JP5924021B2 - Polarization exposure apparatus and polarization exposure method - Google Patents

Description

  The present invention relates to a polarization exposure apparatus and a polarization exposure method for exposing polarized light to an exposed surface.

  A polarization exposure apparatus that performs exposure using linearly polarized light or elliptically polarized light (including circularly polarized light) is used for forming an optical film such as a retardation film, forming an alignment film of a liquid crystal panel, and forming a color filter. Some optical elements such as retardation films and color filters have different optical function parts arranged in parallel in a striped pattern. To form such an optical element, an aperture corresponding to the pattern of the optical function part is used. Exposure through a mask having a pattern is performed.

  Conventionally, such a polarization exposure apparatus includes a light irradiator including a light source including a lamp and a condenser mirror, and an irradiation optical system that guides light emitted from the light source to an exposure surface. Then, a polarizer is provided inside the housing of the light irradiator, and polarized light obtained by passing through the polarizer is emitted from the light irradiator, and is irradiated onto the exposed surface through a mask (described below). Patent Document 1).

JP 2008-164729 A

  In order to perform exposure on a surface to be exposed having a wide width by using such a conventional polarization exposure apparatus, a light source and a polarizer having a wide width corresponding to the width of the surface to be exposed are used. At this time, in the case where a polarizer is provided inside the casing of the light irradiator as in the prior art, the base material of the polarizer needs to be able to withstand the high temperature inside the casing of the light irradiator. . For this reason, when exposing a to-be-exposed surface with a wide width, a wide polarizer is formed by arranging a plurality of quartz-based polarizing plates.

  FIG. 1 is an explanatory view showing a prior art of a polarization exposure apparatus that performs polarization exposure on an exposed surface having a lateral width W of 1500 to 200 mm (FIG. 1A is a side sectional view, FIG. 1B). Is a plan view showing the polarization axis of the polarizing plate and the exposure scanning direction). As shown in FIG. 1A, a plurality of polarizing plates J3 are arranged in the longitudinal direction of the horizontally long lamp or the multi-lamp lamp J2 inside the housing of the light irradiator J1. For each polarizing plate J3, a quartz-based polarizing beam splitter (PBS) or a wire grid is used so as to withstand the high temperature inside the housing of the light irradiator J1. The polarized light emitted from the light irradiator J1 is applied to the exposed surface J5A of the exposure stage J5 through the mask J4.

  According to such a conventional technique, as shown in FIG. 1B, since a plurality of polarizing plates J3 are arranged side by side, in order to make all the angles of the polarization axes a of the polarizing plates J3 coincide, It is necessary to adjust the position and angle with high accuracy, and when the accuracy is lowered, there is a problem in that the polarization axis angle varies along the arrangement direction of the polarizing plates.

  Further, it is necessary to separately provide a reference in order to define the angle of each polarizing plate J3, and in order to achieve consistency between the reference and the exposure scanning direction b, the polarizing axis a of the polarizing plate J3 and the exposure scanning. There was a problem that an angle adjustment with respect to the direction b was necessary.

  Further, according to the prior art, since the mask pattern of the mask J4 is exposed on the exposed surface side, the material generated when the exposed surface is exposed or the material floating between the mask J4 and the exposed surface However, there is a problem that the pattern shape of the mask pattern is disturbed due to the dirt becoming attached inside the opening of the mask pattern.

  This invention makes it an example of a subject to cope with such a problem. In other words, when performing polarization exposure on an exposed surface with a wide width, it is not necessary to adjust the position and angle of each polarizer along the width direction, and polarized light is used when exposing the exposed surface through a mask. The present invention makes it easy to adjust the angle between the polarization axis angle of the optical element and the exposure scanning direction, to prevent the mask pattern pattern from being disturbed by the contamination of the mask pattern opening, and the like. Is the purpose.

In order to achieve such an object, a polarization exposure apparatus according to the present invention comprises at least the following configuration.
A wide light source along a direction intersecting one axis along the exposure scanning direction, and a mask having a width corresponding to the width of the light source, the mask being opposite to the side facing the light source of the mask base material A mask pattern on the surface, and a polarizer layer covering the mask pattern and having a polarization axis angle of a set angle with respect to the one axis , the polarizer layer is a polarizing film, and the polarizing film is A polarized light exposure apparatus comprising a film transporting means that is made of a transport film that can be detached from a mask pattern and transported in the direction of the one axis or in a direction crossing the one axis, and transports the transport film .

According to the polarized light exposure apparatus having such a configuration, since the polarizer layer is provided on the surface opposite to the surface facing the light source in the mask base material, the mask base material blocks heat from the light source, The range of base material options for the child layer can be expanded. Thus, by using the polarization fill beam, it is possible to form a polarizer layer having a uniform polarization axis across the mask.

  In addition, by fixing the polarizer layer to the mask pattern, it is possible to perform highly accurate polarization exposure with the directional axis of the mask pattern coinciding with the exposure scanning direction and the polarization axis angle of the polarizer layer fixed. . According to such a polarization exposure apparatus, it is not necessary to arrange a plurality of polarizers as in the prior art when performing polarization exposure on an exposed surface with a wide width, so the arrangement position for each polarizer along the width direction And adjustment of the angle becomes unnecessary. Moreover, since the angle between the polarization axis angle of the polarizer and the exposure scanning direction is fixed when exposing the surface to be exposed through the mask, it is possible to perform polarization exposure of the mask pattern with high accuracy.

  Furthermore, by making the polarizer layer covering the mask pattern freely removable, when the mask pattern becomes dirty, the mask pattern can be cleaned by removing the polarizer layer from the mask pattern. Disturbance of the pattern shape can be suppressed.

It is explanatory drawing of a prior art. It is explanatory drawing of the polarization exposure apparatus which concerns on one Embodiment of this invention, FIG. 2 (a) is a sectional side view, FIG.2 (b) is the top view which showed the polarization axis and exposure scanning direction of the polarizer layer. . It is explanatory drawing which showed the other structural example of the polarization exposure apparatus which concerns on embodiment of this invention. It is explanatory drawing which showed the other structural example of the polarization exposure apparatus which concerns on embodiment of this invention, and is explanatory drawing of the example which made the conveyance direction of the conveyance film the direction (illustrated Y-axis direction) crossing the exposure scanning direction. . It is explanatory drawing which showed the other structural example of the polarization exposure apparatus which concerns on embodiment of this invention. It is explanatory drawing which showed the other structural example of the polarization exposure apparatus which concerns on embodiment of this invention. It is explanatory drawing which showed the stripe pattern phase difference film and the mask for forming it. It is explanatory drawing which showed the structural example of the mask. FIG. 8 is another explanatory example of the polarization exposure apparatus according to the embodiment of the present invention, and is an explanatory view showing a modification of the example shown in FIG. 6.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 2A and 2B are explanatory views of a polarization exposure apparatus according to an embodiment of the present invention. FIG. 2A is a side sectional view, and FIG. 2B is a plane showing a polarization axis of a polarizer layer and an exposure scanning direction. FIG.

  The polarization exposure apparatus 1 performs exposure on the exposed surface 4A of the exposure stage 4 while scanning the surface to be operated in a uniaxial (X-axis direction in the drawing) direction. The movement in the scanning direction may be either one in which the light source side is fixed and the surface to be exposed is moved, or one in which the surface to be exposed is fixed and the light source side is moved. Denotes one or both of the moving direction of the exposed surface and the moving direction of the polarization exposure apparatus 1. The polarization exposure apparatus 1 includes a light source 2 that is wide along a direction that intersects one axis (X-axis in the drawing) along the exposure scanning direction, and a mask 3 that has a width corresponding to the width of the light source 2.

  The light source 2 is, for example, a mercury lamp disposed in the housing of the light irradiator 20, and emits non-polarized light (ultraviolet light) from a light emission opening 21 provided in the housing of the light irradiator 20. It is. The mask 3 includes a mask base material 30 having heat shielding properties such as quartz, a mask pattern 31 formed on one surface of the mask base material 30, and a polarizer layer 32 formed to cover the mask pattern 31. ing.

  As for the mask pattern 31, the pattern which has the directivity along one axis | shaft (illustrated X-axis) is formed in the surface on the opposite side to the side which faces the light source 2 of the mask base material 30. FIG. In the example shown in the figure, the pattern is a stripe-shaped opening pattern, and the axis b in the longitudinal direction of the opening coincides with the direction along one axis (the X axis in the figure) along the exposure scanning direction.

  The polarizer layer 32 is fixed to the mask pattern 31 and has a polarization axis a having an angle set with respect to one axis (X axis in the drawing) along the exposure scanning direction. That is, the polarization axis a of the polarizer layer 32 is fixed with a set angle with respect to the axis b of the mask pattern 31. Specifically, the polarizer layer 32 here is a polarizing film fixed to the mask pattern 31, a wire grid disposed on the mask pattern 31, a dielectric multilayer film laminated on the mask pattern 31, or the like. However, what is fixed is the mask pattern 31 and has an optical function as a polarizer (a function of obtaining linearly polarized light or elliptically polarized light from non-polarized light emitted from the light source)? Also good.

  According to such a polarization exposure apparatus 1, since the directivity of the mask pattern 31 that coincides with the exposure scanning direction and the polarization axis direction of the polarizer layer 32 are fixed, a highly accurate polarization exposure without complicated position adjustment. It becomes possible to do. Moreover, since the mask base material 30 has a heat shielding function against the heat emitted from the light source 2, the polarizer layer 32 itself does not need high heat resistance, and various materials and configurations are adopted as the polarizer layer 32. can do. As a result, the polarizer layer 32 having a uniform polarization axis can be formed on the entire surface of the mask pattern 31, and the exposed surface 4A having a wide width of 1500 to 2000 mm in the Y-axis direction shown in the figure is shown in the X-axis shown in the figure. Even in the case of scanning exposure along the direction, the arrangement position and angle of the polarizer can be easily adjusted.

  In addition, since the mask pattern 31 is covered with the polarizer layer 32, the presence of the polarizer layer 32 prevents the dirt from directly attaching to the mask pattern 31. By making the polarizer layer 32 detachable, if the dirt is attached to the polarizer layer 32, it can be replaced and the mask pattern 31 can be cleaned.

  FIG. 3 is an explanatory view showing another configuration example of the polarization exposure apparatus according to the embodiment of the present invention. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted. The example shown in FIG. 3 is an example in which a polarizing film is used as the polarizer layer 32. Here, the polarizing film is a transport film 11 transported by a film transport means such as a guide roll 10.

  The transport film (polarizing film) 11 can be fixed to or removed from the mask pattern 31, and as shown in FIG. 3A, exposure is performed in a state of being fixed to the mask pattern 31, and FIG. ), The transport film 11 is transported in a state of being detached from the mask pattern 31 during non-exposure. The mask pattern 31 and the transport film 11 can be fixed by any method as long as the mask pattern 31 and the transport film 11 are fixed, such as adsorption by magnetic force or negative pressure suction force or adhesion by an adhesive. May be. In the example shown in FIG. 3B, the transport film 11 is transported after being detached from the mask pattern 31, but the transport film 11 is transported after being fixed in FIG. You may make it move so that it may slide along the mask pattern 31, without separating from.

  A polarization exposure method using such a polarization exposure apparatus 1 will be described. When exposing the light emitted from the light source 2 through the mask 3 to the exposed surface 4A, a part of the transport film (polarization film) 11 is formed. First exposure is performed with the mask 3 fixed on the mask pattern 31 (see FIG. 3A). Thereafter, the set number of exposures are performed, and when the polarizing film is deteriorated or soiled, the transport film 11 fixed on the mask pattern 31 is detached and the transport film 11 is transported so that the transport film 11 is different. A part is moved on the mask pattern 31 (see FIG. 3B). Then, as shown in FIG. 3A again, the transport film 11 is fixed to the mask pattern 31 and exposure is performed again. In the illustrated example, the transport direction of the transport film 11 is made to coincide with the exposure scanning direction (X-axis direction in the drawing), but not limited to this, the transport direction of the transport film 11 intersects the exposure scanning direction (Y in the drawing). Axial direction).

  According to such an embodiment, since the transport film (polarizing film) 11 covers the mask pattern 31, it is possible to avoid the mask pattern 31 from being directly soiled by the transport film 11. Since the transport film 11 can be fixed to or removed from the mask pattern 31, if the transport film 11 on the mask pattern 11 is soiled or deteriorated, the transport film 11 is peeled off from the mask pattern 31 and transported. A new surface of the transport film 11 can be newly used as the polarizer layer 32.

  FIG. 4 is an explanatory view showing another configuration example of the polarization exposure apparatus according to the embodiment of the present invention, in which the conveyance direction of the conveyance film 11 is set to a direction (Y-axis direction in the drawing) intersecting the exposure scanning direction. It is. Here, the mask pattern 31 is a stripe-shaped opening pattern along the exposure scanning direction (X-axis direction in the drawing). At this time, the transport film (polarizing film) 11 is deteriorated or smeared by exposure in the area within the opening pattern of the mask pattern 31, so that the area on the mask 3 does not correspond to the opening pattern. Has relatively little deterioration and contamination due to exposure. Therefore, in this example, the transport film 11 is moved so that the feeding width of the transport film 11 corresponds to the pattern pitch p of the stripe-shaped opening pattern, and the region corresponding to the opening pattern moves to the adjacent light-shielded region. 11 is conveyed. For example, when the opening width p1 of the opening pattern is equal to the width p2 of the light shielding portion (p1 + p2 = 2p1 = p), the transport width of the transport film 11 is transported by p / 2. According to this, since the transport film 11 can be used efficiently and the feed width can be reduced, the tact time during non-exposure for transporting the transport film 11 can be shortened.

  FIG. 5 is an explanatory view showing another configuration example of the polarization exposure apparatus according to the embodiment of the present invention. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted. Here, the polarization exposure apparatus 1 includes a mask cooling unit 5 that cools the mask 3. The mask cooling means 5 sprays a cooling medium such as air onto the surface of the mask 3 and suppresses the mask 3 from becoming high temperature by spraying the cooling medium onto the mask 3 that is heated with exposure.

  According to this, by cooling the mask 3, it can suppress that the conveyance film 11 fixed to the mask pattern 31 of the mask 3 is heated, The conveyance film (polarizing film) 11 used as the polarizer layer 32 It is possible to prevent deformation and alteration due to heat.

  FIG. 6 is an explanatory view showing another configuration example of the polarization exposure apparatus according to the embodiment of the present invention (FIG. 6A is an explanatory view showing the entire configuration, and FIG. 6B is a mask). Explanatory drawing). Here, the structural example of the polarization exposure apparatus 1 for forming the retardation film of a stripe pattern is shown. The polarization exposure apparatus 1 includes two light irradiators 20 (20A and 20B), and a light source 2 (2A and 2B) is provided in each of the light irradiators 20 (20A and 20B). The mask 3 includes two mask patterns 31 (31A, 31B) in the exposure scanning direction (X-axis direction in the drawing), and two mask patterns 31 (31A, 31B) are irradiated with light so as to irradiate light respectively. A light irradiator 20 (20A, 20B) is provided. In the example shown in the figure, two mask patterns 31A and 31B are provided in one mask 3, but the mask 3 may be divided and arranged for each of the mask patterns 31A and 31B.

  The mask 3 covers the mask pattern 31 (31A, 31B), and the polarizing film (transport film) 11 (11A, 11B) is fixed to the surface of the mask 3 opposite to the light source side so as to be removable. . In the illustrated example, the polarizing film 11 is freely transportable along a direction (Y-axis direction shown) that intersects the exposure scanning direction (X-axis direction shown).

  In this example, as shown in FIG. 7A, the two mask patterns 31A and 31B are arranged such that the positions of the stripe-shaped openings and the light shielding portions are shifted from each other. That is, the light shielding part of the other mask pattern 31B is arranged coaxially with the opening part of one mask pattern 31A, and the opening part of the other mask pattern 31B is arranged coaxially with the light shielding part of one mask pattern 31A. Yes.

  The polarizing film 11A covering one mask pattern 31A is a polarizer for obtaining linearly polarized light (for example, p-polarized light) having the first polarization axis, and the polarizing film 11B covering the other mask pattern 31B is the first This is a polarizer for obtaining linearly polarized light (for example, s-polarized light) having a second polarization axis in a direction different from the polarization axis. In the illustrated example, the polarizing films 11A and 11B are individually provided. However, the polarizing film 11A, the area corresponding to the polarizing film 11A and the area corresponding to the polarizing film 11B are provided in one transport film. 11B can be transported integrally.

  The exposed film F is conveyed along the exposure scanning direction (X-axis direction in the drawing) to the polarization exposure apparatus 1 having such a configuration. For transporting the film F to be exposed, film transport means including a pair of transport rolls F1, F1 and a pair of guide rolls F2, F2 is used. The exposed film F is coated with a photosensitive resin layer on which a retardation layer having different retardation characteristics is formed by irradiating linearly polarized light having polarization axes in different directions.

  According to this, as shown in FIG. 7B, a retardation film having a stripe pattern having two different retardation characteristics can be obtained. That is, the exposed film F includes a stripe-shaped a region irradiated with linearly polarized light (for example, p-polarized light) transmitted through the mask pattern 31A and the polarizing film 11A along the exposure scanning direction, and the mask pattern 31B and the polarizing film 11B. The stripe-shaped b region is irradiated with linearly polarized light (for example, s-polarized light) that has passed through the region, and the a region and the b region have different phase difference characteristics.

  The configuration of the mask 3 shown in FIG. 7A can be replaced with the configuration shown in FIG. 8 by changing the characteristics of the photosensitive resin layer on the film F to be exposed. That is, the configuration example of the mask 3 shown in FIG. 8A is an example in which a reversible resist is used for the photosensitive resin layer. In this case, the exposure scanning direction (the X-axis direction in the drawing) The mask pattern 31A disposed on the downstream side in the conveyance direction of the exposure film F) can be formed into a stripe shape, and the mask pattern 31B disposed on the upstream side in the exposure scanning direction can be a full-open pattern. In this case, since the photosensitive resin is reversible, a region exposed later through the striped mask pattern 31A becomes a region having reversibly different phase difference characteristics. The configuration example of the mask 3 shown in FIG. 8B is an example in the case of using an irreversible resist for the photosensitive resin layer. In this case, the exposure scanning direction (in the X-axis direction in the drawing) The mask pattern 31B arranged on the upstream side in the conveyance direction of the film F to be exposed) can be formed in a stripe shape, and the mask pattern 31A arranged on the downstream side in the exposure scanning direction can be a full-open pattern. In this case, since the photosensitive resin is irreversible, the characteristics of the region previously exposed through the stripe-shaped mask pattern 31B change even if the region is exposed through the mask pattern 31A of the full aperture pattern later. Without being maintained as a region showing different phase difference characteristics.

  FIG. 9 is another configuration example of the polarization exposure apparatus according to the embodiment of the present invention, and is an explanatory view showing a modification of the example shown in FIG. 6 (the parts common to the example shown in FIG. 6 are The same reference numerals are assigned and the duplicate description is omitted). The polarization exposure apparatus 1 includes two light irradiators 20 (20A and 20B), and a light source 2 (2A and 2B) is provided in each of the light irradiators 20 (20A and 20B). Further, two masks 3 (3A, 3B) are arranged in parallel along the exposure scanning direction (X-axis direction in the drawing), and the two masks 3 (3A, 3B) are respectively provided with mask patterns 31 (31A, 31B). ing. Then, two light irradiators 20 (20A, 20B) are provided so as to irradiate the mask pattern 31 (31A, 31B) with light.

  The mask 3 (3A, 3B) covers the mask pattern 31 (31A, 31B), and the polarizing film (conveyance film) 11 (11A, 11B) is provided on the surface opposite to the light source side of the mask 3 (3A, 3B). 11B) is detachably fixed. In this configuration example, the polarizing films 11 </ b> A and 11 </ b> B can be transported along the exposure scanning direction (the X-axis direction in the drawing, the transport direction of the film F to be exposed).

  When forming such a retardation film, the polarization exposure apparatus 1 according to the embodiment of the present invention is particularly effective. That is, the light emitted from the two light irradiators 20 (20A, 20B) passes through the mask pattern 31 (31A, 31B), passes through the polarizing film 11 (11A, 11B), and then has different polarization axes. Since it becomes polarized light, a light shielding plate for partitioning the two mask patterns 31A and 31B becomes unnecessary. Conventionally, since polarizers are provided in two light irradiators, it is necessary to provide a light shielding plate between the two mask patterns so that the two mask patterns do not contain linearly polarized light having different polarization axes. there were. By using the polarization exposure apparatus 1 according to the embodiment of the present invention, such a light shielding plate can be eliminated, so that the apparatus can be made compact and the exposure accuracy can be improved.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

1: Polarization exposure apparatus,
2: Light source,
20: Light irradiator,
3: Mask,
30: Mask base material
31: Mask pattern,
32: Polarizer layer,
4: Exposure stage,
4A: surface to be exposed,
10: Guide roll,
11: Conveyance film (polarizing film),
5: Mask cooling means

Claims (4)

A light source that is wide along a direction intersecting one axis along the exposure scanning direction, and a mask having a width corresponding to the width of the light source;
The mask includes a mask pattern on a surface opposite to the side facing the light source of the mask base material, and a polarizer layer that covers the mask pattern and has a polarization axis angle of a set angle with respect to the one axis. ,
The polarizer layer is a polarizing film;
The polarizing film is made of a transport film that is detachable from the mask pattern and transported in the direction of the one axis or in the direction crossing the one axis,
A polarized light exposure apparatus comprising film transport means for transporting the transport film . The mask pattern is a stripe pattern along the uniaxial direction,
The film conveying means, said conveying film in a direction crossing the axial direction is conveyed to the polarization exposure apparatus according to claim 1, characterized in that the conveying of the feed width corresponding to the pattern pitch of the stripe pattern . Polarization exposure apparatus according to claim 1 or 2, characterized in that it comprises a mask cooling means for cooling the mask. When exposing the surface to be exposed with light emitted from a light source through a mask,
A polarizing film is formed by a transport film that can be transported along one direction, a part of the transport film is fixed on the mask pattern of the mask, the exposure is performed, and after the exposure for a set number of times, the mask pattern The polarization exposure method comprising: releasing the fixing of the transport film fixed on the top, transporting the transport film, and fixing the different portions of the transport film on the mask pattern to perform the exposure. .

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