JP2021193429A - Light source device for exposure, illumination device, exposure apparatus, and exposure method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device for exposure capable of highly accurate alignment adjustment even when an LED is used as a light source, a lighting device using the light source device, an exposure device, and an exposure method.
SOLUTION: A light source device 70 for exposure transmits a first LED array 71 that emits exposure light, a second LED array 75 that emits alignment light, and other light in a specific wavelength band. The dichroic film 81 that reflects light in the wavelength band is arranged at an angle with respect to the common optical axis direction L of the first and second LED arrays 71 and 75, via a dichroic mirror and a dichroic mirror. A fly-eye lens 65 to which light is incident is provided. The first LED array 71 is arranged on the opposite side of the fly-eye lens 65 with respect to the dichroic mirror in the common optical axis direction L, and the second LED array 75 intersects the common optical axis direction L. Then, it is placed on the side of the dichroic mirror.
[Selection diagram] FIG. 4

Description

The present invention relates to an exposure light source device, a lighting device, an exposure device, and an exposure method. More specifically, the present invention relates to an exposure light source device, a lighting device, an exposure device, and an exposure device using light emitted from an LED element as a light source. Regarding the exposure method.

In the proximity exposure device, a mask on which an exposure pattern is formed is placed close to an exposed substrate coated with a photosensitive material with a gap of several tens of μm to several hundreds of μm, and the exposure light from the lighting device is irradiated through the mask. The exposure pattern is transferred to the exposed substrate. In addition, some proximity exposure devices are equipped with a curvature correction mechanism that corrects the curvature of the reflector in the lighting device, and the reflector is locally curved to change the declination angle of the reflector. A device that corrects the shape of an exposure pattern and obtains a highly accurate exposure result has been devised (see, for example, Patent Document 1).

In a proximity exposure device using a lighting device having such a curvature correction mechanism, the exposure light is not a ray perpendicular to the substrate but a ray inclined at an angle because the curvature is corrected by a reflecting mirror. .. Therefore, even if the positions of the alignment mark on the mask side and the alignment mark on the work side are aligned in vertical view, the exposed image (shadow) is displaced.

For example, in the proximity exposure apparatus described in Patent Document 1, since the emission wavelength width of the mercury lamp used as a light source is wide, unexposed light (alignment light) having a wavelength that does not expose the photosensitive material of the substrate by using a cut filter is used. ) To align. As a result, alignment can be performed with high accuracy using the alignment light coaxial with the optical axis of the light from the light source that is the exposure light, and the exposure light and the alignment light do not shift from each other. The exposure accuracy is greatly improved without shifting the exposed image.

International Publication No. 2019/155886

By the way, in recent years, the use of LEDs as a light source has been advancing, but LEDs have a narrower wavelength band than mercury lamps. Therefore, when an LED having a wavelength for exposing the photosensitive material is applied, the light beam having a wavelength that does not expose the photosensitive material is not irradiated, and there is a problem that the LED cannot be applied to the light source device using the cut filter described in Patent Document 1. be.

The present invention has been made in view of the above-mentioned problems, and an object thereof is that alignment adjustment can be performed with high accuracy even when an LED is used as a light source, and therefore the exposure accuracy is greatly improved. It is an object of the present invention to provide a light source device for exposure that can be used, a lighting device using the light source device, an exposure device, and an exposure method.

The above object of the present invention is achieved by the following configuration.
(1) A first LED array having a plurality of first LED elements that emit exposure light having a first peak wavelength, and a first LED array.
A second LED array having a plurality of second LED elements that emit alignment light having a second peak wavelength different from that of the first peak wavelength.
A dichroic film that transmits light in a specific wavelength band and reflects light in other wavelength bands is provided, and the dichroic film is inclined with respect to a common optical axis direction of the first and second LED elements. Dichroic optical elements to be placed and
A fly-eye lens in which the light of the first LED element or the second LED element is incident through the dichroic optical element.
A light source device for exposure, which comprises
One of the first LED array and the second LED array is arranged on the opposite side of the fly-eye lens with respect to the dichroic optical element in the common optical axis direction.
Either or the other of the first LED array and the second LED array intersects the common optical axis direction and is arranged on the side of the dichroic optical element.
Light source device for exposure.
(2) The dichroic optical element includes two dichroic films that are inclined with respect to the common optical axis direction and are arranged in a substantially V shape so as to be in close contact with each other on the fly-eye lens side. The light source device for exposure according to 1).
(3) The other LED array includes two LED arrays that intersect the common optical axis direction and are arranged on both sides of the dichroic optical element.
The exposure according to (2), wherein the length of each of the other LED arrays is shorter than the length of the one of the LED arrays arranged on the opposite side of the fly-eye lens with respect to the dichroic optical element. Light source device for.
(4) The light source device for exposure according to (2) or (3), wherein the dichroic optical element is two dichroic mirrors or dichroic prisms.
(5) The dichroic optical element is two dichroic mirrors each having the dichroic film.
The light source device for exposure according to (2) or (3), wherein the end portion of each dichroic mirror is cut in parallel with the optical axis direction.
(6) The second LED array further includes a plurality of third LED elements that emit exposure light having a third peak wavelength, which is 20 nm or more away from the first peak wavelength of the first LED element. The light source device for exposure according to any one of (1) to (5).
(7) The light source device for exposure according to any one of (1) to (6),
A lighting device including a mirror bending mechanism capable of changing the curvature of a reflecting surface, and a reflecting mirror that reflects light emitted from the fly-eye lens.
(8) The lighting device according to (7) and
The work support part that supports the work and the work support
The mask support part that supports the mask and
An alignment camera capable of simultaneously capturing a projected image of the alignment mark on the mask side projected on the work and the alignment mark on the work side using the alignment light.
The exposure device comprises the above, irradiating the work with the exposure light emitted from the lighting device through the mask, and transferring the pattern of the mask to the work.
(9) An exposure method using the exposure apparatus according to (8).
A step of irradiating the alignment light from the lighting device and simultaneously imaging the projected image of the alignment mark on the mask side projected on the work and the alignment mark on the work side by the alignment camera.
The curvature of the reflector is corrected by the mirror bending mechanism so that the projected image of the alignment mark on the mask side and each center of the alignment mark on the work side coincide with each other, and the work support portion and the mask support are supported. The process of moving parts relatively and
A step of irradiating the work with the exposure light emitted from the lighting device through the mask and transferring the pattern of the mask to the work.
An exposure method comprising.

According to the light source device for exposure of the present invention, the lighting device using the light source device, the exposure device, and the exposure method, alignment adjustment can be performed with high accuracy even when an LED is used as a light source. Therefore, the exposure accuracy can be significantly improved.

It is a front view of the exposure apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the lighting apparatus shown in FIG. (A) is a plan view of the alignment mark on the mask side, and (b) is a plan view of the alignment mark on the work side. It is a schematic block diagram of the light source apparatus of 1st Embodiment. It is a figure for demonstrating the concrete structure of the mirror bending mechanism. It is a flowchart which shows the procedure of alignment adjustment and exposure. (A) is a side view of a main part of a lighting device showing a state before alignment adjustment by a mirror bending mechanism, and (b) is a projection image of an alignment mark on the mask side and alignment on the work side before alignment adjustment. It is explanatory drawing which shows the positional relationship with a mark. (A) is a side view of a main part of the lighting device showing a state where the alignment is adjusted by the mirror bending mechanism, and (b) is a position between the projected image of the alignment mark on the mask side and the alignment mark on the work side. It is explanatory drawing which shows the relationship. It is a schematic block diagram of the light source apparatus of the modification of 1st Embodiment. It is a schematic block diagram of the light source apparatus of 2nd Embodiment. (A) is a side view showing a mounting state of a dichroic mirror as the light source device of the third embodiment, and (b) is an arrow view seen from the direction A of (a). (A) is a side view showing another mounting state of the dichroic mirror as a light source device of a modified example of the third embodiment, and (b) is an arrow view seen from the direction B of (a). .. It is a schematic block diagram of the light source apparatus which concerns on the modification of this invention using a dichroic prism. It is a schematic block diagram of the light source apparatus which concerns on other modification of this invention.

(First Embodiment)
Hereinafter, the first embodiment of the exposure apparatus according to the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the proximity exposure apparatus PE uses a mask M smaller than the work W as an exposed material, holds the mask M on the mask stage (mask support portion) 1, and holds the work W on the work stage (work). The mask is held by the support portion (2) 2, and the mask M and the work W are placed close to each other and opposed to each other with a predetermined exposure gap, and the mask M is irradiated with light for pattern exposure from the lighting device 3. The pattern of M is exposed and transferred onto the work W. Further, the work stage 2 is stepped with respect to the mask M in the biaxial directions of the X-axis direction and the Y-axis direction, and the exposure transfer is performed step by step.

In order to step-move the work stage 2 in the X-axis direction, an X-axis stage feed mechanism 5 for step-moving the X-axis feed table 5a in the X-axis direction is installed on the device base 4. On the X-axis feed base 5a of the X-axis stage feed mechanism 5, a Y-axis stage feed mechanism 6 for step-moving the Y-axis feed base 6a in the Y-axis direction is installed in order to step-move the work stage 2 in the Y-axis direction. Has been done. A work stage 2 is installed on the Y-axis feed table 6a of the Y-axis stage feed mechanism 6. The work W is held on the upper surface of the work stage 2 in a state of being vacuum-sucked by a work chuck or the like. Further, a substrate side displacement sensor 15 for measuring the height of the lower surface of the mask M is arranged on the side portion of the work stage 2. Therefore, the displacement sensor 15 on the substrate side can move in the X and Y axis directions together with the work stage 2.

A plurality of (four in the embodiment shown in the figure) guide rails 51 of the X-axis linear guides are arranged on the device base 4 in the X-axis direction, and each guide rail 51 has a lower surface of the X-axis feeder 5a. A slider 52 fixed to is straddled. As a result, the X-axis feed base 5a is driven by the first linear motor 20 of the X-axis stage feed mechanism 5 and can reciprocate in the X-axis direction along the guide rail 51. Further, a plurality of guide rails 53 of Y-axis linear guides are arranged on the X-axis feed table 5a in the Y-axis direction, and each guide rail 53 has a slider 54 fixed to the lower surface of the Y-axis feed table 6a. Is straddled. As a result, the Y-axis feed base 6a is driven by the second linear motor 21 of the Y-axis stage feed mechanism 6 and can reciprocate in the Y-axis direction along the guide rail 53.

Since the work stage 2 is moved in the vertical direction between the Y-axis stage feed mechanism 6 and the work stage 2, the vertical coarse movement device 7 has a relatively coarse positioning resolution but a large movement stroke and movement speed, and the vertical coarse movement. A vertical fine movement device 8 is installed, which is capable of positioning with higher resolution than the device 7 and finely moves the work stage up and down to finely adjust the gap between the facing surfaces of the mask M and the work W to a predetermined amount.

The vertical coarse movement device 7 moves the work stage 2 up and down with respect to the fine movement stage 6b by an appropriate drive mechanism provided in the fine movement stage 6b described later. The stage coarse movement shafts 14 fixed to the four positions on the bottom surface of the work stage 2 engage with the linear motion bearings 14a fixed to the fine movement stage 6b and are guided in the vertical direction with respect to the fine movement stage 6b. It is desirable that the vertical coarsening device 7 has high repetitive positioning accuracy even if the resolution is low.

The vertical fine movement device 8 includes a fixed base 9 fixed to the Y-axis feed base 6a, and a guide rail 10 of a linear guide attached to the fixed base 9 with its inner end side inclined diagonally downward. A ball screw nut (not shown) is connected to the slide body 12 that reciprocates along the guide rail 10 via the slider 11 straddled by the guide rail 10, and the upper end surface of the slide body 12 is connected. Is slidably in contact with the flange 12a fixed to the fine movement stage 6b in the horizontal direction.

Then, when the screw shaft of the ball screw is rotationally driven by the motor 17 attached to the fixing base 9, the nut, the slider 11 and the slide body 12 are integrally moved in an oblique direction along the guide rail 10. , The flange 12a slightly moves up and down. The vertical fine movement device 8 may drive the slide body 12 by a linear motor instead of driving the slide body 12 by the motor 17 and the ball screw.

The vertical fine movement device 8 is installed on one end side (left end side in FIG. 1) of the Z-axis feed base 6a in the Y-axis direction and two on the other end side, for a total of three units, each of which is independently driven and controlled. It has become so. As a result, the vertical fine movement device 8 independently finely adjusts the heights of the flanges 12a at the three locations based on the measurement results of the gap amount between the mask M and the work W at the plurality of locations by the gap sensor 27, and the work stage 2 Fine-tune the height and tilt of the.
If the height of the work stage 2 can be sufficiently adjusted by the vertical fine movement device 8, the vertical coarse movement device 7 may be omitted.

Further, on the Y-axis feeder 6a, a bar mirror 19 facing the Y-axis laser interferometer 18 that detects the position of the work stage 2 in the Y direction and an X-axis laser that detects the position of the work stage 2 in the X-axis direction. A bar mirror (both not shown) facing the interferometer is installed. The bar mirror 19 facing the Y-axis laser interferometer 18 is arranged along the X-axis direction on one side of the Y-axis feeder 6a, and the bar mirror facing the X-axis laser interferometer is the Y-axis feeder 6a. It is arranged along the Y-axis direction on one end side.

The Y-axis laser interferometer 18 and the X-axis laser interferometer are respectively arranged so as to face the corresponding bar mirrors and are supported by the device base 4. Two Y-axis laser interferometers 18 are installed so as to be separated from each other in the X-axis direction. The two Y-axis laser interferometers 18 detect the position of the Y-axis feeder 6a and, by extension, the work stage 2 in the Y-axis direction and the yawing error via the bar mirror 19. Further, the X-axis laser interferometer detects the position of the X-axis feeder 5a and, by extension, the work stage 2 in the X-axis direction via the opposite bar mirror.

The mask stage 1 is inserted into a mask base frame 24 made of a substantially rectangular frame body and an opening at the center of the mask base frame 24 through a gap in the X, Y, θ directions (in the X, Y plane). A movably supported mask frame 25 is provided, and the mask base frame 24 is held in a fixed position above the work stage 2 by a support column 4a projecting from the device base 4.

A frame-shaped mask holder 26 is provided on the lower surface of the central opening of the mask frame 25. That is, a plurality of mask holder suction grooves connected to a vacuum suction device (not shown) are provided on the lower surface of the mask frame 25, and the mask holder 26 is suctioned to the mask frame 25 via the plurality of mask holder suction grooves. Be retained.

On the lower surface of the mask holder 26, a plurality of mask suction grooves (not shown) for sucking the peripheral portion on which the mask pattern of the mask M is not drawn are provided, and the mask M passes through the mask suction groove. It is detachably held on the lower surface of the mask holder 26 by a vacuum suction device (not shown).

Further, the mask frame 25 is provided with an alignment camera 30 that captures the mask-side alignment mark Ma of the mask M and the work-side alignment mark Wa of the work W. As shown in FIG. 2, the alignment camera 30 includes a half mirror 31, a CCD camera 32, and the like. The half mirror 31 is arranged on the optical path EL between the plane mirror 68 and the mask M, which will be described later, and the CCD camera 32 is arranged above the mask M and on the side of the optical path EL, which is separated from the optical path EL of the light. ing.

As shown in FIGS. 3A and 3B, the mask-side alignment mark Ma and the work-side alignment mark Wa are formed at predetermined positions of the mask M and the work W, which are imaged by each alignment camera 30. There is. The mask-side alignment mark Ma has a shape in which four small circles 33b are provided at the apex of the square in the circle 33a, and the work-side alignment mark Wa has a cross shape. The mask-side alignment mark Ma and the work-side alignment mark Wa are not limited to the illustrated shapes as long as the matching of both alignment marks Ma and Wa can be confirmed.

As a result, the alignment camera 30 uses the alignment light from the light source device 70, which will be described later, to shift the projection image Ma1 of the mask-side alignment mark Ma projected on the upper surface of the work W from the work-side alignment mark Wa of the work W. Image the amount.

As shown in FIG. 2, the lighting device 3 of the exposure device PE of the present embodiment includes a light source device 70, a plane mirror 66 for changing the direction of the optical path EL emitted from the fly-eye lens 65 of the light source device 70, and a plane mirror 66. A collimation mirror 67 that irradiates the light from the light source device 70 as parallel light, a plane mirror 68 that is a reflecting mirror that irradiates the parallel light toward the mask M, and a mirror bending mechanism 90 that can change the curvature of the plane mirror. , Equipped with.

As shown in FIG. 4, the light source device 70 includes a first LED array 71 for irradiating exposure light, two second LED arrays 75 for irradiating alignment light, and the first and second LED arrays. A fly-eye lens including a dichroic mirror 80 (80A, 80B) which is a dichroic optical element to which exposure light and alignment light emitted from the LED arrays 71 and 75 of the above are incident, and a plurality of lens elements 65a arranged in a matrix. It is equipped with 65.

The first LED array 71 is a component in which a plurality of first LED elements 72 are two-dimensionally aligned and arranged on a base plate. The plurality of first LED elements 72 irradiate, for example, exposure light (UV light) having a peak wavelength (first peak wavelength) at any of 360 to 380 nm. The peak wavelength of the first LED element 72 is preferably 360 to 370 nm, and more preferably 365 nm.

The second LED array 75 is a component in which a plurality of second LED elements 76 are two-dimensionally aligned and arranged on a base plate. The plurality of second LED elements 76 irradiate, for example, alignment light (visible light) having a peak wavelength of 546 nm (second peak wavelength). The peak wavelength of the second LED element 76 is different from the peak wavelength of the plurality of first LED elements 72, and is not limited to the e-line having a peak wavelength of 546 nm as long as it is in a region where the photosensitive material is not exposed to light. For example, it may be 500 nm or more.
A lens may be attached to the front surface of the first LED element 72 and the second LED element 76.

The dichroic mirror 80, which is a dichroic optical element, forms a thin film (dichroic film) 81 such as a multilayer film of a dielectric on a plate-shaped transparent medium 82 such as glass or plastic, and reflects light in a specific wavelength band. , An optical element having the property of transmitting light in other wavelength bands.
The dichroic mirror 80 has two dichroic mirrors 80A and 80B (two dichroic films 81) having substantially the same length L3, and the first and second LED elements 72 and 76 emitted from the dichroic mirror 80 are fly-eye lenses. It is arranged in a substantially V shape so as to be inclined with respect to the common optical axis direction L toward 65 (that is, the direction along the optical path EL) and to be in close contact with the fly-eye lens side. In this embodiment, the two dichroic mirrors 80A and 80B are combined at an angle of approximately 90 °.

Then, the first one faces the opening side of the two V-shaped dichroic mirrors 80A and 80B (in the optical axis direction L, the side opposite to the fly-eye lens 65 with respect to the dichroic mirror 80, the left side in FIG. 4). The LED array 71 is arranged. Further, two second LEDs crossing the optical axis direction L (orthogonal in the present embodiment) and on both sides (upper and lower in FIG. 4) of the two V-shaped dichroic mirrors 80A and 80B. Arrays 75 are arranged respectively. As a result, the first LED array 71 and the second LED array 75 both face the V-shaped dichroic mirror 80A or 80B at an angle of approximately 45 °.
In the present embodiment, the fact that the second LED array 75 is orthogonal to the common optical axis direction L is not only when they are exactly orthogonal to each other, but also when the second LED array 75 is incident on the fly-eye lens 65. This includes cases where the directions of light from are orthogonal to the extent permitted.

The length L2 of the second LED array 75 is approximately ½ of the length L1 of the first LED array 71, and is 1 / √2 of the length L3 of the dichroic mirror 80A or 80B. .. Further, the width of the second LED array 75 (in the vertical direction on the paper surface of FIG. 4) is the same as the width of the first LED array 71. The number of the second LED elements 76 of each second LED array 75 is such that when the alignment is adjusted, the amount of light that the projected image Ma1 of each mask-side alignment mark Ma can be accurately recognized by the alignment camera 30 can be obtained. Therefore, it is less than 1/2 of the number of the first LED elements 72. In this case, the plurality of second LED elements 76 are arranged two-dimensionally in the second LED array 75 at intervals of each.

As a result, at the time of exposure, all the light emitted from the first LED array 71 passes through the dichroic mirror 80A or 80B and is incident on the incident surface of the fly-eye lens 65. Further, at the time of alignment, all the light emitted from the two second LED arrays 75 is reflected by the dichroic mirror 80A or 80B and is incident on the incident surface of the fly eye lens 65.

In this way, the two dichroic mirrors 80A and 80B are arranged in a substantially V shape so as to be in close contact with each other on the fly eye lens 65 side, and the first LED array 71 is arranged in a V shape in the common optical axis direction L. The second LED array 75 is arranged on the opposite side of the fly-eye lens 65 with respect to the dichroic mirrors 80A and 80B, and the second LED array 75 is placed on both sides of the V-shaped dichroic mirrors 80A and 80B at right angles to the optical axis direction L. By dividing and arranging the light source device 70, the length from the first LED array 71 to the fly-eye lens 65 can be shortened, and the light source device 70 can be compactly configured. Further, the optical efficiency is improved by arranging the first LED array 71 and the fly-eye lens 65 in close proximity to each other. That is, since the first LED array 71, the second LED array 75, and the fly-eye lens 65 are arranged to directly face (face) the two dichroic mirrors 80A and 80B, the light source device 70 is compact. Designed.

Further, in the present embodiment, both end portions 83 of the two dichroic mirrors 80A and 80B are cut in parallel with the common optical axis direction L from the dichroic mirror 80 toward the fly eye lens 65. As a result, the dichroic films 81 of the two dichroic mirrors 80A and 80B are in contact with each other at the top of the V-shape, so that the dichroic mirrors 80A and 80B receive the light emitted from the first LED array 71 of the dichroic mirror 80. The light transmitted uniformly over the entire width direction (direction orthogonal to the optical axis direction L) and the light emitted from the second LED array 75 can be reflected in a wide range, and the efficiency is improved.

The fly-eye lens 65 is used to make the incident light have an illuminance distribution as uniform as possible on the irradiation surface by a plurality of lens elements 65a arranged in a matrix.

Further, in the present embodiment, the mirror bending mechanism 90 is arranged on the back surface side of the plane mirror 68 constituting the lighting device. The mirror bending mechanism 90 corrects the declination angle of the planar mirror 68 by changing the shape of the planar mirror 68 and locally changing the curvature of the reflecting surface.

As shown in FIG. 3, for example, the mirror bending mechanism 90 has a plurality of pads 92 fixed to a plurality of locations on the back surface of the plane mirror 68, and a plurality of holdings for holding the plurality of pads 92 via ball joints 96, respectively. A member 93 and a plurality of motors 94 provided for each of the plurality of holding members 93 and moving the positions of the holding members 93 with respect to the holding frame 91 are provided. As a specific configuration of the mirror bending mechanism 90, for example, the one described in Japanese Patent Application Laid-Open No. 2019-109445 is applied.

Further, as shown in FIG. 1, the control unit 40 controls various mechanisms of the exposure device PE including the lighting device 3, and in particular, in the present embodiment, the mask captured by the alignment camera 30 at the time of alignment. The amount of deviation between the projected image Ma1 of the side alignment mark Ma and the work side alignment mark Wa is acquired, a plurality of mask driving units 28 are driven, the masks M are moved, and the mirror bending mechanism 90 is applied to the mirror control unit 41. Sends a signal to drive.
The control unit 40 may also control the mirror control unit 41. Further, the control unit 40 may move the work W by the X-axis stage feed mechanism 5 and the Y-axis stage feed mechanism 6 instead of moving the mask M by the mask drive unit 28 at the time of alignment. That is, the moving mechanism that moves the mask M and the work W relative to each other may be a plurality of mask driving units 28, or may be an X-axis stage feed mechanism 5 and a Y-axis stage feed mechanism 6.

Next, a procedure for exposure-transferring the pattern of the mask M onto the work W will be described with reference to FIG. First, the first LED element 72 of the first LED array 71 is turned off, while the second LED element 76 of the second LED array 75 is turned on and the alignment light is emitted from the lighting device 3 (step S1). .. As a result, as shown in FIG. 7, the alignment light is applied to the work W through the mask M, and a projected image Ma1 of the mask-side alignment mark Ma of the mask M is formed on the work W. The alignment camera 30 simultaneously captures the projected image Ma1 of the alignment mark Ma on the mask side projected on the work and the alignment mark Wa on the work side by the alignment camera 30, and aligns the projected image Ma1 with the work side of the work W. The amount of deviation of the mark Wa is acquired (step S2).

At this time, the alignment light applied to the work W is emitted from the light source device 70 along the optical axis direction L common to the exposure light, so that the optical axis is coaxial with the optical axis of the exposure light.

Then, based on the deviation amount acquired by the alignment camera 30, the mask M held by the mask stage 1 is moved to adjust the alignment between the mask M and the work W. Further, as shown in FIG. 8, the amount of deviation remaining after the alignment cannot be adjusted only by the relative movement of the mask M and the work W is a drive signal from the mirror control unit 80 to each mirror bending mechanism 90 of the plane mirror 68. It is transmitted and driven, and the shape of the planar mirror 68 is locally changed to correct the declination angle of the planar mirror 68 (step S3). As a result, the center O1 of the projected image Ma1 of the mask-side alignment mark Ma and the center O3 of the work-side alignment mark Wa are aligned and the alignment is adjusted. In the present embodiment, the center O1 of the projected image Ma1 of the mask-side alignment mark Ma is the intersection of the diagonal lines of a square composed of four small circles 33b, and the center O3 of the work-side alignment mark Wa is a cross shape. It is the intersection of.

Since the alignment light for acquiring the amount of deviation between the projected image Ma1 of the mask-side alignment mark Ma and the work-side alignment mark Wa does not expose the photosensitive material applied to the work W, it is possible to perform the work W before exposure and before the work W is exposed. Alignment can be adjusted while checking the amount of deviation between the projected image Ma1 of the mask-side alignment mark Ma and the work-side alignment mark Wa for each shot, which was difficult with the exposure device. Further, it is possible to adjust the alignment while grasping the movement of the projected image Ma1 of the mask side alignment mark Ma due to the change of the optical axis by each mirror bending mechanism 90 of the plane mirror 68 with the alignment camera 30.
The mirror bending mechanism 90 locally changes the shape of the plane mirror 68 based on the amount of deviation between the alignment mark Ma of the mask M and the alignment mark Wa of the work W that cannot be adjusted due to the relative movement between the mask and the work described above. The declination angle of the plane mirror 68 is corrected.

Next, when it is confirmed by the alignment camera 30 that the amount of deviation between the projected image Ma1 of the mask-side alignment mark Ma and the work-side alignment mark Wa is within the allowable range (steps S4 and S5), the second LED array 75 The second LED element 76 is turned off, while the first LED element 72 of the first LED array 71 is turned on and the exposure light is emitted from the lighting device 3.

Therefore, the traveling direction of the exposure light emitted from the light source device 70 is changed by the plane mirror 66, the collimation mirror 67, and the plane mirror 68. Then, this light is irradiated as light for pattern exposure substantially perpendicular to the surface of the mask M held in the mask stage 1 and the work W held in the work stage 2, and the pattern of the mask M works. The exposure is transferred onto W. (Step S6). Therefore, the optical axis of each other does not shift between the alignment adjustment and the exposure, and the pattern position shift due to the optical axis shift is prevented during the actual exposure, and the pattern is highly accurate. Exposure is possible.

In particular, in the present embodiment, the alignment adjustment and the exposure are performed by turning on / off the LED element, so that the tact time in each process can be significantly shortened.

In the alignment adjustment in step S3 described above, the bending correction of the plane mirror 63 is performed after the mask M is moved, but the movement of the mask M and the bending correction of the plane mirror 63 may be performed at the same time. Further, the acquisition of the deviation amount between the projected image Ma1 of the mask-side alignment mark Ma and the work-side alignment mark Wa may be performed again after moving the mask M and before performing bending correction of the plane mirror 63.
If the deviation amount exceeds the permissible range in step S5, the process returns to step S3, and in step S3, a plurality of alignment marks are comprehensively determined and the mask M is moved or the plane mirror 63 is moved. You may choose whether to perform bending correction.

Further, as a modification of the present embodiment, as shown in FIG. 9, the first LED array 71 and the second LED array 75 can be arranged by exchanging the positions with respect to the two dichroic mirrors 80A and 80B. ..
In particular, the reflected light by the dichroic mirrors 80A and 80B has better optical efficiency than the transmitted light. This is because the light from the LED array arranged on the reflection side passes through the interface of the dichroic mirror 80 once during reflection, whereas the light from the LED array arranged on the transmission side passes through the dichroic mirror 80 once. By passing through the interface of.
Therefore, from the viewpoint of exposure efficiency, the two first LED arrays 71 each including the first LED element 72 that irradiates the exposure light are crossed with respect to the common optical axis direction L, and the dichroic mirror 80A, A second LED array 75, which is arranged on both sides of the 80B and includes a second LED element 76 that irradiates the alignment light, is a fly-eye lens 65 with respect to the dichroic mirrors 80A and 80B in a common optical axis direction L. A modified example arranged on the opposite side is preferable.

Also in this case, the length of the first LED array 71 arranged on the reflection side is shorter than the length of the second LED array 75 arranged on the transmission side (in this embodiment, the length of the second LED array 75). 1/2 of the length), and the width of the first LED array 71 and the width of the second LED array 75 are equal to each other. Further, the plurality of second LED elements 76 are arranged two-dimensionally in the second LED array 75 at intervals of each.

In the present embodiment, the plurality of first LED elements 72 are exposed light having a peak wavelength at any of 360 to 380 nm, but the peak wavelength of the first LED element 72 is changed according to the resist. It is possible, for example, one having a peak wavelength in any of 390 to 410 nm, and one having a peak wavelength in any of 420 to 450 nm.

(Second Embodiment)
Next, the light source device 70 of the second embodiment will be described with reference to FIG. As shown in FIG. 10, the second LED array 75 is exposed to a third peak wavelength, which is 20 nm or more away from the first peak wavelength of the first LED element 72 in addition to the second LED element 76. A plurality of third LED elements 77 that emit light are further provided. Therefore, the second LED array 75 of the present embodiment is a component in which the plurality of second LED elements 76 and the plurality of third LED elements 77 are two-dimensionally aligned and arranged.

That is, in the present embodiment, at the time of exposure, the exposure light from the first LED element 72 of the first LED array 71 and the exposure light from the third LED element 77 of the second LED array 75 are dichroic mirrors. It is synthesized by 80A and 80B and is incident on the incident surface of the fly-eye lens 65.

This is because the first and third LED elements 72, 77 having different peak wavelengths when the resist polymerization initiator has absorption not only at the absorption peak wavelength but also at wavelengths around the absorption peak wavelength. By synthesizing and exposing the light from the light, the photosensitive material can be efficiently exposed to light.

For example, when exposure is performed using only a single-wavelength LED element having a peak wavelength of 365 nm, the pattern formed by the resist is weakly cured, and pattern peeling is likely to occur in the developing process. Peeling is likely to occur at the edges of the pattern and is due to leakage light through the mask pattern and the resist polymerization initiator. Normally, in order to suppress peeling, it is necessary to increase the exposure time or adjust the pre- and post-processes. By using a third LED element 77 having a wavelength of 385 nm, which is easy for light to reach, the pattern can be stabilized.

Further, the number of the second LED elements 76 may be such that the amount of light that can be accurately recognized by the alignment camera 30 by the projected image Ma1 of each mask-side alignment mark Ma at the time of alignment adjustment can be obtained. Therefore, in the present embodiment, the number of the second LED elements 76 is smaller than the number of the third LED elements 77 in the second LED array 75, for example, the number of the second LED elements 76 /. The number of both LED elements 76 and 77 of the second LED array 75 is preferably 20% or less.

In the present embodiment, the first LED element 72 has a main wavelength having a peak wavelength of 360 to 380 nm, and the third LED element 77 has a peak of, for example, 300 to 355 nm or 385 to 410 nm. It is a sub-wavelength having a wavelength. However, the first LED element 72 is a sub-wavelength having a peak wavelength in any of 300 to 355 nm or 385-410 nm, and the third LED element 77 is a main wavelength having a peak wavelength in any of 360 to 380 nm. May be good.

Further, the first LED element 72 and the third LED element 77 are selected so that the peak wavelengths of the respective lights are separated by 20 nm or more. The reason why the peak wavelengths of the light of the first and third LED elements 72 and 77 are separated by 20 nm or more is that the dichroic mirror 80 needs that the two wavelengths to be combined are separated by 20 nm or more due to its performance. It depends.

Therefore, when the peak wavelength of the first LED element 72 is set to, for example, 365 nm, the peak wavelength of the third LED element 77 may be set to 345 nm or less, or set to 385 nm or more. You may.
Other configurations and operations are the same as those of the first embodiment of the present invention.

(Third Embodiment)
Next, the light source device 70 of the third embodiment will be described with reference to FIG. As shown in FIG. 11, the present embodiment describes a method of fixing the two dichroic mirrors 80A and 80B described in the above embodiment by using the two dichroic mirror fixing frames 85.

The dichroic mirror fixed frame 85 is formed by combining three frames 85a, 85b, 85c covering three sides of the four sides of the rectangular dichroic mirrors 80A, 80B in a substantially U-shape, and the dichroic mirrors 80A, 80B. It has a shape that opens the sides facing each other. One side of the dichroic mirrors 80A and 80B is fitted into the groove 86 formed in the frame body 85a of the substantially U-shaped dichroic mirror fixing frame 85, and the upper surfaces of the dichroic mirrors 80A and 80B are formed. It is pressed toward the frame body 85b by the push screw 87 provided on the frame body 85c via the cushioning material 88, and is fixed to the dichroic mirror fixing frame 85.

Further, in FIG. 11, the tip portions 83 of the two dichroic mirrors 80A and 80B butted in a V shape and the tip portions of the dichroic mirror fixing frames 85 (frames 85b and 85c) to which the dichroic mirrors 80A and 80B are fixed, respectively. The 85d is cut in parallel with the optical axis direction L from the dichroic mirror 80 toward the flyeye lens 65, and adheres so as not to have a gap, and preferably adheres so as to have no gap.

Further, the tip portion 85d on the fly-eye lens side of the dichroic mirror fixing frame 85 (frames 85b, 85c) combined in a V shape is cut at right angles to the optical axis direction L from the dichroic mirror 80 toward the fly-eye lens 65. Form planes that are flush with each other. As a result, the two dichroic mirrors 80A and 80B can be brought closer to the fly-eye lens 65 by the cut length of the dichroic mirror fixing frame 85, which improves efficiency and makes the light source device 70 compact. Can be done. In FIG. 11B of the dichroic mirror fixed frame 85 (frame bodies 85a, 85b, 85c) supporting the dichroic mirrors 80A and 80B, the range outside the arrow is arranged outside the optical path of the exposure light. Therefore, the dichroic mirror fixed frame 85 does not interfere with the exposure.

Further, as a modification of the present embodiment, as shown in FIG. 12, in the dichroic mirror fixing frame 85, grooves 86 are formed in each of the three frame bodies 85a, 85b, and 85c, and the three grooves 86 are formed. Each side (three sides) of the dichroic mirrors 80A and 80B may be fitted to the dichroic mirror 80A and 80B and fixed with an adhesive. Further, similarly to the one shown in FIG. 11, the tip portions 83 of the two dichroic mirrors 80A and 80B and the tip portions 85d of the two dichroic mirror fixing frames 85 are in close contact with each other so as not to have a gap, preferably a gap. It is glued so that there is no.

The present invention is not limited to the above-described embodiments, and can be appropriately modified, improved, and the like.
For example, in the above embodiment, the exposure light and the alignment light are incident on the dichroic mirror, but the dichroic optical element of the present invention is not limited to this, and may be a dichroic prism.

As shown in FIG. 13, the dichroic prism 180 is formed by combining three right-angle prisms 181, 182, 183 which are materials having high transmittance such as glass and plastic. Each prism 181, 182, 183 has a substantially right-angled isosceles triangle shape in a side view, and a prism 181 larger than the prisms 182, 183 is used. The dichroic prism 180 has a rectangular shape in a side view in which sides other than the hypotenuse of the prism 181 and the hypotenuses of the prisms 182 and 183 are connected via a dichroic film (not shown). Further, the interface 184 of the prisms 181 and 182 on which the dichroic film is arranged and the interface 185 of the prisms 181 and 183 are inclined at approximately 45 ° with respect to the optical axis direction L, and the two interfaces 184 and 185 are 90 °. Formed to intersect at. As a result, the two dichroic films are arranged in a substantially V shape so as to be in close contact with each other on the fly-eye lens side.

The dichroic prism 180 is the number of times that the light from the first LED array 71 and the second LED array 75 passes through the interfaces 181a, 182a, 182b, 183a, 183b, 184, 185 (including the entrance surface and the emission surface). Can be equal. Further, by using the dichroic prism 180, a structure for bringing the two dichroic mirrors into close contact with each other becomes unnecessary.

Further, as in still another modification shown in FIG. 14, the light source device 70B may be configured by one dichroic mirror 80 instead of the two dichroic mirrors 80A and 80B arranged in a V shape. In this case, the first LED array 71 having the plurality of first LED elements 72 and the second LED array 75 having the plurality of second LED elements 76 are arranged orthogonally, and the dichroic mirror 80 is the first. It is arranged at an angle of 45 ° with respect to the LED array 71 and the second LED array 75. Also in this case, since the first LED array 71, the second LED array 75, and the fly-eye lens 65 are arranged to face the dichroic mirror 80, the light source device 70 is designed compactly.

As a result, the exposure light emitted from the first LED array 71 passes through the dichroic mirror 80 and enters the fly-eye lens 65, and the alignment light emitted from the second LED array 75 is transmitted by the dichroic mirror 80. It is reflected and incident on the fly-eye lens 65.

65 Fly-eye lens 70, 70B Light source device 71 First LED array 72 First LED element 75 Second LED array 76 Second LED element 77 Third LED element 80, 80A, 80B Dichroic optical element (dichroic mirror) )
81 Dichroic film 83 End 85 Dichroic mirror fixing frame 180 Dichroic optical element (dichroic prism)
M Mask PE Proximity exposure device W Work (board)
L1 Length of the first LED array L2 Length of the second LED array

Claims (9)

A first LED array having a plurality of first LED elements that emit exposure light having a first peak wavelength, and a first LED array.
A second LED array having a plurality of second LED elements that emit alignment light having a second peak wavelength different from that of the first peak wavelength.
A dichroic film that transmits light in a specific wavelength band and reflects light in other wavelength bands is provided, and the dichroic film is inclined with respect to a common optical axis direction of the first and second LED elements. Dichroic optical elements to be placed and
A fly-eye lens in which the light of the first LED element or the second LED element is incident through the dichroic optical element.
A light source device for exposure, which comprises
One of the first LED array and the second LED array is arranged on the opposite side of the fly-eye lens with respect to the dichroic optical element in the common optical axis direction.
Either or the other of the first LED array and the second LED array intersects the common optical axis direction and is arranged on the side of the dichroic optical element.
Light source device for exposure. According to claim 1, the dichroic optical element includes two dichroic films that are inclined with respect to the common optical axis direction and are arranged in a substantially V shape so as to be in close contact with each other on the fly eye lens side. The light source device for the described exposure. The one or the other LED array comprises two either LED arrays that intersect the common optical axis direction and are located on either side of the dichroic optics, respectively.
The exposure according to claim 2, wherein the length of each of the other LED arrays is shorter than the length of the one of the LED arrays arranged on the opposite side of the fly-eye lens with respect to the dichroic optical element. Light source device for. The light source device for exposure according to claim 2 or 3, wherein the dichroic optical element is two dichroic mirrors or dichroic prisms. The dichroic optical element is two dichroic mirrors each having the dichroic film.
The light source device for exposure according to claim 2 or 3, wherein the end portion of each dichroic mirror is cut in parallel with the optical axis direction. The second LED array further comprises a plurality of third LED elements that emit exposure light of a third peak wavelength, which is 20 nm or more away from the first peak wavelength of the first LED element. Item 6. The light source device for exposure according to any one of Items 1 to 5. The light source device for exposure according to any one of claims 1 to 6.
A lighting device including a mirror bending mechanism capable of changing the curvature of a reflecting surface, and a reflecting mirror that reflects light emitted from the fly-eye lens. The lighting device according to claim 7 and
The work support part that supports the work and the work support
The mask support part that supports the mask and
An alignment camera capable of simultaneously capturing a projected image of the alignment mark on the mask side projected on the work and the alignment mark on the work side using the alignment light.
The exposure device comprises the above, irradiating the work with the exposure light emitted from the lighting device through the mask, and transferring the pattern of the mask to the work. An exposure method using the exposure apparatus according to claim 8.
A step of irradiating the alignment light from the lighting device and simultaneously capturing a projected image of the alignment mark on the mask side projected on the work and the alignment mark on the work side by the alignment camera.
The curvature of the reflector is corrected by the mirror bending mechanism so that the projected image of the alignment mark on the mask side and each center of the alignment mark on the work side coincide with each other, and the work support portion and the mask support are supported. The process of moving parts relatively and
A step of irradiating the work with the exposure light emitted from the lighting device through the mask and transferring the pattern of the mask to the work.
An exposure method comprising.

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