JPWO2007145038A1 - Proximity exposure apparatus and proximity exposure method - Google Patents

Abstract

The proximity exposure apparatus PE includes a substrate holding unit 21 that holds a substrate W as a material to be exposed, a mask holding unit 12 that holds a mask M having an exposure pattern, and pattern exposure light through the mask M. An illumination optical system 40 for irradiating W, and the mask pattern of the mask M is exposed to the substrate W by the illumination optical system 40 in a state where the mask M and the substrate W are arranged close to each other with a predetermined gap g. Transcript. The illumination optical system 40 includes a collimation mirror 47 and an irradiation angle changing mechanism 71 that changes the irradiation angle θd of light for pattern exposure reflected by the collimation mirror 47 by deforming or moving the collimation mirror 47. .

Description

  In particular, the present invention relates to a proximity exposure apparatus and a proximity exposure method for performing divided successive proximity exposure (proximity exposure) of a mask pattern of a mask on a substrate of a large flat panel display such as a liquid crystal display or a plasma display.

  In proximity exposure, a translucent substrate (material to be exposed) coated with a photosensitive agent on the surface is held on a substrate stage, and the substrate is brought close to a mask held on a mask holding frame of a mask stage, and both are predetermined. In a state where the gaps are arranged in a gap of several tens of micrometers to several hundreds of micrometers, for example. Next, the mask pattern drawn on the mask is transferred onto the substrate by irradiating the exposure light toward the mask by the irradiation means from the side away from the substrate of the mask (for example, Patent Documents 1 to 3 and Non-patent document 1).

  By the way, in proximity exposure, when a substrate or a mask becomes large, these are easily expanded and contracted by a processing solution, heat, or a chuck. When exposure is performed while ignoring this expansion and contraction, a pattern to be transferred to the substrate is shifted. It may occur.

  In the exposure apparatuses described in Patent Documents 1 to 3, in order to prevent exposure shift due to the expansion and contraction of the substrate and the mask, the irradiation angle is changed by moving the integrator and the lens in the optical axis direction. The exposure magnification of the projected mask pattern is adjusted.

In Non-Patent Document 1, it is known to perform double exposure in order to achieve high resolution in lithography technology.
JP 2003-224058 A JP 2006-98649 A JP 2006-98650 A “Nikkei Microdevice”, Nikkei BP Marketing, Japan, April 2006, pages 96-103

  However, in the method of adjusting the deviation of exposure by the irradiation means described in Patent Documents 1 to 3, there is a possibility that the illuminance value on the irradiated surface may be uneven or varied, and the distortion to the irradiated surface or the exposure accuracy. There is a problem that it is difficult to correct (for example, a BM rectangle). Therefore, there has been a demand for a proximity exposure apparatus and a proximity exposure method capable of reducing the unevenness and variation of the illuminance value on the irradiated surface and performing more uniform magnification correction and correcting the exposure accuracy.

  The present invention has been made in view of the above circumstances, and a first object of the invention is to provide a substrate with high resolution, high density, and high accuracy that can perform more uniform magnification correction and exposure accuracy at the same time. A proximity exposure apparatus and a proximity exposure method capable of manufacturing the same. In addition, the second object of the present invention is to manufacture a high-accuracy and low-cost substrate without changing the exposure means due to expansion and contraction of the substrate and mask without changing the irradiation means to a complicated configuration. A proximity exposure apparatus and a proximity exposure method are provided.

The first object of the present invention is achieved by the following configuration.
(1) A substrate holding unit that holds a substrate as an exposed material, a mask holding unit that holds a mask having a mask pattern, and an irradiation unit that irradiates the substrate with light for pattern exposure through the mask. A proximity exposure apparatus that exposes and transfers a mask pattern of a mask to a substrate by an irradiation means in a state where the mask and the substrate are arranged close to each other with a predetermined gap,
The irradiation means includes a collimation mirror, and an irradiation angle changing mechanism that changes at least one of deformation and movement of the collimation mirror and changes an irradiation angle of light for pattern exposure reflected by the collimation mirror. Proximity exposure device.
(2) A deviation amount detecting means for detecting a plane deviation amount between the mask and the substrate is further provided,
The predetermined gap between the mask and the substrate and the irradiation angle of the light for pattern exposure reflected by the collimation mirror are set in accordance with the amount of plane deviation detected by the deviation amount detecting means ( The proximity exposure apparatus according to 1).

(3) A proximity exposure method comprising the proximity exposure apparatus according to (1) or (2),
Performing at least one of deformation and movement of the collimation mirror by the irradiation angle changing mechanism, and changing the irradiation angle of the light for pattern exposure reflected by the collimation mirror;
A step of exposing and transferring the exposure pattern of the mask to the substrate by the light for pattern exposure irradiated by the irradiation means;
A proximity exposure method comprising:
(4) detecting a plane deviation amount between the mask and the substrate by a deviation amount detection means;
Adjusting a predetermined gap between the mask and the substrate;
Further comprising
The predetermined gap between the mask and the substrate and the irradiation angle of the light for pattern exposure reflected by the collimation mirror are set in accordance with the amount of plane deviation detected by the deviation amount detecting means ( The proximity exposure method according to 3).

The second object of the present invention is achieved by the following configuration.
(5) A substrate holding unit that holds a substrate as an exposed material, a mask holding unit that holds a mask having a mask pattern, and light for pattern exposure having a predetermined irradiation angle is irradiated to the substrate through the mask. A mask for a predetermined exposure time in a state in which the mask and the substrate are arranged close to each other with a predetermined gap. A proximity exposure apparatus that exposes and transfers the mask pattern to the substrate by irradiation means,
While moving either one of the substrate holding part and the mask holding part in the vertical direction so as to be a predetermined gap according to the amount of plane deviation detected by the deviation amount detection means,
A proximity exposure apparatus characterized by moving either one of a substrate holding part and a mask holding part in a horizontal direction in accordance with a predetermined gap in a state where exposure transfer is stopped in the middle of a predetermined exposure time.
(6) One of the substrate holding portion and the mask holding portion is tilted with respect to the horizontal direction so that a predetermined gap at the time of exposure transfer varies depending on the amount of plane deviation at each position of the substrate. The proximity exposure apparatus according to (5).
(7) A substrate moving mechanism for moving the substrate holding portion at least in the vertical direction so that a predetermined gap is formed between the substrate and the mask, and a mask holding portion for moving the mask horizontally with respect to the substrate. The proximity exposure apparatus according to (5) or (6), further comprising: a mask moving mechanism that moves at least in a horizontal direction.
(8) Irradiated from the irradiation means in each exposure transfer performed by the first exposure time before the horizontal movement and the second exposure time obtained by subtracting the first exposure time from the predetermined exposure time after the horizontal movement. The proximity exposure apparatus according to any one of (5) to (7), wherein the amounts of light to be emitted are equal to each other.

(9) A substrate holding unit that holds a substrate as an exposed material, a mask holding unit that holds a mask having a mask pattern, and light for pattern exposure having a predetermined irradiation angle is irradiated to the substrate through the mask. A mask for a predetermined exposure time in a state in which the mask and the substrate are arranged close to each other with a predetermined gap. A proximity exposure method of exposing and transferring the mask pattern to the substrate by irradiation means,
A step of moving one of the substrate holding part and the mask holding part in the vertical direction so as to obtain a predetermined gap corresponding to the amount of plane deviation detected by the deviation amount detecting means;
A first exposure step of exposing and transferring the mask pattern of the mask to the substrate by the irradiation means during the first exposure time;
After the first exposure step, a step of moving one of the substrate holding part and the mask holding part in a horizontal direction by a predetermined amount according to a predetermined gap;
A second exposure step of exposing and transferring the mask pattern of the mask to the substrate by the irradiation means during a second exposure time obtained by subtracting the first exposure time from the predetermined exposure time after the horizontal movement;
A proximity exposure method comprising:
(10) The step of inclining one of the substrate holding part and the mask holding part with respect to the horizontal direction so that the predetermined gap at the time of exposure transfer differs according to the amount of plane deviation at each position of the substrate. The proximity exposure method according to (9), further comprising:
(11) The proximity exposure method according to (9) or (10), wherein the amount of light irradiated from the irradiation unit is equal to each other in the first exposure step and the second exposure step.

  According to the proximity exposure apparatus and the proximity exposure method of the present invention, the irradiation means performs at least one of the collimation mirror and the deformation and movement of the collimation mirror, and changes the irradiation angle of the light for pattern exposure reflected by the collimation mirror. Therefore, it is possible to obtain a transfer pattern with an arbitrary magnification by simply changing the irradiation angle of the light reflected by the collimation mirror, and a high-resolution, high-density and high-precision substrate. Can be manufactured. In addition, it is more uniform than the conventional magnification correction, and the exposure accuracy can be corrected at the same time.

  According to another proximity exposure apparatus and proximity exposure method of the present invention, either the substrate holding part or the mask holding part is moved up and down so that a predetermined gap corresponding to the amount of plane deviation detected by the detecting means is obtained. Since either the substrate holding part or the mask holding part is moved in the horizontal direction in accordance with a predetermined gap while the exposure transfer is stopped in the middle of the predetermined exposure time. Without changing the irradiating means to a complicated configuration, it is possible to prevent exposure shift due to expansion and contraction of the substrate and the mask, and to manufacture a substrate with high accuracy and low cost.

FIG. 1 is a partially exploded perspective view for explaining a divided sequential proximity exposure apparatus according to the first embodiment of the present invention. FIG. 2 is a front view of the divided sequential proximity exposure apparatus shown in FIG. FIG. 3 is a block diagram showing the configuration of the control device of the proximity exposure apparatus according to the first embodiment of the present invention. FIG. 4 is a view for explaining the operation of the proximity exposure method according to the first embodiment of the present invention. FIG. 5 is a view for explaining the operation of the proximity exposure method according to the first embodiment of the present invention. FIG. 6 is a partially exploded perspective view for explaining a divided sequential proximity exposure apparatus according to the second embodiment of the present invention. FIG. 7 is a block diagram showing the configuration of the control device of the proximity exposure apparatus according to the second embodiment of the present invention. FIG. 8 is a flowchart of the proximity exposure method according to the second embodiment of the present invention. FIG. 9A to FIG. 9C are diagrams for explaining the operation of the proximity exposure method according to the second embodiment of the present invention. FIGS. 10A to 10C are views for explaining the operation of the proximity exposure method according to the second embodiment of the present invention. FIGS. 11A to 11D are views for explaining a modification of the proximity exposure method according to the second embodiment of the present invention. FIG. 12 is a perspective view of relevant parts for explaining a proximity exposure method according to the third embodiment of the present invention. FIGS. 13A to 13C are views for explaining the operation of the proximity exposure method according to the modification of the present invention. FIG. 14 is a view for explaining the operation of the proximity exposure method according to the modification of the present invention. FIG. 15 is a view for explaining a proximity exposure method according to a modification of the present invention.

Explanation of symbols

12 Mask holding frame (mask holding part)
13 Mask position adjustment mechanism (mask movement mechanism)
17 Gap sensor 18 Alignment camera (deviation amount detection means)
21 Substrate holder 40 Illumination optical system (irradiation means)
47 Collimation mirror 70 Control device 71 Irradiation angle changing mechanism e Plane deviation amount g Gap M Mask PE Step-type proximity exposure device W Glass substrate (material to be exposed)
θd declination angle (irradiation angle)

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

(First embodiment)
FIG. 1 shows a stepwise proximity exposure apparatus PE that divides a mask pattern of a mask onto a large substrate according to the first embodiment and performs proximity exposure. A mask M having a mask pattern is arranged in x, y, and θ directions. A mask stage 10 that is held so as to be movable, a substrate stage 20 that holds a glass substrate W as a material to be exposed so as to be movable in the x, y, and z directions, and a predetermined irradiation angle, that is, the mask M is irradiated. An illumination optical system 40 that is an irradiating means for irradiating the substrate W with light for pattern exposure having a declination angle θd (see FIG. 5) that is the maximum angle that the effective exposure light makes with the optical axis; The control device 70 is mainly configured.

  Note that a glass substrate W (hereinafter simply referred to as “substrate W”) is disposed to face the mask M, and a surface (on the opposite surface side of the mask M) for exposing and transferring a mask pattern drawn on the mask M. ) Is coated with a photosensitive agent.

  The mask stage 10 is mounted on the mask stage base 11 having a rectangular opening 11a formed at the center thereof, and is movable to the opening 11a of the mask stage base 11 so as to be movable in the x-axis, y-axis, and θ directions, and holds the mask M. A mask holding frame 12 that is a mask holding portion to be masked, and a mask position adjusting mechanism 13 that is provided on the upper surface of the mask stage base 11 and is a mask moving mechanism that moves the mask holding frame 12 in the x-axis, y-axis, and θ directions Prepare.

  The mask stage base 11 is supported by a plurality of columns 51 erected on the apparatus base 50 on the substrate stage side, and a z-axis coarse movement mechanism 52 (between the mask stage base 11 and the columns 51). 2), the mask stage base 11 can be moved up and down with respect to the apparatus base 50.

  The mask holding frame 12 is provided with a plurality of suction nozzles (not shown) for sucking the peripheral edge of the mask M on which the mask pattern is not drawn on the lower surface, and the mask M can be freely attached and detached by a vacuum suction mechanism (not shown). Hold.

  The mask position adjusting mechanism 13 includes an actuator such as various cylinders 13x, 13x, and 13y that drives the mask holding frame 12, and a guide mechanism (not shown) provided between the mask stage base 11 and the mask holding frame 12, and the like. The holding frame 12 is moved in the x-axis, y-axis, and θ directions.

  The mask stage 10 includes a plurality of gap sensors 17 (eight in the present embodiment) that are gap detection means for measuring a predetermined gap between the opposing surfaces of the mask M and the substrate W, and an illustration of the mask M side. A plurality of alignment cameras 18 (four in the present embodiment), which are displacement amount detection means for detecting a plane displacement amount between the mask M and the substrate W by imaging an alignment mark that is not shown and an alignment mark (not shown) on the substrate W side. And a masking aperture 19 that shields the mask M as necessary. The gap sensor 17 and the alignment camera 18 may be arranged so as to be driven along the side portion of the mask holding frame 12. In the figure, the masking aperture 19 is shown only at both ends in the x direction of the opening 11a, but is also provided at both ends in the y direction.

  The substrate stage 20 includes a substrate holding unit 21 that holds the substrate W, and a substrate moving mechanism 22 that moves the substrate holding unit 21 in the x, y, and z directions with respect to the apparatus base 50.

  The substrate holding part 21 has a plurality of suction nozzles (not shown) for sucking the substrate W on the upper surface, and detachably holds the substrate W by a vacuum suction mechanism (not shown).

  The substrate moving mechanism 22 includes a y-axis table 23, a y-axis feed mechanism 24, an x-axis table 25, an x-axis feed mechanism 26, and a z-tilt adjustment mechanism 27 below the substrate holding unit 21.

  As shown in FIG. 2, the y-axis feed mechanism 24 includes a linear guide 28 and a feed drive mechanism 29. The slider 30 attached to the back surface of the y-axis table 23 is straddled on two guide rails 31 extending on the apparatus base 50 via rolling elements (not shown). The y-axis table 23 is driven along the guide rail 31 by a motor 32 and a ball screw device 33.

  The x-axis feed mechanism 26 has the same configuration as the y-axis feed mechanism 24 and drives the x-axis table 25 in the x direction with respect to the y-axis table 23. Further, the z-tilt adjusting mechanism 27 has one movable wedge mechanism formed by combining the wedge-shaped moving bodies 34 and 35 and the feed driving mechanism 36 at one end side in the x direction and two at the other end side. Consists of. The feed drive mechanisms 29 and 36 may be a combination of a motor and a ball screw device, or may be a linear motor having a stator and a mover. Further, the number of z-tilt adjustment mechanisms 27 installed is arbitrary.

  Thereby, the substrate moving mechanism 22 feeds and drives the substrate holding unit 21 in the x direction and the y direction, and moves the substrate holding unit 21 in the z-axis direction so as to finely adjust the gap between the mask M and the substrate W. Fine adjustment and tilt adjustment.

  Bar mirrors 61 and 62 are respectively attached to the x-direction side and the y-direction side of the substrate holding unit 21, and a total of three laser interferometers are installed at the y-direction end and the x-direction end of the apparatus base 50. 63, 64, 65 are provided. As a result, the laser beams are irradiated from the laser interferometers 63, 64, 65 to the bar mirrors 61, 62, the laser beams reflected by the bar mirrors 61, 62 are received, and the laser beams and the laser beams reflected by the bar mirrors 61, 62 are received. Interference with light is measured and the position of the substrate stage is detected.

  The illumination optical system 40 is, for example, a high-pressure mercury lamp 41 that is a light source for ultraviolet irradiation, a concave mirror 42 that collects the light emitted from the high-pressure mercury lamp 41, and a switchable arrangement near the focal point of the concave mirror 42. The two types of optical integrator 43, plane mirrors 45 and 46 and a collimation mirror 47 for changing the direction of the optical path, and exposure control arranged between the plane mirror 45 and the optical integrator 43 to control opening and closing of the irradiation optical path. And a shutter 44 for use.

  When the exposure control shutter 44 is controlled to be opened at the time of exposure, the light irradiated from the high-pressure mercury lamp 41 passes through the optical path L shown in FIG. The surface of the substrate W held on the substrate is irradiated as light for pattern exposure, and the mask pattern of the mask M is exposed and transferred onto the substrate W.

  The collimation mirror 47 is a mirror that reflects light irradiated from the high-pressure mercury lamp 41 and converts it into substantially parallel light (more specifically, light having a declination angle θd that is a predetermined irradiation angle). An irradiation angle changing mechanism 71 for changing the declination angle θd by deforming the collimation mirror 47 is attached to the back surface 47b of the reflecting surface 47a formed in a shape.

  As shown in FIG. 4, the irradiation angle changing mechanism 71 pulls or presses the plurality of support members 73 that support the back surface 47 b of the collimation mirror 47 using, for example, a ball screw mechanism or fluid pressure, and collimation mirror 47. Is changed to change the declination angle θd.

  As shown in FIG. 3, the control device 70 includes an input interface circuit 70a having an A / D conversion function for reading detection signals from the alignment camera 18, the gap sensor 17, and the laser interferometers 63, 64, 65 as detection values. And the arithmetic processing unit 70b, the storage device 70c such as ROM and RAM, and the control signals obtained by the arithmetic processing unit 70b are sent to the mask position adjusting mechanism 13, the substrate moving mechanism 22, the z-axis coarse adjustment mechanism 52, and the exposure control. And an output interface circuit 70d for outputting to each drive circuit of the irradiation angle changing mechanism 71.

  The control device 70 controls shutter opening of the illumination optical system 40, feed control of the substrate moving mechanism 22, calculation of step feed error amount, calculation of correction amount at the time of alignment adjustment, and driving of the z-tilt adjustment mechanism 27 at the time of gap adjustment. Control, drive control of the irradiation angle changing mechanism 71, drive of most actuators incorporated in the apparatus, and predetermined arithmetic processing are executed based on sequence control using a microcomputer, a sequencer or the like.

  In the stepped proximity exposure apparatus PE having the above-described configuration, the control device 70 operates the alignment camera 18, the gap sensor 17, and the laser interference with the mask M held on the mask holding frame 12 and the substrate W held on the substrate holding unit 21. Based on the detection signals of the total 63, 64, 65, the mask position adjusting mechanism 13 is driven and controlled so that the initial position of the mask M with respect to the substrate holding unit 21 is adjusted, and the z-axis coarse moving mechanism 52 and the z-tilt adjusting mechanism 27 are driven. The gap between the opposing surfaces of the mask M and the substrate W is adjusted to a predetermined gap, and are arranged close to each other.

  Further, the control device 70 detects the amount of plane deviation e due to the expansion and contraction of the mask M and the substrate W detected when the alignment camera 18 confirms the mark provided on the mask M and the mark provided on the substrate W, and the gap. Based on a predetermined gap g between the opposing surfaces of the mask M and the substrate W detected by the sensor 17, the deformation amount of the collimation mirror 47 necessary for correcting the plane deviation is calculated, and the irradiation angle changing mechanism 71 is operated. The collimation mirror 47 is deformed by operating.

  Since the light for pattern exposure reflected by the collimation mirror 47 has a predetermined declination angle θd, it is possible to adjust a predetermined gap g between the mask M and the substrate W. The magnification correction of the mask pattern is possible. Therefore, a predetermined gap g between the mask M and the substrate W and a declination angle θd of the pattern exposure light reflected by the collimation mirror 47 are arbitrarily set based on the amount of plane deviation detected by the alignment camera 18. The plane deviation may be corrected by adjusting to.

  When the exposure control shutter 44 is opened for a predetermined time, the light for pattern exposure from the lamp 31 is reflected by the collimation mirror 47 with a predetermined declination angle θd and passes through the mask M. The substrate W is irradiated. Thereby, the mask pattern of the mask M is exposed and transferred onto the substrate W.

  Therefore, the collimation mirror 47 is deformed, and as shown in FIGS. 4 and 5, the declination angle of the reflected light for pattern exposure is changed from θd ′ to θd. The mask pattern whose magnification has been corrected from the width P ′ to the line width P is transferred, and the plane deviation due to expansion and contraction of the mask M and the substrate W is corrected.

  As described above, according to the proximity exposure apparatus and the proximity exposure method of the present embodiment, the illumination optical system 40 deforms the collimation mirror 47 and the collimation mirror 47, thereby pattern exposure reflected by the collimation mirror 47. And an irradiation angle changing mechanism 71 that changes the declination angle of light for use, so that a transfer pattern can be obtained at an arbitrary magnification simply by changing the declination angle of the light reflected by the collimation mirror 47. The substrate W with high resolution, high density and high accuracy can be manufactured.

  In addition, since the magnification correction by adjusting the collimation mirror 47 is performed only by the declination angle of light, the illumination surface has less unevenness in illumination and variation than the conventional magnification correction that moves the integrator, and a more uniform magnification. Correction can be made and exposure accuracy can also be corrected at the same time.

  Furthermore, since the magnification correction can be performed by adjusting the gap between the mask and the substrate and adjusting the declination angle of the light for pattern exposure reflected by the collimation mirror 47, the control of the gap is conventionally performed. Compared to this, it can be relaxed, and it can be expected to shorten the tact time and improve the product yield. Further, by applying the magnification correction as in the present embodiment, it is possible to prevent exposure shift due to expansion and contraction of the substrate and the mask, and it is possible to perform exposure transfer while relaxing the temperature management conditions to some extent.

  The irradiation angle changing mechanism 71 of the present invention can not only correct the magnification but also correct the shape by appropriately setting the deformation amount at each position of the reflecting surface 47a of the collimation mirror 47.

  In this embodiment, in order to correct a plane shift due to expansion and contraction of the mask M and the substrate W, the declination angle of the light reflected by the collimation mirror 47 is changed using the irradiation angle changing mechanism 71. The mask pattern of the mask may be used as appropriate when the magnification and shape of the mask pattern are corrected, and an exposure pattern having an arbitrary line width and shape independent of the mask exposure pattern pitch can be transferred.

  Furthermore, in this embodiment, the declination angle θd is changed by deforming the collimation mirror 47. However, the declination angle θd is moved by moving the collimation mirror 47 (horizontal movement or rotational movement). May be changed or a combination of deformation and movement may be performed.

  In addition, the illumination optical system only needs to have at least a collimation mirror and an irradiation angle changing mechanism, and is not limited to that of the present embodiment.

(Second Embodiment)
Next, a proximity exposure apparatus and a proximity exposure method according to a second embodiment of the present invention will be described in detail with reference to the drawings. In addition, about the part equivalent to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

  The stepwise proximity exposure apparatus PE of the present embodiment differs from that of the first embodiment in the illumination optical system 40 and the control device 70. That is, as shown in FIG. 6, the illumination optical system 40 of the present embodiment is different from that of the first embodiment in that it does not have an irradiation angle changing mechanism 71. Further, as shown in FIG. Is different from that of the first embodiment in that a timer 72 is provided.

  Next, the operation of the second embodiment for exposing and transferring the mask pattern drawn on the mask M onto the substrate W using the stepwise proximity exposure apparatus PE having the above-described configuration will be described with reference to the flowchart of FIG.

  Here, the stepwise proximity exposure apparatus PE performs proximity exposure in a plurality of steps, and the exposure operation shown in FIG. 8 is performed for each step. Before performing the exposure operation in FIG. 8, it is assumed that light is emitted from the light source of the irradiation optical system 40 and the exposure control shutter 44 is closed. Further, it is assumed that the predetermined exposure time is 10 seconds and the timer 72 is cleared to zero.

  First, before performing the exposure operation, the control device 70 drives and controls the mask position adjusting mechanism 13 based on the detection signals of the alignment camera 18 and the laser interferometers 63, 64, 65, and the initial position of the mask M with respect to the substrate holder 21. Adjust.

  Here, when the alignment camera 18 confirms the mark provided on the mask M and the mark provided on the substrate W, the amount of plane displacement of the substrate W due to the expansion and contraction of the substrate W is detected (step S2).

  Next, the control device 70 calculates a predetermined gap g between the opposing surfaces of the mask M and the substrate W based on the amount of plane deviation detected in step S2 (step S4), and uses the detection signal of the gap sensor 17 as a detection signal. Based on this, the z-tilt adjusting mechanism 27 is driven to finely adjust the gap between the mask M and the substrate W (step S6). In the present embodiment, the predetermined gap g is 100 to 300 μm.

  Then, opening control of the exposure control shutter 44 is performed (step S8), and the timer 72 is counted (step S10). As a result, the mask M and the substrate W are arranged close to each other with a predetermined gap g until the first exposure time (in this embodiment, 5 seconds which is half the exposure time) is reached. The mask pattern is exposed and transferred onto the substrate W by the irradiation optical system 40 (first exposure step). Here, the amount of light α per shot irradiated by the irradiation optical system 40 in the first exposure step is set to be lower than the threshold γ of the amount of light with which the photosensitive agent applied to the substrate W is completely exposed (FIG. 9 and 10). In particular, in the present embodiment, since the light amount β per shot irradiated by the irradiation optical system 40 in the second exposure step described later is equal to the light amount α of the first exposure step, the threshold γ is 1. It is preferably set to 5α.

  Thereafter, it is determined whether or not the timer 72 has reached 5 seconds (step S12). If the timer 72 has reached 5 seconds, the process proceeds to step S14. If the timer has not reached 5 seconds, the process proceeds to step S14. The process proceeds to step S10. In step S14, the closing control of the exposure control shutter 44 is performed.

  Then, with the exposure transfer stopped, based on the predetermined gap g calculated in step S4, the mask position adjusting mechanism 13 is driven to move the mask M in the horizontal direction by a predetermined amount δ (narrower than the pattern interval of the mask M). A slight movement is performed (step S16). The minute movement at this time is preferably moved by the same amount in the x direction and the y direction simultaneously according to the calculated gap g, but is not limited to this. Depending on the pattern to be formed by exposure, one direction may be sufficient, or it may be preferable.

  Next, opening control of the exposure control shutter 44 is performed (step S18), and the timer 72 is counted (step S20). As a result, the second exposure time (in this embodiment, the predetermined exposure time from 10 seconds to the first exposure time 5 in a state where the mask M and the substrate W are arranged close to each other with a predetermined gap g. The exposure pattern of the mask M is exposed and transferred onto the substrate W with a light amount β (= α) per shot by the irradiation optical system 40 (second exposure step) until 5 seconds (seconds are subtracted).

  Thereafter, it is determined whether or not the timer 72 has reached the exposure time of 10 seconds (step S22). If the timer has reached 10 seconds, the process proceeds to step S24, and the timer has not reached 10 seconds. In step S20, the process proceeds to step S20. In step S24, the exposure control shutter 44 is closed. Thereafter, the process proceeds to step S26, the timer 72 is cleared to zero, and the one-step exposure operation (multiple exposure) is completed.

Next, the effect of this embodiment is demonstrated, referring FIG.
The substrate W expands and contracts due to the processing liquid and heat acting on the substrate W held by the substrate holding unit 21 or by a chuck. If exposure transfer is performed while the substrate W is stretched, the exposure pattern of the mask M is transferred to a position offset from a predetermined position to be transferred.

  For this reason, in this embodiment, the light for pattern exposure from the irradiation optical system 40 is irradiated to the substrate W through the exposure pattern of the mask M with a predetermined irradiation angle (declination angle θ). By using the points and setting a predetermined gap g corresponding to the amount of plane deviation, exposure transfer is performed in accordance with a predetermined position to be transferred.

  For example, as shown in FIG. 9A, when the substrate W does not expand and contract, exposure transfer is performed at a predetermined gap g, and the substrate W extends as shown in FIG. In this case, exposure transfer is performed with a gap larger than the gap g, such as a predetermined gap g ′ according to the amount of plane deviation. The line width P2 of the transfer pattern transferred to the substrate W through the gap g ′ becomes larger than the line width P1 in the mask pattern due to the declination angle θ.

  On the other hand, when exposure transfer is performed while changing the gap g, the line width transferred to the substrate W changes. For this reason, in this embodiment, multiple exposure is performed to correct this change in line width.

  That is, as shown in FIG. 9B, in the predetermined gap g when the substrate W is not expanded or contracted, the predetermined amount δ in the horizontal movement process is set to 0, and the transfer pattern exposed and transferred in the first exposure process is set. The transfer pattern in the second exposure step is transferred on top of it. As a result, as shown in FIG. 9C, a pattern region having a line width P1 corresponding to the pattern interval P1 of the mask M is obtained on the substrate W after development.

  On the other hand, as shown in FIG. 10B, when the substrate W is extended, multiple exposure is performed after the mask M is horizontally moved by a predetermined amount δ corresponding to a predetermined gap g ′ larger than the gap g. Then, the mask pattern in the second exposure step is superimposed and transferred while being displaced by a predetermined amount δ with respect to the exposure pattern exposed and transferred in the first exposure step. As a result, as shown in FIG. 10C, on the substrate W after development, a pattern region having a line width P1 corresponding to the pattern interval P1 of the mask M is located at a predetermined position in a portion where the light amount exceeds the threshold value γ. Is obtained.

  In FIG. 8, the case where the substrate W is extended has been described. However, when the substrate W expands and contracts, a gap smaller than the gap g when the substrate W does not expand and contract is set, and a predetermined amount corresponding to the gap is set. The horizontal movement may be performed during exposure transfer.

  Also, with respect to the expansion and contraction of the mask M, a gap g is set, and a predetermined amount of horizontal movement corresponding to the gap is performed during exposure transfer, thereby preventing exposure deviation due to the expansion and contraction of the mask M. can do.

  Further, the light amount of the light source 31 of the irradiation optical system 40 can be controlled, and the light amounts α and β may be different between the first exposure step and the second exposure step, or as in the present embodiment. May be equal to

  Note that the line width of the transfer pattern can be adjusted by setting multiple exposures with the exposure amount per time set as the resist sensitivity without adjusting the exposure amount. That is, in the first exposure step, as shown in FIG. 11A, the amount of light that the photosensitive agent sensitizes using a mask M in which the line width of the light transmitting portion is P1 and the line width of the light shielding portion is P3. Exposure transfer is performed with a light amount α (α = γ) per shot equal to the threshold value γ. As a result, a transfer pattern having a line width P1 is obtained. In order to simplify the illustration, the light amount of the portion exposed by the declination angle θ is set to zero.

  Next, in the second exposure step, as shown in FIG. 11B, the mask W is horizontally moved by a predetermined amount δ, and similarly, the light quantity α per shot equal to the threshold value γ of the quantity of light that the photosensitive agent sensitizes. Exposure transfer is performed at (α = γ). As a result, the distribution of the amount of light applied to the photosensitive agent has a profile in which the transfer pattern of the second exposure process is overlapped with a predetermined amount δ with respect to the transfer pattern of the first exposure process.

  As a result, in the case of a negative photosensitive agent, as shown in FIG. 11C, a transferred pattern having a line width P1 + δ obtained by adding a predetermined amount δ to the line width P1 of the pattern is obtained on the developed substrate W. . On the other hand, in the case of a positive photosensitive agent, a transfer pattern having a line width P3-δ is obtained as shown in FIG.

  As described above, according to the proximity exposure apparatus and the proximity exposure method of the present embodiment, the z-tilt movement mechanism 27 is moved up and down so as to obtain the predetermined gap g corresponding to the amount of plane deviation detected by the alignment camera 18. Since the mask moving mechanism 13 is moved in the horizontal direction by a predetermined amount in accordance with the predetermined gap g while the exposure transfer is stopped in the middle of the predetermined exposure time, the irradiation optical system 40 is moved. Without changing to a complicated configuration, it is possible to prevent exposure deviation due to expansion and contraction of the substrate W and the mask M, and to manufacture a substrate with high accuracy and low cost. Further, since the exposure shift due to the expansion and contraction of the substrate W and the mask M can be prevented, exposure transfer can be performed while relaxing the temperature management conditions to some extent.

  Further, according to the proximity exposure apparatus and the proximity exposure method of the present embodiment, the amount of light per shot by the irradiation optical system 40 can be reduced by multiple exposure, so that the lamp life can be significantly improved.

(Third embodiment)
Next, a proximity exposure apparatus and a proximity exposure method according to the third embodiment of the present invention will be described in detail with reference to FIG. Note that parts equivalent to those in the second embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  This embodiment is different from the second embodiment in the gap calculation process controlled by the control device 70. In the third embodiment, the z-tilt adjustment mechanism 27 is adjusted in step S6 of FIG. 8 so that the mask M and the substrate W face each other with a predetermined parallelism and a predetermined gap. In the present embodiment, when the amount of plane deviation at each position of the substrate W due to expansion / contraction of the substrate W is different, a predetermined gap between the mask M and the substrate W at the time of exposure transfer is a plane deviation at each position of the substrate W. The z-tilt adjustment mechanism 27 is adjusted so as to vary depending on the amount, and the substrate holding unit 21 is inclined in the horizontal direction, that is, with respect to the lower surface of the mask M.

Thereby, for example, even when the substrate W extends in a trapezoidal shape as shown in FIG. 12, the gap g1 in the lower base region of the trapezoid is larger than the gap g2 in the upper base region. Multiple exposure is performed as in the first embodiment.
Other exposure processes are the same as those in the first embodiment.

  Therefore, according to the proximity exposure apparatus and the proximity exposure method of the present embodiment, the predetermined gap between the mask M and the substrate W at the time of exposure transfer varies according to the amount of plane deviation at each position of the substrate W. Since the z-tilt adjustment mechanism 27 is adjusted so that the substrate holding portion 21 is tilted with respect to the horizontal direction, even if the expansion and contraction of the substrate W and the mask M is nonuniform, exposure deviation is prevented. Therefore, a highly accurate and low cost substrate can be manufactured.

  In the second and third embodiments, during exposure transfer, the mask M is moved in the horizontal direction by finely moving the mask M in the horizontal direction by driving the mask position adjusting mechanism. Even if the moving mechanism 22 is driven to slightly move the substrate W in the horizontal direction, the same effect can be obtained.

  That is, as shown in FIG. 13A, after the first exposure is performed with an illuminance α1 less than the resist sensitivity, the substrate is moved by a predetermined amount δ by position control of the substrate moving mechanism 22. Next, as shown in FIG. 13B, the second exposure is performed with the illuminance β1 at which the resist is completely exposed by the light amount control of the light source. Thereafter, as shown in FIG. 13C, by developing the exposed substrate W, a pattern having a finer line width (P1-δ) than the line width P1 of the mask pattern of the mask M can be obtained. Note that the same effect can be obtained even if exposure is performed while oscillating at a high speed with an amplitude δ until the resist is completely exposed. Further, when the exposed substrate W is shown two-dimensionally, it is as shown in FIG.

  In the above embodiment, the gap control and the line width control are performed in combination. However, only the gap control may be performed. That is, as shown in FIG. 15, by controlling the gap g to an arbitrary amount, the magnification of the mask pattern having the width L can be controlled to the width L ′. This width L ′ is calculated from the declination angle θ of the light source and the gap g.

  In addition, this invention is not limited to this embodiment, In the range which does not deviate from the summary of this invention, it can change suitably. For example, the first embodiment and the second and third embodiments can be combined within a feasible range.

  In each embodiment, the step-type proximity exposure apparatus capable of performing two-dimensional step feed has been described. However, the present invention is also applicable to a step-type proximity exposure apparatus that performs one-dimensional step feed and a proximity exposure apparatus that does not perform step feed. Is possible.

  Further, in the present embodiment, the case where the present invention is applied to an exposure apparatus for a flat panel display is illustrated, but instead, the present invention may be applied to a semiconductor exposure apparatus.

  This application is based on a Japanese patent application filed on June 14, 2006 (Japanese Patent Application No. 2006-164655) and a Japanese patent application filed on June 29, 2006 (Japanese Patent Application No. 2006-179896). Incorporated herein by reference.

Claims (4)

A substrate holding unit for holding a substrate as a material to be exposed; a mask holding unit for holding a mask having a mask pattern; and an irradiation unit for irradiating the substrate with light for pattern exposure through the mask. A proximity exposure apparatus that exposes and transfers the mask pattern of the mask to the substrate by the irradiating means in a state where the mask and the substrate are arranged close to each other with a predetermined gap;
The irradiation means includes a collimation mirror, and an irradiation angle changing mechanism that changes at least one of deformation and movement of the collimation mirror and changes the irradiation angle of the pattern exposure light reflected by the collimation mirror. A proximity exposure apparatus characterized by the above. A deviation amount detecting means for detecting a plane deviation amount between the mask and the substrate;
The predetermined gap between the mask and the previous substrate and the irradiation angle of the pattern exposure light reflected by the collimation mirror are set according to the amount of plane deviation detected by the deviation amount detection means. The proximity exposure apparatus according to claim 1, wherein: A proximity exposure method comprising the proximity exposure apparatus according to claim 1 or 2,
Performing at least one of deformation and movement of the collimation mirror by the irradiation angle changing mechanism, and changing the irradiation angle of the light for pattern exposure reflected by the collimation mirror;
Exposing and transferring the mask pattern of the mask to the substrate with the light for pattern exposure irradiated by the irradiation means;
A proximity exposure method comprising: Detecting a plane deviation amount between the mask and the substrate by the deviation amount detection means;
Adjusting a predetermined gap between the mask and the substrate;
Further comprising
The predetermined gap between the mask and the previous substrate and the irradiation angle of the pattern exposure light reflected by the collimation mirror are set according to the amount of plane deviation detected by the deviation amount detection means. The proximity exposure method according to claim 3.

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