TWI650613B - Light source device and exposure device - Google Patents

Abstract

It is an object of the invention to provide a light source device that uses a plurality of light sources of different wavelengths and that does not have to be closely arranged in a predetermined arrangement.

Each of the plurality of LD modules 1 and 2 includes an LD (laser diode) and a collecting lens, and emits laser light having different wavelengths. The LD of each LD module 1, 2 is controlled by the control device 99, and controls lighting, turning off the light, and its output (illuminance). In the first fiber bundle portion b1, the light emitted from the three LD modules 1 and the one LD module 2 is incident on the first optical fiber 5, and then condensed on the second optical fiber via the first connector 6. 7. The third optical fiber 7 is further guided to the second fiber bundle portion b2, and the emission end side is bundled in accordance with the arrangement of the conductor patterns in the shape of the light irradiation region of the DMD 56 in the exposure head 18, and The optical fiber 9 is connected, and is connected to the incident optical system 40 via the second connector 10 to guide the laser light to the exposure head 18 of the exposure device B.

Description

Light source device and exposure device

The present invention relates to a light source device and an exposure device suitable for use in a direct drawing method used in an exposure step of a photolithography method, such as a printed substrate, a semiconductor wafer, or a liquid crystal display.

Conventionally, a so-called exposure step using a photolithography method to generate a circuit pattern has been widely used as a close-contact exposure apparatus using a photomask. However, in recent years, in order to cope with high density, a DMD (digital micro) which does not use a photomask is gradually used. A direct-drawing type exposure apparatus in which a light modulation element such as a mirror device or a digital micromirror device adjusts light and performs exposure (Patent Document 1).

However, the light source used in the direct-drawing apparatus is often designed to produce a high-definition pattern, and a single wavelength is often used. On the other hand, in the case where the exposed resist has sensitivity to a wide wavelength band, there is a case where the single wavelength is not sufficiently cured or the exposure time becomes long.

Therefore, as disclosed in Patent Document 2, a light source device is proposed which uses light having a plurality of different wavelength characteristics and is condensed by a lens.

[Prior patent documents] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2006-267719

[Patent Document 2] Japanese Special Open 2012-063390

However, in the case where a plurality of types of light sources and lenses having different wavelengths are used, it is necessary to closely arrange the light source array and the lens array of the light source in a predetermined arrangement, which has a problem that the apparatus becomes complicated.

It is an object of the present invention to address the shortcomings of this prior art.

In order to achieve the object, the present invention is characterized in that: a laser diode emits laser light having a predetermined wavelength characteristic; and another laser diode emits light having a different characteristic from the predetermined wavelength. a laser beam having a wavelength characteristic; the plurality of first fiber bundles having: a first optical fiber that emits light from the one laser diode at an incident end and emits at an emission end; another first optical fiber Emitting the emitted light from the other laser diode at the incident end and emitting it at the emitting end; and the second optical fiber condensing the emitted light from the other first optical fiber; a first optical fiber and an emission end side of the other first optical fiber are bundled in a predetermined arrangement, and the emitted light of the first optical fiber and the other first optical fiber is condensed, and then incident on the incident end of the second optical fiber; The optical fiber bundle has a third optical fiber that condenses the light emitted from the second optical fiber, and the emission end sides of the plurality of second optical fibers of the plurality of first optical fiber bundle portions are bundled in a predetermined arrangement. 2, after the light emitted by the optical fiber is concentrated, the incident end of the third optical fiber is injected; and the output portion And connected to the output end of the third optical fiber and used for output to the outside.

It is preferable that the laser diode has a control device that performs at least one of lighting, light-off control, and output control individually. Moreover, in the laser diode, A control device that performs at least one of lighting, light-off control, and output control for each predetermined group is preferable.

Furthermore, the exposure apparatus of the present invention modulates the light emitted from the light source device by arranging the spatial light modulation elements of the plurality of pixel portions independently modulated, and exposes the photosensitive material by the modulated light. A device characterized by the use of the light source device.

According to the light source device and the exposure device of the present invention, since it is a light source having an exposure wavelength mixed by a plurality of wavelengths, it is possible to cope with a wide range of resists. Moreover, it is not necessary to arrange the light source strictly in a predetermined arrangement, and a lens array is not required, and the apparatus can be simplified. Further, the laser diode can be simply added, and the high illumination can be easily performed.

If the control device is further provided and the lighting control or output control of the laser diode is performed, the illuminance ratio of each wavelength can be changed, and the effect of providing optimum exposure conditions and the like can be obtained.

1‧‧‧LD module

2‧‧‧LD module

3‧‧‧LD fiber

4‧‧‧Connector

5‧‧‧1st fiber

6‧‧‧1st connector

7‧‧‧2nd fiber

9‧‧‧3rd fiber

10‧‧‧2nd connector

12‧‧‧Substrate (exposure target)

14‧‧‧Exposure Department

18‧‧‧Exposure head

19‧‧‧Light source unit

40‧‧‧Infrared optical system

41‧‧‧Light Modulation Department

42‧‧‧1st imaging optical system

43‧‧‧Microlens array

43a‧‧‧microlens

44‧‧‧Aperture Array

44a‧‧‧Aperture

45‧‧‧2nd imaging optical system (projection optical system)

56‧‧‧DMD (Space Light Modulation Element)

99‧‧‧Control device

B1‧‧‧1st fiber bundle

B2‧‧‧2nd fiber bundle

A‧‧‧Light source device

B‧‧‧Exposure device

Fig. 1 is a view showing the configuration of an embodiment of a light source device of the present invention.

Fig. 2 is a perspective view showing an embodiment of an exposure apparatus of the present invention.

Fig. 3 is an explanatory view schematically showing the configuration of an exposure head according to an embodiment of the exposure apparatus of the present invention.

Hereinafter, embodiments of the present invention will be described.

The light source device is basically a laser that will differ from a plurality of wavelengths. The light emitted from the polar body is condensed and introduced into the optical fiber, and after being guided to each, a plurality of bundles are bundled in the middle of the optical path, and then the connector is connected to the thicker optical fiber to be mixed.

Hereinafter, the details will be described based on the first to third figures.

As shown in FIG. 1, the light source device A includes a plurality of LD modules 1, 2. Each of the LD modules 1 and 2 includes a laser diode (LD) and a collecting lens. The LD module 1 and the LD module 2 are provided with LDs that emit laser light having different wavelengths (wavelength A and wavelength B). In the present embodiment, the LD module 1 of three wavelengths A and the LD of one wavelength B are used. The module 2 is a group and has three groups of LD modules 1 and 2, and the LD modules 1 and 2 are guided to the connector 4 by the LD fiber 3.

Further, it is preferable that the wavelengths of the LDs of the LD modules 1 and 2 have a wavelength characteristic of 190 to 530 nm.

In the present embodiment, the wavelength A of the LD of the LD module 1 has a wavelength characteristic having a sharp peak near 375 nm, and the wavelength B of the LD of the LD module 2 has a wavelength characteristic having a sharp peak near 405 nm.

The LDs of the LD modules 1 and 2 are controlled by the control device 99, and are configured to control their lighting, turning off the lights, and their outputs (illuminance). The LDs of the LD modules 1 and 2 may be configured to be individually controlled by the control device 99, or may be configured to be controlled in groups by the control device 99.

The first optical fiber 5 of the first optical fiber bundle portion b1 is connected to each of the connectors 4, and the light emitted from the LDs of the LD modules 1 and 2 is incident on the incident end of the first optical fiber 5, and further, at the emission end thereof. Shoot out. The first fiber bundle portion b1 includes the first optical fiber 5, the first connector 6, and the second optical fiber 7.

The light emitted from the three LD modules 1 and the one LD module 2 is incident on the first fiber bundle portion b1, and is condensed in the first via the first connector 6 through the four first fibers 5 2 fiber 7.

The first optical fibers 5 of the LD modules 1 and 2 are bundled in a predetermined arrangement on the emission end side, and are connected to one second optical fiber 7 via the first connector 6.

The second optical fiber 7 has a core having a size equal to or larger than that of the light-emitting region in which the first optical fibers 5 are bundled in four bundles. As described above, the light from the four LD modules 1 and 2 is condensed. A second optical fiber 7.

In the present embodiment, three first fiber bundle portions b1 are provided, and a total of twelve LD modules 1 and 2 are collected by the three first fiber bundles 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 uniformed by interference of light in the optical fiber or interaction between modes.

The third optical fiber 7 is guided to the second optical fiber bundle portion b2, and the emission end side is the third bundled with the aligned conductor pattern in the shape of the light irradiation region of the DMD 56 in the exposure head 18 to be described later. Optical fiber 9.

The third optical fiber 9 bundled by the three second optical fibers 7 is configured such that the emission end side thereof is connected to the incident optical system 40 via the second connector 10, and the laser beam is guided to the exposure head 18 of the exposure device B.

Further, in this embodiment, an example in which laser light of two kinds of wavelengths is used is shown, but a wider variety of wavelengths may be used, and the output of the device may be increased by appropriately adding the LD modules 1 and 2.

In the light source device A described above, the laser light from the LD modules 1 and 2 is bundled by forming the emission end sides of the first optical fiber 5 and the second optical fiber 7 Since it is synthesized, it is not necessary to arrange the LD modules 1 and 2 at a predetermined position, and each of the LD modules 1 and 2 can be independently arranged. Therefore, the degree of freedom in setting the LD modules 1 and 2 is improved.

Further, by controlling the number of lighting or output of the LDs of the LDs of the LD modules 1 and 2 by the control device 99, the illuminance ratio of each wavelength can be changed, and the optimum exposure conditions required can be provided.

The configuration of the digital exposure device (image exposure device) B using the light source device A will be described based on Fig. 2 .

The exposure apparatus B includes a base 11 which is formed into a substantially rectangular flat plate and is horizontally disposed, and a movable table 13 which is slidably attached to the base 11 and which adsorbs and holds the substrate 12 to be exposed on the surface; and an exposure section 14. Exposing the substrate 12 held by the moving table 13 to the substrate 12.

The substrate 12 is, for example, a printed wiring board on which a photosensitive material is applied or bonded, or a glass substrate for a flat panel display. The digital exposure device B exposes the substrate 12 as described above, and the photosensitive material is recorded on the substrate 12 by, for example, a wiring pattern or the like without a mask. Further, in the present embodiment, in the description, the moving direction of the moving table 13 is referred to as the Y direction, and the direction orthogonal to the Y direction in the horizontal plane is referred to as the X direction (the width direction of the substrate 12), and The vertical direction orthogonal to the horizontal plane is set to the Z direction. The base 11 is formed to be long in the Y direction.

The base 11 is supported by the feet 115 mounted at each corner of the four corners. Two guide rails 16 substantially parallel to the Y direction are provided on the upper surface 11a of the base 11. The moving table 13 is attached to the base 11 so as to be slidable in the Y direction via the respective guide rails 16. Moreover, in the mobile workbench 13, a linear motor or the like is connected. The drive mechanism (not shown) is configured to move in the Y direction in response to the drive of the drive mechanism.

The exposure unit 14 is attached to the center portion of the chassis 11 in the Y direction via a pair of pillars 17 . Each of the pillars 17 is fixed to both end portions of the base 11 in the X direction. Each of the pillars 17 holds the exposure portion 14 at a predetermined distance from the upper surface 11a of the base 11 so as to pass under the exposure portion 14 when the moving table 13 moves in the Y direction. The exposure unit 14 has 16 exposure heads 18. Each of the exposure heads 18 irradiates light to the substrate 12 passing under the exposure portion 14.

Each of the exposure heads 18 is arranged in eight rows in the X direction. Each of the exposure heads 18 of the second row is arranged such that the respective exposure heads 18 of the first column are shifted by 1/2 in the X direction so that the respective centers are located near the center of the adjacent ones of the respective exposure heads 18 of the first column. spacing. By disposing in this manner, the exposure heads 18 of the second column expose the portions which are not exposed by the respective exposure heads 18 of the first column, and the substrate 12 is subjected to exposure recording without a gap in the X direction. Further, the number of the exposure heads 18 or the arrangement of the exposure heads 18 provided in the exposure unit 14 can be appropriately changed in accordance with the size of the substrate 12 or the like.

The image processing unit 21 inputs image data (image information) in response to a conductor pattern or the like recorded on the substrate 12. The image processing unit 21 creates frame data of each exposure head 18 based on the input image data. Further, the image processing unit 21 inputs the frame material to each of the exposure heads 18 via the signal cable 22. The frame data is, for example, data indicating the density of each pixel constituting the image by a binary value (the presence or absence of the recording of the dot).

Each of the exposure heads 18 modulates the laser light incident from the light source device A according to the frame data, and then projects the modulated light to the mobile workbench 13 The substrate 12 is carried. Thereby, the image corresponding to the image data input by the image processing unit 21 is exposed and recorded on the substrate 12.

In the base 11, more settings are formed The glyph door 23 and a pair of length measuring machines 24 attached to one end of the Y direction. The door 23 is mounted on the base 11 so as to be substantially parallel to the X direction so as to straddle the guide rails 16. Three cameras 25 are attached to the door 23. Each of the cameras 25 is connected to a controller (not shown) that integrally controls the entire digital exposure device 10.

Each camera 25 captures the moving table 13 passing through the door 23 and outputs the acquired image data to the controller. The controller calculates the amount of deviation of the substrate 12 from the X position, the Y direction, and the θ direction (rotation in the Z direction) of the appropriate position on the moving table 13 based on the image data acquired by each camera 25. The calculated amount of deviation is input to the image processing unit 21 and used to correct the frame data. In addition, the number of the cameras 25, the arrangement interval, and the like may be appropriately changed depending on the size of the substrate 12 or the like. Moreover, the calculation of the amount of deviation can be performed by well-known image processing. At this time, in order to easily calculate the amount of deviation, it is preferable to provide an alignment mark or the like on the substrate 12.

Each of the length measuring machines 24 is connected to the controller like the respective cameras 25. Each of the length measuring machines 24 irradiates the laser beam to the side end surface of the moving table 13, and receives the light by the reflected light to measure the position of the moving table 13. Moreover, the length measuring machine 24 outputs the measured position of the moving table 13 to the controller. Further, in the present embodiment, the so-called laser light interferometric length measuring machine 24 is shown. However, the present invention is not limited thereto. For example, any other position that can measure the moving table 13 such as an ultrasonic wave or a stereo camera may be used. Device.

According to FIG. 3, the exposure head of the exposure apparatus B of this configuration will be described. Details of the portion of the connection with the light source device A.

The exposure head 18 is composed of an incident optical system 40, a light modulation unit 41, a first imaging optical system 42, a micro lens array (MLA) 43, an aperture array (APA: aperture array) 44, and a second imaging optical system. (Projection optical system) 45 is constructed. The incident optical system 40 is disposed to face the emission end of the third optical fiber 9 via the second connector 10 . The incident optical system 40 includes a condensing lens 50 that condenses laser light (LB: laser beam) emitted from the third optical fiber 9; and a rod-shaped optical integrator 51 is disposed in the optical lens The laser beam LB passes through the optical path of the condensing lens 50; the imaging lens 52 images the laser light LB that has passed through the optical integrator 51; and the mirror 53 reflects the laser light LB imaged by the imaging lens 52. And it is incident on the light modulation portion 41.

The optical integrator 51 is, for example, a translucent rod formed in a quadrangular prism shape. The optical integrator 51 is a light beam in which the laser beam LB traveling inside while being totally reflected on one side becomes close to parallel light and the intensity in the beam cross section is uniformized. Thereby, a high-definition image in which the intensity of the illumination light is uneven is exposed to the substrate 12. Further, in order to increase the light transmittance, the incident end surface and the output end surface of the optical integrator 51 are preferably coated with an anti-reflection film.

The optical modulation unit 41 includes a TIR (total internal reflection) 稜鏡 55 and a DMD (digital micro mirror device) 56 that is a spatial light modulation element. The TIR 稜鏡 55 is such that the laser light LB incident through the mirror 53 is reflected toward the DMD 56. The DMD56 is a two-dimensionally arranged SRAM (Static Random Access Memory) unit, and the micromirrors constituting the pixels are supported by the pillars and arranged to be tilted freely. Mirror device.

The DMD 56 changes the tilt angle of the micromirror to reflect the state in which the irradiated laser light LB is reflected toward the first imaging optical system 42 in accordance with the digital signal written in the SRAM cell, and the direction of the irradiated laser light LB is omitted. The state in which the light absorber is reflected. The light modulation unit 41 controls the tilt of the micromirrors of the pixels of the DMD 56 in response to the frame data input from the image processing unit 21, thereby generating image light corresponding to the frame data.

The first imaging optical system 42 is composed of lenses 57 and 58, and the image light generated by the light modulation unit 41 is amplified by a predetermined magnification and imaged on the MLA 43.

MLA43 is formed, for example, by quartz glass to form a substantially rectangular flat plate. Further, in the MLA 43, a plurality of microlenses 43a which are two-dimensionally arranged in correspondence with the respective pixels of the DMD 56 are formed. Each of the microlenses 43a is a plano-convex lens having a flat surface on the upper surface and a convex surface on the lower surface. Each of the microlenses 43a individually images the image light from each of the micromirrors of the DMD 56, and brightens the image light amplified by the first imaging optical system 42. Further, the shape of each of the microlenses 43a is not limited to a plano-convex lens, and may be, for example, a lenticular lens or the like.

The APA44 is light-shielding and forms a plurality of apertures 44a for passing image light. Each of the apertures 44a is two-dimensionally arranged in correspondence with each of the pixels of the DMD 56, similarly to the respective microlenses 43a. The APA 44 is disposed such that the respective apertures 44a face the respective microlenses 43a, and the image light imaged by the respective microlenses 43a passes through the respective individually corresponding apertures 44a. The APA44 prevents the light generated by the chattering of the micromirrors of the DMD 56 from passing through, and improves the sharpness of the exposed image.

The second imaging optical system 45 includes lenses 60, 61 and a pair of pupils 62, and projects image light that has passed through the APA 44 onto the substrate 12. Each of the lenses 60, 61 amplifies the image light that has passed through the APA 44 to a predetermined magnification, or injects it into the pair 62 at an equal magnification. The 62-series is provided so as to be movable in the vertical direction, and the focus of the image light on the substrate 12 is adjusted by moving up and down.

Further, in this embodiment, the DMD 56 is shown as the spatial light modulation element. However, the spatial light modulation element is not limited thereto, and may be, for example, a liquid crystal shutter. Further, in this embodiment, the substrate 12 to which the photosensitive material is applied or bonded is shown as an exposure target, but the exposure target is not limited thereto, and may be, for example, a photographic film or a photographic paper.

Claims (6)

A light source device comprising: a laser diode emitting laser light having a peak at a first wavelength; and another laser diode emitting a second wavelength different from the first wavelength a laser beam having a peak; the plurality of first fiber bundles having: a first optical fiber, wherein the emitted light from the one of the laser diodes is incident at the incident end and is emitted at the exit end; the other first optical fiber Emitting the emitted light from the other laser diode at the incident end and emitting it at the emitting end; and the second optical fiber condensing the emitted light from the other first optical fiber; a first optical fiber and an emission end side of the other first optical fiber are bundled in a predetermined arrangement, and the emitted light of the first optical fiber and the other first optical fiber is condensed, and then incident on the incident end of the second optical fiber; The optical fiber bundle has a third optical fiber that condenses the light emitted from the second optical fiber, and the emission end sides of the plurality of second optical fibers of the plurality of first optical fiber bundle portions are bundled in a predetermined arrangement. 2, after the light emitted by the optical fiber is collected, the incident end of the third optical fiber is incident; and the output portion is connected to the first The output end of the optical fiber is connected and output to the outside; and the control device individually controls the lighting of the laser diode and the other laser diode to change the illumination of each wavelength. proportion. The light source device of claim 1, wherein the control device performs a lighting and light-off control device for the group of the one laser diode and the other group of the laser diodes. The light source device of claim 1, wherein the first wavelength and the second wavelength have a wavelength region of 190 nm to 530 nm. A light source device according to claim 1, wherein the first wavelength is in the vicinity of 375 nm, and the second wavelength is in the vicinity of 405 nm. An exposure apparatus for modulating light emitted from a light source device by arranging spatial light modulation elements of a plurality of independently modulated pixel portions, and exposing the photosensitive material to the exposure device by using the modulated light A light source device according to any one of claims 1 to 4. An exposure apparatus according to claim 5, further comprising a microlens array in which a plurality of microlenses each condensing a plurality of light beams modulated by the plurality of pixel portions are individually collected.