JP2008310249A - Proximity scanning exposure apparatus and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a proximity exposure apparatus for improving exposure precision by being floated with a floating unit and accurately controlling the floating amount of a supported substrate, and to provide its control method. <P>SOLUTION: The proximity scanning exposure apparatus 1 includes: a substrate conveying mechanism 10 provided with the supporting floating unit 16 and a substrate drive unit 17 by floating the substrate W; a mask holding part 11 for holding a mask M; and a substrate gap sensor 60 for detecting the floating amount of the substrate W. The proximity scanning exposure apparatus includes: regulating an air flow rate and air pressure of the floating unit 16 with a control part 15 based on a difference between the floating amount and a target floating amount of the substrate W detected by the substrate gap sensor 60; and accurately controlling the floating amount of the substrate W. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a proximity scan exposure apparatus and a control method thereof, and more specifically, a proximity scan exposure apparatus that performs exposure while controlling the flying height of a substrate levitated and held by a flying unit to be a target flying height, and the same It relates to a control method.

Conventionally, as a manufacturing method of a large flat panel display such as a liquid crystal display or a plasma display used for a large thin television, a method of exposing and transferring a mask pattern onto the substrate while conveying the substrate is known. (For example, refer to Patent Document 1). In the exposure apparatus described in Patent Document 1, a substrate drive that floats a substrate on an intake / exhaust air pad that ejects gas from an exhaust hole and sucks ejected gas from an intake hole on the lower side of the substrate, and grips one end of the substrate The substrate is exposed while being transported in a certain direction by the unit.
JP 2007-72267 A

  By the way, if the distance between the substrate and the air intake / exhaust air pad changes greatly, the amount of reflected light from the air intake / exhaust air pad varies during exposure, and the exposure accuracy decreases such as uneven exposure and reduced resolution. The exposure apparatus described in Patent Document 1 conveys a side edge portion of a substrate floating on an intake / exhaust air pad by a gas such as air with a substrate holding portion having a pair of grips in a predetermined direction. The floating amount of the substrate on the intake / exhaust air pad is controlled by controlling the operation of the gas supply device and the gas suction device to adjust the gas ejection pressure from the exhaust hole and the intake pressure from the intake hole. However, a specific control method for maintaining the flying height of the substrate at a predetermined flying height is not described.

  Also, if the substrate thickness varies only by controlling the flying height of the substrate, it is not possible to cope with this, and the gap between the mask and the upper surface of the substrate fluctuates, and the exposure accuracy is adversely affected. there were. In particular, since the intake holes of all intake / exhaust air pads are adjusted to a single intake pressure, and the exhaust holes of all intake / exhaust air pads are adjusted to a single exhaust pressure, the board thickness within a single substrate varies. There is a problem that even some cases cannot be handled.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a proximity scan exposure apparatus that can accurately control the flying height of a substrate levitated by a levitating unit and improve exposure accuracy, and its It is to provide a control method.

The above object of the present invention can be achieved by the following constitution.
(1) A substrate transport mechanism including a floating unit that floats and supports a substrate, a substrate driving unit that transports the substrate in a predetermined direction while gripping the substrate, a mask holding unit that holds a mask, and the substrate transport mechanism And a sensor for detecting the flying height of the substrate, irradiating the substrate with the exposure light through the mask on the substrate conveyed in a predetermined direction while approaching the mask, A method of controlling a proximity scanning exposure apparatus that exposes a pattern,
Detecting the flying height of the substrate by the sensor;
When the difference between the detected flying height of the substrate and the target flying height exceeds an allowable value, controlling at least one of the air flow rate and the air pressure of the flying unit;
A control method for a proximity scan exposure apparatus, comprising:
(2) detecting the thickness of the substrate by the sensor;
Driving a mask driving unit for moving the mask holding unit so as to correct the gap between the substrate and the mask based on the flying height of the substrate and the detected thickness of the substrate;
(1) The proximity scanning exposure apparatus control method according to (1).
(3) A proximity scan exposure apparatus that irradiates exposure light through the mask onto a substrate conveyed in a predetermined direction while approaching the mask, and exposes the mask pattern on the substrate,
A substrate transport mechanism including a floating unit that floats and supports the substrate, and a substrate drive unit that transports the substrate in a predetermined direction while gripping the substrate;
A mask holding unit for holding the mask;
A sensor for detecting the flying height of the substrate transported to the substrate transport mechanism;
The sensor detects the flying height of the substrate, and controls at least one of the air flow rate and the air pressure of the flying unit when the difference between the detected flying height of the substrate and the target flying height exceeds an allowable value. A control unit,
A proximity scan exposure apparatus comprising:

  According to the proximity scan exposure apparatus and the control method thereof of the present invention, the flying height of the substrate that is transported by the substrate transport mechanism and that is floated and supported on the floating unit is detected by the sensor, and the detected floating of the substrate is detected. When the difference between the amount and the target flying height exceeds the allowable value, at least one of the air flow rate and air pressure of the flying unit is controlled. Accordingly, the substrate can be supported with a flying height within the allowable value of the target flying height, and the exposure accuracy can be improved.

  In addition, the thickness of the substrate is detected by the sensor, and the mask driving unit for moving the mask holding unit is driven based on the flying height of the substrate and the thickness of the substrate to correct the gap between the substrate and the mask. Thus, even when the thickness of the substrate fluctuates, exposure with high accuracy can be performed by absorbing the fluctuation.

  Hereinafter, an embodiment of a proximity scan exposure apparatus and a control method thereof according to the present invention will be described in detail with reference to the drawings.

  First, the configuration of the proximity scan exposure apparatus 1 of the present embodiment will be schematically described. As shown in FIGS. 1 and 2, the proximity scanning exposure apparatus 1 of the present embodiment floats and supports a substrate (color filter substrate) W and transports the substrate in a predetermined direction (X direction in FIG. 1). A plurality of mechanisms 10 and a plurality of masks M are respectively held and arranged in two rows in a staggered manner along a direction (Y direction in FIG. 1) intersecting a predetermined direction (6 in each of the left and right in the embodiment shown in FIG. 1). ) Mask holding units 11, a mask driving unit 12 for moving the mask holding unit 11, a plurality of irradiation units 14 arranged on the top of the plurality of mask holding units 11 to irradiate exposure light, And a control unit 15 that controls the movement of each operating part of the proximity scan exposure apparatus 1.

  The substrate transport mechanism 10 includes a floating unit 16 provided in a region for transporting the substrate W in the X direction, that is, a region below the plurality of mask holders 11 and a region extending from the bottom region to both sides in the X direction. And a substrate driving unit 17 that holds the one side in the Y direction (the upper side in FIG. 1) and conveys it in the X direction. The levitation unit 16 includes a plurality of exhaust air pads 20 and intake / exhaust air pads 21 respectively provided on a plurality of frames 19, and is connected to the exhaust air pads 20 and the intake / exhaust air pads 21 via pumps 45 and 55 and solenoid valves 44 and 54. Exhaust or intake / exhaust air. As shown in FIG. 1, the substrate driving unit 17 includes a suction pad 22 that holds one end of the substrate W that is levitated and supported by the levitating unit 16, and includes a motor 23, a ball screw 24, and a nut (not shown). The substrate W is transported in the X direction along the guide rail 26 by the ball screw mechanism 25. As shown in FIG. 2, the plurality of frames 19 are arranged via another level block 28 on the apparatus base 27 installed on the ground via the level block 18. Further, the substrate W may be transported by a linear servo actuator instead of the ball screw mechanism 25.

  The mask drive unit 12 is attached to a frame (not shown), and is attached to the X direction drive unit 31 that drives the mask holding unit 11 along the X direction, and the tip of the X direction drive unit 31. Is attached to the tip of the Y direction drive unit 32, and the mask holding unit 11 is rotationally driven in the θ direction (around the horizontal plane of the X and Y directions). A θ-direction drive unit 33 and a Z-direction drive unit 34 that is attached to the tip of the θ-direction drive unit 33 and drives the mask holding unit 11 in the Z direction (vertical direction of the horizontal plane composed of the X and Y directions). Accordingly, the mask holding unit 11 attached to the tip of the Z direction driving unit 34 can be moved in the X, Y, Z, and θ directions by the mask driving unit 12. Note that the order of arrangement of the X, Y, θ, and Z direction drive units 31, 32, 33, and 34 can be changed as appropriate.

  Further, as shown in FIG. 1, a mask changer 2 capable of simultaneously exchanging the masks M of the mask holding portions 11a and 11b between the carry-in side and carry-out side mask holding portions 11a and 11b arranged in two rows in a staggered manner. Is arranged. The used or unused mask M transported by the mask changer 2 is transferred to and from the mask stockers 3 and 4 by the loader 5. The mask M is pre-aligned by a mask pre-alignment mechanism (not shown) during the transfer between the mask stockers 3 and 4 and the mask changer 2.

  As shown in FIG. 2, the irradiation unit 14 disposed on the upper part of the mask holding unit 11 includes a light source 6, a mirror 7, an optical integrator (not shown), a shutter (not shown), and the like. As the light source 6, for example, an ultra-high pressure mercury lamp, a xenon lamp or an ultraviolet light emitting laser that emits exposure light EL including ultraviolet light is used.

  Such a proximity scan exposure apparatus 1 floats and holds the substrate W by the air flow of the exhaust air pad 20 and the intake / exhaust air pad 21 of the levitation unit 16, and adsorbs one end of the substrate W by the substrate drive unit 17 in the X direction. Transport to. Then, the exposure light EL from the irradiation unit 14 is irradiated to the substrate W located below the mask holding unit 11 through the mask M, and the pattern of the mask M is transferred to the color resist applied to the substrate W. To do.

  Here, as shown in FIG. 3, in the levitation unit 16, the intake / exhaust air pad 21 has a plurality of openings on the upper surface facing the substrate W to be transported, and is similarly transported to the exhaust holes 41 communicating with each other. And an intake hole 51 having a plurality of openings on the upper surface facing the substrate W to be communicated with each other.

  The exhaust hole 41 is connected to a positive pressure control valve 44 whose opening degree can be adjusted so as to adjust the air pressure and the air flow rate, and a positive pressure pump 45, and between the intake / exhaust air pad 21 and the positive pressure control valve 44. The pressure sensor 42 for detecting the air pressure of the compressed air supplied to the exhaust hole 41 and the flow rate sensor 43 for detecting the air flow rate of the compressed air supplied to the exhaust hole 41 are arranged. The intake hole 51 is connected to a vacuum pressure control valve 54 whose opening degree can be adjusted to adjust air pressure and air flow rate, and a vacuum pressure pump 55, and between the intake / exhaust air pad 21 and the vacuum pressure control valve 54. The pressure sensor 52 for detecting the air pressure sucked from the intake hole 51 and the flow sensor 53 for detecting the air flow rate sucked from the intake hole 51 are arranged. The positive pressure pump 45 and the vacuum pressure pump 55 may not be provided for each intake / exhaust air pad 21, but may share a single positive pressure pump 45 and a single vacuum pressure pump 55, or an intake / exhaust air pad. 21 may be grouped and provided for each group.

  Further, as shown in FIGS. 1 and 4, a plurality of substrate gap sensors 60 are arranged along the Y direction on the substrate carry-in side from the mask holding unit 11 and below the substrate W to be transported. A mask gap sensor 61 is disposed above each mask holder 11.

  The substrate gap sensor 60 is for detecting the positions of the lower surface Wb and the upper surface Wa of the substrate W to be transferred. For example, the substrate gap sensor 60 detects reflected light reflected from the lower surface Wb and the upper surface Wa of the substrate W. It is an optical sensor. Since the substrate gap sensor 60 is fixed to the frame 19, the gap G <b> 1 between the flying unit 16 and the substrate W, that is, the flying height of the substrate W is detected by detecting the position of the lower surface Wb of the substrate W. Further, the thickness t of the substrate W is obtained from the difference between the position of the lower surface Wb of the substrate W and the position of the upper surface Wa.

  Similar to the substrate gap sensor 60, the mask gap sensor 61 is, for example, an optical sensor that detects the reflected light of the irradiated light, and the position of the upper surface Ma and the position of the lower surface Mb of the mask M held by the mask holding unit 11. And the position of the upper surface Wa of the substrate W are detected in the non-exposed region of the mask M. Further, the gap G2 between the mask M and the substrate W is obtained from the detected position of the lower surface MS of the mask M and the position of the upper surface Wa of the substrate W.

  Therefore, the control unit 15 uses the pressure sensors 42 and 52 so that the floating amount G1 of the substrate W becomes the target floating amount based on the floating amount G1 between the substrate W and the floating unit 16 detected by the substrate gap sensor 60. While the air pressure and air flow rate of the air exhausted and taken in by the flow rate sensors 43 and 53 are detected, the solenoid valve is controlled to open and close by an electric signal so that the predetermined air pressure and air flow rate are obtained. Thereby, the fluid pressure balance between the substrate W and the flying unit 16 is adjusted, and the flying height of the substrate W is controlled to be the target flying height.

  Hereinafter, specific control of the flying height of the substrate W will be described with reference to FIGS. First, on the carry-in side from the mask holding unit 11, the substrate W levitated and supported by the exhaust air pad 20 is transported toward the mask holding unit 11 by the substrate driving unit 17. Then, the intake / exhaust is performed by the exhaust holes 41 and the intake holes 51 on the intake / exhaust air pad 21 on the carry-in side from the mask holding unit 11, thereby adjusting the fluid pressure balance between the substrate W and the floating unit 16. W rises.

  Note that the air pressure and air flow rate of the exhaust hole 41 and the intake hole 51 of the intake / exhaust air pad 21 are obtained in advance by actual measurement using the actual substrate W, as shown in FIG. The air pressure and air flow corresponding to the target flying height are obtained from the flying characteristics data. Since this levitation characteristic data is obtained by actual measurement, it is possible to grasp the relative relationship including the resistance due to piping routing, that is, the length of the piping and the loss due to bending, which cannot be calculated by calculation.

  Then, as shown in FIGS. 5 and 7, when the substrate W is transported and reaches the position of the substrate gap sensor 60, the substrate gap sensor 60 is positioned at the lower surface Wb (first layer) and the upper surface Wa. The (second layer) is detected and taken in (step S1), and the flying height G1 of the substrate W and the thickness t of the substrate W are obtained by calculation (step S2). It is determined whether or not the obtained flying height G1 is abnormal (step S3). If the flying height G1 is abnormal, it is determined that there is a flying height error, and the Z direction driving unit 34 of the mask driving unit 12 is operated to retract the mask holding unit 11. In addition, the substrate W and the mask M are prevented from interfering with each other, and the substrate drive unit 17 stops the conveyance of the substrate W to prevent the substrate W and the mask M from being damaged (step S4).

  If the flying height is normal, it is determined whether the flying height is within the allowable value with respect to the target flying height (step S5). If the flying height is within the allowable value, the control counter value is cleared (step S6). It is determined whether or not the thickness t of the substrate W is within an allowable value (step S7). If the plate thickness t is not within the allowable value, it is determined that the substrate W has a plate thickness that cannot be corrected by the Z-direction drive unit 34, and a substrate plate thickness error process is performed (step S8). On the other hand, if the plate thickness t of the substrate W is within the allowable value, the Z-direction drive unit 34 of the mask drive unit 12 is operated based on the detected flying height of the substrate W and the plate thickness t, and the substrate W and the mask M The gap G2 is corrected to a predetermined exposure gap (step S9). Thereby, even if the flying height G1 and the plate thickness t of the substrate W fluctuate, the error corresponding to the fluctuation can be absorbed.

  Further, when it is determined in step S5 that the flying height G1 is not within the allowable value, after the flying height control counter is incremented (step S10), it is determined whether the flying height control counter value is within the allowable value. (Step S11). If the flying height control counter value is not within the allowable value, it is determined that the flying height control described later is not controlled to the target flying height, and the flying height control impossible error process is performed (step S12).

  On the other hand, if the flying height control counter value is within the allowable value, the flow proceeds to the flying height control sequence. Specifically, in this sequence, as shown in FIG. 8, the flying height of the substrate W measured by the substrate gap sensor 60 is confirmed (step S13), and the flying height to be corrected is determined from the difference from the target flying height. The corresponding air pressure and air flow rate are obtained (step S14).

  Then, the control unit 15 detects the air pressure and the air flow rate of the air exhausted and sucked from the exhaust hole 41 and the intake hole 51 by the pressure sensors 42 and 52 and the flow rate sensors 43 and 53, and the predetermined air pressure and air flow. The solenoid valve is opened / closed to control the air pressure and the air flow rate so as to achieve the flow rate (step S15).

  Next, it is determined whether the air flow rate is within the allowable range (step S16). If the air flow rate is out of the allowable range, air flow error processing is performed (step S17). It is determined whether or not there is (step S18). If it is out of the allowable range, an air pressure error process is performed (step S19). If it is within the allowable range, the process returns to step S1 again and the same control is repeated. The above-described substrate plate thickness error processing, flying height control impossible error processing, air flow error processing, and air pressure error processing are performed by operating the Z direction driving unit 34 and the mask holding unit 11 in the same manner as the above flying height error processing. Is taken out, and the substrate driving unit 17 stops the conveyance of the substrate W.

  As a result, the pressure and flow rate of the air exhausted and sucked from the exhaust hole 41 and the intake hole 51 of the intake / exhaust air pad 21 are controlled, and the substrate W is positioned below the mask M while being accurately controlled to the target flying height. Be transported.

  6, when the substrate W reaches the position of the mask gap sensor 61, the mask gap sensor 61 detects the position of the upper surface Wa of the substrate W and the position of the lower surface MS of the mask M, and the substrate W And a gap G2 between the mask M and the mask M are obtained. Then, the control unit 15 operates the Z direction driving unit 34 of the mask driving unit 12 to move the mask holding unit 11 so that the gap G2 obtained by the mask gap sensor 61 becomes a predetermined exposure gap. Thereafter, the exposure light EL is irradiated from the irradiation unit 14 through the mask M, and the pattern of the mask M is exposed and transferred to the substrate W.

  Further, since a plurality of substrate gap sensors 60 are arranged along the Y direction, the flying height G1 and the board thickness t obtained by each substrate gap sensor 60 are the Y direction positions where the substrate gap sensors 60 are located. Are used to control the air flow rate and air pressure of each of the intake / exhaust air pads 21 and to control the gap between the substrate W and the mask M. Accordingly, the flying height of the substrate W can be varied for each intake / exhaust air pad 21, and it is possible to cope with the exposure unevenness caused by the flying height of the substrate by changing the flying height of the substrate W according to the exposure result. . In addition, by controlling the air flow rate and air pressure of at least three intake / exhaust air pads, the tilt correction of the substrate W can be performed without providing a tilt mechanism in the mask holding unit 11. Further, even when the thickness of the substrate W in the Y direction varies, the Z direction driving unit 34 of each mask holding unit 11 can be driven to perform exposure with a uniform gap, thereby improving exposure accuracy. Can do.

  According to the proximity scan exposure apparatus 1 and its control method of the present embodiment, the substrate gap sensor 60 determines the flying height G1 of the substrate W that is transported by the substrate transport mechanism 10 and that is floated and supported on the flying unit 16. When the difference between the detected flying height G1 of the substrate W and the target flying height exceeds the allowable value, the air flow rate and the air pressure of the flying unit 16 are controlled. It can be accurately supported within the amount tolerance. As a result, the exposure accuracy can be improved.

  Further, the substrate gap sensor 60 detects the plate thickness t of the substrate W, and drives the mask drive unit 12 for moving the mask holding unit 11 based on the flying height G1 of the substrate W and the plate thickness t of the substrate W. Since the gap G2 between the substrate W and the mask M is corrected, even when the thickness t of the substrate W varies, the variation can be absorbed and high-precision exposure can be performed.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. For example, in the above embodiment, the case where the substrate W is a color filter substrate has been described. However, the present invention is not limited to this, and any substrate such as a semiconductor substrate may be used as long as it forms a predetermined exposure pattern.
In the above embodiment, the positive pressure control valve 44 and the vacuum pressure control valve 54 may control either the air flow rate or the air pressure.

It is a top view of the scanning exposure apparatus which is embodiment of this invention. It is a front view of the scanning exposure apparatus in FIG. It is explanatory drawing which shows schematic structure of the floating unit which floats and supports a board | substrate. It is a schematic diagram which shows the positional relationship of a substrate gap sensor and a mask gap sensor. It is a schematic diagram which shows the state in which the flying height of the board | substrate conveyed by a board | substrate gap sensor is detected. It is a schematic diagram which shows the state by which the gap between a mask and a board | substrate is detected by a mask gap sensor. It is a flowchart which shows the procedure which controls the flying height of a board | substrate by controlling the air pressure and air flow rate from a floating unit. It is a flowchart which shows the procedure which controls the flying height of a board | substrate by controlling the air pressure and air flow rate from a floating unit. It is a table which shows the floating characteristic data of the floating amount of a board | substrate, an air flow rate, and an air pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Proximity scanning exposure apparatus 10 Substrate conveyance mechanism 11 Mask holding part 12 Mask drive part 15 Control part 16 Levitation unit 17 Substrate drive unit 60 Substrate gap sensor (sensor)
EL exposure light G1 Gap between flying unit and substrate (flying amount)
G2 Gap between substrate and mask M Mask t Substrate thickness W Substrate

Claims (3)

A floating unit that floats and supports the substrate, a substrate transport mechanism that includes a substrate driving unit that transports the substrate in a predetermined direction while gripping the substrate, a mask holding unit that holds a mask, and the substrate transport mechanism that transports the substrate A sensor that detects the flying height of the substrate, and irradiates the substrate with the exposure light through the mask and exposes the pattern of the mask to the substrate that is transported in a predetermined direction while being close to the mask. A method for controlling a proximity scan exposure apparatus, comprising:
Detecting the flying height of the substrate by the sensor;
When the difference between the detected flying height of the substrate and the target flying height exceeds an allowable value, controlling at least one of the air flow rate and the air pressure of the flying unit;
A control method for a proximity scan exposure apparatus, comprising: Detecting the thickness of the substrate by the sensor;
Driving a mask driving unit for moving the mask holding unit so as to correct the gap between the substrate and the mask based on the flying height of the substrate and the detected thickness of the substrate;
The method of controlling a proximity scan exposure apparatus according to claim 1, comprising: A proximity scan exposure apparatus that irradiates a substrate conveyed in a predetermined direction while approaching a mask with exposure light through the mask and exposes the pattern of the mask on the substrate,
A substrate transport mechanism including a floating unit that floats and supports the substrate, and a substrate drive unit that transports the substrate in a predetermined direction while gripping the substrate;
A mask holding unit for holding the mask;
A sensor for detecting the flying height of the substrate transported to the substrate transport mechanism;
The sensor detects the flying height of the substrate, and controls at least one of the air flow rate and the air pressure of the flying unit when the difference between the detected flying height of the substrate and the target flying height exceeds an allowable value. A control unit,
A proximity scan exposure apparatus comprising:

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