WO2020179740A1 - Light source device for exposure, exposure device, and exposure method - Google Patents

Abstract

The present invention provides a light source device for exposure that is able to synthesize light from a plurality of LED elements having different peak wavelengths, and is compactly configured, an exposure device using the light source device, and an exposure method. This light source device for exposure is provided with: a first LED array (71) having a plurality of first LED elements (72) that emit light of a first peak wavelength; a second LED array (75) having a plurality of second LED elements (76) that emit light of a second peak wavelength different from the first peak wavelength; a photosynthetic element (80) that is provided with two dichroic films (81) for transmitting light in a specific wavelength band and reflecting light in the other wavelength bands, and synthesizes light from the first and second LED arrays (71, 75); and a fly-eye lens (65) on which the light synthesized by the photosynthetic element (80) is incident.

Description

Light source device for exposure, exposure device, and exposure method

The present invention relates to a light source device for exposure, an exposure device, and an exposure method, and more particularly, to a light source device for exposure, a light exposure device, and an exposure method that use light emitted from an LED element as a light source.

Conventionally, mercury lamps have been used as UV light sources in exposure devices used for lithography such as flat panel displays, printed circuit boards, and semiconductor elements. However, in recent years, restrictions on the use of mercury have become stricter, and the use of LEDs as UV light sources has been promoted.

Here, if the conventional resist that matches the wavelength range with the mercury lamp is used as it is, the wavelength band of the single-wavelength LED element is narrower than that of the mercury lamp. Therefore, it is known that a UV light source is a combination of LED elements having a plurality of wavelengths corresponding to g-line (436 nm), h-line (405 nm), and i-line (365 nm) of a mercury lamp with a high output from a high-pressure mercury lamp. (See, for example, Patent Documents 1 and 2).

In Patent Document 1, UV light from a plurality of LED elements that irradiate light of wavelengths corresponding to g-line (436 nm), h-line (405 nm), and i-line (365 nm), which have a high output with a high-pressure mercury lamp, are X-shaped. A light source device that combines waves using a type of dichroic mirror is described. Further, in Patent Document 2, a plurality of LED light sources each emitting UV light in a wavelength band of 360 nm to 380 nm, 390 nm to 410 nm, 420 nm to 450 nm, and a plurality of dichroic mirrors arranged for the respective LED light sources. An LED type ultraviolet irradiator comprising the above is described. Further, Patent Document 2 describes that UV LED light emitted at a wavelength of less than 300 nm, for example, a nominal wavelength of 240 nm is used.

Japanese Patent Laid-Open No. 2018-10294 Japanese Patent Laid-Open No. 2010-263218

By the way, it is preferable that the set wavelength of the UV light source is such that the resist can be efficiently exposed to light because the power consumption of the LED light source is low and the cooling work due to heat generation of the light source can be reduced. In the exposure apparatus, generally, there is a demand to make the UV light source compact in order to reduce the number of parts, effectively use the space in the apparatus, and reduce the weight. Although the light from the LED array has a condenser lens attached to each LED element, the light is not parallel and tends to be diffused unless an optical member such as a convex lens is separately used. Therefore, shorten the optical path length,
There is a strong need to make the light source device compact. In particular, in an exposure apparatus for a display, it is necessary to expose a large area at a time, so that the light source size also becomes large, and there is a strong need for downsizing.

The light source device described in Patent Document 1 uses an X-shaped dichroic mirror to reduce the installation area, but there is room for further compactification. Further, the LED type ultraviolet irradiator described in Patent Document 2 uses three or more dichroic mirrors in series, and there is room for further improvement as a compact LED light source.

Also, when the inventor tested using a conventional resist, a resist with high exposure sensitivity at a wavelength shorter than i-line (365 nm) was found. This is because the polymerization initiator of the resist absorbs not only the absorption peak wavelength but also the peripheral wavelengths, but if the absorbing wavelength range extends to the visible light range, problems may occur depending on the use of the resist. It is considered that this is because the absorption peak wavelength is intentionally set to a wavelength shorter than the g-line, h-line, and i-line of the mercury lamp. Examples of such applications include resists for color filters of displays and image sensors. Therefore, a light source device that sensitizes such a resist more efficiently has also been desired.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is a light source device for exposure, which is a compactly configured light source device that synthesizes light from a plurality of LED elements having different peak wavelengths. It is an object of the present invention to provide an exposure apparatus and an exposure method using the above.

The above object of the present invention is achieved by the following configurations.
(1) A first LED array having a plurality of first LED elements that emit light having a first peak wavelength, and
A second LED array having a plurality of second LED elements that emit light having a second peak wavelength different from the first peak wavelength.
A photosynthesis element for synthesizing light from the first and second LED arrays;
A fly-eye lens on which the light combined by the light combining element is incident,
A light source device for exposure, comprising:
The photosynthetic element includes two dichroic films that transmit light in a specific wavelength band and reflect light in other wavelength bands, and the two dichroic films are optical axes extending from the photosynthetic element toward the fly-eye lens. Is inclined with respect to the direction, and is arranged in a substantially V shape so as to be in close contact with the fly-eye lens side,
The first LED array is arranged on the opposite side of the fly-eye lens with respect to the photosynthetic element in the optical axis direction.
The second LED array is a light source device for exposure, which is arranged on the side of the photosynthetic element so as to intersect the optical axis direction.
(2) The peak wavelength of the light emitted from either the first LED element or the second LED element is 360 to 380 nm.
The peak wavelength of the light emitted from the other of the first LED element and the second LED element is 300 to 355 nm or 385 to 410 nm,
The light source device for exposure according to (1), wherein the peak wavelengths of the first LED element and the second LED element are separated by 20 nm or more.
(3) The length of the second LED array arranged laterally of the photosynthetic element is
The light source device for exposure according to (1) or (2), which is shorter than the length of the first LED array arranged on the side opposite to the fly-eye lens with respect to the light combining element.
(4) The light source device for exposure according to any one of (1) to (3), wherein the light combining element is two dichroic mirrors or dichroic prisms.
(5) The photosynthetic element is two dichroic mirrors each having the dichroic film.
The light source device for exposure according to (1), wherein the end portion of each dichroic mirror is cut in parallel with the optical axis direction.
(6) The dichroic mirrors are fixed to each other, and further provided are two dichroic mirror fixing frames opened on a side where the two dichroic mirrors are in close contact with each other.
The light source device for exposure according to (5), wherein a tip of the dichroic mirror fixing frame on the fly-eye lens side is cut at a right angle to the optical axis direction.
(7) The second LED array has two types of two second LED arrays alternately arranged at 90° intervals on a plane orthogonal to the optical axis direction, (1) The light source device for exposure according to any one of to (6).
(8) A lighting device having the light source device for exposure according to any one of (1) to (7), and
A work support part for supporting the work,
A mask support part for supporting the mask,
An exposure apparatus, which comprises: a light emitted from the illumination device; and irradiating the work through the mask to transfer the pattern of the mask onto the work.
(9) An exposure method in which the light emitted from the lighting device is applied to the work through the mask by using the exposure device according to (8) to transfer the pattern of the mask to the work.
(10) A plurality of first LED elements that emit light having a first peak wavelength in the range of 360 to 380 nm, which corresponds to the photosensitive wavelength of the polymerization initiator of the photosensitive material provided on the substrate, and 300 to 355 nm. A plurality of second LED elements that emit light having a second peak wavelength in the range, and
Equipped with
A light source device for exposure in which the light of the first LED element and the light of the second LED element are mixed and emitted to a fly-eye lens.
(11) The light source device for exposure according to (10), comprising an LED array in which the first LED element and the second LED element are arranged in a mixed manner.
(12) A first LED array having the plurality of first LED elements,
A second LED array having the plurality of second LED elements;
A photosynthesis element for synthesizing light from the first and second LED arrays;
Equipped with
The photosynthetic element is a dichroic film that transmits light in a specific wavelength band and reflects light in other wavelength bands, and is arranged to be inclined with respect to the optical axis direction from the photosynthetic element to the fly-eye lens.
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 photosynthetic element in the optical axis direction.
The exposure according to (9), wherein either or the other of the first LED array and the second LED array intersects the optical axis direction and is arranged on the side of the photosynthetic element. Light source device.
(13) An illumination device including the light source device for exposure according to any one of (10) to (12),
A work support part for supporting the work,
A mask support part for supporting the mask,
An exposure device that irradiates the work with the light emitted from the lighting device through the mask and transfers the pattern of the mask to the work.
(14) An exposure method in which the light emitted from the lighting device is applied to the work through the mask using the exposure device according to (13) to transfer the pattern of the mask to the work.

According to the light source device for exposure, the exposure device using the light source device, and the exposure method of the present invention, the light source device capable of synthesizing light from a plurality of LED elements having different peak wavelengths is compactly configured, and It is possible to efficiently expose the photosensitive material with synthetic light and improve the exposure work efficiency.

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. It is a schematic block diagram of the light source apparatus of 1st Embodiment. (A) is a graph which shows the transmissivity of a dichroic mirror which is an example, and (b) is an enlarged view of the IV section of (a). (A) is a graph which shows the reflectance of the dichroic mirror of FIG. 4, (b) is an enlarged view of the V section of (a). 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 the light source device of the modified example of the third embodiment, and (b) is an arrow view seen from the direction B of (a). .. FIG. 11 is a schematic plan view showing two types of second LED arrays and two dichroic mirrors arranged on a plane perpendicular to the optical axis direction in the case as the light source device of the fourth embodiment. 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 front view of the LED array which is a light source device which concerns on another modification of this invention. It is a front view of the LED array which is the light source device which concerns on still another 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 a work W as a material to be exposed, holds the mask M on a mask stage (mask support portion) 1, and holds the work W on a work stage (workpiece). The mask M is irradiated with the light for pattern exposure from the illuminating device 3 in a state of being held by the supporting portion 2 and the mask M and the work W are arranged close to each other and face each other with a predetermined exposure gap. The pattern of M is exposed and transferred onto the work W. Further, the work stage 2 is moved stepwise 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 for each step.

In order to move the work stage 2 stepwise in the X-axis direction, an X-axis stage feed mechanism 5 that moves the X-axis feed table 5a stepwise 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 move the work stage 2 in steps in the Y-axis direction. Has been done. A work stage 2 is installed on the Y-axis feed base 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, on the side portion of the work stage 2, a substrate side displacement sensor 15 for measuring the height of the lower surface of the mask M is arranged. Therefore, the substrate side displacement sensor 15 can move together with the work stage 2 in the X and Y axis directions.

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 feed base 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 Y-axis linear guide guide rails 53 are arranged on the X-axis feed base 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 base 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 having 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 enables positioning with higher resolution than the device 7 and finely adjusts the gap between the facing surfaces of the mask M and the work W to a predetermined amount by finely moving the work stage up and down.

The vertical coarsening 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 at 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 should be noted that it is desirable that the vertical coarse movement device 7 has a high repeat positioning accuracy even though the resolution is low.

The vertical fine movement device 8 includes a fixing base 9 fixed to the Y-axis feed base 6a and a guide rail 10 of a linear guide attached to the fixing 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 straddling 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 fixed base 9, the nut, the slider 11 and the slide body 12 are integrally moved in an oblique direction along the guide rail 10, whereby 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.

This vertical fine movement device 8 is installed at one end in the Y-axis direction (left end side in FIG. 1) of the Z-axis feed base 6a and two at the other end, 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 positions based on the measurement results of the gap amounts between the mask M and the work W at the plurality of positions by the gap sensor 27, and the work stage 2 Finely adjust the height and inclination of.
If the height of the work stage 2 can be sufficiently adjusted by the fine vertical movement device 8, the vertical coarse movement device 7 may be omitted.

Further, on the Y-axis feed table 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 at one end side.

The Y-axis laser interferometer 18 and the X-axis laser interferometer are always arranged so as to face the corresponding bar mirrors and 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 feed base 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 in the X-axis direction of the X-axis feed table 5a and by extension, the work stage 2 via the facing bar mirror.

The mask stage 1 is inserted into the mask base frame 24 made of a substantially rectangular frame and the opening at the center of the mask base frame 24 through a gap in the X, Y, θ directions (in the X, Y plane). The mask base frame 24 is movably supported, and the mask base frame 24 is held at a fixed position above the work stage 2 by a column 4 a protruding from the apparatus 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 sucks the mask frame 25 through the plurality of mask holder suction grooves. Retained.

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 on the lower surface of the mask holder 26, and the mask M passes through the mask suction grooves. It is detachably held on the lower surface of the mask holder 26 by a vacuum suction device (not shown).

As shown in FIG. 2, the lighting device 3 of the exposure device PE of the present embodiment is a plane for changing the direction of the light source device 70 for irradiating ultraviolet rays and the light path EL emitted from the fly-eye lens 65 of the light source device 70. A mirror 66, a collimation mirror 67 that irradiates light from the light source device 70 as parallel light, and a flat mirror 68 that irradiates the parallel light toward the mask M are provided.

In the lighting device 3, the light emitted from the light source device 70 is incident on the incident surface of the fly-eye lens 65. The fly-eye lens 65 is used to make the incident light have an illuminance distribution as uniform as possible on the irradiation surface. Then, the light emitted from the exit surface of the fly-eye lens 65 is converted into parallel light while its traveling direction is changed by the plane mirror 66, the collimation mirror 67, and the plane mirror 68. Then, this parallel light is irradiated as light for pattern exposure substantially perpendicularly to the surface of the mask M held by the mask stage 1 and further the surface of the work W held by the work stage 2, and the pattern of the mask M is changed. It is exposed and transferred onto the work W.

Next, the light source device 70 will be described in detail with reference to FIG. The light source device 70 of the present embodiment is
The first and second LED arrays 71 and 75 emit light having different peak wavelengths, and the photosynthetic element synthesizes light having different peak wavelengths emitted from the first and second LED arrays 71 and 75. It includes a dichroic mirror 80 (80A, 80B) and a fly-eye lens 65 including a plurality of lens elements 65a arranged in a matrix.

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

In the second LED array 75, a plurality of second LED elements 76 are arranged two-dimensionally. The plurality of second LED elements 76 irradiate, for example, UV light having a peak wavelength (second peak wavelength) at either 300 to 355 nm or 385 to 410 nm. The peak wavelength of the second LED element 76 is preferably 300 to 355 nm, more preferably 325 to 355 nm, and even more preferably 335 nm.

The first LED element 72 and the second LED element 76 are selected so that the peak wavelengths of their respective lights are separated by 20 nm or more. The reason why the peak wavelengths of the light of the first and second LED elements 72 and 76 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.

When the peak wavelength of the first LED element 72 is set to, for example, 365 nm,
The peak wavelength of the second LED element 76 may be set to 345 nm or less, or may be set to 385 nm or more.

The dichroic mirror 80, which is a photosynthetic element, forms a thin film (dichroic film) 81 such as a dielectric multilayer film on a plate-shaped transparent medium 82 such as glass or plastic, and reflects light in a specific wavelength band. It is an optical element having a characteristic of transmitting light in other wavelength bands.
In the dichroic mirror 80, two dichroic mirrors 80A and 80B (two dichroic films 81) having substantially the same length L3 are along the optical axis direction L (that is, along the optical path EL) from the dichroic mirror 80 toward the fly-eye lens 65. It is arranged in a substantially V shape so as to be inclined with respect to the direction) and to be in close contact with the fly-eye lens side. In the present 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. 3). The LED array 71 is arranged. In addition, the second LED array is provided on both sides (upper and lower in FIG. 3) of the two V-shaped dichroic mirrors 80A and 80B, which intersect with the optical axis direction L (orthogonal in the present embodiment). 75 are arranged. As a result, both the first LED array 71 and the second LED array 75 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 optical axis direction L is not limited to the case where the second LED array 75 is strictly orthogonal, and the second LED array 75 is incident on the fly-eye lens 65. Including the case where the directionality of light is orthogonal to an allowable degree.

Note that the number of the second LED elements 76 of the second LED array 75 is half the number of the first LED elements 72 of the first LED array 71. That is, the length L2 of the second LED array 75 is approximately ½ of the length L1 of the first LED array 71, and 1 / √2 of the length L3 of the dichroic mirror 80A or 80B. Is. As a result, all the light emitted from the first LED array 71 is transmitted through the dichroic mirror 80A or 80B, and all the light emitted from the two second LED arrays 75 is dichroic mirror 80A or 80B. The light reflected from the first LED array 71 and the light emitted from the second LED array 75 are combined and incident on the incident surface of the fly-eye lens 65.

Thus, 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 the 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 V-shaped dichroic mirrors 80A and 80B, and the second LED array 75 is orthogonal to the optical axis direction L of the V-shaped dichroic mirrors 80A and 80B. By arranging the light source device 70 on both sides, 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.

In FIG. 3, the first LED array 71 has a main wavelength having a peak wavelength in any of 360 to 380 nm, and the second LED array 75 has a peak wavelength of, for example, 300 to 355 nm or 385 to 410 nm. As the sub-wavelength. However, the present embodiment is not limited to this, and the first LED array 71 has a sub-wavelength having a peak wavelength at, for example, 300 to 355 nm or 385 to 410 nm, and the second LED array 75 has a wavelength of 360 to 380 nm. It may be a main wavelength having a peak wavelength in either of them.

Further, since the reflected light by the dichroic mirrors 80A and 80B has better optical efficiency than the transmitted light, it can be appropriately selected according to the photosensitive sensitivity of the resist used. The lengths of the first LED array 71, the second LED array 75, and the dichroic mirrors 80A and 80B can also be changed according to the specifications.

The second LED array 75 passes through the interface of the dichroic mirror 80 once during reflection, whereas the first LED array 71 passes through the interface of the dichroic mirror 80 twice. Further, the light of the second LED array 75 is reflected by the dichroic mirror 80, but since the film thickness of the dichroic mirror 80 is proportional to the reflection wavelength, the shorter the wavelength of the reflected light, the thicker the film thickness. It can be made thinner and easier to manufacture. Therefore, when the dichroic mirror 80 is used, one having a relatively long peak wavelength is applied to the first LED array 71, and one having a relatively short peak wavelength is applied to the second LED array 75. Is preferable.

Specifically, preferred combinations of the peak wavelength of the first LED array 71 and the peak wavelength of the second LED array 75 include the following two combinations (A) and (B).
(A) Peak wavelength of the first LED array 71: 360 to 380 nm
Peak wavelength of the second LED array 75: 300-355 nm
(B) Peak wavelength of the first LED array 71: 385 to 410 nm
Peak wavelength of the second LED array 75: 360-380 nm

Further, in general, the exposure sensitivity when the color resist whose absorption peak wavelength range is adjusted to the i-line (365 nm) is exposed by using the LED element having each peak wavelength is confirmed by a test, and is shown in Table 1. The difference in sensitivity was obtained. Table 1 is based on 365 nm.

As can be seen from Table 1, for example, since the exposure sensitivity of light having a wavelength of 330 nm is three times that of light having a wavelength of 365 nm, the same performance can be obtained even if the output of the LED element of 365 nm is about 30%. Therefore, by combining two types of LED elements according to the absorption peak wavelength range of the resist, it is possible to shorten the exposure time and improve the efficiency of the exposure process.

As an example, when the second LED element 76 has a main wavelength of 365 nm and the first LED element 72 has a sub wavelength of 385 nm, the LED element in the long wavelength region (385 nm) is longer than the 365 nm LED element. Although the exposure sensitivity is low, the output is high and the transmittance is high due to the long wavelength. Specifically, as shown in FIG. 4, the 385 nm LED element arranged in the first LED array 71 has a transmittance of about 98%, and as shown in FIG. 5, the second LED array 75 has a transmittance. The arranged 365 nm LED element has a reflectance of about 100%, and the loss as a whole is about 2%. 4 is a graph showing the transmittance of the dichroic mirror 80, which is an example, and FIG. 5 is a graph showing the reflectance of the dichroic mirror 80 of FIG. In each graph, the light emitted from the LED elements 72 and 76 is in the range of angles θ1 and θ2 (see FIG. 3) substantially 42 ° to 48 ° with respect to the surfaces of the dichroic mirrors 80A and 80B by the condenser lens. Assuming that the light is incident on the dichroic mirrors 80A and 80B, the transmittance and reflectance at θ1, θ2 = 42 °, 45 °, and 48 ° are shown.

In this way, the exposure time can be shortened by combining the above two types of LED elements. As the combination of the two types of LED elements, those having a peak wavelength of 365 nm and those having a peak wavelength of 330 nm may be used, and the exposure time can be shortened with the same output.

Further, by combining the LED element having the main wavelength and the LED element having a wavelength longer than the main wavelength, the formed pattern can be stabilized.
For example, when exposure is performed using only a single-wavelength LED element having a peak wavelength of 365 nm, the pattern formed depending on the resist is weakly cured, and pattern peeling easily occurs in the developing process. The exfoliation is likely to occur at the end of the pattern, and is caused by the leak light passing through the pattern of the mask and the polymerization initiator of the resist. Normally, in order to suppress peeling, it is necessary to increase the exposure time or adjust the pre- and post-processes, but as in this example, the higher the output and the longer the wavelength, the higher the transmittance for the resist, and the deep part of the resist. It is possible to stabilize the pattern by using a combination of LED elements having a wavelength of 385 nm that light easily reaches.

(Second embodiment)
Next, the light source device 70 of the second embodiment will be described with reference to FIG. As shown in FIG. 6, in the light source device 70 of the present embodiment, both ends 83 of the two dichroic mirrors 80A and 80B are cut in parallel with the optical axis direction L from the dichroic mirror 80 toward the fly-eye lens 65. There is. 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. Light can be uniformly transmitted 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, improving efficiency.
Also in this case, 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.
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. 7, in the present embodiment, a method of fixing the two dichroic mirrors 80A and 80B described in the above embodiment using two dichroic mirror fixing frames 85 will be described.

In the dichroic mirror fixing frame 85, three frame bodies 85a, 85b, 85c covering three sides of the four sides of the rectangular dichroic mirrors 80A, 80B are combined in a substantially U-shape, and the dichroic mirrors 80A, 80B have the same shape. It has a shape that opens the side surfaces facing each other. Then, one side surface 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 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. 7, corresponding to the second embodiment, the tip portions 83 of the two dichroic mirrors 80A and 80B butted in a V shape and the dichroic mirror fixing frame 85 to which the dichroic mirrors 80A and 80B are fixed, respectively. The front end portion 85d of the ( frames 85b, 85c) is cut parallel to the optical axis direction L from the dichroic mirror 80 toward the fly-eye lens 65, and adheres so that there is no gap, preferably, there is no gap. ing.

Further, the tip portion 85d of the dichroic mirror fixing frame 85 ( frames 85b, 85c) combined in a V shape on the fly-eye lens side is cut at a right angle 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, the efficiency is improved, and the light source device 70 is made compact. You can 7B of the dichroic mirror fixing frame 85 ( frames 85a, 85b, 85c) supporting the dichroic mirrors 80A, 80B, the range outside the arrow is located 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. 8, the dichroic mirror fixing frame 85 has grooves 86 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 that shown in FIG. 7, the tip end portions 83 of the two dichroic mirrors 80A and 80B and the tip end portions 85d of the two dichroic mirror fixing frames 85 are in close contact with each other so that there is no gap. There is no adhesive.

(Fourth Embodiment)
Next, the light source device 70 of the fourth embodiment will be described with reference to FIG. As shown in FIG. 9, in the present embodiment, two types of two second LEDs are formed on a plane perpendicular to the optical axis direction L on the side of the two V-shaped dichroic mirrors 80A and 80B. Arrays 75A and 75B are arranged. Further, the two second LED arrays 75A and 75A on one side and the two second LED arrays 75B and 75B on the other side are alternately arranged at 90° intervals on the plane.

For example, the first LED array 71 uses an LED element 72 having a peak wavelength of 365 nm, while the second LED array 75A uses an LED element 76A having a peak wavelength of 385 nm, and the other second LED. The array 75B uses an LED element 76B having a peak wavelength of 330 nm. Then, when the first LED array 71 and one second LED array 75A are used, and when the first LED array 71 and the other second LED array 75B are used, two different types are used. The dichroic mirrors 80 and 90 of the above are switched and used. Therefore, the dichroic mirrors 80 and 90 are detachably arranged in a mirror mounting portion (not shown) with different mounting postures.
The dichroic mirror 90 is composed of two dichroic mirrors 90A and 90B, like the dichroic mirror 80 described in the first to third embodiments. However, in the present embodiment, the dichroic mirrors 80 and 90 have different characteristics of reflecting the characteristic wavelength band according to the two second LED elements 76A and 76B.

When switching the use of the second LED arrays 75A and 75B, the dichroic mirror 80 when using the first LED array 71 and the one second LED array 75A, the first LED array 71 and the other When the second LED array 75B is used, the dichroic mirror 90 is arranged so that the arrangement directions of the dichroic mirrors 80A, 80B, 90A, and 90B are orthogonal to each other on the plane.

As a result, when the light source device switches between the two types of the second LED elements 76A and 76B to allow exposure, the second LED arrays 75A and 75B can be replaced by simply replacing the dichroic mirrors 80 and 90. There is no need to replace the second LED arrays 75A and 75B, and the replacement work of the electric system and the cooling system becomes unnecessary.

Further, as a modified example of the present embodiment, the dichroic mirror 80 may be configured to be rotatable when the peak wavelengths of the two types of second LED arrays 75A and 75B are the same. Then, when the LED arrays 75A and 75B are used, the direction of the dichroic mirror 80 is rotated according to the LED arrays 75A and 75B to be used.

It should be noted that the present invention is not limited to the above-described embodiments, and can be modified, improved, and the like as appropriate.
For example, in the above-described embodiment, the light having different peak wavelengths is described to be combined by the dichroic mirror, but the light combining element of the present invention is not limited to this, and may be a dichroic prism.

As shown in FIG. 10, the dichroic prism 180 is a combination of three right- angle prisms 181, 182, 183 made of a material having a high transmittance such as glass or 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 °. It is 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 number of times 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 light incident surface and the light exit surface) of the dichroic prism 180. 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, in the above embodiment, the dichroic mirrors arranged in a V shape are used, and the light emitted from the two LED arrays is emitted to the fly-eye lens 65 via the dichroic mirrors. On the other hand, as the other optical device 70A of the present invention, as shown in FIG. 11, the dichroic mirrors 80A and 80B are not provided, and the optical device 70A is composed of only one LED array 78, and the LED array 78 is used as the fly-eye lens 65. They may be arranged directly facing each other.

In this case, the LED array 78 is arranged so that the first LED element 72 and the second LED element 76 are mixed and arranged. Therefore, the light emitted from the LED array 78 is mixed with the light of the first LED element 72 and the light of the second LED element 76, and is emitted to the fly-eye lens 65.

The peak wavelength of the light emitted from the second LED element 76 is any wavelength of 300 to 355 nm in accordance with the sensitivity of the peak wavelength (photosensitive wavelength) of the polymerization initiator of the photosensitive material. The peak wavelength of the light emitted from the LED element 72 of the above is any wavelength in the range of 360 to 380 nm, with the sensitivity adjusted to the absorption hem portion of the polymerization initiator. Specifically, the peak wavelength of the light emitted from the second LED element 76 is set to, for example, 335 nm, and the peak wavelength of the light emitted from the first LED element 72 is set to, for example, 365 nm. ing.

As a result, the resist can be efficiently exposed to light, a photosynthetic element such as a dichroic mirror for synthesizing light is not required, and the LED array 78 can be arranged close to the fly-eye lens 65, resulting in high efficiency. improves. Further, there is no need to restrict the wavelengths of light of the first and second LED elements 72 and 76 by 20 nm or more, and the peak wavelength can be freely set according to the sensitivity of the photosensitive material.

Further, as in still another modification shown in FIG. 12, 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
A second LED array 75 having a plurality of second LED elements 76 is arranged orthogonally, and a dichroic mirror 80 is arranged at a 45° angle with respect to the first LED array 71 and the second LED array 75. There is.

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

The color filter resist is prepared by mixing a polymerization initiator, a pigment, a polymerizable monomer, a polymer, and a solvent. As a polymerization initiator having an absorption peak in the range of 300 to 355 nm, the following (1) The items (1) to (10) are listed. Among these polymerization initiators, (9) Irgacure OXE01 and (10) Irgacure OXE02, which have high sensitivity, are preferable.

(1) Name: Omnirad184 (registered trademark), manufactured by IGM Resins BV (1-hydroxycyclohexyl-phenyl ketone)

(2) Name: Omnirad1173 (registered trademark), manufactured by IGM Resins BV (2-hydroxy-2-methyl-1-phenylpropanone)

(3) Name: Omnirad651 (registered trademark), manufactured by IGM Resins BV (2,2-dimethoxy-2-phenylacetophenone)

(4) Name: Omnirad2959 (registered trademark), manufactured by IGM Resins BV (1-[4-(2-hydroxyethoxyl)-phenyl]-2-hydroxy-methylpropanone)

(5) Name: Omnirad127 (registered trademark), manufactured by IGM Resins BV (2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one )

(6) Name: Omnirad369 (registered trademark), manufactured by IGM Resins BV (2-benzyl-2- (dimethylamino) -4'-morpholinobutyrophenone)

(7) Name: Omnirad379EG (registered trademark), manufactured by IGM Resins BV (2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one )

(8) Name: Omnirad MBF (registered trademark), IGM Resins BV (Methylbenzoylformate)

(9) Name: Irgacre OXE01 (registered trademark), manufactured by BASF Japan Ltd. (1,2-Octanedione, 1- [4- (phenylthio) phenyl]-, 2- (o-benzoyloxime)

(10) Name: Irgacre OXE02 (registered trademark), manufactured by BASF Japan Ltd. (Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-) acetyloxime)

Note that this application is based on a Japanese patent application (Japanese Patent Application No. 2019-038939) filed on March 4, 2019, the contents of which are incorporated herein by reference.

65 Fly- eye lens 70, 70A, 70B Light source device 71 First LED array 72 First LED element 75, 75A, 75B Second LED array 76, 76A, 76B Second LED element 78 LED array (light source device)
80, 80A, 80B Photosynthetic element (dichroic mirror)
81 dichroic film 83 edge 85 dichroic mirror fixing frame 180 photosynthetic element (dichroic prism)
M Mask PE Proximity Exposure Device W Work (Substrate)
L1 Length of the first LED array L2 Length of the second LED array

Claims (14)

1. A first LED array having a plurality of first LED elements that emit light having a first peak wavelength,
   A second LED array having a plurality of second LED elements that emit light having a second peak wavelength different from the first peak wavelength;
   A photosynthetic element that synthesizes the light of the first and second LED arrays, and
   A fly-eye lens into which the light synthesized by the photosynthetic element is incident, and
   A light source device for exposure, comprising:
   The photosynthetic element includes two dichroic films that transmit light in a specific wavelength band and reflect light in other wavelength bands, and the two dichroic films are optical axes from the photosynthetic element toward the fly-eye lens. It is arranged in a substantially V shape so as to be inclined with respect to the direction and to be in close contact with the fly-eye lens side.
   The first LED array is arranged on the opposite side of the fly-eye lens with respect to the light combining element in the optical axis direction,
   The light source device for exposure, wherein the second LED array intersects with the optical axis direction and is arranged laterally of the photosynthetic element.
2. The peak wavelength of light emitted from either the first LED element or the second LED element is 360 to 380 nm,
   The peak wavelength of the light emitted from either the first LED element or the second LED element is 300 to 355 nm or 385 to 410 nm.
   The light source device for exposure according to claim 1, wherein the peak wavelengths of the first LED element and the second LED element are separated by 20 nm or more.
3. The length of the second LED array arranged on the side of the photosynthetic element is
   The light source device for exposure according to claim 1, wherein the light source device for exposure is shorter than the length of the first LED array arranged on the opposite side of the fly-eye lens with respect to the light combining element.
4. The light source device for exposure according to any one of claims 1 to 3, wherein the photosynthetic element is two dichroic mirrors or dichroic prisms.
5. The photosynthetic element is two dichroic mirrors each having the dichroic film.
   The light source device for exposure according to claim 1, wherein an end portion of each of the dichroic mirrors is cut parallel to the optical axis direction.
6. Each of the dichroic mirrors is fixed, and two dichroic mirror fixing frames opened on the side where the two dichroic mirrors are in close contact with each other are further provided.
   The light source device for exposure according to claim 5, wherein the tip of the dichroic mirror fixing frame on the fly-eye lens side is cut at a right angle to the optical axis direction.
7. 7. The second LED array comprises two types of two second LED arrays alternately arranged at 90° intervals on a plane orthogonal to the optical axis direction. The light source device for exposure according to any one item.
8. A lighting device having a light source device for exposure according to any one of claims 1 to 7.
   A work support part for supporting the work,
   A mask support part for supporting the mask,
   An exposure device that irradiates the work with the light emitted from the lighting device through the mask and transfers the pattern of the mask to the work.
9. An exposure method of using the exposure apparatus according to claim 8 to irradiate the work irradiated with the light emitted from the illumination device through the mask to transfer the pattern of the mask onto the work.
10. A plurality of first LED elements that emit light having a first peak wavelength in the range of 360 to 380 nm corresponding to the photosensitive wavelength of the polymerization initiator of the photosensitive material provided on the substrate, and a first LED element in the range of 300 to 355 nm. A plurality of second LED elements that emit light having a peak wavelength of 2 and
    Equipped with
    A light source device for exposure, wherein the light of the first LED element and the light of the second LED element are mixed and emitted to a fly-eye lens.
11. The light source device for exposure according to claim 10, comprising an LED array in which the first LED element and the second LED element are arranged in a mixed manner.
12. A first LED array having the plurality of first LED elements,
    A second LED array having the plurality of second LED elements,
    A photosynthetic element that synthesizes the light of the first and second LED arrays, and
    Equipped with
    In the photosynthetic element, a dichroic film that transmits light in a specific wavelength band and reflects light in other wavelength bands is arranged so as to be inclined with respect to the optical axis direction from the photosynthetic element toward the fly-eye lens.
    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 photosynthetic element in the optical axis direction.
    11. The exposure apparatus according to claim 10, wherein the other one of the first LED array and the second LED array is arranged laterally of the photosynthesis element, intersecting with the optical axis direction. Light source device.
13. A lighting device having a light source device for exposure according to any one of claims 10 to 12.
    A work support part for supporting the work,
    A mask support part for supporting the mask,
    An exposure device that irradiates the work with the light emitted from the lighting device through the mask and transfers the pattern of the mask to the work.
14. An exposure method, wherein the exposure apparatus according to claim 13 is used to irradiate the work with the light emitted from the illumination device through the mask to transfer the pattern of the mask to the work.

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