WO2016194378A1 - Light source device, exposure device, and light source control method - Google Patents

Abstract

Disclosed are: a light source device capable of outputting, at a desired light quantity ratio, light having a plurality of different wavelengths; an exposure device provided with the light source device; and a light source control method. A light source device (19) is provided with a control unit (10), which generates output control signals for separately controlling an output of a first light emitting element and an output of a second light emitting element, and which outputs thus generated output control signals to the first light emitting element and the second light emitting element, respectively, said output control signals being generated on the basis of: a predetermined light quantity ratio between light having first wavelength characteristics and light having second wavelength characteristics; and light quantity measurement values outputted from a sensor that measures the quantity of the light having the first wavelength characteristics and the quantity of the light having the second wavelength characteristics, said light having the first wavelength characteristics and light having the second wavelength characteristics being included in output light accumulated by means of a light accumulating unit.

Description

Light source apparatus, exposure apparatus, and light source control method

The present invention relates to a light source device, an exposure device, and a light source control method.

Conventionally, a contact type exposure apparatus using a photomask has been widely used for circuit patterning using a photolithography method, that is, an exposure process. However, in recent years, in order to match the high definition and high density of circuits, exposure is performed by modulating light using a spatial light modulation element such as DMD (Digital Micromirror Device (registered trademark)) that does not use a photomask. Therefore, a direct drawing type exposure apparatus has been used (Patent Document 1 (Japanese Patent Laid-Open No. 2006-267719)). An exposure apparatus using a spatial light modulator is called a DI (direct image) exposure apparatus.
However, the light source used in the DI exposure apparatus often has a single wavelength in order to enable high-definition patterning. On the other hand, some exposed resists have a sensitivity in a wide wavelength range, and there are cases where a single wavelength does not sufficiently cure or the exposure time becomes long.
Therefore, in Patent Document 2 (Japanese Patent Laid-Open No. 2012-063390), a plurality of light sources having different wavelength characteristics, lenses corresponding to the plurality of light sources, and images formed by these lenses are superimposed and synthesized. A light source device including an optical synthesis element is disclosed.

JP 2006-267719 A JP 2012-063390 A

By the way, the wavelength of light includes a wavelength that contributes to the curing of the resist, a wavelength that contributes to the gloss of the resist, and the like, and the light amount ratio that indicates the ratio of the light amount for each wavelength optimum for exposure differs depending on the type of resist. However, in the technique described in Patent Document 2 (Japanese Patent Laid-Open No. 2012-063390), the light quantity ratio is only set at the time of design and cannot be adjusted thereafter. Therefore, when the resist is changed, it is not possible to perform exposure with light having an optimal light amount ratio according to the type of resist.
Moreover, the light emitting element which comprises a light source deteriorates by use for a long time, and illumination intensity falls. And the ratio of the fall of the illumination intensity differs for every light emitting element. For this reason, the light amount ratio changes due to long-term use, and stable exposure cannot be performed.
Accordingly, an object of the present invention is to provide a light source device that can emit light having a plurality of different wavelengths at a desired light amount ratio, an exposure apparatus including the light source device, and a light source control method.

In order to solve the above-described problem, an aspect of the light source device according to the present invention includes a first light emitting element that emits light having a first wavelength characteristic, and a second wavelength characteristic that is different from the first wavelength characteristic. A second light emitting element that emits the first light, an optical integration unit that integrates the outgoing light from the first light emitting element and the outgoing light from the second light emitting element, and light having the first wavelength characteristic A predetermined light amount ratio between the light having the second wavelength characteristic and the light amount having the first wavelength characteristic and the light having the second wavelength characteristic included in the emitted light integrated by the optical integration unit. Output control signals for individually controlling the outputs of the first light emitting element and the second light emitting element are generated based on the light intensity measurement values output from the sensors that respectively measure the light intensity of The output control signal is sent to each of the first light emitting element and the second light emitting element. And a control unit which forces the.
Thereby, the light of a several different wavelength can be radiate | emitted by the desired light quantity ratio. In addition, even when the illuminance of a light emitting element that emits light of a specific wavelength decreases due to aging, the output of light of each wavelength can be individually controlled, so the light quantity ratio can be kept constant. Stable light can be emitted.

Further, in the above light source device, the optical integrated unit includes a first optical fiber that receives light emitted from the first light emitting element at an incident end and emits light at the outgoing end, and the second light emitting element. A second optical fiber that enters the outgoing light at the incident end and emits the outgoing light at the outgoing end, and a third optical fiber that integrates the outgoing light of the first optical fiber and the outgoing light of the second optical fiber; And bundling the emission end sides of the first optical fiber and the second optical fiber in a predetermined arrangement, and the emission light of the first optical fiber and the emission light of the second optical fiber. It is also possible to construct a fiber bundle that integrates the light into the incident end of the third optical fiber.
Thus, it is necessary to strictly arrange a plurality of light emitting elements in a predetermined arrangement by bundling the emission ends of the first optical fiber and the second optical fiber and synthesizing lights having different wavelengths. In addition, the degree of freedom of installation can be improved. In addition, uniform light with no wavelength bias can be easily generated and emitted. Furthermore, since it is possible to easily increase the number of light emitting elements, it is easy to increase the illuminance.

The light source device further includes an output unit that outputs the emitted light collected by the optical integration unit to an exposure head provided in an exposure apparatus, and the control unit includes the output unit on the exposure surface of the exposure apparatus. The light quantity measurement value measured by the sensor may be acquired. As described above, by individually controlling the outputs of the first light emitting element and the second light emitting element using the light quantity measurement value measured on the exposure surface, the emitted light can be adjusted to light suitable for exposure. it can.
The light source device may further include an output unit that outputs the emitted light collected by the optical integrating unit to an exposure head provided in an exposure apparatus, and the control unit emits the emitted light from the output unit. The light quantity measurement value measured by the sensor may be acquired at the light incident portion of the exposure head where the light is incident. In this way, by measuring the amount of light at the light incident portion of the light from the output portion to the exposure head, high-precision measurement can be performed.

Furthermore, in the above light source device, the control unit sends a control signal for individually turning on and off the first light emitting element and the second light emitting element to the first light emitting element and the second light emitting element. The first light-emitting element and the first light-emitting element measure the light amount of the first wavelength characteristic measured when the first light-emitting element is turned on and the second light-emitting element is turned off. The light amount measurement value of the light having the second wavelength characteristic measured when the light emitting element is turned off and the second light emitting element is turned on may be acquired from one sensor. In this way, the amount of light can be measured by one sensor, so that it is possible to prevent a decrease in measurement accuracy due to individual differences between sensors.

In the light source device, the light emitting element may be a laser diode or a light emitting diode. Thereby, it is possible to easily realize a light source device that emits light including a plurality of different wavelengths.
Furthermore, in the above light source device, an output unit that includes a plurality of the optical integration units and outputs the emitted light respectively integrated by the plurality of optical integration units to a plurality of exposure heads provided in an exposure apparatus. The control unit further includes the light amount measurement value measured by the sensor for each of the plurality of exposure heads, and is emitted from the exposure head between the plurality of exposure heads based on the light amount measurement value. You may correct | amend the light quantity difference of the light to be performed. Thereby, the dispersion | variation in the output between exposure heads can be suppressed.

According to another aspect of the exposure apparatus of the present invention, any one of the light source devices described above, an exposure head on which light emitted from the light source device is incident, the light amount of the light having the first wavelength characteristic, and the first And a sensor for measuring the light quantity of the light having the two wavelength characteristics. In this case, optimal exposure conditions can be provided by the light source device, and stable and appropriate exposure is possible.
Further, in the above exposure apparatus, the exposure head includes a spatial light modulation unit in which pixel units that modulate light from the light source device are arranged, and exposes a photosensitive material with light modulated by the spatial light modulation unit. You may let them. Thereby, stable and appropriate exposure is possible in the DI exposure apparatus.

In one aspect of the light source control method according to the present invention, the emitted light having the first wavelength characteristic emitted from the first light emitting element and the first wavelength characteristic emitted from the second light emitting element When the light having different second wavelength characteristics is integrated and output to the outside, the light having the first wavelength characteristics and the light having the first wavelength characteristics included in the emitted light integrated by the optical integration unit, measured by a sensor. In the acquisition step of acquiring the respective light quantity measurement values with the light of the second wavelength characteristic, the predetermined light quantity ratio of the light of the first wavelength characteristic and the light of the second wavelength characteristic, and in the acquisition step A generation step for generating an output control signal for individually controlling outputs of the first light emitting element and the second light emitting element based on the acquired light quantity measurement value, and the generation generated in the generation step The output control signal is sent to the first Comprising an output step of outputting each of the optical element and the second light-emitting element.
Thereby, the light of a several different wavelength can be radiate | emitted by the desired light quantity ratio. In addition, even when the illuminance of a light emitting element that emits light of a specific wavelength decreases due to aging, the output of light of each wavelength can be individually controlled, so the light quantity ratio can be kept constant. Stable light can be emitted.

According to the light source device of the present invention, it is possible to emit light having a plurality of different wavelengths at a desired light quantity ratio. Therefore, according to the exposure apparatus provided with the light source device, it is possible to perform exposure with light having an optimal light amount ratio according to the type of resist.
The above-described objects, aspects, and advantages of the present invention, and objects, aspects, and effects of the present invention that have not been described above will be understood by those skilled in the art to implement the following invention by referring to the attached drawings and the claims. This will be understood from the following description (detailed description of the invention).

FIG. 1 is a schematic block diagram showing an example of an exposure apparatus in the present embodiment. FIG. 2 is a schematic configuration diagram illustrating an example of a light source unit included in the light source device. FIG. 3 is a schematic block diagram showing an example of an exposure head. FIG. 4 is a control block diagram of the light quantity ratio control. FIG. 5 is a flowchart showing the light quantity ratio control processing procedure. FIG. 6 is a control block diagram of total light quantity control. FIG. 7 is a flowchart showing the total light amount control processing procedure. FIG. 8 is a diagram showing the wavelength distribution of the mercury lamp. FIG. 9 is a diagram illustrating an example of the wavelength distribution of the laser diode.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic block diagram showing an exposure apparatus 100 in the present embodiment.
The exposure apparatus 100 is an apparatus that exposes light that has been modulated by a spatial light modulation unit (spatial light modulation element) through an imaging optical system, and forms an image of the light on a photosensitive material (resist). Since such an exposure apparatus directly forms an image with a spatial light modulation element, no mask (or reticle) is required, and it is called a DI (direct image) exposure apparatus.
The exposure apparatus 100 is formed in a substantially rectangular flat plate shape, and is arranged horizontally, and a movable stage 13 that is slidably attached to the base 11 and holds a substrate (workpiece) 12 to be exposed on the surface. And an exposure unit 14 that exposes the substrate 12 held on the moving stage 13.

The substrate 12 is, for example, a printed wiring board or a glass substrate for flat panel display in which a photosensitive material is applied or pasted on the surface. The exposure apparatus 100 exposes the substrate 12 to record, for example, a wiring pattern or the like on the photosensitive material of the substrate 12 without a mask. In this embodiment, the moving direction of the moving stage 13 is described as the Y direction, the direction orthogonal to the Y direction on the horizontal plane (the width direction of the substrate 12) is set as the X direction, and the vertical direction orthogonal to the horizontal plane is described as the Z direction. The base 11 is formed long in the Y direction.

The base 11 is supported by a plurality of legs 15 (for example, four attached to each of the four corners). Two guide rails 16 substantially parallel to the Y direction are provided on the upper surface 11 a of the base 11. The moving stage 13 is attached to the base 11 through a guide rail 16 so as to be slidable in the Y direction. In addition, the moving stage 13 is provided with an electromagnet 16a that configures the moving mechanism of the moving stage 13 as an example. In the present embodiment, a linear motor stage is employed as the moving mechanism. The linear motor stage applies a magnetic force to a moving body on a planar platen provided with a ferromagnetic convex pole in a grid pattern or a line shape, and between the moving body and the convex pole of the platen. It is a mechanism that moves the moving body by changing the magnetic force. The moving stage 13 moves in the Y direction according to the driving of the moving mechanism. As the moving mechanism, for example, a mechanism using a ball screw can be adopted.

The exposure unit 14 is attached to the center of the base 11 in the Y direction via a pair of support columns 17. Each column 17 is fixed to both ends of the base 11 in the X direction. Each column 17 holds the exposure unit 14 at a predetermined distance from the upper surface 11a of the base 11 so that the movement stage 13 passes directly under the exposure unit 14 when the movement stage 13 moves in the Y direction.
The exposure unit 14 includes a plurality (16 in FIG. 1) of exposure heads 18 arranged in a substantially matrix of m rows and n columns. These exposure heads 18 irradiate light onto the substrate 12 that passes directly below. A specific configuration of the exposure head 18 will be described later.

In FIG. 1, eight exposure heads 18 are arranged in two rows in the Y direction, eight in the X direction. The exposure heads 18 in the second row are arranged in the X direction with respect to the exposure heads 18 in the first row so that their centers are located near the centers of the adjacent ones of the exposure heads 18 in the first row. They are shifted by 1/2 pitch. By disposing in this way, the portion that cannot be exposed by each exposure head 18 in the first row is exposed by each exposure head 18 in the second row, and exposure recording is performed in the X direction of the substrate 12 without any gap. Note that the number and arrangement of the exposure heads 18 provided in the exposure unit 14 may be appropriately changed according to the size of the substrate 12 and the like.
Laser light is incident on each exposure head 18 from the light source device 19 through the optical fiber 20. In the present embodiment, the light source device 19 mixes a plurality of lights having different wavelengths and outputs them to each exposure head 18. The configuration of the light source device 19 will be described in detail later.

Image data (image information) corresponding to a wiring pattern or the like recorded on the substrate 12 is input to the image processing unit 21. The image processing unit 21 creates frame data for each exposure head 18 to be written based on the input image data. Then, the image processing unit 21 inputs frame data to each exposure head 18 via the signal cable 22. The frame data is, for example, data representing the density of each pixel constituting the image with binary values (whether or not dots are recorded).
Each exposure head 18 modulates the laser light incident from the light source device 19 based on the frame data, and projects the modulated light onto the substrate 12 conveyed by the moving stage 13. As a result, an image corresponding to the image data input to the image processing unit 21 is exposed and recorded on the substrate 12.

The base 11 is further provided with a gate-like gate 23 and a pair of length measuring devices 24 attached to one end in the Y direction. The gate 23 is attached to the base 11 substantially parallel to the X direction so as to straddle each guide rail 16. A plurality of (three in FIG. 1) cameras 25 are attached to the gate 23. Each camera 25 is connected to a controller (not shown) that controls the overall exposure apparatus 100.
The camera 25 images the moving stage 13 passing through the gate 23 and outputs the acquired image data to the controller. Based on the image data acquired by the camera 25, the controller calculates the amount of shift in the X direction, Y direction, and θ direction (rotation direction about the Z direction) of the substrate 12 with respect to the appropriate position on the moving stage 13. To do. The calculated shift amount is input to the image processing unit 21 and used for correcting the frame data. Note that the number and arrangement interval of the cameras 25 may be appropriately changed according to the size of the substrate 12 and the like. The amount of deviation may be calculated by well-known image processing. At this time, an alignment mark or the like may be provided on the substrate 12 so that the amount of deviation can be easily calculated.

Each length measuring device 24 is connected to the controller in the same manner as each camera 25. Each length measuring device 24 measures the position of the moving stage 13 by irradiating the side end surface of the moving stage 13 with laser light and receiving the reflected light. Each length measuring device 24 outputs the measured position of the moving stage 13 to the controller. In the present embodiment, the so-called laser interference type length measuring device 24 is shown. However, the present invention is not limited to this, and for example, the position of the movable stage 13 can be measured using an ultrasonic wave or a stereo camera. Any other material may be used.

(Configuration of light source device 19)
Next, the configuration of the light source device 19 will be described.
The light source device 19 includes a plurality of light source units that are provided so as to correspond to the plurality of exposure heads 18 and inject light, which is obtained by synthesizing a plurality of light beams having different wavelengths, into each exposure head 18.
FIG. 2 is a schematic configuration diagram illustrating an example of the light source unit 19 a that configures the light source device 19. In FIG. 2, only one light source unit 19a corresponding to one exposure head 18 is shown. Actually, the light source device 19 includes the same number of light source units 19 a as the exposure head 18.
The light source unit 19 a includes a plurality of light sources (LD modules) 1 and 2. Each of the light sources 1 and 2 includes one laser diode (LD), which is a light emitting element, and a condenser lens. The light source 1 and the light source 2 include LDs that emit laser beams having different wavelengths (wavelength A and wavelength B). In the example illustrated in FIG. 2, the light source unit 19 a includes three light sources 1 and one light source 2, and includes a total of three sets and twelve light sources. Light emitted from the light sources 1 and 2 is guided to the connector 4 by the LD optical fiber 3, respectively.

The light emitted from the light sources 1 and 2 has a wavelength characteristic in the range of 190 nm to 530 nm. For example, light of wavelength A of the light source 1 has a first wavelength characteristic having a peak near 375 nm, and light of wavelength B of the light source 2 has a second wavelength characteristic having a peak near 405 nm.
The light sources 1 and 2 are configured such that lighting, non-lighting (extinguishing), and output illuminance thereof can be individually controlled by the control unit 10. The light sources 1 and 2 may be configured to be individually controlled by the control unit 10 or may be configured to be controlled for each group (set).

A first optical fiber 5 is connected to each connector 4, and light emitted from each of the light sources 1 and 2 enters at the incident end of the first optical fiber 5, and enters from the output end of the first optical fiber 5. It is comprised so that it may radiate | emit. The emission ends of the first optical fibers 5 are bundled in a predetermined arrangement for each set of light sources, and are connected to the second optical fiber 7 via a common first connector 6.
The first optical fiber 5, the first connector 6, and the second optical fiber 7 constitute a first fiber bundle part B1. That is, light emitted from three light sources 1 and one light source 2 is input to one first fiber bundle portion B1 via four first optical fibers 5 and passes through the first connector 6. Then, it is configured to be integrated into one second optical fiber 7. The second optical fiber 7 has a core having a size equal to or larger than that of the light emission region in a state where four first optical fibers 5 are bundled.

In the example shown in FIG. 2, since the light source unit 19a includes three sets of light sources, it includes three first fiber bundle portions B1. That is, a total of 12 LD modules are integrated in the three second optical fibers 7 in the three first fiber bundle portions B1.
The second optical fiber 7 is a multi-mode optical fiber, and is configured to be uniformized by interference of light in the fiber and interaction between modes.
The three second optical fibers 7 are guided to a common second fiber bundle part B2. The emission ends of the three second optical fibers 7 are bundled in a predetermined arrangement according to the shape of the light irradiation region to the DMD 42b in the exposure head 18 described later in the second fiber bundle portion B2, and the optical fiber described above The third optical fiber 8 corresponding to 20 is obtained. The third optical fiber 8 is configured such that its emission end is connected to an incident optical system 41 in an exposure head 18 to be described later via a second connector 9 and guides laser light to the exposure head 18. The second connector 9 is an output unit that outputs the emitted light integrated by the first fiber bundle unit B1 and the second fiber bundle unit B2 to the exposure head 18.

Thus, since the light source unit 19a bundles the output ends of the first optical fiber 5 and the second optical fiber 7 and combines the laser light from the light sources 1 and 2, the light sources 1 and 2 are arranged in a predetermined arrangement. Therefore, the degree of freedom of installation of the light sources 1 and 2 can be improved. Furthermore, since it is possible to easily increase the number of light emitting elements (LD), it is easy to increase the illuminance.
In addition, it is preferable to set the arrangement pattern when the first optical fiber 5 and the second optical fiber 7 are bundled so that there is no positional deviation for each wavelength. Thereby, it is possible to irradiate uniform light with no wavelength deviation on the DMD 42b surface described later.
In FIG. 2, the first optical fiber 5 that enters the light emitted from the LD of the light source 1 that is the first light emitting element at the incident end and emits the light from the output end corresponds to the first optical fiber. The first optical fiber 5 that enters the light emitted from the LD of the light source 2 that is the light emitting element at the incident end and emits the light from the light emitting end corresponds to the second optical fiber. Further, the second optical fiber 7 and the third optical fiber 8 that integrate the first optical fiber 5 correspond to the third optical fiber that integrates the outgoing light of the first optical fiber and the outgoing light of the second optical fiber. is doing.

(Configuration of exposure head 18)
Hereinafter, the configuration of the exposure head 18 will be described with reference to FIG.
FIG. 3 is a schematic block diagram of the exposure head 18. As shown in FIG. 3, the exposure head 18 includes an incident optical system 41, a light modulator 42, a first imaging optical system 43, a microlens array (MLA) 44, and a second imaging optical system 45. And a focus adjustment unit 46.
The incident optical system 41 includes a condenser lens 41a, a transflective optical element 41b, an optical integrator 41c, an imaging lens 41d, and a mirror 41e. Laser light emitted from the light source unit 19a is incident on the condensing lens 41a and condenses the incident laser light. The semi-transmissive optical element 41b is a half mirror, for example, and transmits part of the laser light collected by the condenser lens 41a and reflects part of it.

The optical integrator 41c is disposed on the optical path of the laser light reflected by the semi-transmissive optical element 41b. The optical integrator 41c is, for example, a translucent rod formed in a quadrangular prism shape. The optical integrator 41c converts the laser light traveling inside while being totally reflected into a light beam that is close to parallel light and has a uniform beam cross-sectional intensity. As a result, a high-definition image without variations in illumination light intensity is exposed on the substrate 12. Note that an antireflection film may be coated on the incident end face and the exit end face of the optical integrator 41c in order to increase the light transmittance.
The imaging lens 41d forms an image of the laser beam that has passed through the optical integrator 41c, and enters the mirror 41e. The mirror 41 e reflects the laser light imaged by the imaging lens 41 d and enters the light modulation unit 42.

The light modulation unit 42 includes a TIR (Total Internal Reflection) prism 42a and a DMD (Digital Micromirror Device) 42b which is a spatial light modulation element. The TIR prism 42a reflects the laser beam incident through the mirror 41e toward the DMD 42b. The DMD 42b is a mirror device in which micromirrors constituting pixels are provided on a memory cell (for example, SRAM cell) arranged two-dimensionally and supported by a column so as to be tiltable.
The DMD 42b reflects the irradiated laser beam toward the first imaging optical system 43 according to the digital signal written in the SRAM cell, and the irradiated laser beam is a light absorber not shown. The inclination angle of the micromirror is changed to the state of reflecting toward the screen. The light modulation unit 42 generates image light corresponding to the frame data by controlling the inclination of the micromirror of each pixel of the DMD 42b according to the frame data input from the image processing unit 21.

The first imaging optical system 43 includes lenses 43 a and 43 b, and enlarges the image light generated by the light modulation unit 42 to a predetermined magnification and forms an image on the MLA 44.
For example, the MLA 44 is formed in a substantially rectangular flat plate shape using quartz glass. In addition, the MLA 44 is formed with a plurality of microlenses arranged two-dimensionally corresponding to each pixel of the DMD 42b. Each microlens is a plano-convex lens having a flat upper surface and a convex lower surface. Each microlens individually images the image light from each micromirror of the DMD 42 b and sharpens the image light enlarged by the first imaging optical system 43. Note that the shape of each microlens is not limited to a plano-convex lens, and may be, for example, a biconvex lens.
The second imaging optical system 45 includes lenses 45a and 45b, and enlarges the image light that has passed through the MLA 44 to a predetermined magnification, or enters the prism pair 46 at an equal magnification. The prism pair 46 is provided so as to be movable in the vertical direction, and adjusts the focus of the image light on the substrate 12 by moving up and down.

In addition, a light receiving sensor 51 for measuring the amount of laser light that has passed through the semi-transmissive optical element 41 b is provided in the vicinity of the semi-transmissive optical element 41 b in each exposure head 18. The light receiving sensor 51 receives the laser light at the light incident part (incident optical system 41) of the exposure head 18 to which the laser light emitted from the light source part 19a is incident, and measures the amount of the received laser light. One exposure sensor 52 for measuring the amount of laser light emitted from each exposure head 18 toward the exposure surface is provided on the exposure surface (base 11 or moving stage 13) of the exposure apparatus 100.
In the present embodiment, the light receiving sensor 51 and the light receiving sensor 52 are sensors having equivalent sensitivity to light in the same wavelength band. The light receiving sensor may be provided for each light source, or may be built in the light source.

The control unit 10 acquires the light amount measurement value output from the light receiving sensor 51, and based on the acquired light amount measurement value, the light amount ratio that is the ratio of the light amount of the light of the wavelength A and the light of the wavelength B is a predetermined light amount. The outputs of the light source 1 and the light source 2 are individually controlled so that the ratio (target value) is obtained (light quantity ratio control). Here, the target value can be appropriately set according to the type of resist, the target finish state (appearance such as gloss), and the like.
Moreover, the control part 10 acquires the light quantity measurement value which the light reception sensor 52 output, and controls the output of the light source 1 and the light source 2 separately based on the acquired light quantity measurement value, thereby the plurality of exposure heads 18. The light amount difference (total light amount difference) of the light emitted from the exposure head 18 is corrected (total light amount control). In the present embodiment, the outputs of the light source 1 and the light source 2 are controlled so that the total light amount on the exposure surface is the same for all the exposure heads 18.

(Light ratio control)
Hereinafter, the light amount ratio control will be described in detail.
FIG. 4 is a control block diagram of the light quantity ratio control. As shown in FIG. 4, the control unit 10 includes a light amount ratio calculation unit 10a and a light source output control unit 10b. In the light source part 19a, the light emitted from the light sources 1 and 2 is bundled by the fiber bundle part B (first fiber bundle part B1 and second fiber bundle part B2). The light receiving sensor 51 measures the amount of light immediately after being emitted from the light source unit 19a, and outputs the light amount to the light amount ratio calculation unit 10a as a light amount measurement value (digital value).
The light quantity ratio calculation unit 10a inputs the light quantity measurement value for each wavelength output from the light receiving sensor 51, and calculates the light quantity ratio. The control unit 10 turns on and off the light source 1 and the light source 2 individually, and acquires a light amount measurement value from the light receiving sensor 51 when one of the light sources 1 and 2 is on and the other is off. In other words, the light receiving sensor 51 measures the light amount of the light having the wavelength A from the light source 1 and the light amount of the light having the wavelength B from the light source 2, and outputs each light amount measurement value to the control unit 10.

Further, the light quantity ratio calculation unit 10a calculates the outputs of the light sources 1 and 2 such that the light quantity ratio becomes a target value (for example, 10: 1) based on the calculated light quantity ratio, and outputs the calculated result as output control. It outputs to the light source output control part 10b as quantity instruction | indication value. The light source output control unit 10b outputs an output control signal for controlling the current flowing through the LD of each of the light sources 1 and 2 to the light sources 1 and 2 based on the output control amount instruction value. Controls the amount of light emitted.
In FIG. 4, one light source 1 and two light sources are illustrated, but actually there are a plurality of light sources 1 and 2. The outputs of the light sources 1 and 2 can be individually controlled, so that the light quantity ratio of the light emitted from the light source unit 19a can be freely adjusted. By grouping for each wavelength and turning ON / OFF, the light quantity can be measured for each wavelength even with one light receiving sensor 51, and the light quantity ratio can be calculated.

FIG. 5 is a flowchart showing a light amount ratio control processing procedure executed by the control unit 10. The processing shown in FIG. 5 can be executed at a predetermined timing for adjusting the light amount ratio, for example, before the exposure by the exposure apparatus 100 is started. Note that the adjustment of the light quantity ratio may be performed at a predetermined time or may be performed at an arbitrary timing instructed by the operator.
First, in step S <b> 1, the control unit 10 outputs a control signal for turning on the light source 1 with a predetermined output and turning off the light source 2 to the light sources 1 and 2. Here, the predetermined output may be a predetermined initial value or may be an output value at the time of the previous exposure. Thus, the control part 10 lights only the light source 1, and transfers to step S2. In step S <b> 2, the control unit 10 acquires a light amount measurement value from the light receiving sensor 51. The light quantity measurement value acquired at this time is the light quantity of light of wavelength A emitted from the light source unit 19a.

Next, in step S <b> 3, the control unit 10 outputs a control signal for turning on the light source 2 with a predetermined output and turning off the light source 1 to the light sources 1 and 2. Here, the predetermined output may be a predetermined initial value or may be an output value at the time of the previous exposure. Thus, the control part 10 lights only the light source 2, and transfers to step S4. In step S <b> 4, the control unit 10 acquires a light amount measurement value from the light receiving sensor 51. The light quantity measurement value acquired at this time is the light quantity of the light having the wavelength B emitted from the light source unit 19a.
In step S5, the control unit 10 calculates a light amount ratio based on the light amount measurement value of the wavelength A acquired in step S2 and the light amount measurement value of the wavelength B acquired in step S4. Next, in step S6, the control unit 10 calculates an output control amount instruction value such that the light amount ratio calculated in step S5 becomes a target value (for example, 10: 1). As a preliminary preparation, for each of the light sources 1 and 2, the change in the amount of light when the current value is changed is measured in advance, and the output characteristics of the light sources 1 and 2 are stored. And the control part 10 calculates the output control amount instruction | indication value from which the light quantity ratio becomes a target value based on the output characteristic of the light sources 1 and 2 memorize | stored beforehand. In step S <b> 7, the control unit 10 generates an output control signal based on the output control amount instruction value calculated in step S <b> 6, and outputs the generated output control signal to the light sources 1 and 2, thereby outputting the light sources 1 and 2. Are controlled individually. Thereby, the light quantity ratio can be made to coincide with the target value set according to the type of resist and the target finish state (appearance such as gloss).

(Total light control)
Next, the total light quantity control will be described in detail.
FIG. 6 is a control block diagram of total light quantity control. As shown in FIG. 6, the control unit 10 includes a light amount ratio calculation unit 10c and a light source output control unit 10d. In the light source part 19a, the light emitted from the light sources 1 and 2 is bundled by the fiber bundle part B (first fiber bundle part B1 and second fiber bundle part B2) and emitted. The light emitted from each light source unit 19a is incident on the exposure head 18 (optical system), and is emitted from the exposure head 18 to the exposure surface. The light receiving sensor 52 measures the light amount of light emitted from the exposure head 18 on the exposure surface, and outputs the light amount measurement value (digital value) to the light amount ratio calculation unit 10c.

The light quantity ratio calculation unit 10c inputs the light quantity measurement value for each wavelength output from the light receiving sensor 52 for each exposure head 18, and calculates the light quantity ratio. The control unit 10 turns on and off the light source 1 and the light source 2 individually, and acquires a light amount measurement value from the light receiving sensor 52 when one of the light sources 1 and 2 is on and the other is off. That is, the light receiving sensor 52 measures the light amount of the light with the wavelength A from the light source 1 and the light amount of the light with the wavelength B from the light source 2 in the same manner as the light receiving sensor 51 described above, and the respective light amount measurement values are measured. Output to the control unit 10.
In addition, the light amount ratio calculation unit 10 c calculates the total light amount on the exposure surface for each exposure head 18. Then, the light quantity ratio calculation unit 10c calculates and calculates the outputs of the light sources 1 and 2 such that the total light quantity on the exposure surface is equal for all the exposure heads 18 while keeping the light quantity ratio obtained by calculation constant. The result is output to the light source output control unit 10d as an output control amount instruction value. The light source output control unit 10d outputs an output control signal for controlling the current flowing through the LD of each of the light sources 1 and 2 to the light sources 1 and 2 based on the output control amount instruction value. Controls the amount of light emitted.

The control unit 10 may acquire the light amount measurement value from the light receiving sensor 52 when both the light source 1 and the light source 2 are lit. That is, the light receiving sensor 52 can measure the amount of light including both the light with the wavelength A from the light source 1 and the light with the wavelength B from the light source 2, and can output the measured light amount to the control unit 10. As described above, the light receiving sensor 51 described above is used as a sensor for separately measuring the amount of light for each wavelength in each exposure head 18, and the light receiving sensor 52 directly determines the total amount of light on the exposure surface for each exposure head 18. You may use as a sensor to measure.
In this case, the light amount ratio calculation unit 10c keeps the light amount ratio obtained by the light amount comparison calculation unit 10a constant based on the total light amount on the exposure surface for each exposure head 18 measured by the light receiving sensor 52. What is necessary is just to calculate the outputs of the light sources 1 and 2 such that the total light amount on the exposure surface is the same for all the exposure heads 18 and output the calculated result to the light source output control unit 10d as the output control amount instruction value. With this configuration, when the light quantity measurement value is acquired from the light receiving sensor 52, it is not necessary to individually turn on and off the light sources 1 and 2, and the control can be simplified.

FIG. 7 is a flowchart showing the total light amount control processing procedure executed by the control unit 10. The processing shown in FIG. 7 can be performed after performing a predetermined timing for adjusting the total light amount, for example, the light amount ratio control described above. However, the timing for adjusting the total light amount is not limited to the above.
First, in step S11, the control unit 10 turns on only the light source 1 in the light source unit 19a corresponding to the predetermined exposure head 18 selected as the measurement target, similarly to step S1 in FIG. 5, and proceeds to step S12. In step S <b> 12, the control unit 10 acquires a light amount measurement value from the light receiving sensor 52. The light quantity measurement value acquired at this time is the light quantity of light of wavelength A emitted from the light source unit 19a.

Next, in step S13, the control unit 10 turns on only the light source 2 in the light source unit 19a corresponding to the predetermined exposure head 18 selected as the measurement target, similarly to step S3 in FIG. 5, and proceeds to step S14. In step S <b> 14, the control unit 10 acquires a light amount measurement value from the light receiving sensor 52. The light quantity measurement value acquired at this time is the light quantity of the light having the wavelength B emitted from the light source unit 19a.
In step S15, the control unit 10 calculates a light amount ratio based on the light amount measurement value of the wavelength A acquired in step S12 and the light amount measurement value of the wavelength B acquired in step S14. Next, in step S16, the control unit 10 calculates the total light amount based on the light amount measurement value of the wavelength A acquired in step S12 and the light amount measurement value of the wavelength B acquired in step S14.
In step S <b> 17, the control unit 10 determines whether or not the total light amount has been measured for all the exposure heads 18. If the total light amount has not been measured for all the exposure heads 18, the unmeasured exposure head 18 is selected as the measurement target of the total light amount, and the process returns to step S11. On the other hand, if the total light amount has been measured for all the exposure heads 18, it is determined that the measurement has been completed, and the process proceeds to step S18.

In step S18, the control unit 10 calculates an output control amount instruction value so that the total light amounts in the exposure heads 18 are all equal while maintaining the light amount ratios in the exposure heads 18 at the light amount ratios calculated in step S15. . In step S19, the control unit 10 generates an output control signal based on the output control amount instruction value calculated in step S18, and outputs the generated output control signal to the light sources 1 and 2 to output the light sources 1 and 2. Are controlled individually.
If the intensity of the light emitted from the plurality of exposure heads 18 is different, there will be a difference in the finish of the substrate 12 after exposure. Therefore, in this embodiment, the total light amount is measured for each exposure head 18 by the light receiving sensor 52 installed on the exposure surface. Then, the output of the light sources 1 and 2 is controlled so that the total light amount becomes equal in all the exposure heads 18 while keeping the light amount ratio for each wavelength constant. Thereby, variation in the amount of light between the exposure heads 18 can be suppressed, and appropriate exposure processing with reduced processing unevenness can be performed.

As described above, in the present embodiment, the light source device 19 includes the light source 1 having the LD that emits the light having the wavelength A, the light source 2 having the LD that emits the light having the wavelength B, and the light emitted from the light source 1. And a fiber bundle unit that integrates light emitted from the light source 2. In this way, the light source device 19 synthesizes light of a plurality of different wavelengths and outputs them to the exposure head 18.
Conventionally, mercury lamps have been widely used as light sources for exposure apparatuses. As shown in FIG. 8, the mercury lamp has a wavelength distribution in which intensity peaks are respectively formed at a wavelength of 365 nm, a wavelength of 405 nm, and a wavelength of 436 nm. Therefore, the resist used for exposure is often designed to be sensitive to each peak wavelength of the mercury lamp. However, the LD light source emits light having a single wavelength of 405 nm, for example, as shown in FIG. Therefore, when one LD is used as the light source, the resist may not be sufficiently cured or the exposure time may be longer than when a mercury lamp is used.

On the other hand, as described above, the light source device 19 in the present embodiment uses a plurality of LDs that emit light having different wavelengths, and synthesizes and emits light having different wavelengths. As the light source, a light source 1 having a wavelength characteristic having a peak near 375 nm and a light source 2 having a wavelength characteristic having a peak near 405 nm are used. In this way, since light having a plurality of different wavelengths is synthesized using a light source having a peak near the peak wavelength of the mercury lamp, light close to the mercury lamp can be emitted, and appropriate exposure becomes possible.
The light source device 19 calculates a light amount ratio between the light of the wavelength A and the light of the wavelength B based on the light amount measurement values of the light of the wavelength A and the light of the wavelength B, and the calculated light amount ratio is the target. The output of the light sources 1 and 2 is individually controlled so as to be a value. Therefore, it is possible to adjust the exposure to light having an optimal light amount ratio according to the type of resist.

The light source 1 emits light having a wavelength characteristic having a peak near 375 nm, and the light source 2 emits light having a wavelength characteristic having a peak near 405 nm. Light having a wavelength of 405 nm mainly contributes to the curing of the resist, and light having a wavelength of 375 nm mainly contributes to the appearance such as gloss of the resist. Therefore, by adjusting the light amount ratio, it is possible to adjust the appearance such as gloss to a desired state even with the same resist. Furthermore, even if the illuminance of a light emitting element (LD) that emits light of a specific wavelength is reduced due to deterioration over time, the light quantity ratio can be kept constant by controlling the output of light of each wavelength, so that it is stable. Exposure is possible.
Here, the light intensity measurement values of the light of wavelength A and the light of wavelength B are the light receiving sensors provided in the light incident part of the exposure head 18 where the light emitted from the light source device 19 (light source part 19a) is incident. Measured by 51. As described above, the light receiving sensor 51 measures the amount of light immediately after emitted from the light source device 19 (light source unit 19a). Therefore, the light receiving sensor 51 can accurately measure the light amount for each wavelength, and the light source device 19 can appropriately control the light amount ratio. As a result, the light source device 19 can emit light having a plurality of different wavelengths at a desired light quantity ratio.

Further, the light source device 19 calculates the total light amount of the laser light emitted from each exposure head 18 based on the respective light amount measurement values of the light with the wavelength A and the light with the wavelength B. Thus, the outputs of the light sources 1 and 2 are individually controlled so that the difference in total light quantity becomes zero.
Therefore, it is possible to perform an appropriate exposure process that suppresses processing unevenness. Here, the light quantity measurement values of the light of wavelength A and the light of wavelength B are measured by the light receiving sensor 52 provided on the exposure surface. Light emitted from the light source device 19 is emitted to the exposure surface via the exposure head 18. The exposure head 18 is configured by combining a plurality of lenses, and is incident from a light incident portion of the exposure head 18. The entire laser beam cannot be used as exposure light, for example, by being reflected by a lens. Therefore, by measuring the total light amount of the light emitted from the exposure head 18 using the light receiving sensor 52 provided on the exposure surface and performing the total light amount control, exposure light uniformized with a desired light amount can be obtained. Can do.

Further, the light source device 19 turns on and off the light sources 1 and 2 individually, and measures the light amount measurement value of the light of wavelength A measured when only the light source 1 is turned on, and turns on only the light source 2. The light quantity measurement value of the light of the wavelength B to be measured is acquired from one sensor. Thus, the light quantity for every wavelength can be measured with one sensor by individually controlling the outputs of the light sources 1 and 2 and turning on and off each wavelength.
When the light quantity for each wavelength is measured without turning on and off the light sources 1 and 2 individually (with both the light sources 1 and 2 turned on) as in the present embodiment, the emitted light from the light sources 1 and 2 It is necessary to measure the amount of light individually before accumulating. In this case, a sensor is required for each wavelength, and the cost increases, the installation space of the sensor increases, and it is difficult to reduce the size of the apparatus. Further, the measurement result of the light amount varies due to individual differences among sensors.
On the other hand, in this embodiment, since light of a plurality of different wavelengths is measured by a single sensor, it is possible to reduce costs and reduce the size of the apparatus as compared with the case where a plurality of sensors are installed. it can. Moreover, since there is no difference between sensors, the measurement accuracy can be improved.

(Modification)
In the above-described embodiment, an example in which laser light having two types of wavelengths is used as the light source device 19 has been described, but three or more types of wavelengths may be used. Further, the number of light sources 1 and 2 is not limited to the number shown in FIG. The number of the light sources 1 and 2 can be determined according to the intensity of the light emitted from the light source device 19.
Moreover, although the case where a laser diode (LD) was used as a light emitting element was demonstrated in the said embodiment, a light emitting diode (LED) may be sufficient. However, the LED has a larger light emitting area than the LD. For this reason, when an LED is used as the light emitting element, part of the light emitted from the light source toward the optical fiber cannot enter the optical fiber, which may result in a loss. Therefore, it is preferable to use an LD having a smaller light emitting area than an LED from the viewpoint of energy use efficiency.

Furthermore, although the case where two light receiving sensors 51 and 52 are used has been described in the above embodiment, the present invention is not limited to this, and only one of the light receiving sensors can be used. Note that it is preferable to use only the light receiving sensor 52 because the light quantity ratio control and the total light quantity control can be realized by one sensor installed on the exposure surface. However, when the light passes through the optical system (exposure head 18), the light is spread, and the amount of light tends to be difficult to measure on the exposure surface. Therefore, the light quantity measurement value used particularly for the light quantity ratio control is output by the light receiving sensor 51 that measures light before passing through the optical system (exposure head 18), that is, light immediately emitted from the light source device 19 (light source unit 19a). It is preferable to use a measured light amount value.

Further, in the above embodiment, the light receiving sensor 51 is arranged in the vicinity of the semi-transmissive optical element 41b in the exposure head 18, and is configured to measure the amount of laser light that has passed through the semi-transmissive optical element 41b. However, the light receiving sensor 51 only needs to be able to measure the amount of laser light at the light incident portion of the exposure head 18 where the light emitted from the light source device 19 is incident, and the arrangement position is not limited to the above. For example, the mirror 41e may be configured with a half mirror or the like, and the light receiving sensor 51 may be disposed in the vicinity of the mirror 41e so as to measure the amount of laser light that has passed through the mirror 41e.
Furthermore, in the above-described embodiment, when the amount of light is measured for each wavelength, if the prescribed amount of light is not reached, it may be notified that maintenance is necessary.
In the above embodiment, as shown in FIG. 2, the light source unit 19 a is integrated in two stages with the first optical fiber 5 that guides the emitted light from each of the light sources 1 and 2, and is output to the exposure head 18. It was set as the structure which outputs an incident light. However, the configuration of the light source unit 19a is not limited to this, and the first optical fiber 5 that guides the emitted light from the light sources 1 and 2 may be integrated in one stage, or in three or more stages. You may accumulate.

Furthermore, although the case where DMD42b which is a reflection type spatial light modulation element is used as the spatial light modulation element has been described in the above embodiment, for example, a transmission type spatial light modulation element using liquid crystal can also be used. However, it is preferable to use a DMD having high light use efficiency as a spatial light modulation element because light from a light source can be efficiently used as exposure light.
In the above-described embodiment, the case where the enlarged imaging optical system is used as the first imaging optical system 43 has been described. However, the first imaging optical system 43 may be an equal magnification imaging optical system, It may be a reduced imaging optical system. Further, although the case where an enlarged image forming optical system or an equal magnification image forming optical system is used as the second image forming optical system 45 has been described, the second image forming optical system 45 may be a reduced image forming optical system.
Although specific embodiments have been described above, the embodiments are merely examples and are not intended to limit the scope of the present invention. The devices and methods described herein can be embodied in forms other than those described above. In addition, omissions, substitutions, and changes can be made as appropriate to the above-described embodiments without departing from the scope of the present invention. Such omissions, substitutions, and modifications are included in the scope of the claims and their equivalents, and belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1, 2 ... Light source (LD module) 10 ... Control part, 12 ... Board | substrate, 13 ... Moving stage, 14 ... Exposure part, 18 ... Exposure head, 19 ... Light source device, 19a ... Light source part, 42b ... DMD, 44 ... MLA, 51, 52 ... light receiving sensor, 100 ... exposure apparatus

Claims (10)

1. A first light emitting element that emits light having a first wavelength characteristic;
   A second light emitting element that emits light having a second wavelength characteristic different from the first wavelength characteristic;
   An optical integration unit for integrating the emitted light from the first light emitting element and the emitted light from the second light emitting element;
   A predetermined light amount ratio between the light with the first wavelength characteristic and the light with the second wavelength characteristic; and the light amount of the light with the first wavelength characteristic included in the emitted light integrated by the optical integration unit; Output control for individually controlling the outputs of the first light emitting element and the second light emitting element based on the light quantity measurement values output from the sensors that respectively measure the light quantity of the light having the second wavelength characteristic. A control unit that generates a signal and outputs the generated output control signal to each of the first light emitting element and the second light emitting element;
   A light source device comprising:
2. The optical integration unit is
   A first optical fiber that receives light emitted from the first light-emitting element at the incident end and exits at the output end, and light emitted from the second light-emitting element enters the incident end and exits from the output end. A second optical fiber, and a third optical fiber that integrates the outgoing light of the first optical fiber and the outgoing light of the second optical fiber,
   The emission end sides of the first optical fiber and the second optical fiber are bundled in a predetermined arrangement, and the emission light of the first optical fiber and the emission light of the second optical fiber are integrated to form the The light source device according to claim 1, wherein the light source device includes a fiber bundle that allows light to enter the incident end of the third optical fiber.
3. An output unit that outputs the emitted light integrated by the optical integration unit to an exposure head provided in an exposure apparatus;
   The light source device according to claim 1, wherein the control unit acquires the light quantity measurement value measured by the sensor on an exposure surface of the exposure apparatus.
4. An output unit that outputs the emitted light integrated by the optical integration unit to an exposure head provided in an exposure apparatus;
   The said control part acquires the said light quantity measured value which the said sensor measured in the light incident part of the said exposure head in which the said emitted light from the said output part injects, The any one of Claim 1 to 3 characterized by the above-mentioned. The light source device according to Item 1.
5. The controller is
   A control signal for individually turning on and off the first light emitting element and the second light emitting element is output to each of the first light emitting element and the second light emitting element,
   A light amount measurement value of the light having the first wavelength characteristic measured when the first light emitting element is turned on and the second light emitting element is turned off, and the first light emitting element is turned off and the second light emitting element is turned off. The light amount measurement value of the light having the second wavelength characteristic measured when the light emitting element is turned on is acquired from one of the sensors. The light source device described.
6. The light source device according to claim 1, wherein the light emitting element is a laser diode or a light emitting diode.
7. A plurality of the optical integration units;
   An output unit that outputs the emitted light respectively integrated by the plurality of optical integration units to a plurality of exposure heads provided in an exposure apparatus;
   The control unit acquires the light quantity measurement value measured by the sensor for each of the plurality of exposure heads, and emits light from the exposure head between the plurality of exposure heads based on the light quantity measurement value The light source device according to claim 1, wherein the light amount difference is corrected.
8. The light source device according to any one of claims 1 to 7,
   An exposure head on which light emitted from the light source device is incident;
   A sensor for measuring a light amount of the light having the first wavelength characteristic and a light amount of the light having the second wavelength characteristic included in the emitted light integrated by the optical integration unit;
   An exposure apparatus comprising:
9. The exposure head includes a spatial light modulation unit in which pixel units that modulate light from the light source device are arranged,
   The exposure apparatus according to claim 8, wherein the photosensitive material is exposed by light modulated by the spatial light modulator.
10. An output light having a first wavelength characteristic emitted from the first light emitting element and a light having a second wavelength characteristic different from the first wavelength characteristic emitted from the second light emitting element are integrated. When outputting to the outside,
    An acquisition step of acquiring respective light quantity measurement values of the light having the first wavelength characteristic and the light having the second wavelength characteristic included in the emitted light integrated by the optical integration unit, measured by a sensor; ,
    Based on a predetermined light amount ratio between the light having the first wavelength characteristic and the light having the second wavelength characteristic, and the light amount measurement value acquired in the acquiring step, the first light emitting element and the first light emitting element A generation step of generating an output control signal for individually controlling the outputs of the two light emitting elements;
    An output step of outputting the output control signal generated in the generating step to each of the first light emitting element and the second light emitting element.
    

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