KR101110516B1 - Light s0urce f0r exp0sure - Google Patents

Abstract

assignment

A plurality of surface light emitting elements are used as light emitting sources instead of lamps, and a light source for high output parallel light exposure is provided by using the surface light emitting elements and the optical system.

Solution

The light emitted from the plurality of surface light emitting elements mounted on the substrate 1 is used as a light emitting source, and the light is incident from the end face of the optical polygonal column 3 arranged in proximity to the surface light emitting element, and the optical polygonal column 3 The roughness is made uniform. The light 9 emitted from another end face of the optical polygonal column 3 is condensed by the lens 4 and irradiated to the curved mirror 5, and the curved mirror 5 is converted into parallel light 11, Parallel light 11 is irradiated to the mask 6. The exposure which transfers the pattern drawn on the photomask 6 to the photosensitive film formed on the board | substrate 7 by the parallel light 11 irradiated to the photomask 6 is performed.

Light source, exposure, lens

Description

Light source for exposure {LIGHT S0URCE F0R EXP0SURE}

1 is a conceptual diagram showing the configuration of a light source for exposure in a first embodiment according to the present invention;

FIG. 2 is an enlarged view of an area enclosed by A in FIG. 1. FIG.

3 is a view taken along the line III-III of FIG. 2;

Fig. 4 is a conceptual diagram showing the configuration of a light source for exposure in a second embodiment according to the present invention.

Fig. 5 is a conceptual diagram showing the configuration of a light source for exposure in a third embodiment according to the present invention.

FIG. 6 is a view of a plurality of light irradiation units used for the light source for exposure in the third embodiment as seen from arrow VI-VI in FIG. 7; FIG.

FIG. 7 is an X-ray arrow of FIG. 6; FIG.

Fig. 8 is a conceptual diagram (side view) showing the configuration of an exposure light source in a fourth embodiment according to the present invention.

9 is a front view of a lens group employed in a light source for exposure in a fourth embodiment according to the present invention.

Fig. 10 is a conceptual diagram showing a first configuration of an exposure light source in a fifth embodiment of the present invention.

Fig. 11 is a conceptual diagram showing the second configuration of the light source for exposure in the fifth embodiment according to the present invention.

(Explanation of symbols for the main parts of the drawing)

1, 101: substrate 2, 102: surface light emitting element

3: optical polygonal column 3A: optical square column

4, 104 lens 4A lens group

5, 105, 205: curved mirror 6, 106, 206: photo mask

7, 107, 207: Exposed substrate 7A: Cooling section

8, 9, 10, 10A, 108, 109, 110, 210: light

11, 211: parallel light 113: fly-eye lens

112, 212: light irradiation unit 220a, 220b: exposure station

Technical field

INDUSTRIAL APPLICABILITY The present invention is used for an exposure process for transferring a pattern drawn on a photomask onto a photosensitive film formed on a surface of a substrate by irradiating light through a photomask on which a pattern is drawn on a photoresist film (photoresist) formed on a surface of a substrate. The light source for exposure is provided.

Conventional technology

Conventionally, the light source for exposure used for the exposure process which transfers the pattern drawn on the photomask on the photosensitive film formed on the surface of the board | substrate by irradiating light through the photomask on which the pattern was drawn on the photosensitive film formed on the surface of the board | substrate emits light As a source, a lamp such as a mercury lamp that emits light having a short wavelength ranging from ultraviolet to blue suitable for photosensitive film has been used. This type of lamp is widely used because it is relatively easy to manufacture high-power products, but includes the following problems. That is, this type of lamp uses a hazardous substance such as mercury, and there is a risk of rupture because the lamp has high internal pressure. In addition, in recent years, the area of the substrate subjected to the exposure treatment has been used in accordance with the tendency to increase, but a high output lamp is used, and accordingly, the calorific value also becomes very large, resulting in an increase in cooling and cooling loads.

However, although this kind of lamp includes the problems described above, until now, there is no outstanding light emitting source of high power in place of this kind of lamp, and although some high power lasers are used, it is very expensive and popular. It doesn't last. For this reason, as a light emitting source of an exposure light source, many lamps, such as a mercury lamp, are used now.

The background art of the invention relating to the present application has been described based on general technical information acquired by the applicant. However, the applicant has information that should be disclosed as prior art document information before the application of the present application, to the extent that the applicant remembers. No patent application or the like of the applicant's own patent application preceded by the present application is recognized.

The problem to be solved by the present invention is to provide a light source for exposure using a light emitting source in place of a lamp including the problem described above. In recent years, in the semiconductor surface light emitting device, which has been developed and put into practical use, products that emit light having a short wavelength ranging from ultraviolet rays to blue have also been put into practical use, and products with high outputs have been put to practical use. Semiconductor surface emitting devices have many advantages over lamps. That is, it has a very long life, easy control of 0N and 0FF, low heat generation, and light weight and small size. Accordingly, an object of the present invention is to realize a light source for exposure using a light emitting source instead of a lamp by using a semiconductor surface light emitting device having such advantages.

The semiconductor surface light emitting device can be said to have a high output product, but the output per device is considerably lower than the output of the lamp. Therefore, if a semiconductor light emitting device is used instead of the lamp and a light source for exposure is realized, Many devices must be used. On the other hand, since it is necessary to faithfully transfer the pattern drawn on the photomask which becomes increasingly high in recent years, the light calculated | required as a light source for exposure is parallel light with uniform illumination. In order to obtain the parallel light of the light quality permitted in the exposure process, the condition is that the geometric optical light emitting source is as small as a short arc lamp that is conventionally used. Since it is smaller than the arc which is the light-emitting body of a short arc lamp, it is possible to use it as one light emitting source sufficient for obtaining parallel light by selecting the appropriate quantity of semiconductor surface light emitting elements which are gathered in planar shape.

According to the light source for exposure based on this invention, it becomes possible to implement | achieve the light source for exposure of the high performance high output parallel light which solved the problem of the exposure light source using the conventional lamp.

Hereinafter, the light source for exposure using the surface light emitting element based on this invention is demonstrated in detail. First, the light emitted from the surface light emitting element is collected by using a light emitting source having a plurality of surface light emitting elements gathered in a planar shape and an optical system, irradiated with a curved mirror, and converted into parallel light by the curved mirror to irradiate the exposed surface. It is an exposure light source.

Next, when a preferable form is shown, at least one optical polygonal cross section is arranged to approach a plurality of surface light emitting elements gathered in a planar shape, and the light emitted from the surface light emitting element is emitted from the optical. After passing through the polygonal column to make the illuminance uniform, the light is condensed by the lens and irradiated with a curved mirror, and converted into parallel light by the curved mirror to irradiate the exposed surface.

In addition, in order to obtain a high-output light source for exposure, a plurality of light emitting units composed of a plurality of surface light emitting elements gathered in a planar shape and one optical system are provided, and light emitted from each light irradiation unit is focused on a fly-eye lens. The light passing through the fly-eye lens may be irradiated with a curved mirror to be converted into parallel light.

Moreover, the photosensitive wavelength of the photoresist film (photoresist) formed on the surface of the board | substrate currently used most is h (405 nm) line | wire, i (365 nm) line | wire, and g (436 nm) which are the main wavelengths of the light emitted by a mercury lamp. Since it corresponds to a line, it is preferable that a plurality of surface light emitting elements emit light of a wavelength corresponding to the plurality of light emission wavelengths of the mercury lamp even when the surface light emitting element is a light emitting source. For this reason, the wavelength of the light emitted from the plurality of surface light emitting elements gathered in the plane shape may be constituted by light emitting elements of different types. What is necessary is just to comprise with the surface light emitting element of the light emission wavelength corresponding to a some light emission wavelength, respectively.

Further, a plurality of light irradiation units having a plurality of surface light emitting elements, optical polygonal columns and lenses assembled in a planar shape are provided, and the light emitted from the plurality of light irradiation units is irradiated with a curved mirror to provide parallel light. May be irradiated to the exposed surface. The plurality of light irradiation units may be arranged in a circle orthogonal to the light irradiation direction, and the light emission area may be made smaller to improve the light quality of parallel light.

In addition, the lenses used for the plurality of light irradiation units are rectangular, and the plurality of rectangular lenses corresponding to the plurality of light irradiation units are placed in close contact with each other in a direction orthogonal to the light irradiation direction, and are arranged so as to emit light. The optical quality of the parallel light may be improved by making it smaller. Further, the lenses used for the plurality of light irradiation units are hexagonal, and the plurality of hexagonal lenses corresponding to the plurality of light irradiation units are placed in close contact with each other in a direction orthogonal to the light irradiation direction, and are arranged so as to emit light. The optical quality of the parallel light may be improved by making it smaller.

Moreover, you may use the optical polygonal column which served as a lens function by making at least one surface of the said optical polygonal column into a spherical surface.

Further, by providing a selectable method of irradiating light from all of the plurality of light irradiating units and a method of irradiating light only from a predetermined number of light irradiating units, light can be emitted only from all the light irradiating units. Compared to the method of irradiation, the illuminance can be easily adjusted. Moreover, although illumination intensity falls by reducing the number of light irradiation units which irradiate light, since light output area becomes small, the light quality of parallel light improves and it becomes possible to transfer the pattern of a photo mask to a board | substrate more faithfully.

Moreover, if it has two exposure stations and changes the irradiation direction or irradiation position of the said several light irradiation unit, and makes it irradiate light alternately to said two exposure stations, it will irradiate light to two exposure stations with one light source. The exposure apparatus can be manufactured at low cost.

A representative example of the surface light emitting element described above is a light emitting diode (LED) as a semiconductor surface light emitting element, but may be another surface light emitting element.

Moreover, in the optical system which obtains the said high output light source for light, what is necessary is just to comprise the said several light irradiation unit from which the wavelength of the irradiated light differs, and if it is specified, the wavelength of the irradiated light corresponding to the several emission wavelength of a mercury lamp, respectively, What is necessary is just to comprise a some light irradiation unit.

In addition, although it is said that it is preferable that a plurality of surface light emitting elements emit light of the wavelength corresponding to each of the light emission wavelength of a mercury lamp, it is good to correspond at least two wavelengths of the light emission wavelength of a mercury lamp, and light emission wavelength is also a mercury lamp. The wavelength may be close to the emission wavelength, even if it does not exactly match the emission wavelength.

(First embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, the 1st Example of the exposure light source based on this invention is described with reference to drawings. First, referring to FIG. 1 and FIG. 2, the light 8 emitted from the plurality of surface light emitting elements 2 mounted on the substrate 1 is used as a light emitting source, and the light 8 is used as the surface light emitting element. It enters from the cross section of the optical polygonal column 3 arrange | positioned approaching (2), and the illuminance is equalized by the optical polygonal column 3. The light 9 emitted from another end face of the optical polygonal column 3 is condensed by the lens 4 and irradiated to the curved mirror 5, and is converted into parallel light 11 by the curved mirror 5. Parallel light 11 is irradiated to the mask 6. The exposure which transfers the pattern drawn on the photomask 6 to the photosensitive film formed on the to-be-exposed board | substrate 7 by the parallel light 11 irradiated to the photomask 6 is performed. In the above-described configuration, one optical polygonal column 3 may be used, but a thin optical polygonal column may be bundled. In addition, although the lens 4 is shown as one in FIG. 1, you may combine multiple sheets.

Next, as shown in FIG. 2 and FIG. 3, the plurality of surface light emitting elements 2 are assembled and mounted on the substrate 1. In the drawing, the surface light emitting elements 2 are spaced apart for easy description, but are actually compacted at a minimum interval. As described above, the size of the light emitting source is limited in order to obtain the parallel light of the light quality acceptable in the exposure process, but the size of the surface light emitting element 2 is about 1 mm to 2 mm, and a plurality of dozen light emitting sources are collected. It is also possible to obtain parallel light without any practical practical problems.

(Second embodiment)

FIG. 4 is a diagram showing the configuration of the light source for exposure in the second embodiment based on the present invention in order to obtain high output parallel light. The light 108 emitted from the plurality of surface light emitting elements 102 mounted on the substrate 101 (only one is shown in FIG. 4 for convenience of description) is used as a light emitting source, and the light 108 is used to emit light of the semiconductor surface. The element 102 is incident on the lens 104 disposed close to the element 102. In addition, a plurality of light irradiation units 112 composed of the substrate 101, the semiconductor surface light emitting element 102, and the lens 104 are provided, and the light 109 emitted from each light irradiation unit 112 is provided with a lens. Condensed light on the fly-eye lens 113 for equalizing the illuminance provided at the intermediate position between the 104 and the curved mirror 105, and the light 110 passed through the fly-eye lens 113, the curved mirror 105 Is irradiated to the parallel light 111 and irradiated to the photomask 106. The exposure which transfers the pattern drawn on the photomask 106 by the parallel light 111 irradiated to the photomask 106 to the photosensitive film formed on the to-be-exposed board | substrate 107 is performed. Thus, at least several times the high output light source for exposure can be realized compared with the light source for exposure in the Example shown in FIG.

(Third embodiment)

5 is a diagram showing another embodiment for obtaining high power parallel light. The light irradiation unit 212 used in this third embodiment has a configuration as shown in Figs. 1 to 3, and includes a substrate 1, a plurality of surface light emitting elements 2, an optical polygonal column 3, and the like. It consists of the lens 4. In FIG. 5, the some light irradiation unit 212 is shown by the some rectangle for convenience.

In the second embodiment shown in FIG. 4, the fly-eye lens 113 is used, but in the present embodiment, the light 210 is applied to the curved mirror 205 directly from the plurality of light irradiation units 212. The light is irradiated to the parallel light 211 by the curved mirror 205, and light is irradiated to the photomask 206 and the exposed substrate 207. In the present embodiment, since the plurality of light irradiation units 212 are disposed at substantially the same position where the fly-eye lens 113 is provided in the configuration of the second embodiment shown in FIG. 4, the optical path is shortened. It becomes possible.

6 and 7 are examples showing the arrangement of the plurality of light irradiation units 212 used in the configuration of the third embodiment shown in FIG. When parallel light is obtained using the plurality of light irradiation units 212, in order to improve the quality of parallel light, that is, the parallelism of the light, the perpendicularity to the exposure surface, and the like, It is preferable to reduce the circumscribed circle 213. Therefore, it is important to arrange the plurality of light irradiation units 212 in a circle orthogonal to the light irradiation direction. FIG. 7 is a diagram in which 19 light irradiation units 212 are arranged in a circle, but, for example, when light irradiation units of approximately the same quantity are arranged in a rectangle, an empty space is generated in the circumscribed circle, and the circumscribed circle becomes large and parallel. It becomes the cause which worsens the light quality of light. In addition, although the structure shown in FIG. 7 which arrange | positioned the several light irradiation unit 212 in densely packed in the circle | round | yen is seen also in polygonal arrangement | positioning, it is assumed that it is contained in arrangement | positioning in circle | round | yen.

In addition, although the board | substrate 1 is provided in each light irradiation unit 212 in FIG. 6, you may mount the surface light emitting element 2 on an integrated board | substrate. In any configuration, in order to obtain high output, the surface light emitting element 2 preferably has a structure in which the surface light emitting element 2 is water cooled. In addition, it is effective for the plurality of light irradiation units 212 to be assembled to one support member for the purpose of improving the assembly accuracy and reducing the cost.

(Example 4)

In the third embodiment shown in Figs. 6 and 7, the lens used for each light irradiation unit is a general circular lens, but Figs. 8 and 9 show another embodiment in which the lens is a quadrangle. FIG. 8 is a side view of the surface light emitting element 2, the optical square 3A, the lens group 4A, and the cooling unit 7A of the surface light emitting element 2 in which each light irradiation unit is mounted on the substrate 1; It shows that it is comprised.

FIG. 9 is a front view of the lens group 4A, in which a rectangular lens is arranged so that the rectangular lenses of three vertical and horizontal angles and a total of nine rectangular lenses are in close contact with each other in a direction orthogonal to the light irradiation direction. That is, the light source comprised from nine light irradiation units is shown. 6 and 7, the light emitted from the surface light emitting element 2 passes through the optical square column 3A and the lens group 4A, is focused on a curved mirror (not shown), and is converted into parallel light. It changes and irradiates an exposure surface. In addition, the light condensed from the lens group 4A to the curved mirror is represented by light 10A.

According to this fourth embodiment, since each light irradiation unit can be densified more than the circular lens, the light emitting area becomes small, and high quality parallel light can be obtained. In addition, since the lenses can be bonded to each other and integrated, there is an advantage that the assembly of the lenses is easier than that of the circular lenses.

In this embodiment, the lens group 4A is represented by two lenses in the optical axis direction, but the number of lenses is limited based on this embodiment, including nine lenses in a direction orthogonal to the optical axis direction. It is not. Moreover, although the case where a square lens was used for 4 A of lens groups was shown, the same effect can also be acquired by using a hexagonal lens.

(Fifth Embodiment)

Next, FIG. 10 and FIG. 11 show that in the exposure apparatus having two exposure stations 220a and 220b, the irradiation directions or the irradiation positions of the plurality of light irradiation units 212 are changed, and the two exposure stations 220a, 220b) shows a configuration in which light is alternately irradiated.

FIG. 10 rotates the plurality of light irradiation units 212 around the rotation center C, and makes it possible to irradiate light alternately to the two exposure stations 220a and 220b. FIG. 11 shows two exposure stations 220a and 220b by providing an inversion mirror 214 between the plurality of light irradiation units 212 and the curved mirror 205 and rotating the inversion mirror 214. The structure which irradiates light alternately is shown. In addition, although the inversion mirror 214 shows the plane mirror in FIG. 11, when it is desired to shorten an optical path, it is also possible to use a curved mirror.

As described above, in the exposure apparatus having two exposure stations, when the two exposure stations 220a and 220b are irradiated with light alternately by changing the irradiation direction or the irradiation position of the plurality of light irradiation units 212, Light can be irradiated to two exposure stations with one light source. As a result, it becomes possible to manufacture an exposure apparatus at low cost.

In addition, by selectively selecting a method of irradiating light from all the numbers of the plurality of light irradiation units and a method of irradiating light only from a predetermined number of light irradiation units, it is possible to irradiate light only from all the light irradiation units. Compared to the system, the illuminance can be easily adjusted. Moreover, although illumination intensity falls by reducing the number of light irradiation units which irradiate light, since light output area becomes small, the light quality of parallel light improves and it becomes possible to transfer the pattern of a photo mask to a board | substrate more faithfully.

In addition, the lamps used in the prior art are easily broken because they are made of glass and have limitations in the direction of attachment. Also suitable for. Moreover, since there is no restriction | limiting in the attachment direction like a lamp, and it is small, compared with a lamp light source, it is easy to shorten or simplify a light path, and it can provide the light source for exposure highly reliable.

It is also possible to use an optical polygonal column having a lens function with at least one surface of the optical polygonal column used in each of the above embodiments as a spherical surface.

As mentioned above, the said embodiment and the Example disclosed this time are an illustration in all the points, and are not based on a limited interpretation. Moreover, it is possible to obtain the light source for exposure which becomes a desired structure by combining the structure of embodiment and each Example suitably. Therefore, the technical scope of this invention is not interpreted only by said embodiment, It is determined based on description of a claim. Also included are all equivalents of the claims and their equivalents.

According to the light source for exposure based on this invention, it becomes possible to implement | achieve the light source for exposure of the high performance high output parallel light which solved the problem of the exposure light source using the conventional lamp.

Claims (16)

The light emitted from the surface light emitting element is condensed by using a light emitting source having a plurality of surface light emitting elements gathered in a planar shape and an optical system, irradiated with a curved mirror, and converted into parallel light by the curved mirror to irradiate light to an exposed surface. In the exposure light source, With respect to the plurality of surface light emitting elements gathered in the planar shape, the end faces of at least one optical polygonal column are placed close to each other, and the light emitted from the surface light emitting element is directly incident on the optical polygonal column and passed through the optical polygonal column. The light source for exposure characterized by uniformizing illuminance, condensing by a lens, irradiating to said curved mirror, and converting into parallel light by said curved mirror, and irradiating to an exposure surface. delete delete delete delete delete delete The method of claim 1, A plurality of surface light emitting elements gathered in the plane shape, the optical polygonal column, and a plurality of light irradiation units having the lens are provided, and the light emitted from the plurality of light irradiation units is irradiated to the curved mirror to parallel light. The light source for exposure characterized by irradiating light to the exposure surface. delete The method of claim 8, The lenses used for the plurality of light irradiation units are rectangular, and the plurality of rectangular lenses corresponding to the plurality of light irradiation units are bonded to each other in a direction orthogonal to the light irradiation direction and are arranged so as to be dense. Light source. delete delete delete The method of claim 8 or 10, A light source for exposure, which rotates the plurality of light irradiation units to irradiate two exposure stations alternately by changing the light irradiation direction or the light irradiation position. delete delete

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