JP2011022529A - Light source device and exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device which individually regulates the intensities of a plurality of wavelengths in a practical level. <P>SOLUTION: In the light source device, a reflection coating film for shielding a light having one emission line wavelength of an emission line spectrum is provided to reflect a light flux or to have a plurality of openings to transmit and pass the light flux, the maximum dimension of the plurality of openings is a small dimension so that the plurality of openings are arranged within a surface irradiated with the light flux having a predetermined wavelength, and at least one property of the light flux having a selected predetermined wavelength is determined by the shape, the interval and the number of the fine openings. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In the present invention, light emitted from a light source that emits light having an emission line spectrum having one or more emission lines of a predetermined wavelength is incident, and a passing amount for each emission line spectrum (generally, reflection amount when used in reflection in optics, The present invention relates to a light source device that emits light having an adjusted transmission amount, which is referred to as “passage amount” in the sense of indicating both, and an exposure apparatus.

  In recent years, there has been a growing demand for fine processing of semiconductors due to integration of semiconductor circuits and downsizing of semiconductors. Among them, in the production of circuit boards, it is used as a mask for parts left unetched or not plated, or to cover parts that do not require soldering when mounting and soldering parts. In addition, a technique for forming a resist pattern having a predetermined shape is widely used.

  As one of the methods for forming such a resist pattern, a photosensitive resist is applied on a substrate by a coating apparatus to form a resist film, a desired circuit pattern is exposed to the resist film by an exposure apparatus, and then A method of forming a resist pattern by performing a predetermined post-treatment is used. In addition, among resist patterns, there are those using a photo-curing resist that is hardened by light irradiation, and those using a photoresist that is formed by developing an exposed portion.

Therefore, since the shape of the final circuit pattern formed on the substrate is determined by the shape of the resist pattern, the cross-sectional shape of the resist pattern is also important for forming a fine circuit board. It becomes an element.
In general, the cross-sectional shape of the resist pattern is preferably a straight shape (rectangular shape) that rises perpendicular to the substrate surface. However, depending on the application, there may be a need for a reverse tapered (inverted trapezoidal) cross section where the portion close to the light receiving surface (upper layer) is widened. In some cases, a taper-shaped (trapezoidal) cross section in which a portion (lower layer) is widened is required.

  Conventionally, in order to form resist patterns having various cross-sectional shapes, it is necessary to manufacture a photosensitive resist having a different composition for each cross-sectional shape and apply a different photosensitive resist to the substrate for each cross-sectional shape. It was. For this reason, various types of photosensitive resists have been developed for the photosensitive resist. For example, a resist pattern having a cross-sectional shape closer to a rectangle is observed by paying attention to the absorbance of light with respect to a predetermined wavelength of the compound. A method for producing a resist film for obtaining the same has also been proposed. (For example, refer to Patent Document 1.)

  In addition, in order to obtain resist patterns having various cross-sectional shapes other than rectangular shapes, it is generally necessary to manufacture the photosensitive resist itself applied to the substrate by changing the composition according to each cross-sectional shape. . Accordingly, when a resist pattern having a cross-sectional shape different from the rectangular shape is required, it is difficult to quickly respond to the change in the cross-sectional shape, and it is necessary to prepare many types of photosensitive resists, which increases the manufacturing cost. There was a problem.

  In order to form resist patterns having various cross-sectional shapes without changing this photosensitive resist, it corresponds to at least one wavelength among the light of the wavelength of two or more bright line portions output from the ultraviolet light source portion There has been proposed an exposure apparatus provided with light intensity changing means that can change the optical intensity of the wavelength by changing the incident angle of the light of the wavelength by changing the installation angle of the optical filter. (For example, see Patent Document 2.)

  According to the exposure apparatus of Patent Document 2, by changing the installation angle of the optical filter mechanically, the incident angle of the light is changed, and thereby the pass characteristic of the filter (generally reflection characteristics when used in reflection in optics, When used in transmission, the center wavelength of transmission characteristics is referred to as “transmission characteristics” in the sense of indicating both, but the center wavelength is shifted between the short wavelength side and the long wavelength side. When the center wavelength is shifted to the long wavelength side or the short wavelength side, the filter pass rate (generally referred to as reflectivity when used for reflection in optics, and transmittance when used as transmission, compared to when not shifted) In the sense of indicating both, it is referred to as “passing rate”) and the optical intensity is weakened. In Patent Document 2, by combining filters of a plurality of wavelengths and adjusting the optical intensity of each wavelength by the above method, the side surface angle in the cross-sectional shape of the resist pattern is adjusted, and a resist pattern cross section having a tapered shape or an inversely tapered shape is obtained. I am doing so.

  Further, as an optical filter device for adjusting the intensity of the wavelength, a mechanical movable such as a waveguide-type Mach-Zehnder (MZ) optical filter, an acoustic-optic tunable filter (AOTF), or the like is possible. There is known a variable optical filter that has no part and can change the loss characteristic of the wavelength by electrical means.

JP 2007-150171 A JP 2007-12970 A

  As an optical filter for controlling the pass rate for each wavelength, a method of coating a flat glass with a predetermined film thickness is generally used. However, a coating that achieves a complicated wavelength pass rate is difficult to design and expensive.

  Further, each of the optical filters described above has a problem that the range in which the wavelength intensity can be adjusted is small, is sensitive to fluctuations in voltage and temperature, is difficult to control, and its control means is complicated. For example, according to the exposure apparatus of Patent Document 2, the side angle in the cross-sectional shape of the resist pattern is adjusted by mechanically changing the installation angle of the optical filter to obtain a resist pattern cross-section having a taper shape or a reverse taper shape. However, since the adjustment is performed by mechanically changing the installation angle of the optical filter and shifting the center wavelength, the shift amount is very partial compared to the entire wavelength intensity. The adjustment range is limited. Therefore, the adjustment range of the filter pass rate and the adjustment range of the optical intensity are limited to a narrow range compared to the range to be adjusted.

  Therefore, in each of the optical filters described above, the amount that can form a tapered shape or a reverse tapered shape in the cross section of the resist pattern is small with respect to the change in the installation angle of the mechanical optical filter. That is, there is a problem that the adjustment range of the filter pass rate and the adjustment range of the optical intensity with respect to the change in the installation angle of the optical filter are very small, and the light intensity cannot be sufficiently adjusted at a practical level. Conventionally, since the intensity cannot be adjusted sufficiently, the exposure apparatus may deteriorate the illuminance uniformity of the exposure area.

  SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a light source device and an exposure apparatus that can individually adjust the intensities of a plurality of wavelengths at a practical level.

In order to solve the above problems, in the light source device according to the embodiment of the present invention, the light beam generated by the light source that generates a light beam having a plurality of bright lines is collected by a concave mirror, and an optical filter is formed from the collected light beam. A light source device that selects a light beam having a predetermined wavelength by a selection unit having an apparatus and irradiates an object to be illuminated with the light beam having the predetermined wavelength, the optical filter device having a wavelength of at least one bright line of the bright line spectrum. A reflective coating that blocks light is provided so as to have a plurality of apertures that reflect or transmit the light beam, and a plurality of openings have a maximum dimension within the irradiation surface of the light beam having the predetermined wavelength. The size of the apertures can be arranged, and at least one characteristic of the selected light flux having a predetermined wavelength is determined by the shape, interval, and number of the apertures.
In this embodiment, it is not necessary to design and manufacture an optical filter coating based on the specification of the wavelength pass rate by providing a minute opening in the optical device and determining the shape and number of the openings, and the emission line wavelength. Characteristics such as strength can be adjusted at a practical level. Further, illumination σ unevenness and xy wavelength illumination unevenness can be taken.

In the light source device according to an embodiment of the present invention, the optical filter device provided with the plurality of minute apertures is a partial region having a different shape, interval, or number of the apertures in an irradiation surface of the light beam having the predetermined wavelength. Drive means for moving each optical filter unit of the optical filter device so that the ratio of the partial region in the irradiation surface of the light flux varies.
In the present embodiment, adjustment of characteristics such as the intensity of the emission line wavelength can be facilitated by having the partial regions having different shapes, intervals, or numbers of the openings and having the movable device of the optical filter unit.

In the light source device according to an embodiment of the present invention, the optical filter device includes a plurality of optical filter units arranged in series, and each optical filter unit generates the light source with respect to another optical filter unit. At least one of the optical characteristics with respect to the light beam, the shape of the openings, the interval between the openings, and the number of the openings may be different.
In this embodiment, by having a plurality of optical filter portions having different shapes, intervals, or numbers of openings, it is possible to easily adjust complex characteristics with respect to frequencies such as the intensity of the emission line wavelength.

The light source device according to an embodiment of the present invention may include illumination uniformizing means for uniformizing illuminance for illuminating each part of the illumination object with the light flux that has passed through the optical filter device.
In the present embodiment, the light beam emitted to the photomask and the positive resist can be made uniform by making the emitted light beam uniform.

In order to solve the above problems, in the light source device according to the embodiment of the present invention, the light beam generated by the light source that generates a light beam having a plurality of bright lines is collected by a concave mirror, and an optical filter is formed from the collected light beam. An exposure apparatus that selects a light beam having a predetermined wavelength by a selection unit having an apparatus and irradiates the positive resist as illumination light through a predetermined pattern formed on a photomask, the optical filter The apparatus is provided with a plurality of apertures for reflecting or transmitting the light beam, and the maximum size of the plurality of apertures can be arranged in the irradiation surface of the light beam having the predetermined wavelength. The selected dimension determined by the shape, spacing and number of the minute apertures, and the light beam having the predetermined wavelength passed through the optical filter device. Having an illumination uniformizing means for uniformizing the illuminance to illuminate the respective portions of the bright object, the made uniform, the light flux of the predetermined wavelength that has passed through the photomask is irradiated onto the positive resist.
In this embodiment, by providing a minute opening in the optical device and determining the shape and number of the openings, characteristics such as the intensity of the emission line wavelength are adjusted at a practical level, and a desired frequency is obtained with respect to the positive resist. Can be exposed at a desired intensity.

In the light source device according to an embodiment of the present invention, the light beam having the predetermined wavelength may include at least one wavelength of i-line, h-line, and g-line that are bright lines of the light beam generated by the light source. .
In this embodiment, it is possible to deal with i-line, h-line, and g-line that are bright lines of the ultraviolet light source.

In order to solve the above-described problem, in the light source device according to the embodiment of the present invention, light emitted from a light source that emits light of a bright line spectrum having a bright line of a predetermined wavelength is incident, and a passing amount for each bright line spectrum. A light source device that emits light with adjusted wavelength, wherein a reflection coating that blocks light having a wavelength of at least one emission line of the emission line spectrum is provided in part, and a surface region that the reflection coating passes and a surface region that blocks the reflection region By varying the area ratio with respect to each total surface area, an optical filter unit provided with at least two partial regions adjacent to each other with different filter pass rates of light having the wavelength of the emission line, and the optical filter unit individually The position of the irradiation region of the light in the optical filter unit is continuously crossed across the boundary line of each partial region from one of the two partial regions to the other. A driving means that can be driven so as to be able to be moved, and by changing the area ratio of the two partial regions in the light irradiation region by moving the optical filter portion, the optical filter portion in the optical filter portion A passing wavelength control unit that controls a passing amount of the light incident on the irradiation region.
In this embodiment, the optical filter having a predetermined transmission characteristic with respect to the emission line wavelength is provided with partial regions having different filter pass rates, and the position of the light irradiation region in the optical filter is continuously crossed across the boundary line of each partial region. By controlling the brightness, the intensity of the emission line wavelength can be adjusted at a practical level.

In the light source device according to an embodiment of the present invention, the optical filter unit includes at least a first optical filter unit and a second optical filter unit, and the first optical filter unit is a surface on a first transparent substrate. At least a first partial region and a second partial region, and a first reflective coating that blocks the light on the first transmission characteristic coating having a predetermined transmission characteristic with respect to light having the first emission line wavelength, The second optical filter section is formed with at least a third partial area and a fourth partial area on the surface of the second transparent substrate. A second reflective coating for blocking the light on a second transmission characteristic film having a predetermined transmission characteristic for light having a second emission line wavelength different from the light having the first emission line wavelength, and the third partial region. Different physics from the fourth partial area The drive means has at least a first drive means and a second drive means, and the first drive means determines the position of the irradiation region in the first optical filter section. The second partial area can be driven so that it can be continuously moved across the boundary line between the first partial area and the second partial area, and the second driving means is configured to emit the irradiation area in the second optical filter section. The position of the third partial region and the fourth partial region can be continuously moved across the boundary line, and the passing wavelength control unit includes the first driving unit and the The amount of light passing through each of the optical filter units may be controlled by controlling the driving amount of the second driving unit.
In this embodiment, each of a plurality of optical filters having different transmission characteristics with respect to a plurality of emission line wavelengths is provided with a partial region having a different filter transmission rate, and the position of the light irradiation region in each optical filter is defined as the boundary line of each partial region. By continuously controlling across, the intensities of a plurality of wavelengths can be individually adjusted at a practical level.

In the light source device according to the embodiment of the present invention, each of the first optical filter unit and the second optical filter unit is provided with a rotation shaft capable of individually rotating, and the first driving unit includes: , By rotating and driving the first optical filter unit, the position of the light irradiation region is continuously moved across the boundary line between the first partial region and the second partial region, and the second driving means Can rotate the second optical filter unit to continuously move the position of the light irradiation region across the boundary line between the third partial region and the fourth partial region. It may be driven.
In this embodiment, since the filter pass rate of each optical filter is controlled by rotational movement, the position of the irradiation region can be easily controlled by a stepping motor or the like.

In the light source device according to an embodiment of the present invention, the first optical filter unit and the second optical filter unit may be individually moved linearly with the first driving unit and the first optical filter unit. 2 is attached to the driving means, and the first driving means linearly drives the first optical filter unit to thereby position the irradiation region of the light between the first partial area and the second partial area. The second driving means drives the second optical filter unit linearly by moving the light continuously across the line, thereby changing the position of the light irradiation region to the third partial region and the fourth partial portion. You may make it drive so that it can move continuously across the boundary line of an area | region.
In this embodiment, since the filter pass rate of each optical filter is controlled by linear movement, the position of the irradiation region can be easily controlled by a rack and pinion that converts the motor and rotational motion into linear motion.

In the light source device according to the embodiment of the present invention, the optical filter unit further includes a third optical filter unit, and the third optical filter unit includes at least a fifth partial region on the surface of the third transparent substrate. A third partial region provided with a sixth partial region for blocking the light on a third transmission characteristic film having a predetermined transmission characteristic with respect to light having a third emission line wavelength different from the first emission line wavelength and the second emission line wavelength; The reflective coating is formed so as to have different filter pass rates in the fifth partial region and the sixth partial region, the driving means further includes third driving means, and the third driving means It can be driven so that the position of the irradiation region in the third optical filter unit can be continuously moved across the boundary line of the fifth partial region and the sixth partial region, and the passing wavelength control unit Is the third wheel drive Driving amount of means may be to control, may control also passes the amount of light of the third optical filter unit.
In this embodiment, since it is combined with the third optical filter, it is possible to control light more complicatedly individually for each wavelength.

In the light source device according to the embodiment of the present invention, each reflective coating having a different filter pass rate for each partial region of each optical filter unit uses a predetermined graphic pattern corresponding to the filter pass rate for masking. In addition, the filter pass rates may be made different by forming the ratios of the regions where the respective reflective coatings are formed and the regions where the respective reflective coatings are not formed.
In the optical filter of this embodiment, the light filter in the optical filter is provided by providing an irradiation region and a non-irradiation region using masking on the coating on the surface of the plurality of optical filters having different transmission characteristics for a plurality of emission line wavelengths. Since the pass rate is controlled, it is easy to form partial regions having different filter pass rates.

In the light source device according to the embodiment of the present invention, each of the reflective coatings may be a reflective coating that reflects light of a corresponding wavelength.
In the optical filter of this embodiment, in the optical filter of this embodiment, since the reflective film is a reflective film, a metal material or the like can be used for the film, so that it is easy to form partial regions having different filter pass rates. is there.

  In the light source device according to an embodiment of the present invention, the regions of the reflective coating in the optical filter portions in the predetermined graphic pattern are alternately arranged in a band shape in which the partial regions having different filter pass rates radially reach the peripheral portion from the center. The partial regions having different filter pass rates may be formed alternately in a plurality of concentric rings having different diameters, or the partial regions having different filter pass rates. May be formed so as to be a plurality of circular portions and surrounding portions thereof, or the partial regions having different filter pass rates may be alternately formed in a slit shape, or the filter passes through. Partial regions having different rates may be alternately formed in a staggered pattern.

  In addition, when a plurality of optical filters having different pass characteristics with respect to a plurality of emission line wavelengths are radially provided with partial regions having different filter pass rates, the optical filters are rotated to individually adjust the filter pass rates of the optical filters. be able to. When concentrically providing partial regions with different filter pass rates for each of the plurality of optical filters having different pass characteristics for a plurality of emission line wavelengths, the optical filter is linearly driven to individually adjust the filter pass rates of the optical filters. can do. When providing a partial region having different filter pass rates to each of a plurality of optical filters having different transmission characteristics for a plurality of emission line wavelengths so as to be a circular portion and its peripheral portion by a predetermined graphic pattern, the interval or diameter of the circular portions is set. When changing, it is easy to form regions of optical filters having different filter pass rates.

  In addition, when partial areas having different filter pass rates are alternately provided in a slit shape with a predetermined graphic pattern in each of a plurality of optical filters having different pass characteristics with respect to a plurality of emission line wavelengths, the filter passes by changing the slit width. It is easy to form regions of optical filters having different rates. In the case where partial areas having different filter pass rates are alternately provided in a staggered pattern with a predetermined graphic pattern in each of a plurality of optical filters having different transmission characteristics for a plurality of emission line wavelengths, the size of the staggered pattern can be changed. Therefore, it is easy to form regions of optical filters having different filter pass rates.

In the light source device according to the embodiment of the present invention, the predetermined pass characteristic in the optical filter unit may be at least one pass characteristic among a low pass filter, a band pass filter, and a high pass filter.
In this embodiment, each of the plurality of optical filters has different wavelength pass characteristics and is at least one of a low-pass filter, a band-pass filter, and a high-pass filter, so that the adjustment range can be widened.

In the light source device according to the embodiment of the present invention, at least one of the first transmission characteristic film of the first optical filter section and the second transmission characteristic film of the second optical filter section is a first emission line wavelength. A band-pass filter for light of the above and a high-pass filter for light of the second emission line wavelength may be provided.
In this embodiment, since at least one of the plurality of optical filters has a composite pass characteristic of a band pass of one wavelength and a high pass of another wavelength, it is possible to cope with a complicated wavelength and light intensity.

In the light source device according to an embodiment of the present invention, at least one of the optical filter units is provided with at least three or more partial areas on the surface of the transparent substrate, and the filter of the coating in each partial area You may make it form so that a passage rate may differ, respectively.
In the present embodiment, since three or more partial regions having different filter pass rates are provided, the filter pass rate can be adjusted more variously.

In the light source device according to the embodiment of the present invention, among the optical filter portions, the optical filter portion that is uniform without being provided with the partial regions having different filter pass rates is replaced with the other optical filter provided with the partial regions. You may make it form in the opposite surface to the said filter surface in the transparent substrate in which the part was formed.
In the present embodiment, by providing the optical filter portion having a uniform filter passing rate on the opposite surface of the other optical filter portion with the substrate interposed therebetween, the number of substrates can be reduced and the man-hours and costs can be reduced.

In order to solve the above problems, in a light source device according to an embodiment of the present invention, the optical filter device according to claim 1, a light source, and light emitted from the light source is incident on the optical filter device. And an exit optical system for condensing the light emitted from the optical filter device onto the irradiation area of the irradiated object.
When the optical filter of the present invention is used in a light source device, a partial region having a different filter pass rate is provided in each of a plurality of optical filters having different pass characteristics with respect to a plurality of emission line wavelengths, and the position of the light irradiation region in each optical filter. Is controlled continuously across the boundary line of each partial region, whereby the intensities of a plurality of wavelengths can be individually adjusted.

In the light source device according to the embodiment of the present invention, the light source is an ultraviolet light source having a plurality of emission line wavelengths, and the light having the first emission line wavelength in the optical filter device is an i-line having an ultraviolet emission line wavelength. The light having the second emission line wavelength in the optical filter device may be h-ray having an ultraviolet emission line wavelength.
In this embodiment, it is possible to control the filter pass rate of the first emission line wavelength (i line) and the second emission line wavelength (h line) among the plurality of emission line wavelengths of the ultraviolet ray for exposure, so that the cross section of the resist pattern It is possible to easily control the taper angle of the side surface in the shape.

In order to solve the above-described problems, in the exposure apparatus according to the embodiment of the present invention, the photosensitive resist applied on the substrate is exposed to light emitted from the light source device through a predetermined pattern. An exposure apparatus for forming a circuit of the predetermined pattern on a substrate, comprising: a light source device comprising the optical filter device according to claim 1; and a light passage amount from the light source by the passage wavelength control unit. A control unit that controls the position of the predetermined pattern irradiated with light from the light source and the position of the substrate to be exposed in conjunction with the control.
When the optical filter of the present invention is used in an exposure apparatus, the intensity of light having two or more wavelengths irradiated on the photosensitive resist can be individually adjusted, so that the side surface in the cross-sectional shape of the resist pattern can be changed without changing the photosensitive resist. The angle can be controlled at a practical level. For example, the cross-sectional shape of the resist pattern can be quickly and easily controlled to a straight shape, a tapered shape, a reverse tapered shape, or the like.

  According to the optical filter device of the embodiment of the present invention, the optical filter having the transmission characteristic with respect to the emission line wavelength is provided with the partial regions having different filter pass rates, and the position of the light irradiation region in the optical filter is set to the boundary between the partial regions. Since the control is continuously performed across the line, the intensity of the emission line wavelength can be adjusted at a practical level.

It is a block diagram which shows schematic structure of the projection exposure apparatus of 1st Embodiment which concerns on this invention. It is a flowchart which shows an example in the case of forming a circuit pattern in a printed circuit board using the projection exposure apparatus 1 of this embodiment. It is a figure which shows the relationship between each filter passage rate in the several emission line wavelength of an ultraviolet light source, and the cross-sectional shape of the pattern circuit formed on a circuit board, (a) is a standard branching characteristic in the case of having no optical filter, and the case (B) Spectral characteristics when (b) attenuates the first wavelength and the second wavelength, and (c) Spectral characteristics when the first wavelength and the second wavelength are further attenuated. The cross-sectional shape at that time, (d) shows the branching characteristics when the third wavelength is attenuated in addition to (c), and the cross-sectional shape at that time. It is a perspective view which shows an example of the principal part in the light source device of 1st Embodiment which concerns on this invention, (a) shows the case where an optical filter part is circular, (b) shows the case where an optical filter part is a square. Show. It is a top view which shows the other example of the principal part in the light source device of 1st Embodiment which concerns on this invention, (a) arrange | positions the partial area | region of an optical filter part in a revolver shape by varying the space | interval of the micro aperture of the same diameter (B) shows the case where the partial regions of the optical filter section in which minute apertures having different diameters are provided at the same interval are arranged in a revolver shape. It is a side view which shows the modification of the principal part in the light source device of 1st Embodiment which concerns on this invention, (a) shows the case where an optical filter part is a transmission type, (b) is an optical filter part is a reflection type. A case is shown, and (c) shows a case where pass-type optical filter sections having different characteristics are arranged in series. It is a perspective view which shows the other example of the film formation pattern in the principal part of an optical filter apparatus, (a) is a radial pattern, (b) shows the case of a concentric pattern. It is a perspective view which shows an example of the principal part in the light source device of 2nd Embodiment which concerns on this invention, (a) shows the case where an optical filter part is circular, (b) shows the case where an optical filter part is square. Show. It is a perspective view which shows an example in the case of using the some optical filter in the light source device of 2nd Embodiment which concerns on this invention, (a) is a partial area | region which formed the film of the incident side surface of a board | substrate, and a partial area | region which does not form (B) shows the case of dividing into 4 parts by the partial area where the coating on the incident side surface of the substrate is formed and the partial area where it is not formed, and (c) shows the filter passing through the incident side surface of the substrate. A case is shown in which a partial area where a film having different levels in three stages is formed and a partial area where the film is not formed are equally divided into four. It is a figure which shows the change of the filter passage rate by the area ratio of the reflective partial area | region in each optical filter part single-piece | unit of the light source device of 2nd Embodiment concerning this invention changing, (a) is an area ratio of 100%, The single optical filter unit characteristics in each case of 75%, 50%, and 25% are shown, and (b) is the second optical filter unit in each case of the area ratio of 100%, 75%, 50%, and 25%. The simple substance characteristics are shown. It is a figure which shows the relationship between the filter transmittance at the time of combining the 1st optical filter part and 2nd optical filter part of the light source device of 2nd Embodiment which concern on this invention, and a wavelength characteristic, (a) is an area ratio of 100. The filter pass rate when combining the first optical filter part of 50% and the second optical filter part of 50% is shown, and the wavelength characteristic when (b) is (a) is shown. It is a figure which shows the change of the filter passage rate at the time of combining with the 1st optical filter part of the light source device of 2nd Embodiment which concerns on this invention, and a 2nd optical filter part, and the change of a wavelength characteristic including those relationships. , (A) shows the filter pass rate when combined with a first optical filter unit with an area ratio of 100% and a second optical filter unit varying between 0% and 100%, and (b) shows (a). The change of the wavelength characteristic in the case of is shown. It is a perspective view which shows an example of the principal part in the optical filter apparatus of 3rd Embodiment which concerns on this invention, (a) divided into 2 parts with the partial area | region which formed the film | membrane of the incident side surface of a board | substrate, and the partial area | region which does not form (B) shows a case where the partial area where the coating on the incident side surface of the substrate is formed and a partial area where the coating is not formed are divided into four equal parts, and (c) shows three stages of filter pass rates on the incident side surface of the substrate. Fig. 5 shows a case where the partial area where the coating film of different levels is formed and the partial area where the film is not formed are divided into four equal parts. It is a figure which shows the change of the filter passage rate of the 2nd optical filter part of the special characteristic of the light source device of 4th Embodiment which concerns on this invention, and the change of a wavelength characteristic including those relationships, (a) is an area. The filter pass rate of the 2nd optical filter part of the special characteristic from which a ratio changes between 0%-100% is shown, (b) is the 2nd optical filter part from which an area ratio changes between 0%-100% (C) shows the change of the wavelength characteristics when (c) is (b). It is a top view which shows the other example of the principal part in the light source device of 5th Embodiment which concerns on this invention.

A projection exposure apparatus, a light source apparatus, and an optical filter according to a first embodiment of the present invention will be described in detail below with reference to the drawings.
<First Embodiment>
FIG. 1 is a block diagram showing a schematic configuration of a projection exposure apparatus according to the first embodiment of the present invention.
Here, an optical filter device that emits light that is emitted from a light source that emits light having an emission line spectrum having an emission line of a predetermined wavelength according to the present embodiment, and that adjusts the amount of passage for each emission line spectrum, and its optical A light source device using a filter device and a projection exposure device using a light source including the optical filter device will be described.

  The projection exposure apparatus 1 irradiates the circuit pattern formed on the photomask 20 with the light emitted from the light source apparatus 10 including the light source 2, and projects light including the image of the circuit pattern that has passed through the photomask 20. 50 is an apparatus for projecting onto the printed circuit board 100 through 50 and exposing. More specifically, it is an apparatus for forming a printed wiring portion on a printed circuit board material by exposing a circuit pattern to a photosensitive material (photoresist) uniformly applied on the printed circuit board material before exposure. The exposure apparatus includes a solder resist and a pattern resist (such as a dry film resist) corresponding to the photosensitive material used. A solder resist is used when solder is attached in a subsequent process, and a pattern resist is used when the copper foil layer of the substrate is etched.

  The solder resist forms a protective layer of a wiring or a copper foil pattern by, for example, dipping in a solder bath in a state in which the solder is prevented from adhering to a place where solder should not be attached. When a photosensitive solder resist is used, the solder can be attached only to the exposed part or excluding the exposed part. The photosensitive pattern resist is evenly applied on a copper foil or the like in a printed circuit board material (for example, a resin plate having a copper foil layer on its surface: a copper clad laminate), and a circuit pattern is formed on the photosensitive pattern resist. Is exposed to an exposure device and baked, and after removing the unexposed photosensitive pattern resist, the copper foil layer is etched to remove only the exposed portion or the exposed portion of the copper foil is etched. Can be removed.

  1 includes, for example, a light source 2, a reflecting mirror 3, a collimator lens 4, a first optical filter unit 5, a second optical filter unit 6, a third optical filter unit 7, an illumination uniformizing unit 8, and a light collecting unit. A lens 9, a passing wavelength control unit 11, a first driving unit 12, a second driving unit 13, and a third driving unit 14 are included. The light source device 10 forms light emitted from the light source 2 into a light beam having a predetermined uniformity / irradiation area, and irradiates the target irradiation surface with the light beam. By using such a light source device 10 for the projection exposure apparatus, a photosensitive photoresist can be exposed.

  The light source 2 is, for example, a laser light generator, an arc lamp, a mercury lamp, or the like, and emits light having an emission line spectrum having emission lines in a plurality of predetermined wavelength ranges. The wavelength of the light source 2 includes light in any wavelength region including an X-ray region, an ultraviolet region, a visible region, and an infrared region. The light source device 10 may be configured by one light source 2 or may include two or more light sources 2 for each wavelength or wavelength band. In the present embodiment, the light source 2 is an ultraviolet light source (ultraviolet lamp) having a plurality of emission line wavelengths, and the light having the first emission line wavelength in the optical filter device is i-line having the emission line wavelength of ultraviolet rays. The light having the second emission line wavelength is h-line having the ultraviolet emission line wavelength, and the light having the third emission line wavelength in the optical filter device is g-line having the ultraviolet emission line wavelength.

The reflecting mirror 3 is a condensing means that constitutes an incident optical system that makes the light emitted from the light source 2 incident on the optical filter device, and generally an elliptical mirror or a hyperboloidal mirror is used. The reflecting mirror 3 converges the light emitted from the light source 2 to the entire periphery at one point or makes it a diffused light having a level close to parallel light. By this reflecting mirror 3, the light incident on each optical filter can be converged on the irradiation region.
The collimator lens 4 emits the light that has become diffused light close to the convergent light or parallel light by the reflecting mirror 3 as parallel light. By making it parallel light, the irradiation area of the light incident on each optical filter can be made substantially the same.

The first optical filter unit 5 is irradiated with the light emitted from the light source 2 and collected by the reflecting mirror 3, and emits light with adjusted passage amount for each first emission line wavelength (i-line) spectrum, for example. The optical filter device or a part of the optical filter device. For example, the first optical filter unit 5 is formed with a first transmission characteristic film having a predetermined transmission characteristic with respect to light having the first emission line wavelength on the surface of the first transparent substrate, and blocks ultraviolet rays thereon. A first reflective coating is formed. However, the first pass characteristic coating may be formed uniformly on the surface of the first transparent substrate, but the first reflective coating is not formed evenly on the surface. The predetermined pass characteristic in the first optical filter unit 5 is at least one pass characteristic among a low pass filter, a band pass filter and a high pass filter.
The adjustment range of the entire optical filter can be expanded by making the pass characteristics of the wavelengths of the plurality of optical filter portions different.

  The first reflective coating is provided on the surface of the first transparent substrate so that at least two partial regions are adjacent to each other, and the reflective coating is formed on the surface so that the filter transmittance of the first emission line wavelength in each partial region is different. Are formed with different total areas. The predetermined transmission characteristic is, for example, a characteristic that passes or blocks light having the first emission line wavelength. Further, a method for forming the first reflective coating on the first transparent substrate will be described in more detail later with reference to FIGS. 5 and 9. As the first reflective coating, a coating that absorbs ultraviolet rays and a reflective coating can be used. In this embodiment, a reflective coating is used. As the reflective film, a metal film, a single-layer / multi-layer dielectric film, or a combination thereof can be used.

As a material for the dielectric film, a material having a high refractive index and a low refractive index is known. As the high refractive index material, Al ₂ O ₃ , ZrO ₂ , HfO ₂ , Sc ₂ O ₃ , Y ₂ O ₃ , NdF ₃ , LaF ₃ , YbF ₃ , CeF ₃ , ThF ₄ or the like can be used. As the low refractive index material, SiO ₂ , MgO, MgF ₂ , Na ₃ AlF ₆ , Na ₅ Al ₃ F ₁₄ , AlF ₃ , CaF ₂ , NaF, LiF, or the like can be used.

  The second optical filter unit 6 receives the light emitted from the first optical filter unit 5 and, for example, emits light with adjusted passage amount for each second emission line wavelength (h-line) spectrum or Part of the optical filter device. For example, the second optical filter unit 6 is formed on the surface of the second transparent substrate with a second transmission characteristic film having a predetermined transmission characteristic with respect to light having the second emission line wavelength, and blocks ultraviolet rays thereon. A second reflective coating is formed. However, the second pass characteristic coating may be formed uniformly on the surface of the second transparent substrate, but the second reflective coating is not formed evenly on the surface.

  The second reflective coating is provided on the surface of the second transparent substrate so that at least two partial regions are adjacent to each other, and the second reflective coating is provided on the surface so that the filter transmittance of the second emission line wavelength in each partial region is different. The total area to be formed is different. The predetermined transmission characteristic is, for example, a characteristic that passes or blocks light having the second emission line wavelength. Further, a method of forming the second reflective coating on the second transparent substrate will be described in more detail later with reference to FIGS. As the second reflective film, a film that absorbs ultraviolet rays and a reflective film can be used. In this embodiment, a reflective film is used.

  The third optical filter unit 7 receives the light emitted from the second optical filter unit 6 and, for example, an optical filter device that emits light with adjusted passage amount for each third emission line wavelength (g-line) spectrum or Part of the optical filter device. For example, the third optical filter unit 7 is formed on the surface of the third transparent substrate with a third transmission characteristic film having a predetermined transmission characteristic with respect to light of the third emission line wavelength, and blocks ultraviolet rays thereon. A third reflective coating is formed. However, the third pass characteristic coating may be formed uniformly on the surface of the third transparent substrate, but the third reflective coating is not uniformly formed on the surface.

  The third reflective coating is provided on the surface of the third transparent substrate so that at least two partial regions are adjacent to each other, and the third reflective coating is provided on the surface so that the filter pass rate of the third emission line wavelength in each partial region is different. The total area to be formed is different. The predetermined transmission characteristic is, for example, a characteristic that passes or blocks light having the third emission line wavelength. A method for forming the third reflective coating on the third transparent substrate will be described in more detail later with reference to FIGS. 5 and 9. As the third reflective film, a film that absorbs ultraviolet rays and a reflective film can be used. In this embodiment, a reflective film is used.

  In the present embodiment, the third optical filter unit 7 is used in combination with the first and second optical filter units 5 and 6, but the third optical filter unit 7 is not provided depending on the characteristics required for the optical filter. In some cases. When the third optical filter unit 7 is used, the light can be controlled more complicatedly individually for each wavelength.

  In the case of using a plurality of optical filters, depending on the intensity characteristics of the wavelength that is finally required, the first reflective coating, the second reflective coating, or the third reflective coating is not formed. Can be. In that case, a first pass characteristic film, a second pass characteristic film, and a third pass characteristic film that do not form a reflective film are formed on the unused back surface of the substrate surface on which another filter film is formed. Also good.

  The wavelength pass characteristics of each optical filter can be arbitrarily set by selecting the coating film to be coated. Also, by using a plurality of combinations such as a combination of a band pass filter and a high pass filter, the desired wavelength can be obtained. Characteristics can be obtained. Further, as in the present embodiment, the intensity (illuminance) for each wavelength can be controlled by forming a reflective coating partially on each optical filter and controlling the area of the irradiation region. In addition, the irradiation area may be controlled by forming masking or the like in a lattice shape or a punching shape for the reflective coating.

  In addition, for example, among the optical filter units 5, 6, and 7, when the third optical filter unit 7 is uniform without a partial region having a different filter pass rate, another third filter unit with the partial region is provided You may make it form in the surface opposite to the said filter surface in the 1st transparent substrate 120 in which the 1st optical filter part 5 and the 2nd optical filter part 6 were formed, or the 2nd transparent substrate 130. In that case, the number of substrates can be reduced and the man-hours and costs can be reduced by providing an optical filter portion with a uniform filter passing rate on the opposite surface of the other optical filter portion with the substrate interposed therebetween.

The illumination uniformizing means 8 is means for uniformizing and emitting the light emitted from the third optical filter unit 7 by internally reflecting the light so as to diffuse. Illumination uniformizing means 8 is composed of, for example, a lens having a structure in which a large number of square or hexagonal lenses are spread, and a large number of light source images, which are shifted little by little, are generated and superimposed so that the illumination surface has a uniform illuminance. There are known fly-eye type integrators that improve the performance and rod lens type integrators that improve the illuminance uniformity of the irradiated surface by repeating total reflection in a cylindrical or prismatic glass rod.
The condensing lens 9 is a condensing unit that constitutes an output optical system that condenses the light emitted from the optical filter device on the irradiation region of the irradiated object, and the light emitted from the illumination uniformizing unit 8 is, for example, And converge on the photomask 20 or the like.

  The passing wavelength control unit 11 moves the optical filter units 5, 6, and 7 to change the area ratio of the two partial regions in the light irradiation region by mechanical movement, so that the optical filter units 5, 6 are moved. , 7 controls the amount of light incident on the irradiation area. Further, a method for forming a reflective film on each transparent substrate of each of the optical filter portions 5, 6, 7 will be described in detail later with reference to FIGS. 5 and 9. The passing wavelength control unit 11 increases the amount of light reflected from the reflective coating portion from the state where all of the light is reflected by the reflective coating portion to the state where all the light passes through the portion without the reflective coating portion. On the contrary, the amount of the light reflected by the reflective coating portion can be decreased, and the amount of the light passing through the portion without the reflective coating can be increased. Thereby, it can change so that the intensity | strength of the light which passes each optical filter part 5, 6, 7 may be increased, and can also be changed so that the intensity | strength of light may be decreased. Further, the pass wavelength control unit 11 can change the intensity of light of all wavelengths that can be changed by the optical filter units 5, 6, and 7, and can be changed by the optical filter units 5, 6, and 7. It is also possible to change only the intensity of light of a part of the wavelength.

  The 1st drive means 12 is connected with the 1st optical filter part 5, and the 1st optical filter part 5 which can be driven so that the position of the irradiation area of the light in the 1st optical filter part 5 can be moved can be moved. It is a drive part. In the case of controlling the position by moving each optical filter in the rotation direction as in this embodiment, for example, a stepping motor or the like can be used. When the filter pass rate of each optical filter is controlled by rotational movement, the position of the irradiation region can be easily controlled by a stepping motor or the like. In the case of controlling the position by moving each optical filter in the linear direction, for example, a motor and a rack and pinion can be used in combination, or a linear motor or the like can be used.

  The 2nd drive means 13 is connected with the 2nd optical filter part 6, and the 2nd optical filter part 6 which can be driven so that the position of the irradiation region of the light in the 2nd optical filter part 6 can be moved can be moved. It is a drive part.

  The third drive unit 14 is connected to the third optical filter unit 7 and can be driven so that the position of the light irradiation region in the third optical filter unit 7 can be moved. It is a drive part.

  The photomask-side microscope 15 is used when adjusting the coordinate values of the mask mark 25 on the photomask 20 and the stage mark 75 or the alignment mark 105 on the printed circuit board 100 using light having a wavelength to be exposed. use. The photomask side microscope 15 includes a plurality of microscopes, such as two or four, and a camera such as an image sensor that captures images obtained from the microscopes. By using a plurality of photomask side microscopes 15, it is possible to measure the amount of positional deviation between the plurality of mask marks 25 and the stage mark 75.

  The photomask 20 is also referred to as a reticle, and allows the light emitted from the light source device 10 to pass through except for the circuit pattern portion, or to pass only the circuit pattern portion, and shields the remaining portion of the light. It is. A mask mark 25 is formed on one surface of the photomask 20.

  The mask mark 25 is used when alignment between the photomask 20 and the stage mark 75 placed on the stage 60 is performed. As an alignment method, for example, the photomask side microscope 15 is inserted on the mask mark 25, and the positional deviation amount between the mask mark 25 and the stage mark 75 is measured by the photomask side microscope 15. The measured data is processed by the mark measuring unit 70, and the coordinate value relationship on which coordinate value on the stage the projected image of the photomask 20 is projected is stored.

  Next, the substrate side microscope 65 is moved onto the stage mark 75, and the positional deviation amount between the projection image of the mask mark 25 and the stage mark 75 is measured by the substrate side microscope 65. The measured data is similarly processed by the mark measuring unit 70, and the coordinate value relationship between the coordinate value measured by the substrate side microscope 65 and the projected image of the photomask 20 is stored.

  When the printed circuit board 100 is mounted on the stage 60, the measurement result of the alignment mark 105 on the printed circuit board 100 measured by the substrate-side microscope 65 is corrected using the above-described storage of coordinate value relationships. Thus, the projection image of the photomask 20 can be accurately aligned with the printed circuit board 100 and exposed.

  The XY independent magnification correction unit 30 is disposed between the photomask 20 and the projection optical system 50, particularly immediately below the photomask 20, or between the projection optical system 50 and the printed circuit board 100, particularly directly above the printed circuit board 100. The projection light is corrected so as to reduce the magnification difference (bias) between the X direction and the Y direction in the circuit pattern. More specifically, the XY independent magnification correction unit 30 corrects the scaling factor in any one of the X direction and the Y direction orthogonal to each other on the printed circuit board. The XY independent magnification correction unit 30 is driven and controlled by the projection magnification control unit 90.

  The movable plate 40 is movable above the photomask 20 while being parallel to the photomask 20, and functions as a blind that blocks out-of-field light out of the exposure light applied to the photomask 20. To do. The area of the exposure field is changed by driving a movable plate 40 provided on the photomask 20 and functioning as a blind having a light shielding function. The opening area of the movable plate 40 is controlled by the movable plate control unit 85.

  The projection optical system 50 is an optical system including a lens that projects light for exposing a circuit pattern onto a substrate, and the incident light is once condensed inside and then diffused and emitted to the substrate. . The projection optical system 50 has a built-in magnification correction mechanism 55 that can correct an isotropic substrate magnification error by driving a lens. The magnification correction mechanism 55 is driven and controlled by the projection magnification control unit 90 in the same manner as the XY independent magnification correction unit 30 described above.

The stage 60 is, for example, a table on which a printed board material is placed, and can be moved in the X direction and the Y direction to finely adjust the exposure position.
The substrate-side microscope 65 includes a plurality of microscopes and a camera such as an image sensor that captures images obtained from the microscopes. Each alignment mark 105 is measured using the substrate-side microscope 65.

The mark measurement unit 70 measures the magnifications of two axes (X direction and Y direction) orthogonal to each other on the printed circuit board by measuring a plurality of the above-described marks.
The stage mark 75 is provided on the stage 60, and a positional deviation amount with respect to the mask mark 25 is measured by the substrate side microscope 65.

  The control unit 80 controls the position of the photomask 20, controls the projection magnification of exposure, controls the exposure range / exposure coordinate value of the printed circuit board 100, and gives an intensity instruction for each wavelength to the passing wavelength control unit 11, thereby forming a substrate pattern To control the cross-sectional shape. The control unit 80 includes, for example, an interface between a calculation element such as a microprocessor, a storage element, and each peripheral device, and controls the magnification of the projection image by the projection magnification control unit 90 based on the result measured by the mark measurement unit 70. To do. Furthermore, when changing the exposure range, the movable plate 40 is used to sequentially move the exposure field, and the stage controller 95 is instructed so that the printed circuit board 100 is moved to the actual exposure field by an appropriate coordinate value by the stage 60. The coordinate value is controlled so that the projection light can be exposed.

  The projection magnification control unit 90 receives a control signal from the control unit 80 and drives the lens interval of the magnification correction mechanism 55 and the cylindrical lens in the XY independent magnification correction unit 30 by a drive mechanism such as a motor and various gears, for example. To do.

  The printed circuit board 100 is a printed circuit board material in which a copper thin plate or the like is pasted on the surface of an insulating resin serving as a base. When the printed circuit board 100 is installed in the projection exposure apparatus 1, a pattern resist is further applied on the copper sheet. The pattern resist is exposed by irradiating the pattern resist with exposure light of the circuit pattern that has passed through the photomask 20. The types of substrates include, for example, a paper phenol substrate in which core paper is impregnated with thermosetting phenol resin, a paper epoxy substrate in which core paper is impregnated with thermosetting epoxy resin, and core glass. There are glass epoxy substrates in which fibers are impregnated with an epoxy resin.

  The alignment mark 105 is provided on the printed circuit board 100 so that the coordinate value with the mask mark 25 on the photomask 20 matches. For example, the surface of the printed circuit board 100 is melted with a laser beam, or a machine such as a drill is used. The substrate material is melted by laser, the substrate material is melted by laser, a metal foil or resist layer is provided on the substrate, exposure and etching are performed, or silk screen printing is performed.

  As described above, in the light source device of the first embodiment, the light beam generated by the light source that generates a light beam having a plurality of bright lines is condensed by the concave mirror, and the selection unit having the optical filter device is selected from the collected light beam by the selection unit. A light flux having a wavelength is selected, and the illumination target is irradiated with the light flux having the predetermined wavelength. The predetermined wavelength includes at least one wavelength of i-line, h-line, and g-line that are bright lines of the light flux generated by the light source 2. In addition, the optical filter device is provided with a plurality of apertures that reflect or transmit a light beam having a predetermined wavelength. The maximum dimension of the plurality of openings is that the plurality of openings are arranged in the region of the irradiation surface in the irradiation surface of the light beam of the predetermined wavelength, that is, the irradiation surface of the optical filter device irradiated with the light beam of the predetermined wavelength. The small dimensions that are possible. This minute dimension is, for example, a case where the diameter of the opening is smaller than 1/5 or 1/10 with respect to the maximum dimension such as the diameter of the irradiation region.

Further, the optical filter device of the light source device according to the first embodiment has a partial region within the irradiation surface of the light beam having a predetermined wavelength. And it has a drive means (not shown) which moves each optical filter part 5-7 of an optical filter apparatus so that the ratio of the partial area | region in the irradiation surface of a light beam may fluctuate. The plurality of optical filter units 5 to 7 of the optical filter device are arranged in series, and each optical filter unit 5 to 7 has an optical characteristic with respect to a light beam generated by the light source 2 and an aperture with respect to the other optical filter units. At least one of the shape, the spacing between the openings, and the number of openings.
Further, the optical filter device of the light source device of the first embodiment includes illumination uniformizing means for uniformizing the illuminance for illuminating each part of the illumination object such as the photomask 20 by the light flux that has passed through the optical filter units 5 to 7. Have. As the illumination uniformizing means, for example, any of the above-described fly-eye integrator and rod lens integrator can be used.

  When the light source device according to the first embodiment is used for the exposure apparatus 1, a light beam having a predetermined wavelength from the light source device is first irradiated onto the photomask. Thereafter, a light beam having a predetermined wavelength passes through a predetermined pattern formed on the photomask, or is irradiated onto a positive resist applied on a printed circuit board or the like as illumination light that has passed through other than the pattern. Then, the positive resist is irradiated with a light beam having a predetermined wavelength that has been made uniform by the illumination uniformizing means 8 of the light source device of the first embodiment and passed through the photomask.

FIG. 2 is a flowchart illustrating an example of forming a circuit pattern on a printed board using the projection exposure apparatus 1 of the present embodiment.
A photomask 20 in which a mask mark 25 is provided on a circuit pattern to be exposed by the projection exposure apparatus 1 is created (S1). Next, the printed board material such as a copper clad laminate provided with the alignment mark 105 is cut to a size to be exposed (S2), and a photoresist is applied to the surface of the copper foil layer (S3). Is placed on the stage 60 of the projection exposure apparatus 1 (S4). The projection exposure apparatus 1 measures the plurality of alignment marks 105 of the printed circuit board material using the mark measurement unit 70 or the like (S5). Here, the projection exposure apparatus 1 measures two axes (X direction and Y direction) orthogonal to each other on the plane of the circuit pattern projected onto the printed circuit board material 100 installed in the projection exposure apparatus 1.

  The projection exposure apparatus 1 calculates a correction amount to be executed by the magnification correction mechanism 55 and the XY independent magnification correction unit 30 based on the detected biaxial magnification (the expansion / contraction state of the printed circuit board material) (S6). The projection exposure apparatus 1 sets the area of the exposure field and the exposure order based on the calculated error and correction amount (S7), and sets the magnification of the exposure light by the magnification correction mechanism 55 and the XY independent magnification correction unit 30. The circuit pattern is repeatedly exposed to the printed circuit board material after correction (S8). The projection exposure apparatus 1 sequentially moves the stage 60 so that the coordinate value of the alignment mark 105 on the printed circuit board 100 matches the design alignment mark coordinate value stored in advance in a storage element or the like. As design alignment mark coordinate values, coordinate values obtained from design or coordinate values measured using a reference substrate are used. By repeating this process, the circuit pattern on the photomask 20 can be sequentially transferred to a plurality of exposure fields on the printed circuit board 100, respectively.

  By etching the printed circuit board material after exposure, unnecessary wiring portions are removed (S9). When the etching is completed, the photoresist is removed (S10), a post-process such as through-hole processing is performed on the printed circuit board material (S11), and finally a coating for protecting the surface of the printed circuit board is performed (S12).

  In this embodiment, any photosensitive resist can be used as the “photosensitive resist”. For example, a photo-curing resist that cures the exposed portion, a negative mold that exposes the exposed portion to the developer, and an exposed portion that develops. Includes positive photoresists that are soluble in the liquid. The photosensitive resist includes a liquid type and a film type, and any type can be used. In the case of a liquid photosensitive resist, it is applied onto the substrate in advance by a coating apparatus such as a spin coater, a roller coater, or a slit coater, and exposure is performed by an exposure apparatus.

  Further, by inserting a reticle or the like on which a circuit pattern is drawn in the middle of an optical path from the light source device 10 to the photosensitive resist, the desired circuit pattern can be exposed to the photosensitive resist.

  The “resist pattern” formed by post-treatment after exposure is, for example, an etching resist used as a mask for a portion to be left by etching, a plating resist used as a mask for a portion not to be plated, or soldering by mounting components. Sometimes, it can be used as a solder resist for covering a portion where solder is unnecessary.

FIG. 3 is a diagram showing the relationship between each filter pass rate at a plurality of emission line wavelengths of the ultraviolet light source and the cross-sectional shape of the resist pattern formed on the circuit board, and (a) is a standard branching without an optical filter. Characteristics and cross-sectional shape at that time, (b) Spectral characteristics when the first wavelength and the second wavelength are attenuated, and cross-sectional shape at that time, (c) When the first wavelength and the second wavelength are further dimmed (D) shows the branching characteristics and the cross-sectional shape at that time when the third wavelength is also attenuated in addition to (c).
In circuit board manufacturing, it is used as a mask for parts left unetched or unplated, or to cover parts that do not require soldering when mounting and soldering parts. The technique for forming the resist pattern is widely spread. As one of the methods for forming such a resist pattern, a photosensitive resist is applied on a substrate by a coating apparatus to form a resist film, a desired circuit pattern is exposed to the resist film by an exposure apparatus, and then A method of forming a resist pattern by performing a predetermined post-treatment is used. In addition, among resist patterns, there are those using a photo-curing resist that is hardened by light irradiation, and those using a photoresist that is formed by developing an exposed portion.

  Since the shape of the final circuit pattern formed on the substrate is determined by the shape of the resist pattern, the cross-sectional shape of the resist pattern is also an important factor in forming a fine circuit board. It becomes. In general, as shown in FIG. 3B, the cross-sectional shape of the resist pattern is preferably a straight shape (rectangular shape) rising perpendicular to the substrate surface. However, depending on the application, as shown in FIG. 3 (a), there may be a need for a reverse tapered (reverse trapezoidal) cross section in which a portion close to the light receiving surface (upper layer) is widened. In addition, as shown in FIG. 3C, a taper-shaped (trapezoidal) cross section in which a portion (lower layer portion) away from the light receiving surface spreads may be required. In addition, as shown in FIG. 3D, a trapezoidal shape that is basically a straight shape but whose upper part is straight and only the lower part spreads may be required in order to increase the adhesion of the resist pattern to the substrate.

  4A and 4B are perspective views showing an example of a main part of the light source device according to the first embodiment of the present invention. FIG. 4A shows a case where the optical filter part is circular, and FIG. 4B shows a square optical filter part. The case is shown.

  The optical filter unit 501 shown in FIG. 4A includes a reflective film 511 having a predetermined graphic pattern on the surface of the transparent substrate 200 having a predetermined filter characteristic of the filter function 501 in the optical filter unit 501. Is formed. The reflective coating 511 is formed to be a plurality of circular portions and surrounding portions. That is, in the optical filter unit 501 of FIG. 4A, the partial regions having different filter pass rates (the region of the transmission characteristic film 512 and the region of the reflective film 511) are formed so as to be a plurality of circular portions and surrounding portions. The In the present embodiment, the plurality of circular portions are openings and have minute dimensions. This minute dimension is, for example, a case where the diameter of the opening 513 is smaller than 1/5 or 1/10 with respect to the maximum dimension such as the diameter of the irradiation region 550.

  What is necessary is just to change the space | interval of each circular part according to a filter passage rate. When the coating is formed in this way, a partial region having a different filter transmittance is provided in each of the plurality of optical filters having different pass characteristics with respect to a plurality of emission line wavelengths so as to be a circular portion and its peripheral portion. By changing the distance or the diameter, it is easy to form regions of optical filters having different filter pass rates.

  The optical filter unit 601 shown in FIG. 4B includes a reflective coating 611 having a predetermined graphic pattern on the surface of the transparent substrate 200 in which the coating 612 having a predetermined pass characteristic of the filter function is formed. Is formed. The reflective coating 611 is formed to be a plurality of circular portions and surrounding portions. In other words, in the optical filter unit 601 of FIG. 4B, the partial regions having different filter pass rates (the region of the transmission characteristic film 612 and the region of the reflective film 611) are formed to have a plurality of circular parts and surrounding parts. The In the present embodiment, the plurality of circular portions are openings and have minute dimensions. This minute dimension is, for example, a case where the diameter of the opening 613 is smaller than 1/5 or 1/10 with respect to the maximum dimension such as the diameter of the irradiation region 650.

  FIG. 5 is a plan view showing another example of the main part of the light source device according to the first embodiment of the present invention. FIG. 5A shows a partial region of the optical filter part by changing the minute openings having the same diameter at different intervals. The case where it arrange | positions in the shape of a revolver is shown, (b) shows the case where the partial area | region of the optical filter part which provided the micro aperture from which the diameter was varied at the same space | interval is arrange | positioned in a revolver shape.

  In FIG. 5A, the first partial region 521, the second partial region 522, and the third partial region 523 are formed in a circular optical filter 520 in a revolver (rotary magazine) -like arrangement. . A reflective coating is formed on the first partial region 521 except for the plurality of minute openings 561. Each minute opening 561 is formed apart from other openings 561 adjacent vertically and horizontally by a distance 565. Similarly, a reflective coating is formed in the second partial region 522 except for the plurality of minute openings 562. The minute openings 562 are formed so as to be separated from other openings 562 adjacent in the vertical and horizontal directions by an interval 566. Further, a reflective coating is formed on the third partial region 523 except for the plurality of minute openings 563. Each minute opening 563 is formed apart from other openings 563 adjacent in the vertical and horizontal directions by an interval 567.

  In FIG. 5A, the circular micro openings 561, micro openings 562, and micro openings 563 in the optical filter 520 have the same diameter, but the intervals 565, 566, and 567 are increased in this order. Yes. As a result, the reflective film of the first partial region 521 is less than the second partial region 522, and the reflective coating of the second partial region 522 is fewer than the third partial region 523. Therefore, the filter pass rate of light is smaller in the second partial region 522 than in the first partial region 521, and smaller in the third partial region 523 than in the second partial region 522. The optical filter 520 can be rotated by rotating the outer periphery via a circular pulley or the like by a driving device such as the first driving unit 12, and the first partial region 521 and the second partial region with respect to the irradiation region 550. A region having a desired passing rate can be selected from 522 and the third partial region 523.

  Also in FIG. 5B, the first partial region 531, the second partial region 532, and the third partial region 533 are formed in a revolver (rotary magazine) -like arrangement in the circular optical filter 530. . A reflective coating is formed on the first partial region 531 except for the plurality of minute openings 571. Each minute opening 571 is formed apart from other openings 571 adjacent in the vertical and horizontal directions by an interval 575. Similarly, a reflective coating is formed in the second partial region 532 except for the plurality of minute openings 572. Each minute opening 572 here is formed apart from other openings 572 adjacent vertically and horizontally by a distance 576. Further, a reflective coating is formed on the third partial region 533 except for the plurality of minute openings 573. Each of the minute openings 573 is formed apart from other openings 573 adjacent in the vertical and horizontal directions by an interval 575.

  In FIG. 5B, the diameters of the circular minute openings 571, the minute openings 572, and the minute openings 573 in the optical filter 530 are different, and the distances between the centers of the openings are the same. 575, the interval 576, and the interval 577 are narrowed in this order. As a result, the reflective film of the first partial region 531 is larger than the second partial region 532, and the reflective coating of the second partial region 532 is larger than the third partial region 533. Therefore, the filter passage rate of light is larger in the second partial region 532 than in the first partial region 531, and is greater in the third partial region 533 than in the second partial region 532. The optical filter 530 can also be rotated by rotating the outer periphery via a circular pulley or the like by a driving device such as the first driving unit 12, and the first partial region 531 and the second partial region with respect to the irradiation region 550. A region having a desired passing rate can be selected from 532 and the third partial region 533.

  FIG. 6 is a side view showing a modification of the main part of the light source device according to the first embodiment of the present invention, where (a) shows the case where the optical filter part is a transmission type, and (b) shows the optical filter part. Shows a case where is a reflection type, and (c) shows a case where transmission type optical filter sections having different characteristics are arranged in series.

  FIG. 6A shows a case where the passing light passes through the optical filter 501, and the optical axis 700 of the passing light extends from one surface of the optical filter 501 to the other surface. In this case, the reflective coating is provided with a plurality of minute openings to adjust the amount of transmitted light.

  On the other hand, FIG. 6B shows a case where the passing light is reflected by the surface of the optical filter 502, and the optical axis 700 of the passing light is reflected by one surface of the optical filter 501, and the other surface has Do not penetrate. In this case, the reflective coating is provided with a plurality of minute openings, or a reflective coating is provided inside the minute openings to adjust the amount of transmitted light.

  FIG. 6C shows a case where the passing light passes through three optical filters 503, 504, and 505 having different characteristics. The optical axis 700 of the passing light is incident from one surface of the optical filter 503, and the optical The light is emitted from the other surface of the filter 505. Each optical filter in this case may have the same configuration as in FIG. 6A, but the optical characteristics of each filter and the quality and amount of light transmitted by the reflective coating are adjusted.

  What is necessary is just to change the space | interval of each circular part according to a filter passage rate. When the coating is formed in this way, a partial region having a different filter transmittance is provided in each of the plurality of optical filters having different pass characteristics with respect to a plurality of emission line wavelengths so as to be a circular portion and its peripheral portion. By changing the distance or the diameter, it is easy to form regions of optical filters having different filter pass rates.

  In the optical filter unit 201 of FIG. 7A, a reflective film 211 having a predetermined graphic pattern is formed. The reflective coating 211 is alternately formed in a band shape that reaches the peripheral portion radially from the center. That is, in the optical filter unit 201 of FIG. 7A, partial regions having different filter pass rates (the region of the coating 212 and the region of the reflective coating 211) are alternately formed in a strip shape that radially reaches the peripheral portion from the center. What is necessary is just to change a strip | belt-shaped space | interval according to a filter passage rate. The filter pass rate of the optical filter can be individually adjusted.

Also in the optical filter unit 202 of FIG. 7B, a reflective coating 221 having a predetermined graphic pattern is formed. The reflective coatings 221 are alternately formed in a plurality of concentric rings having different diameters. That is, in the optical filter unit 202 of FIG. 7B, partial regions (regions of the coating 222 and regions of the reflective coating 221) having different filter pass rates are alternately formed in a plurality of concentric rings having different diameters. What is necessary is just to change the space | interval of a concentric circle according to a filter passage rate. The filter pass rate of the optical filter can be individually adjusted.
In addition, the optical filter unit having an intermediate filter pass rate is not limited to the above, and for example, a houndstooth, a polygonal shape, a mesh shape, or the like that combines circular lines in a radial direction can be used, and the shape, quantity, size, Arrangement and combinations thereof can be arbitrarily selected.

Second Embodiment
FIG. 8 is a perspective view showing an example of a main part of the light source device according to the second embodiment of the present invention, where (a) shows a case where the optical filter part is circular, and (b) shows a square optical filter part. The case is shown.

  The optical filter unit 5 shown in the upper side of FIG. 8A is provided with a partial region 122 and a partial region 123 on the surface of a circular transparent substrate 120, and has a predetermined transmission characteristic for light having an emission line wavelength. The characteristic coating 126 is formed on the entire surface of the transparent substrate 120 or in the region where the reflective coating 127 is not formed. Further, the reflective coating 127 that blocks light on the substrate surface is divided into the partial region 122 and the partial region 123. It is formed to have different filter pass rates.

  The reflective coating 127 having a different filter pass rate for each of the partial regions 122 and 123 of the optical filter unit 5 uses a predetermined graphic pattern formed so as to achieve each filter pass rate for masking, and uses the reflective coat 127 as a mask. By forming the area ratio of the area where the film is formed and the area where the reflective coating 127 is not formed to be different, the filter pass rate can be made different. The reflective coating 127 of this embodiment is a reflective coating that reflects light of a corresponding wavelength. Since a metal material or the like can be used for the reflective coating 127, it is possible to easily form partial regions having different filter pass rates.

  In the angle-passage characteristic graph shown on the lower side of FIG. 8A, the horizontal axis represents the rotation angle and the vertical axis represents the pass rate. For example, the irradiation region 121 is a portion where the reflective coating 127 is formed on the entire surface. In this example, the region 123 moves from the region 123 to the partial region 122 where the transmission characteristic film 126 is formed on the entire surface. Thus, by rotating the optical filter unit 5, the ratio of the area of the partial region 122 and the partial region 123 in the irradiation region 121 can be changed, and the transmission rate of the light having the emission line wavelength can be controlled.

  The optical filter unit 5 shown in the upper side of FIG. 8B is provided with a partial region 152 and a partial region 153 on the surface of a rectangular transparent substrate 150, and has a predetermined transmission characteristic for light having an emission line wavelength. The characteristic coating 156 is formed on the entire surface of the transparent substrate 150 or in the region where the reflective coating 157 is not formed. Further, the reflective coating 157 that blocks light on the substrate surface includes the partial region 152 and the partial region 153. It is formed to have different filter pass rates.

  The reflective coating 157 having a different filter pass rate for each of the partial regions 152 and 153 of the optical filter unit 5 uses a predetermined graphic pattern formed so as to be able to achieve each filter pass rate for masking. By forming the area ratio between the area where the film is formed and the area where the reflective coating film 157 is not formed to be different, the filter pass rate can be made different. The reflective coating 157 of this embodiment is a reflective coating that reflects light of a corresponding wavelength. Since a metal material or the like can be used for the reflective coating 157, it is easy to form partial regions having different filter pass rates.

  In the angle-passage characteristic graph shown on the lower side of FIG. 8B, the horizontal axis indicates the rotation angle, and the vertical axis indicates the pass rate. For example, the irradiation region 151 is a portion where the reflective coating 157 is formed on the entire surface. In this example, the region 153 moves from the region 153 to the partial region 152 in which the transmission characteristic film 156 is formed on the entire surface. In this way, by moving the optical filter unit 5 linearly (for example, vertically), the area ratio of the partial region 152 and the partial region 153 in the irradiation region 151 can be changed, and the transmission rate of the light having the emission line wavelength can be controlled. it can.

  FIG. 9 is a perspective view showing an example in which a plurality of optical filter units are used in the light source device according to the second embodiment of the present invention. FIG. 9A shows a partial region in which a coating on the incident side surface of the substrate is formed. This shows a case where the partial area not formed is divided into two, (b) shows a case where the partial area where the coating on the incident side surface of the substrate is formed and a partial area where it is not formed is divided into four, and (c) shows the incidence of the substrate A case is shown in which the partial area where the filter passage rate of the side surface is formed in three stages and the partial area where the film is formed and the partial area where the film is not formed are divided into four equal parts.

  The optical filter unit in FIG. 9A includes a first optical filter unit 5, a second optical filter unit 6, and a third optical filter unit 7, and the first optical filter unit 5 is on the first transparent substrate 120. A first partial region 122 and a second partial region 123 are provided on the surface, and a first transmission characteristic film 126 having a predetermined transmission characteristic with respect to light having the first emission line wavelength is formed on the entire surface of the first transparent substrate 120. Alternatively, the first reflective coating 127 that is formed in a region where the first reflective coating 127 is not formed and further blocks light on the substrate surface has different filter pass rates in the first partial region 122 and the second partial region 123. Formed to be.

  The first reflective coating 127 having a different filter pass rate for each of the partial regions 122 and 123 of the first optical filter unit 5 uses a predetermined graphic pattern formed so as to achieve each filter pass rate for masking. By forming the first reflective coating 127 so that the ratio of the region where the first reflective coating 127 is formed and the region where the first reflective coating 127 is not formed is different, the filter pass rate can be made different. The first reflective coating 127 of the present embodiment is a reflective coating that reflects light of a corresponding wavelength. Since a metal material or the like can be used for the first reflective coating 127, it is possible to easily form partial regions having different filter pass rates.

  The second optical filter unit 6 is provided with a third partial region 132 and a fourth partial region 133 on the surface of the second transparent substrate 130, and is predetermined for light having a second emission line wavelength different from the light having the first emission line wavelength. The second reflective film 137 is formed in the entire region of the surface on the second pass characteristic film 136 having the above-mentioned pass characteristics or in the area where the second reflective film 137 is not formed, and further, the second reflective film 137 that blocks light on the substrate surface The third partial region 132 and the fourth partial region 133 are formed to have different filter pass rates.

  The second reflective coating 137 having a different filter pass rate for each of the partial regions 132 and 133 of the second optical filter unit 6 uses a predetermined figure pattern formed so as to achieve each filter pass rate for masking. Since the ratio of the region where the second reflective coating 137 is formed and the ratio of the region where the second reflective coating 137 is not formed is different, the filter pass rate can be made different. The second reflective coating 137 of the present embodiment is a reflective coating that reflects light of a corresponding wavelength. By using the second reflective coating 137 as a reflective coating, a metal material or the like can be used for the coating, so that it is possible to easily form partial regions having different filter pass rates.

  The third optical filter unit 7 includes a fifth partial region 142 and a sixth partial region 143 provided on the surface of the third transparent substrate 140, and has a third emission line wavelength different from the light having the first emission line wavelength and the second emission line wavelength. A third reflection that is formed in the entire region of the surface on the third transmission characteristic film 146 having a predetermined transmission characteristic with respect to light or an area where the third reflection film 147 is not formed, and further blocks light on the substrate surface. The coating 147 is formed so as to have different filter pass rates in the fifth partial region 142 and the sixth partial region 143.

  The third reflective film 147 having a different filter pass rate for each of the partial regions 142 and 143 of the third optical filter unit 7 uses a predetermined figure pattern formed so as to achieve each filter pass rate for masking. By forming the third reflective coating 147 and the region where the third reflective coating 147 is not formed at different ratios, the filter pass rates can be made different. The third reflective coating 147 of the present embodiment is a reflective coating that reflects light of a corresponding wavelength. By using the third reflective coating 147 as a reflective coating, a metal material or the like can be used for the coating, so that it is possible to easily form partial regions having different filter pass rates.

  The first optical filter unit 5, the second optical filter unit 6, and the third optical filter unit 7 can be driven by being individually contacted or coupled to a driving device such as a rotary rotor, for example.

  The driving unit of the present embodiment includes a first driving unit 12, a second driving unit 13, and a third driving unit 14. The first drive unit 12 rotates the first optical filter unit 5 to move the position of the irradiation region 121 in the first optical filter unit 5 from the first partial region 122 to the second partial region 123. It can be driven so that it can be moved continuously across the boundary line between the two. The irradiation region 121 is a region through which light having the optical axis 700 as the center passes.

The second driving means 13 rotates the first optical filter unit 5 to move the position of the irradiation region 131 in the second optical filter unit 6 across the boundary line between the third partial region 132 and the fourth partial region 133. So that it can be moved continuously.
The third driving means 14 rotates the first optical filter unit 5 to move the position of the irradiation region 141 in the third optical filter unit 7 across the boundary line between the fifth partial region 142 and the sixth partial region 143. So that it can be moved continuously.

  The transmission wavelength control unit 11 controls the drive amounts of the first drive unit 12, the second drive unit 13, and the third drive unit 14, respectively, so that the light passage amounts of the optical filter units 5, 6, and 7 are respectively controlled. Control.

  In the first optical filter unit 5 in FIG. 9B, the first pass characteristic film 126 and the first reflective film 127 are formed so as to divide the substrate surface into two in the optical filter unit in FIG. 9A. On the other hand, the first passage characteristic film 126 and the first reflection film 127 are formed so as to divide the substrate surface into four parts. When divided into four, the drive distance can be controlled to be smaller than when divided into two. The second optical filter unit 6 and the third term prison filter unit 6 have the same configuration.

  The optical filter unit of FIG. 9C is an intermediate portion between the first partial region 122 that does not have the first reflective coating 127 and the second partial region 123 that is covered with the first reflective coating 127. Partial regions 122 to 125 having a filter pass rate of an arbitrary value of 100% are provided. Here, the first optical filter unit 5 is provided with three or more partial regions on the surface of the transparent substrate 120, and the filters of the first reflective coatings 127, 128, and 129 in the partial regions 122, 123, 124, and 125 are provided. The passage rates are different from each other. The second optical filter unit 6 and the third term prison filter unit 6 have the same configuration.

  As described above, the optical filter unit of the present embodiment is provided with the first part formed in a part that reflects light of a predetermined wavelength in the area of the substrate surface and the second part that is the remaining part that transmits the light. The position of the light irradiation area is freely moved between the first part and the second part.

FIG. 10 is a diagram showing a change in the filter pass rate due to a change in the area ratio of the reflective partial region in each optical filter unit of the light source device according to the first embodiment of the present invention, in which (a) passes. The unit ratio characteristics of the first optical filter unit in each of the case where the area ratio is approximately 100%, 75%, 50%, and 25% are shown, and the area ratio that (b) passes is approximately 100%, 75%, and 50%. , 25% shows the single unit characteristics of the second optical filter part.
FIG. 11 is a diagram showing the relationship between the filter pass rate and the wavelength characteristic when the first optical filter unit and the second optical filter unit of the light source device according to the first embodiment of the present invention are combined. The filter passing rate when the second optical filter unit with a passing area ratio of 100% and the first optical filter unit with 50% are combined is shown, and the wavelength characteristic when (b) is (a) is shown.
FIG. 12 shows the relationship between the change in the filter pass rate and the change in the wavelength characteristic when the first optical filter unit and the second optical filter unit of the light source device according to the first embodiment of the present invention are combined. It is a figure which shows, (a) Filter passage at the time of combining with the 2nd optical filter part whose area ratio to pass is 100%, and the 1st optical filter part from which the area ratio to pass changes between 0%-100% The ratio of the wavelength characteristic when (b) is (a) is shown.

  For example, when the first optical filter unit 5 has the characteristics of FIG. 10A and the second optical filter unit 6 has the characteristics of FIG. 10B, both filters are arranged in series with respect to the passing light. In this case, the filter of the conventional configuration and method can obtain the characteristics shown in FIG. 10A, but cannot make the characteristics shown in FIG. 10B effective.

  On the other hand, in this embodiment, the filter pass rate of the first optical filter unit 5 having the characteristics of FIG. 10A can be controlled to an arbitrary ratio between 0% and 100%. 1 The filter passing rate of the optical filter unit 5 is set to 50%. In this case, the filter pass rate when the first optical filter unit and the second optical filter unit are combined is shown in FIG. 11A, and the wavelength characteristic is shown in FIG. 11B. From FIG. 11B, it can be seen that in this embodiment, the intensity (filter pass rate) of only an arbitrary bright line among the multiple bright lines can be changed.

  Next, FIG. 12A shows a case where the area ratio through which the first optical filter unit 5 of FIG. 11A passes is changed between 0% and 100%. In FIG. The intensity change of the bright line in that case is shown. From this FIG. 12A and FIG. 12B, it can be seen that in the present embodiment, only an arbitrary bright line of the multiple bright lines can be controlled to an arbitrary intensity (filter pass rate).

  12 (a) and 12 (b) show a case where only the first bright line at the left end is changed, but in this implementation Keita, the first filter device 5, the second filter device 6, and Since the filter pass rate can be arbitrarily set in all of the third filter devices 7, it can be seen that the relative wavelengths shown in FIGS. 3A to 3D can be easily obtained.

  Therefore, in this embodiment, a partial region having a different filter pass rate is provided in an optical filter having a predetermined transmission characteristic with respect to the emission line wavelength, and the position of the light irradiation region in the optical filter crosses the boundary line of each partial region. By continuously controlling the filter, the filter pass rates (intensities) of the first emission line wavelength (i line) and the second emission line wavelength (h line) out of the plurality of emission line wavelengths of the ultraviolet rays for exposure are individually practically used. Can be controlled. For example, the i-line filter pass rate is 30% (70% cut) for the h-line filter pass rate of 100%, or the i-line filter pass rate is 100% for the h-line filter pass rate of 20%. The wavelength ratio (illuminance ratio) can be freely controlled, and the intensity of a plurality of emission line wavelengths can be adjusted. Therefore, in the exposure apparatus using the optical filter of the present embodiment, the side taper angle control in the cross-sectional shape of the resist pattern can be easily performed. Moreover, the optical filter of this embodiment can be manufactured comparatively easily, and can suppress a cost increase.

<Third Embodiment>
In the first embodiment described above, a case where an arbitrary filter pass rate is obtained for each emission line wavelength by rotating and moving a region where the filter is circular and the filter pass rate is different has been described. However, the filter is linearly moved squarely. In any case, an arbitrary filter pass rate can be obtained for each emission line wavelength. Such a case will be described below as a third embodiment. In the following description, the description of the same configuration and method as in the first embodiment will be omitted, and only the configuration and method different from those in the first embodiment will be described.

  FIG. 13 is a perspective view showing an example of a main part in the optical filter device according to the third embodiment of the present invention. FIG. 13A shows a partial region where a coating on the incident side surface of the substrate is formed and a partial region where it is not formed. (B) shows the case of dividing into 4 parts by the partial area where the coating on the incident side surface of the substrate is formed and the partial area where it is not formed, and (c) shows the filter passing through the incident side surface of the substrate. A case is shown in which a partial area where a film having different levels in three stages is formed and a partial area where the film is not formed are equally divided into four.

  In FIG. 13A, the first optical filter unit 5, the second optical filter unit 6, and the third optical filter unit 7 are connected to the first driving unit 12 so that each of them can be individually moved linearly. It is attached to the second drive means 13 and the third drive means 14. The first drive unit 12 drives the first optical filter unit 5 linearly, thereby continuously changing the position of the light irradiation region 151 across the boundary line between the first partial region 152 and the second partial region 153. It can be driven so that it can be moved.

The second driving unit 13 drives the second optical filter unit 6 linearly, thereby continuously changing the position of the light irradiation region 161 across the boundary line between the third partial region 162 and the fourth partial region 163. It can be driven so that it can be moved.
The third driving unit 14 drives the third optical filter unit 7 linearly, thereby continuously changing the position of the light irradiation region 171 across the boundary line between the fifth partial region 172 and the sixth partial region 173. It can be driven so that it can be moved.

  In the optical filter section of FIG. 13B, in the first optical filter section 5 of FIG. 13A, the first pass characteristic film 156 and the first reflective film 157 are formed so as to divide the substrate surface into two parts. On the other hand, the first pass characteristic film 156 and the first reflective film 157 are formed so as to divide the substrate surface into four parts. When divided into four, the drive distance can be controlled to be smaller than when divided into two. The second optical filter unit 6 and the third optical filter unit 6 have the same configuration.

The optical filter unit of FIG. 13C is an intermediate portion between the first partial region 152 that does not have the first reflective coating 157 and the second partial region 153 that is covered with the first reflective coating 157, from 0% to Partial regions 152 to 125 having a filter pass rate of an arbitrary value of 100% are provided. Here, the first optical filter unit 5 is provided with three or more partial regions on the surface of the transparent substrate 120, and the filters of the first reflective coatings 127, 128, and 129 in the partial regions 122, 123, 124, and 125 are provided. The passage rates are different from each other. The second optical filter unit 6 and the third term prison filter unit 6 have the same configuration.
As described above, in this embodiment, since the filter pass rate of each optical filter is controlled by linear movement, the position of the irradiation region is controlled by a rack and pinion that converts the motor and rotational motion into linear motion, or a linear motor. Can be easily controlled.

  Also in this embodiment, it is possible to use an optical filter portion having a plurality of missing portions on the surface of the reflective coating and having an intermediate filter pass rate.

<Fourth embodiment>
In the first embodiment and the third embodiment described above, the combination in the case where the optical filter unit is a high-pass filter has been described. However, as recent optical filters, a band-pass filter, a multi-band band-pass filter, and a band-pass filter can be used. An optical filter that combines a high-pass filter and a high-pass filter can be manufactured. A case where such a special optical filter is used will be described below as a fourth embodiment. In the following description, the description of the same configuration and method as those of the first embodiment and the third embodiment is omitted, and only the configuration and method different from those of the first embodiment and the third embodiment are described. To do.

  FIG. 14 is a diagram showing the change in the filter pass rate and the change in the wavelength characteristic of the second optical filter unit having special characteristics of the light source device of the first embodiment according to the present invention, including the relationship between them. a) shows the filter pass rate of the second optical filter part having a special characteristic in which the area ratio changes between 0% and 100%, and (b) shows the filter pass rate in which the area ratio changes between 0% and 100%. 2 shows changes in the filter pass rate of the optical filter section, and shows changes in wavelength characteristics when (c) is (b).

  In the present embodiment, the first pass characteristic film of the second optical filter unit 6 has the pass characteristics of the band pass filter for the light of the first emission line wavelength and the high pass filter for the light of the second emission line wavelength shown in FIG. Have That is, at least one of the plurality of optical filters has a composite pass characteristic of a band pass with one wavelength and a high pass with another wavelength. And the 1st passage characteristic film of the 1st optical filter part 5 is the characteristic of Drawing 10 (a), and makes it a filter passage rate of 33%. FIG. 14B shows a characteristic in which the first optical filter unit 5 and the second optical filter unit 6 in that case are combined in series in the light traveling direction. And the wavelength characteristic of each bright line part in that case is shown in FIG. By using an optical filter having special characteristics in this way, it becomes possible to cope with more various and complicated wavelengths and light intensities.

<Fifth Embodiment>
FIG. 15: is a top view which shows the other example of the principal part in the light source device of 5th Embodiment concerning this invention.
The optical filter unit 5 shown in FIG. 15 has a predetermined amount of light in addition to the partial region 122 that transmits light of the emission line wavelength on the surface of the circular transparent substrate 120 and the partial region 123 that reflects the light. A partial region 524 in which a plurality of minute openings 564 to be passed is formed is provided. A transmission characteristic film 126 having a predetermined transmission characteristic with respect to light of the emission line wavelength is formed on the surface of the transparent substrate 120 in the partial area 122 so that the partial area 122 and the partial area 123 have different filter pass rates. Then, a reflective coating 127 that blocks the light is formed in the partial region 123. The interval between the minute openings 564 in the partial region 524 varies depending on the rotation angle position of the optical filter unit 5 and is formed so that the interval gradually decreases from the partial region 122 toward the partial region 123 in the clockwise direction. ing. By forming the optical filter unit 5 in this manner, an optical filter having the characteristics of both the first embodiment and the second embodiment can be obtained depending on the rotation angle of the optical filter unit 5.

  In the present embodiment, the case where the light source device provided with the optical filter of the present invention is used in an exposure apparatus has been described. For example, in the wavelength division multiplexing (WDM) field, a wavelength variable filter that selectively extracts light of an arbitrary wavelength Can also be used. It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

1 projection exposure apparatus,
2 light source,
3 Reflector,
4 collimator lens,
5 1st optical filter part,
6 Second optical filter section,
7 Third optical filter section,
8 Illumination equalization means,
9 Condensing lens,
10 light source device,
11 Passing wavelength control unit,
12 1st drive means,
13 Second driving means,
14 3rd drive means,
15 Photomask side microscope,
20 Photomask,
25 Mask mark,
30 XY independent magnification correction unit,
40 Movable plate,
50 projection optics,
60 stages,
65 Substrate side microscope,
70 mark measuring unit,
80 control unit,
90 projection magnification control unit,
100 printed circuit board,
105 alignment marks,
120 first transparent substrate,
121 irradiation region 122 first partial region,
123 second partial region,
126 first pass characteristic coating;
127 first reflective coating,
130 second transparent substrate,
132 third partial region,
133 the fourth partial region,
136 second pass characteristic coating;
137 second reflective coating,
140 third transparent substrate,
142 fifth partial region,
143 sixth partial region,
146 third pass characteristic coating,
147 Third reflective coating,
150 the optical axis (of the passing light),
151 Irradiation region 122 First partial region,
123 second partial region,
126 first pass characteristic coating;
127 first reflective coating,
200 transparent substrate,
500 optical filter section,
501 optical filter section;
511, 611 reflective coating,
512 transmission characteristics coating,
513, 613 opening,
520 optical filter,
521 first partial region;
522 second partial region,
523 third partial region,
524 subregions,
550, 650 irradiation area,
561, 562, 563, 564 micro aperture,
565, 566, 567, 568 intervals,
600, 601 optical filter section,
700 optical axis.

Claims (9)

A light beam generated by a light source that generates a light beam having a plurality of bright lines is condensed by a concave mirror, a light beam having a predetermined wavelength is selected from the collected light beam by a selection unit having an optical filter device, and the light beam having the predetermined wavelength is selected. A light source device for illuminating an illumination object,
In the optical filter device, a reflection coating that blocks light having a wavelength of at least one emission line of the emission line spectrum is provided so as to have a plurality of openings that reflect or transmit the light flux, It has an optical filter part that controls the filter pass rate of light of the wavelength of the emission line,
The maximum dimension of the plurality of openings is a minute dimension in which a plurality of openings can be arranged in the irradiation surface of the light beam having the predetermined wavelength,
The light source device, wherein at least one characteristic of the selected light beam having a predetermined wavelength is determined by the shape, interval, and number of the minute apertures. The optical filter section is
A plurality of partial regions having at least one different shape, interval or number of the openings,
2. The light source device according to claim 1, further comprising a driving unit configured to move the optical filter unit so as to move an irradiation surface of the light beam from one partial region to another partial region. A light beam generated by a light source that generates a light beam having a plurality of bright lines is condensed by a concave mirror, a light beam having a predetermined wavelength is selected from the collected light beam by a selection unit having an optical filter device, and the light beam having the predetermined wavelength is selected. A light source device for illuminating an illumination object,
The optical filter device is provided with a reflective coating for partially blocking light having a wavelength of at least one bright line, and at least two partial regions having the reflective coating and a partial region not having the reflective coating are adjacent to each other. An optical filter section provided
A light source apparatus comprising: a driving unit that moves the optical filter unit so that an area ratio of one partial region to another partial region on the irradiation surface of the light flux is changed. The light source device according to claim 5, further comprising an illumination uniformizing unit configured to uniformize an illuminance for illuminating each part of the illumination target object with a light beam that has passed through the optical filter device. The light source device according to claim 1, wherein the driving unit moves the partial regions by rotationally driving the optical filter unit. The light source device according to claim 1, wherein the driving unit moves the partial regions by linearly driving the optical filter unit. The optical filter device includes a plurality of the optical filter units having different optical characteristics with respect to at least the light beam, and each optical filter unit is arranged in series with the optical axis of the light beam. 7. The light source device according to any one of 6. The light source device according to claim 1, wherein the light beam having the predetermined wavelength includes at least one wavelength of i-line, h-line, and g-line that are bright lines of the light beam generated by the light source. . A light beam having a predetermined wavelength is selected using the optical filter device of the light source device according to claim 1,
Irradiating a predetermined pattern formed on a photomask with the light beam having the predetermined wavelength;
An exposure apparatus that irradiates the positive resist as illumination light with the light beam having the predetermined wavelength that has passed through the photomask.

Images