JP6503235B2 - Light source device, exposure apparatus, and light source control method - Google Patents

Description

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

Conventionally, a contact-type exposure apparatus using a photomask has been widely used in circuit patterning using a photolithographic method, so-called exposure process. However, in recent years, in order to match with high definition and high density of circuits, light is modulated using a spatial light modulation element such as DMD (digital micro mirror device (registered trademark)) that does not use a photomask for exposure. A direct writing type exposure apparatus has come to be used (Patent Document 1). Thus, an exposure apparatus using a spatial light modulation element is referred to as 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 of the resists to be exposed have sensitivities in a wide wavelength range, and there is also a case where curing is not sufficiently performed with a single wavelength or the exposure time is prolonged.
Therefore, Patent Document 2 discloses a light source device including a light source having a plurality of different wavelength characteristics, a lens corresponding to each of the plurality of light sources, and an optical combining element that combines and combines images formed by these lenses. It is disclosed.

Unexamined-Japanese-Patent No. 2006-267719 JP, 2012-063390, A

The wavelength of light includes a wavelength that contributes to the curing of the resist and a wavelength that contributes to the gloss of the resist, and the light amount ratio indicating the ratio of the light amount for each wavelength optimum for exposure varies depending on the type of resist. However, in the technology described in Patent Document 2, the light amount ratio is only set at the time of design, and can not be adjusted thereafter. Therefore, when the resist is changed, the exposure can not be performed with the light having the optimal light amount ratio according to the type of the resist.
Moreover, the light emitting element which comprises a light source deteriorates by long-term use, and illumination intensity falls. And the rate of the fall of the illumination intensity is different for every light emitting element. Therefore, the light amount ratio changes due to long-term use, and stable exposure can not be performed.
Then, this invention makes it a subject to provide the exposure apparatus provided with the light source device which can radiate | emit the light of a several different wavelength by a desired light quantity ratio, the light source device, and a light source control method.

In order to solve the above-mentioned subject, one mode of a light source device concerning the present invention is the 1st light emitting element which emits light of the 1st wavelength characteristic, and the 2nd wavelength characteristic different from the 1st wavelength characteristic. A second light emitting element for emitting light from the first light emitting element, a plurality of light integrating portions for integrating the light emitted from the first light emitting element and the light emitted from the second light emitting element, and the first wavelength characteristic A predetermined light amount ratio of the light of the second wavelength characteristic and the light amount of the light of the first wavelength characteristic included in the emitted light integrated by the light accumulation unit and the second wavelength characteristic An output control signal for individually controlling the outputs of the first light emitting element and the second light emitting element based on the light quantity measurement value output from the sensor that respectively measures the light quantity of the light of Of the first light emitting element and the second light emitting element. And a control unit for outputting to Les, the outgoing light integrated respectively by a plurality of the optical integrated unit, an output unit for outputting each to a plurality of exposure heads provided in the exposure apparatus, wherein the control unit, the The plurality of light quantity measurement values measured by the first sensors respectively provided to the light incident parts of the plurality of exposure heads to which the outgoing light from the output part is incident are obtained, and the plurality of light quantities are measured based on the light quantity measurement values. The light amount ratio between the light of the first wavelength characteristic and the light of the second wavelength characteristic is controlled to be the predetermined light amount ratio for each of the exposure heads, and each of the plurality of exposure heads is controlled. The light intensity measurement value measured by one second sensor provided on the exposure surface of the exposure apparatus is acquired, and the exposure head between the plurality of exposure heads is acquired based on the light intensity measurement value. Correcting the light amount difference of the light emitted from the.
Thus, light of a plurality of different wavelengths can be emitted from the plurality of exposure heads at a desired light amount ratio, and variations in output among the exposure heads can be suppressed. Further, even when the illuminance of the light emitting element for emitting light of a specific wavelength by aging is decreased, because the output of the light of each wavelength is individually controllable, coercive Chitsutsu the quantity ratio constant, The total amount of light on the exposure surface can be made equal in all exposure heads, and stable light can be emitted.

In the light source device described above, the light collecting unit may include a first optical fiber that emits light from the first light emitting element at an incident end and emits the light at an output end, and the second light emitting element. And a third optical fiber for integrating the light emitted from the first optical fiber and the light emitted from the second optical fiber. , And the outgoing end sides of the first optical fiber and the second optical fiber are bundled in a predetermined arrangement, and the outgoing light of the first optical fiber and the outgoing light of the second optical fiber Can be integrated and incident on the incident end of the third optical fiber.
As a result, since the light emitting ends of the first optical fiber and the second optical fiber are bundled to combine light of different wavelengths, it is necessary to strictly arrange a plurality of light emitting elements in a predetermined arrangement. It is possible to improve the freedom of installation. In addition, uniform light without wavelength deviation can be easily generated and emitted. Furthermore, since the number of light emitting elements can be easily increased, it is easy to increase the illuminance.

  Furthermore, in the above light source device, the control unit controls the first light emitting element and the second light emitting element to individually turn on and off the first light emitting element and the second light emitting element. And the light quantity measurement value of the light of 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 And the light intensity measurement value of the light of the second wavelength characteristic measured when the second light emitting element is turned on, may be acquired from one of the sensors. As described above, since it is possible to measure the amount of light by one sensor, it is possible to prevent a drop in measurement accuracy due to individual differences of the sensors.

Further, in the above light source device, the light emitting element may be a laser diode or a light emitting diode. Thus, a light source device that emits light including a plurality of different wavelengths can be easily realized .

In one aspect of the exposure apparatus according to the present invention, the light source device according to any one of the above, the plurality of exposure heads to which the light emitted from the light source device is incident, and the light amount of light of the first wavelength characteristic And the first sensor and the second sensor that respectively measure the amount of light of the second wavelength characteristic. The light source device can provide optimum exposure conditions and enables stable and appropriate exposure.
Further, in the above-described exposure apparatus, the exposure head includes a spatial light modulation unit in which pixel units for modulating light from the light source device are arrayed, and the photosensitive material is exposed by the light modulated by the spatial light modulation unit. You may This enables stable and appropriate exposure in the DI exposure apparatus.

In one aspect of the light source control method according to the present invention, the first emission characteristic of the first wavelength characteristic emitted from the first light emitting element, and the first wavelength characteristic emitted from the second light emitting element Is measured by a first sensor respectively provided at the light incident portion of the plurality of exposure heads when the light of different second wavelength characteristics is accumulated and output to the plurality of exposure heads provided in the exposure apparatus. and a first acquisition step of acquiring each of the light amount measurement value of the light of the light with the second wavelength characteristic of the first wavelength characteristic included in the outgoing light condensed product, the plurality of exposure The light of the first wavelength characteristic and the light of the second wavelength characteristic included in the accumulated outgoing light measured by one second sensor provided on the exposure surface of the exposure apparatus for each of the heads Measure each light quantity with light Based a second obtaining step Tokusuru, a predetermined light amount ratio of the light of the light with the second wavelength characteristic of the first wavelength characteristic, the said light intensity measurements obtained in said first obtaining step The light amount ratio between the light of the first wavelength characteristic and the light of the second wavelength characteristic for each of the plurality of exposure heads is the predetermined light amount ratio, and the second acquisition The first light emitting element and the second light emission so as to correct the light amount difference of the light emitted from the exposure head among the plurality of exposure heads based on the light amount measurement value acquired in the step A generation step of generating an output control signal for individually controlling an output of the element; and outputting the output control signal generated in the generation step to each of the first light emitting element and the second light emitting element Including an output step that, a.
Thus, light of a plurality of different wavelengths can be emitted from the plurality of exposure heads at a desired light amount ratio, and variations in output among the exposure heads can be suppressed. Further, even when the illuminance of the light emitting element for emitting light of a specific wavelength by aging is decreased, because the output of the light of each wavelength is individually controllable, coercive Chitsutsu the quantity ratio constant, The total amount of light on the exposure surface can be made equal in all exposure heads, and stable light can be emitted.

  According to the light source device of the present invention, light of a plurality of different wavelengths can be emitted at a desired light amount ratio. Therefore, according to the exposure apparatus provided with the light source device, it is possible to perform exposure with light of an optimal light amount ratio according to the type of resist and the like.

It is a schematic block diagram which shows an example of the exposure apparatus in this embodiment. It is a schematic block diagram which shows an example of the light source part which comprises a light source device. It is a schematic block diagram which shows an example of an exposure head. It is a control block diagram of light quantity ratio control. It is a flowchart which shows the light quantity ratio control processing procedure. It is a control block diagram of total light control. It is a flowchart which shows a total light quantity control processing procedure. It is a figure which shows wavelength distribution of a mercury lamp. It is a figure which shows an example of wavelength distribution of a laser diode.

Hereinafter, embodiments of the present invention will be described based on 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 passes light modulated by a spatial light modulation unit (spatial light modulation element) through an imaging optical system, forms an image of this light on a photosensitive material (resist), and exposes the light. Such an exposure apparatus does not require a mask (or reticle) because it directly forms an image with a spatial light modulation element, and is called a DI (direct image: direct writing) exposure apparatus.
The exposure apparatus 100 is formed in a substantially rectangular flat plate shape and is horizontally arranged, and a moving stage 13 slidably mounted on the base 11 and holding a substrate (workpiece) 12 to be exposed on a surface by suction. And an exposure unit 14 that exposes the substrate 12 held by the moving stage 13.

  The substrate 12 is, for example, a printed wiring board, a glass substrate for flat panel display, or the like in which a photosensitive material is applied or stuck on the surface. The exposure apparatus 100 performs maskless recording of, for example, a wiring pattern or the like on the photosensitive material of the substrate 12 by performing exposure on the substrate 12. In the present embodiment, the moving direction of the moving stage 13 will be described as a Y direction, a direction (width direction of the substrate 12) orthogonal to the Y direction on a horizontal plane will be taken as an X direction, and a vertical direction perpendicular to the horizontal plane will be taken as a Z direction. The base 11 is formed long in the Y direction.

  The base 11 is supported by a plurality of (for example, four attached to each of four corners) legs 15. On the upper surface 11 a of the base 11, two guide rails 16 substantially parallel to the Y direction are provided. The moving stage 13 is attached to the base 11 slidably in the Y direction via the guide rails 16. In addition, the moving stage 13 is provided with an electromagnet 16 a which has a 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 movable body on a planar platen provided with a convex pole of a ferromagnetic material in a grid shape or a line shape, so that the movable body and the convex pole of the platen are separated. 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. In addition, as a movement mechanism, the mechanism using a ball screw is also employable, for example.

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

In FIG. 1, the exposure heads 18 are arranged in two rows in the Y direction, eight in the X direction. Each exposure head 18 in the second row is located in the X direction with respect to each exposure head 18 in the first row so that the center of each exposure head 18 is located near the center of adjacent ones of the exposure heads 18 in the first row. They are arranged at a half pitch offset. By displacing in this manner, portions that can not be exposed by the exposure heads 18 in the first row are exposed by the exposure heads 18 in the second row, and exposure recording is performed without gaps in the X direction of the substrate 12. 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 or the like.
Laser light is incident on each exposure head 18 from the light source device 19 via the optical fiber 20. In the present embodiment, the light source device 19 mixes light of a plurality of different wavelengths and outputs the light to each of the exposure heads 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 to be recorded on the substrate 12 is input to the image processing unit 21. The image processing unit 21 creates frame data for each of the exposure heads 18 to write 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 an image in binary (presence or absence of dot recording).
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 transported by the moving stage 13. Thus, 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 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 in parallel with 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 entire exposure apparatus 100 as a whole.
The camera 25 photographs 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 deviation of the substrate 12 with respect to the appropriate position on the moving stage 13 in the X, Y, and θ directions (rotational directions with respect to the Z direction). Do. The calculated amount of deviation is input to the image processing unit 21 and used for correction of frame data. The number of cameras 25 and the arrangement interval may be appropriately changed according to the size of the substrate 12 and the like. Further, the calculation of the amount of deviation may be performed by 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 a controller as with each camera 25. Each length measuring device 24 irradiates a laser beam to the side end surface of the movable stage 13 and receives the reflected light to measure the position of the movable stage 13. Then, 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, but the present invention is not limited to this. For example, the position of the moving stage 13 can be measured, such as using ultrasonic waves or a stereo camera. As long as it is a thing, you may use any other thing.

(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 provided corresponding to the plurality of exposure heads 18 and configured to cause the respective combined light beams having different wavelengths to be incident on the respective exposure heads 18.
FIG. 2 is a schematic configuration view showing an example of a light source unit 19 a constituting the light source device 19. In FIG. 2, only one light source unit 19 a corresponding to one exposure head 18 is shown. In practice, the light source device 19 includes the same number of light source units 19 a as the exposure heads 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) as a light emitting element and a condenser lens. The light source 1 and the light source 2 include LDs that emit laser beams of different wavelengths (wavelength A and wavelength B). In the example shown in FIG. 2, the light source unit 19 a includes three light sources 1 and one light source 2 as one set, and includes a total of three sets of twelve light sources. The 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 wavelength characteristics in the range of 190 nm to 530 nm. For example, the light of the wavelength A of the light source 1 has a first wavelength characteristic having a peak around 375 nm, and the light of the wavelength B of the light source 2 has a second wavelength characteristic having a peak around 405 nm.
The light sources 1 and 2 are configured so that lighting, non-lighting (lighting-off) and output illuminance thereof can be individually controlled by the control unit 10. The light sources 1 and 2 may be configured to be controlled individually by the control unit 10, or may be configured to be controlled for each group (group).

The first optical fiber 5 is connected to each connector 4, and the light emitted from each of the light sources 1 and 2 is incident on the incident end of the first optical fiber 5, and from the emission end of the first optical fiber 5 It is configured to emit light. The emission end of the first optical fiber 5 is bundled in a predetermined arrangement for each set of light sources, and connected to the second optical fiber 7 via the common first connector 6.
The first optical fiber 5, the first connector 6 and the second optical fiber 7 constitute a first fiber bundle portion B1. That is, the emitted light of the three light sources 1 and the one light source 2 is input to one first fiber bundle part B1 via the four first optical fibers 5 and passes through the first connector 6 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 the light emission area in a state in which four first optical fibers 5 are bundled.

In the example illustrated in FIG. 2, the light source unit 19 a includes three first fiber bundle units B <b> 1 because it includes three light sources. That is, a total of 12 LD modules are integrated in the three second optical fibers 7 in the three first fiber bundle sections B1.
The second optical fiber 7 is a multimode optical fiber, and is configured to be homogenized by the interference of light in the fiber and the interaction between modes.
The three second optical fibers 7 are led to the common second fiber bundle unit B2. The output ends of the three second optical fibers 7 are bundled in a predetermined arrangement according to the shape of the light irradiation area to the DMD 42b in the exposure head 18 described later in the second fiber bundle section B2, and the above-described optical fiber The third optical fiber 8 corresponds to 20. The output end of the third optical fiber 8 is connected to an incident optical system 41 in an exposure head 18 described later via a second connector 9 so as to guide laser light to the exposure head 18. The second connector 9 is an output unit that outputs the emitted light accumulated by the first fiber bundle unit B1 and the second fiber bundle unit B2 to the exposure head 18.

As described above, 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 beams from the light sources 1 and 2, the light sources 1 and 2 are arranged in a predetermined manner. It is not necessary to strictly arrange them, and the freedom of installation of the light sources 1 and 2 can be improved. Furthermore, since the number of light emitting elements (LDs) can be easily increased, it is easy to increase the illuminance.
In addition, it is preferable to set the arrangement pattern at the time of bundling the 1st optical fiber 5 and the 2nd optical fiber 7 so that there may be no positional deviation for every wavelength. As a result, it is possible to irradiate uniform light without wavelength deviation on the surface of the DMD 42b described later.
In FIG. 2, the first optical fiber 5 corresponding to the first optical fiber is a first optical fiber 5 that emits light from the LD of the light source 1, which is the first light emitting element, at the input end and emits the light from the output end. A first optical fiber 5 corresponding to the second optical fiber receives light emitted from the LD of the light source 2 which is a light emitting element at the input end and emits the light from the output end. Further, the second optical fiber 7 and the third optical fiber 8 for integrating the first optical fiber 5 correspond to the third optical fiber for integrating the emitted light of the first optical fiber and the emitted light of the second optical fiber 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 view of the exposure head 18. As shown in FIG. 3, the exposure head 18 includes an incident optical system 41, a light modulation unit 42, a first imaging optical system 43, a micro lens array (MLA) 44, and a second imaging optical system 45. And a focus adjustment unit 46.
The incident optical system 41 includes a condensing lens 41a, a semi-transmissive optical element 41b, an optical integrator 41c, an imaging lens 41d, and a mirror 41e. The laser beam emitted from the light source unit 19a is incident on the condensing lens 41a, and condenses the incident laser beam. The semi-transmissive optical element 41 b is, for example, a half mirror, and transmits a part of the laser light condensed by the condensing lens 41 a and reflects a part thereof.

The optical integrator 41c is disposed on the optical path of the laser beam reflected by the semi-transmissive optical element 41b. The optical integrator 41c is, for example, a translucent rod formed in a square pole shape. The optical integrator 41 c converts the laser light traveling inside while being totally reflected into a light beam which is close to parallel light and whose intensity in the beam cross section is uniformed. As a result, the substrate 12 is exposed to a high-definition image with no variation in illumination light intensity. In addition, in order to improve the light transmittance, an antireflection film may be coated on the incident end face and the output end face of the optical integrator 41c.
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 42 a and a DMD (digital micro mirror device) 42 b 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 42 b is a mirror device in which micromirrors constituting pixels are provided on a two-dimensionally arranged memory cell (for example, an SRAM cell), supported by a support and tiltable.
The DMD 42 b has a state in which the irradiated laser light is reflected toward the first imaging optical system 43 according to the digital signal written in the SRAM cell, and a light absorber whose irradiated laser light is not shown. The tilt angle of the micro mirror is changed to reflect light. The light modulation unit 42 generates the image light according to the frame data by controlling the tilt of the micro mirror of each pixel of the DMD 42 b 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 magnifies the image light generated by the light modulation unit 42 to a predetermined magnification to form an image on the MLA 44.
The MLA 44 is formed of, for example, quartz glass in a substantially rectangular flat plate shape. Further, in the MLA 44, a plurality of microlenses two-dimensionally arranged corresponding to each pixel of the DMD 42b are formed. Each microlens is a plano-convex lens having a flat upper surface and a convex lower surface. The respective microlenses individually image the image light from the respective micro mirrors of the DMD 42 b and sharpen the image light expanded by the first imaging optical system 43. 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 magnifies the image light having passed through the MLA 44 to a predetermined magnification, or causes the prism pair 46 to enter with equal magnification. The prism pair 46 is provided to be movable in the vertical direction, and adjusts the focus of the image light on the substrate 12 by moving up and down.

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

The control unit 10 acquires the light quantity measurement value output by the light receiving sensor 51, and based on the acquired light quantity measurement value, the light quantity ratio which is the ratio of the light quantity of the light of wavelength A to the light of wavelength B is a predetermined light quantity The outputs of the light source 1 and the light source 2 are individually controlled so that the ratio (target value) is obtained (light amount ratio control). Here, the target value can be appropriately set in accordance with the type of resist, the target finish state (appearance such as gloss), and the like.
In addition, the control unit 10 acquires the light quantity measurement value output by the light receiving sensor 52, and individually controls the outputs of the light source 1 and the light source 2 based on the acquired light quantity measurement value, thereby a plurality of exposure heads 18 The light amount difference (the total light amount difference) of the light emitted from the exposure head 18 between the two 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 amount of light on the exposure surface becomes equal in all the exposure heads 18.

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

Further, the light quantity ratio calculation unit 10a calculates the output of the light sources 1 and 2 such that the light quantity ratio becomes the target value (for example, 10: 1) based on the calculated light quantity ratio, and outputs the calculated result It outputs to the light source output control unit 10b as a quantity instruction value. The light source output control unit 10 b outputs an output control signal for controlling the current flowing to the LD of each of the light sources 1 and 2 to the light sources 1 and 2 based on the output control amount indication value, thereby the light sources 1 and 2 Control the amount of light emitted.
Although one light source 1 and two light sources are illustrated in FIG. 4, in reality, a plurality of light sources 1 and 2 exist respectively. The outputs of the light sources 1 and 2 can be individually controlled, and the light amount ratio of the light emitted from the light source unit 19a can be freely adjusted. By grouping and turning ON / OFF for each wavelength, even if only one light receiving sensor 51 can measure the light quantity for each wavelength, it is possible to calculate the light quantity ratio.

FIG. 5 is a flowchart showing the light amount ratio control processing procedure executed by the control unit 10. The process shown in FIG. 5 can be performed at a predetermined timing for adjusting the light amount ratio, for example, before the exposure by the exposure apparatus 100 is started. The adjustment of the light amount ratio may be performed at a predetermined time or may be performed at an arbitrary timing instructed by the operator.
First, in step S1, the control unit 10 turns on the light source 1 with a predetermined output and outputs a control signal to turn off the light source 2 to the light sources 1 and 2. Here, the predetermined output may be a predetermined initial value or an output value at the time of the last exposure. Thus, the control unit 10 turns on only the light source 1 and shifts to step S2. In step S2, the control unit 10 acquires the light quantity measurement value from the light receiving sensor 51. The light quantity measurement value acquired at this time is the light quantity of the light of the wavelength A emitted from the light source unit 19a.

Next, in step S3, the control unit 10 turns on the light source 2 with a predetermined output and outputs a control signal to turn off the light source 1 to the light sources 1 and 2. Here, the predetermined output may be a predetermined initial value or an output value at the time of the last exposure. Thus, the control unit 10 turns on only the light source 2 and shifts to step S4. In step S4, the control unit 10 acquires the light quantity measurement value from the light receiving sensor 51. The light quantity measurement value acquired at this time is the light quantity of the light of the wavelength B emitted from the light source unit 19a.
In step S5, the control unit 10 calculates the light intensity ratio based on the light intensity measurement value of the wavelength A acquired in step S2 and the light intensity measurement value of the wavelength B acquired in step S4. Next, in step S6, the control unit 10 calculates an output control amount indication value such that the light amount ratio calculated in step S5 becomes the target value (for example, 10: 1). Note that, as preparation in advance, the change in light amount when the current value is changed is measured in advance for each of the light sources 1 and 2, and the output characteristic of each of the light sources 1 and 2 is stored. Then, based on the output characteristics of the light sources 1 and 2 stored in advance, the control unit 10 calculates an output control amount indication value such that the light amount ratio becomes the target value. In step S7, the control unit 10 generates an output control signal based on the output control amount indication value calculated in step S6, and outputs the generated output control signal to the light sources 1 and 2 to thereby output the light sources 1 and 2 Control individually. Thereby, the light amount ratio can be made to coincide with the target value set in accordance with the type of resist and the finish state (appearance such as gloss) to be targeted.

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

The light amount ratio calculation unit 10c inputs the light amount measurement value for each wavelength output from the light receiving sensor 52 for each exposure head 18, and calculates the light amount ratio. The control unit 10 individually turns on and off the light source 1 and the light source 2 and acquires the light intensity 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 quantity of the light of the wavelength A from the light source 1 and the light quantity of the light of the wavelength B from the light source 2 similarly to the light receiving sensor 51 described above, and measures each light quantity Output to the control unit 10.
Further, the light amount ratio calculation unit 10 c calculates the total light amount on the exposure surface for each of the exposure heads 18. Then, the light amount ratio calculation unit 10 c calculates and calculates the outputs of the light sources 1 and 2 such that the total light amount on the exposure surface becomes equal for all the exposure heads 18 while keeping the calculated light amount ratio 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 10 d outputs an output control signal for controlling the current flowing to the LD of each of the light sources 1 and 2 to the light sources 1 and 2 based on the output control amount indication value, thereby the light sources 1 and 2 Control the amount of light emitted.

The control unit 10 may acquire the light quantity measurement value from the light receiving sensor 52 when both the light source 1 and the light source 2 are on. That is, the light receiving sensor 52 can also measure the light quantity of light including both the light of the wavelength A from the light source 1 and the light of the wavelength B from the light source 2 and output the light quantity measurement value to the control unit 10. As described above, the light receiving sensor 51 described above is used as a sensor for separately measuring the light amount of light for each wavelength in each exposure head 18, and the light receiving sensor 52 directly measures the total light amount 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 determined by the light amount comparison calculation unit 10a described above constant based on the total light amount on the exposure surface for each exposure head 18 measured by the light receiving sensor 52. The outputs of the light sources 1 and 2 may be calculated so that the total light quantity on the exposure surface becomes equal in all the exposure heads 18, and the calculated result may be output to the light source output control unit 10d as an output control amount indication value. With this configuration, when acquiring the light intensity measurement value from the light receiving sensor 52, it is not necessary to individually turn on and off the light sources 1 and 2 and control can be simplified.

FIG. 7 is a flowchart showing the procedure of the total light amount control process executed by the control unit 10. The process shown in FIG. 7 can be performed after a predetermined timing for adjusting the total light amount, for example, the light amount ratio control described above is performed. However, the timing of 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 as in step S1 of FIG. 5, and shifts to step S12. In step S12, the control unit 10 acquires the light intensity measurement value from the light receiving sensor 52. The light quantity measurement value acquired at this time is the light quantity of the light of the 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 as in step S3 of FIG. 5, and shifts to step S14. In step S14, the control unit 10 acquires the light quantity measurement value from the light receiving sensor 52. The light quantity measurement value acquired at this time is the light quantity of the light of the wavelength B emitted from the light source unit 19a.
In step S15, the control unit 10 calculates the light intensity ratio based on the light intensity measurement value of the wavelength A acquired in step S12 and the light intensity measurement value of the wavelength B acquired in step S14. Next, in step S16, the control unit 10 calculates the total light quantity based on the light quantity measurement value of the wavelength A acquired in step S12 and the light quantity measurement value of the wavelength B acquired in step S14.
In step S17, the control unit 10 determines whether the total light amount of all the exposure heads 18 has been measured. Then, when the total light amount has not been measured for all the exposure heads 18, the exposure head 18 which has not been measured is selected as the measurement object of the total light amount, and then the process returns to step S11. On the other hand, when the total light amount of all the exposure heads 18 is measured, it is determined that the measurement is completed, and the process proceeds to step S18.

In step S18, the control unit 10 calculates an output control amount instruction value such that the total light amount in each exposure head 18 becomes equal while keeping the light amount ratio in each exposure head 18 at the light amount ratio calculated in step S15. . In step S19, the control unit 10 generates an output control signal based on the output control amount indication value calculated in step S18, and outputs the generated output control signal to the light sources 1 and 2 to thereby output the light sources 1 and 2 Control individually.
If the intensity of light emitted from the plurality of exposure heads 18 is different, the finish of the substrate 12 after exposure is different. Therefore, in the present embodiment, the total light quantity is measured for each of the exposure heads 18 by the light receiving sensor 52 installed on the exposure surface. Then, while keeping the light amount ratio for each wavelength constant, the outputs of the light sources 1 and 2 are controlled so that the total light amount becomes equal in all the exposure heads 18. Thereby, the variation of the light amount between the exposure heads 18 can be suppressed, and appropriate exposure processing with suppressed 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 for emitting the light of the wavelength A, the light source 2 having the LD for emitting the light of the wavelength B, and the emission light from the light source 1 And a fiber bundle unit for integrating the light emitted from the light source 2. As described above, the light source device 19 combines light of a plurality of different wavelengths and outputs the combined light to the exposure head 18.
Conventionally, a mercury lamp has been widely used as a light source of an exposure apparatus. As shown in FIG. 8, the mercury lamp has a wavelength distribution in which peaks of intensity are 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 have sensitivity to each peak wavelength of the mercury lamp. However, as shown in FIG. 9, for example, the LD light source emits light of a single wavelength of 405 nm. Therefore, when one LD is used as a 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 emitting light of different wavelengths, synthesizes and emits light of different wavelengths. Further, as a 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. As described above, since light 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.
Further, the light source device 19 calculates the light amount ratio of the light of the wavelength A and the light of the wavelength B based on the light amount measurement value of each of the light of the wavelength A and the light of the wavelength B, and the calculated light amount ratio is a target The outputs of the light sources 1 and 2 are individually controlled to become values. Therefore, it is possible to adjust and expose to the light of the optimal light quantity ratio according to the kind of resist.

The light source 1 emits light having wavelength characteristics having a peak near 375 nm, and the light source 2 emits light having wavelength characteristics having a peak near 405 nm. The light of wavelength 405 nm mainly contributes to the curing of the resist, and the light of wavelength 375 nm mainly contributes to the appearance such as the 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 the light emitting element (LD) that emits light of a specific wavelength is lowered due to age-related deterioration, the light amount ratio can be kept constant by controlling the light output of each wavelength. Exposure is possible.
Here, each light quantity measurement value of the light of the wavelength A and the light of the wavelength B is a light receiving sensor provided in the light incident portion of the exposure head 18 to which the light emitted from the light source device 19 (light source portion 19a) is incident. Measured by 51. As described above, the light receiving sensor 51 measures the amount of light immediately after being emitted from the light source device 19 (light source unit 19a). Therefore, the light receiving sensor 51 can accurately measure the light quantity for each wavelength, and the light source device 19 can perform appropriate light quantity ratio control. As a result, the light source device 19 can emit light of a plurality of different wavelengths at a desired light amount ratio.

Furthermore, the light source device 19 calculates the total light amount of the laser light emitted from each of the exposure heads 18 based on the light amount measurement value of each of the light of the wavelength A and the light of the wavelength B. The outputs of the light sources 1 and 2 are individually controlled so that the difference between the total light amounts is zero.
Therefore, appropriate exposure processing with suppressed processing unevenness is possible. Here, the light quantity measurement value of each of the light of the wavelength A and the light of the wavelength B is measured by the light receiving sensor 52 provided on the exposure surface. The light emitted from the light source device 19 is emitted to the exposure surface through the exposure head 18. The exposure head 18 is configured by combining a plurality of lenses, and is incident from the light incident portion of the exposure head 18. The entire laser beam can not be used as exposure light because it is reflected by a lens or the like. Therefore, the total light quantity of the light emitted from the exposure head 18 is measured using the light receiving sensor 52 provided on the exposure surface, and the total light quantity control is performed to obtain the uniformed exposure light with the desired light quantity. Can.

In addition, when the light source device 19 turns on and off the light sources 1 and 2 individually and the light quantity measurement value of the light of the wavelength A measured when only the light source 1 is turned on, and only the light source 2 is turned on. The light quantity measurement value of the light of wavelength B to be measured is obtained from one sensor. As described above, by controlling the outputs of the light sources 1 and 2 individually and turning on and off for each wavelength, it is possible to measure the light quantity for each wavelength with one sensor.
When it is going to measure the light quantity for every wavelength without turning on and off the light sources 1 and 2 individually (with both the light sources 1 and 2 being turned on) like this embodiment, the emitted light from the light sources 1 and 2 It is necessary to measure the amount of light individually before integrating the In this case, a sensor is required for each wavelength, which increases the cost, increases the installation space of the sensor, and makes it difficult to miniaturize the device. Furthermore, variations in the measurement results of the light amount occur due to the individual differences of the sensors.
On the other hand, in the present embodiment, since light of a plurality of different wavelengths is measured by one sensor, cost reduction and downsizing of the device can be realized as compared with the case where a plurality of sensors are installed. it can. Moreover, since individual differences among sensors do not occur, measurement accuracy can be improved.

(Modification)
In the said embodiment, although the example which used the laser beam of two types of wavelength was shown as the light source device 19, three or more types of wavelengths may be sufficient. Further, the number of light sources 1 and 2 is not limited to the number shown in FIG. The number of light sources 1 and 2 can be determined according to the intensity of the light emitted from the light source device 19.
Moreover, in the said embodiment, although the case where a laser diode (LD) was used as a light emitting element was demonstrated, a light emitting diode (LED) may be sufficient. However, the light emitting area of the LED is larger than that of the LD. Therefore, when an LED is used as a light emitting element, part of the light emitted from the light source toward the optical fiber can not 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 the LED in terms of energy utilization efficiency.

  Furthermore, in the said embodiment, although the case where two light reception sensors 51 and 52 were used was demonstrated, it is not limited to this, Only any one light reception sensor can also be used. If only the light receiving sensor 52 is used, it is preferable because the light amount ratio control and the total light amount control can be realized by one sensor provided on the exposure surface. However, when passing through the optical system (exposure head 18), the light is spread, and the light quantity tends to be difficult to measure on the exposure surface. Therefore, the light quantity measurement value used particularly for light quantity ratio control is output by the light receiving sensor 51 that measures the light before passing through the optical system (exposure head 18), that is, the light immediately after emitted from the light source device 19 (light source unit 19a). It is preferable to use a light quantity measurement value.

Further, in the above embodiment, the light receiving sensor 51 is disposed in the vicinity of the semi-transmissive optical element 41 b in the exposure head 18 and configured to measure the light amount of the laser light that has passed through the semi-transmissive optical element 41 b. However, the light receiving sensor 51 only needs to be capable of measuring the light amount of the 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 by a half mirror or the like, and the light receiving sensor 51 may be disposed in the vicinity of the mirror 41e to measure the light amount of the laser beam having passed through the mirror 41e.
Furthermore, in the above-described embodiment, when the light amount of light is measured for each wavelength, when the predetermined light amount is not reached, it may be notified that maintenance is necessary.
Further, in the above embodiment, as shown in FIG. 2, the light source unit 19 a integrates the first optical fiber 5 for guiding the light emitted from each of the light sources 1 and 2 in two steps and outputs it to the exposure head 18. It was set as the structure which outputs a radiation. However, the configuration of the light source unit 19a is not limited to this, and the first optical fiber 5 for guiding the light emitted from each of the light sources 1 and 2 may be integrated in one step, or in three or more steps. It may be accumulated.

Furthermore, in the above embodiment, although the case where DMD 42b which is a reflective spatial light modulator is used as the spatial light modulator is described, for example, a transmissive spatial light modulator using liquid crystal can also be used. However, it is preferable to use a DMD having high light utilization efficiency as a spatial light modulator, because light from a light source can be efficiently used as exposure light.
In the above embodiment, although the case of using the magnifying imaging optical system as the first imaging optical system 43 has been described, the first imaging optical system 43 may be an equal-magnification imaging optical system. It may be a reduction imaging optical system. In addition, although the case of using a magnifying imaging optical system or an equal magnification imaging optical system as the second imaging optical system 45 has been described, the second imaging optical system 45 may be a reduction imaging optical system.

  1, 2 ... light source (LD module), 10 ... control unit, 12 ... substrate, 13 ... moving stage, 14 ... exposure unit, 18 ... exposure head, 19 ... light source device, 19a ... light source unit, 42b ... DMD, 44 ... MLA, 51, 52 ... light receiving sensor 100 ... exposure device

Claims (7)

A first light emitting element that emits light of a first wavelength characteristic;
A second light emitting element that emits light of a second wavelength characteristic different from the first wavelength characteristic;
A plurality of optical integration units that integrate the light emitted from the first light emitting element and the light emitted from the second light emitting element;
A predetermined light amount ratio between the light of the first wavelength characteristic and the light of the second wavelength characteristic, and the light amount of the light of the first wavelength characteristic included in the outgoing light integrated by the light accumulation unit Output control for individually controlling the outputs of the first light emitting element and the second light emitting element based on a light quantity measurement value output from a sensor that respectively measures the light quantity of light of 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;
And an output unit for outputting the emitted light respectively accumulated by the plurality of light collecting units to a plurality of exposure heads provided in the exposure apparatus.
The control unit
The light quantity measurement value measured by a first sensor provided in each of the light incident parts of the plurality of exposure heads to which the outgoing light from the output part is incident is obtained, and the light quantity measurement value is obtained based on the light quantity measurement value The light amount ratio of the light of the first wavelength characteristic to the light of the second wavelength characteristic is controlled to be the predetermined light amount ratio for each of the plurality of exposure heads.
The light quantity measurement value measured by one second sensor provided on the exposure surface of the exposure apparatus for each of the plurality of exposure heads is acquired, and based on the light quantity measurement value, between the plurality of exposure heads A light source device that corrects a difference in light amount of light emitted from the exposure head ; The light collecting unit is
A first optical fiber for emitting light emitted from the first light emitting element at the incident end and emitting the light at the emitting end, and light emitted from the second light emitting element at the incident end and emitting the light at the output end A third optical fiber for integrating the light emitted from the first optical fiber and the light emitted from the second optical fiber;
The outgoing end sides of the first optical fiber and the second optical fiber are bundled in a predetermined arrangement, and the outgoing light of the first optical fiber and the outgoing light of the second optical fiber are integrated and the The light source device according to claim 1, wherein the light source device comprises a fiber bundle to be incident on an incident end of the third optical fiber. The control unit
Outputting a control signal for turning on and off the first light emitting element and the second light emitting element separately to each of the first light emitting element and the second light emitting element;
The light quantity measurement value of the light of 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 3. The light source device according to claim 1, wherein the light amount measurement value of the light of the second wavelength characteristic measured when the light emitting element is turned on is acquired from one of the sensors. The light source device according to any one of claims 1 to 3 , wherein the light emitting element is a laser diode or a light emitting diode. The light source device according to any one of claims 1 to 4 ;
The plurality of exposure heads into which the light emitted from the light source device is incident;
The first sensor and the second sensor each measure the light amount of the light of the first wavelength characteristic and the light amount of the light of the second wavelength characteristic included in the emitted light accumulated by the optical integration unit . Sensor,
An exposure apparatus comprising: The exposure head includes a spatial light modulation unit in which pixel units for modulating light from the light source device are arranged.
The exposure apparatus according to claim 5 , wherein the photosensitive material is exposed by the light modulated by the spatial light modulation unit. Integrate the emitted light of the first wavelength characteristic emitted from the first light emitting element and the light of the second wavelength characteristic emitted from the second light emitting element and different from the first wavelength characteristic When outputting to a plurality of exposure heads provided in the exposure apparatus ,
Wherein the plurality of measured by the first sensor provided respectively on the light incident portion of the exposure head, the light with the second wavelength characteristic of the first wavelength characteristic included in the outgoing light condensed product light A first acquisition step of acquiring respective light intensity measurement values of
The light of the first wavelength characteristic included in the integrated emitted light and the second wavelength measured by one second sensor provided on the exposure surface of the exposure apparatus for each of the plurality of exposure heads A second acquisition step of acquiring respective light intensity measurement values with light of wavelength characteristics of a second light intensity ratio, a predetermined light intensity ratio of light of the first wavelength characteristics and light of the second wavelength characteristics, and the first light intensity ratio The light amount ratio between the light of the first wavelength characteristic and the light of the second wavelength characteristic is the predetermined value for each of the plurality of exposure heads based on the light amount measurement value acquired in the acquiring step of The light amount difference of the light emitted from the exposure head among the plurality of exposure heads is corrected based on the light amount measurement value acquired in the second acquisition step so that the light amount ratio is obtained. to, A generation step of generating a serial output control signals for individually controlling the output of the first light emitting element and the second light emitting element,
A light source control method, comprising: an output step of outputting the output control signal generated in the generation step to each of the first light emitting element and the second light emitting element.

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