object is present (Yes in step S22 or step S25).

  Thus, even if the detection result is output in the detection sensor 453 as if, for example, the amount of received light has decreased due to the occurrence of chattering, the output of the detection sensor 454 is detected with a delay. As a result, it is possible to prevent erroneous detection of interference. Similarly, even when chattering occurs in the detection sensor 454, it is confirmed by comparison with the output of the detection sensor 453 that has been detected in advance, so that erroneous detection of interference can be prevented. Therefore, the substrate processing apparatus 1c can prevent a decrease in detection accuracy due to chattering in the detection sensors 453 and 454.

  In the substrate processing apparatus 1c, the operation when an interference is detected and the operation when no interference is detected are the same as those of the substrate processing apparatus 1, respectively.

  As described above, also in the substrate processing apparatus 1c according to the fourth embodiment, it is possible to prevent the detection accuracy of the interference object from being lowered, similarly to the substrate processing apparatuses 1, 1a, and 1b according to the above-described embodiment.

  In particular, by detecting the scanning range of the slit nozzle by the effective detection ranges of each of the plurality of detection sensors and comparing the detection results, erroneous detection due to chattering can be prevented, and deterioration in detection accuracy can be prevented. be able to.

  When the substrate processing apparatus 1c in the fourth embodiment uses the large substrate 90 as the substrate to be processed, the detection sensor 453 is, for example, the detection sensor 45 (a plurality of detection sensors) shown in the first embodiment. In addition, the detection sensor 454 can be handled by the detection sensor 45 as well.

<5. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  For example, each detection sensor 45a shown in the third embodiment is composed of two detection sensors having the same position in the Y-axis direction and arranged in the X-axis direction, and comparing the detection results, By using the detection result of the detection sensor 45a, erroneous detection due to chattering or the like can be prevented even when the detection direction of the detection sensor is substantially perpendicular to the surface of the substrate, and a decrease in detection accuracy can be suppressed. Can do.

  Further, in the position adjustment work in the Z-axis direction of the detection sensors 453 and 454 shown in the fourth embodiment, the position of the detection sensor 453 and the position of the detection sensor 454 are set to be different from each other in the Z-axis direction. You may comprise so that the target object in a different position may be detected. For example, the position of the detection sensor 453 is adjusted to the (+ Z) side, and the position of the detection sensor 454 is adjusted to the (−Z) side. In this case, if the object is detected only by the detection sensor 453, it is determined as “false detection” due to chattering or the like, and the process is continued. If the object is detected only by the detection sensor 454, it is determined that some unevenness has occurred, and only a warning is given. Furthermore, when an object is detected by both the detection sensors 453 and 454, it is determined that there is an object in contact with the slit nozzle 41, and the process is stopped. That is, based on the detection results of the detection sensors 453 and 454, more appropriate control according to the situation can be performed.

It is a front view of the substrate processing apparatus in the 1st Embodiment of this invention. It is an enlarged view in the peripheral part of the detection sensor of the substrate processing apparatus in 1st Embodiment. It is the figure which looked at the scanning range of the slit nozzle from the + Z direction. It is a flowchart which shows the operation | movement in the coating process of a substrate processing apparatus. It is a flowchart which shows the operation | movement in the coating process of a substrate processing apparatus. It is a figure which shows a mode that a detection sensor detects an interference object. It is a figure which shows a mode that a detection sensor detects an interference object. It is an enlarged view in the peripheral part of the detection sensor of the substrate processing apparatus in 2nd Embodiment. It is a rear view which shows the substrate processing apparatus in 3rd Embodiment. It is a figure which shows the slit nozzle and detection sensor of the substrate processing apparatus in 4th Embodiment. It is a figure which shows the positional relationship on the XY plane of the scanning range and effective detection range in 4th Embodiment. It is a figure which shows the example of the detection result of a detection sensor. It is a figure which shows the example of the detection result of the other detection sensor in the example shown in FIG. It is a conceptual diagram for demonstrating the principle in which the transmissive | pervious laser sensor used for the conventional coating device detects an interference object. It is a conceptual diagram for demonstrating the principle in which the transmissive | pervious laser sensor used for the conventional coating device detects an interference object. It is a conceptual diagram for demonstrating the principle in which the transmissive | pervious laser sensor used for the conventional coating device detects an interference object. It is a conceptual diagram for demonstrating the principle in which the transmissive | pervious laser sensor used for the conventional coating device detects an interference object.

Explanation of symbols

1, 1a, 1b, 1c Substrate processing apparatus 3 Stage 30 Holding surface 4 Bridge structure 40 Nozzle support portion 41 Slit nozzle 42 Gap sensor 43, 44 Lifting mechanism 45, 45a, 450, 451, 452, 453, 454 Detection sensor 5 Movement Mechanism 50 Linear motor 51 Linear encoder 7 Controller 90, 91 Substrate E0, EL0 Scanning range E1, E2, E3, EL1, EL2 Effective detection range

Claims (2)

A substrate processing apparatus for applying a predetermined processing liquid to a substrate,
Holding means for holding the substrate;
A slit nozzle for discharging a predetermined processing liquid from a slit-shaped discharge portion to the substrate held by the holding means;
Moving means for moving the slit nozzle relative to the substrate held by the holding means, and executing scanning by the slit nozzle for the substrate;
While moving integrally with the slit nozzle while maintaining a relative distance from the slit nozzle, each irradiates a laser beam, whereby each of the slit nozzles defined with respect to the scanning range with respect to the substrate is defined. A plurality of transmission type laser sensors for detecting an object existing in an effective detection range;
Control means for controlling the moving means based on detection results by the plurality of transmission type laser sensors;
With
The detection directions of the plurality of transmissive laser sensors are substantially parallel to the substrate held by the holding means, and substantially perpendicular to the scanning direction by the slit nozzle,
The respective effective detection ranges are arranged at different positions in the detection direction,
Each of the laser beams emitted from the plurality of transmission type laser sensors is focused at least in an effective detection range corresponding to the laser beam and in a region other than the effective detection range corresponding to the laser beam. The luminous flux is spreading,
A substrate processing apparatus, characterized in that the slit nozzle and interfere object during scanning by the slit nozzle is detected by sharing the effective detection range of the respective. The substrate processing apparatus according to claim 1,
The substrate processing apparatus, wherein the plurality of transmission type laser sensors are attached to the moving means.

Images