JP2009251581A - Mask for exposure and exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mask for exposure that increases surface flatness of a color filter and improves precision of the color filter by suppressing swelling of an overlap of a black matrix and an outer edge of a picture element portion as small as possible. <P>SOLUTION: The mask for exposure having a region comprising a plurality of light transmission holes 4<SB>1</SB>in the same shape which have exposure patterns 4 arranged on at least one line at a predetermined pitch and a region comprising a plurality of light transmission portions 4<SB>2</SB>and 4<SB>3</SB>arranged on at least one line parallel to the line at a predetermined pitch and in a shape similar to the shape of the light transmission holes is intermittently irradiated with exposure light to transfer the light transmission portions 4<SB>1</SB>to 4<SB>3</SB>as exposure patterns onto a color filter substrate W. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exposure mask used for manufacturing a color filter such as a liquid crystal panel or a plasma display, and an exposure apparatus using the same, and more particularly to an exposure mask used for proximity exposure using a flash lamp and the exposure thereof. It relates to the device.

A color filter for a liquid crystal panel is manufactured by applying a negative photosensitive composition containing a colorant to the entire surface of a substrate on which a black matrix is formed, and using a proximity exposure apparatus to make red (R) and green on the substrate. (G), a colored layer pattern (hereinafter simply referred to as “picture element part”) separated by a black matrix on a substrate by performing development after sequentially performing exposure on portions where a colored layer of blue (B) is to be formed. .) Is produced, but the flatness of the surface is lowered when the overlapping portion of each pixel part outer edge and the black matrix is raised as shown in FIG. 7A.
Therefore, as a method for preventing the bulge, the gap between the exposure mask and the substrate as the object to be exposed (hereinafter referred to as “proximity gap”) is adjusted, and defocus exposure is performed to thereby reduce the overlap portion. A method of reducing the exposure amount so that the overlapping portion is easily dissolved and removed by development to reduce the bulge amount (Patent Document 1), or an exposure light transmission portion of the exposure mask (hereinafter simply referred to as “transmission hole”). ) ”Is used to form each pixel part in an island shape inside the black matrix opening (Patent Document 2), etc. It has been.

JP-A-9-159815 JP 2001-33613 A

However, in defocus exposure, because the exposure mask is bent by its own weight, the proximity gap cannot be kept uniform over the entire exposure area, and it is necessary to use a plurality of small exposure masks. For each exposure mask, the proximity gap must be adjusted. As a result, the proximity gap varies with each exposure mask, and the thickness of the overlapping portion between the exposure masks varies. This may cause new problems with surface flatness.
Further, when a contact hole or a through hole that requires a sharp edge is mixed in a portion to be exposed as shown in FIG. 10, the defocus exposure method cannot cope.

  On the other hand, in the method using the shape of the light transmission hole of the exposure mask that is several μm inside the periphery of the opening of the black matrix, it is difficult to position the exposure mask with respect to the opening of the black matrix. If there is a variation, the picture element portions cannot be provided in islands at appropriate positions inside the opening, so that a so-called white-out portion is generated and the quality of the color filter may be deteriorated.

  The present invention has been made in view of the above circumstances, and suppresses the bulge in the overlapping portion of the black matrix and the outer edge of the picture element portion as much as possible, thereby improving the surface flatness of the color filter and the color filter. An object of the present invention is to provide an exposure mask that can improve the accuracy of the exposure.

The present invention is characterized by the following points in order to solve the above problems.
That is, the exposure mask according to claim 1 is an exposure mask having a transparent base material, a light shielding film formed on one surface of the transparent base material, and an exposure pattern region formed on the light shielding film, An exposure pattern region is arranged at a predetermined pitch on at least one line, and is composed of a plurality of light transmitting holes having the same shape, and the predetermined pitch on at least one line parallel to the line And a region composed of a plurality of light-transmitting portions having a shape similar to the shape of the light-transmitting holes.

  The proximity exposure apparatus according to claim 2 is an exposure mask having a transparent base material, a light shielding film formed on one surface of the transparent base material, and an exposure pattern region formed on the light shielding film, wherein the exposure pattern The region is arranged at a predetermined pitch on a region composed of a plurality of transparent holes having the same shape and disposed at a predetermined pitch on at least one line, and on at least one line parallel to the line. An exposure mask having a plurality of light-transmitting portions having a shape similar to the shape of the light-transmitting holes and a predetermined similarity, and disposed above the exposure mask, An exposure light source that intermittently irradiates the exposure mask with exposure light, and a flat object to be exposed, which is disposed below the exposure mask and coated with a photosensitive substance, are fixed in the other direction of the exposure mask. A transfer device for transferring at a speed of Imaging means for imaging a position serving as a reference of an exposure target portion on the exposure object conveyed by a stage, and control means for controlling the timing of intermittent irradiation of the exposure light source based on data from the imaging means, It is characterized by providing.

The present invention has the following excellent effects.
According to the first and second aspects of the invention, by irradiating the exposure mask with exposure light, the exposure object is irradiated with a plurality of similar exposure light along the arrangement direction of the light transmitting portions. can do.
Therefore, the exposure mask and the object to be exposed are moved relative to each other as will be described later, and the exposure mask is irradiated with sequential exposure light, so that substantially similar exposure light is superimposed on the object to be exposed. Therefore, the amount of exposure light (hereinafter simply referred to as “exposure amount”) for the overlapping portion of the black matrix and the outer edge of the picture element portion is determined by the exposure amount for the picture element portion inside the opening of the black matrix. Can be reduced.
Thereby, the thickness of the overlapping portion can be reduced and the thickness of the picture element portion inside the opening of the black matrix can be increased without generating the white portion.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a plan view showing an exposure mask 1 according to an embodiment of the present invention, and FIG. 2 is a perspective view taken along line AA ′ of FIG. FIG. 3 is a conceptual diagram showing a proximity exposure apparatus 10 according to an embodiment of the present invention.
In the description of the present embodiment, the case of exposure of the color filter substrate W will be described. As shown in FIG. 4, the color filter substrate W used here is Cr or the like on one surface of a transparent glass substrate 5. A black matrix (hereinafter simply referred to as “BL”) 7 composed of an opaque film made of a material and a large number of pixels 8 (picture element portion formation planned portions) are formed in a matrix shape and are exposed on the upper surface. A predetermined color resist is applied as a conductive resin.

The exposure mask 1 enables exposure while moving a color filter substrate W, which is an object to be exposed, in a predetermined direction, and includes a transparent base material 2, a light shielding film 3, and a plurality of light transmitting holes 4. ing.
The transparent substrate 2 is a transparent glass substrate that transmits ultraviolet light and visible light with high efficiency, and is made of, for example, quartz glass. As shown in FIG. 2, a light shielding film is formed on one surface 2 a of the transparent substrate 2. 3 is formed.

The light shielding film 3 shields exposure light and is formed of an opaque thin film of, for example, chromium (Cr). The light shielding film 3 has a predetermined shape of light transmitting holes 4 (4 ₁ to 4 ₁₎ that transmits the exposure light. 4 ₃₎ is formed with a plurality arranged in a matrix, light-transmitting hole 4 ₁ region, light-transmitting hole 4 ₂ regions, it has an area of light-transmitting hole 4 _3.
That is, the arrangement of the light transmitting holes 4 (4 ₁ to 4 ₃ ) is arranged in the “column” direction (parallel arrangement in the Y direction in FIG. 1) and the “row” direction (alignment in the X direction in FIG. 1). Each has a matrix of 5 rows and 3 columns, 5 rows and 2 columns, and 5 rows and 1 column.
The “line” in the claims corresponds to the “row”.
The shapes of the light transmitting holes 4 ₁ to 4 ₃ are substantially similar to each other and increase in the order of 4 ₁ to 4 ₃ .
The light transmitting hole 4 can irradiate the color filter substrate W conveyed opposite to the exposure mask 1 with exposure light, and on the pixel 8 to be exposed of BL7 formed on the color filter substrate W described later, The shape of the light transmitting hole 4 is transferred as an exposure pattern.

The light transmitting holes 4 are arranged at intervals of 3 pitches of pixels 8 (described later) (P1 in FIG. 1) in a direction perpendicular to the conveyance direction of the object to be exposed. In the parallel direction, the pixels 8 are arranged at the same pitch interval (P in FIG. 1), and the numbers of the “rows” of the light transmitting holes 4 ₁ to 4 ₃ are 3, 2, and 1, respectively. .
In order to make the film thickness of the picture element part in the pixel 8 (opening of BL7) thicker than the surrounding film thickness, the number of times of exposure light irradiation to the picture element part in the pixel 8 is changed. This is to increase the number of times of exposure light irradiation to this portion.

In the present embodiment, the shapes of the light transmitting holes 4 ₁ to 4 ₃ are sequentially increased. However, the shape is not limited to this, and the light transmitting holes 4 ₁ to 4 ₃ may be sequentially decreased. The order of the sizes may be irregular.
Furthermore, although there are three types of translucent holes 4 ₁ to 4 ₃ , the present invention is not limited to this, and at least two or more types of translucent holes 4 may be provided.
Further, the number of "columns" of the light-transmitting hole ₄₁ to _3, with the color resist of exposure performance (e.g., such as the amount of the relationship between the film thickness to be exposed formation on exposure light quantity), of the flash lamp 11a 1 The optimum number is determined according to the relationship with the amount of radiation per flash.

The light-transmitting hole _{4 1} of the shape (width _{4 1} a and a length ₄ 1 b), as in FIGS. 4 and 5, which substantially coincides with the shape of the pixel 8 (the width Wa and the length Wb), The pixel 8 is formed at intervals corresponding to the three pitch intervals (the same pixel pitch of the R, G, and B pixel elements in FIG. 4).
In this embodiment, light-transmitting hole 4 _3, wherein the light-transmitting hole 4 a ₁ a similar shape (with shape pixels 8 similar figure), a width 4 _{3 a} and a length 4 _{3 b} is a pixel 8 near BL7 width (BLa, BLb) are divided only widely formation, light-transmitting hole _{4 2} is an intermediate of the shapes of the light-transmitting hole _{4 1} and light-transmitting hole _{4 3.}

By sequentially exposing the exposure patterns of the light transmitting holes 4 ₁ to 4 ₃ to the pixels 8 of the color filter substrate W, the exposure amount for the pixels 8 is distributed as shown in FIG. The film thickness of the color resist as shown in FIG. 6C is formed. As a result, the cross section of the picture element portion of the pixel 8 has a shape as shown in FIG.
Note that since the exposure light has a slight opening angle, as shown in FIG. 6C, a taper having a gentle slope is formed at a position irradiated with the exposure light.

The proximity exposure apparatus 2 includes an exposure light source 11, an exposure mask 1, a transport device 12 that transports the color filter substrate W, an optical detection unit 13, and a control device 17 that controls these. .
The exposure light source 11 is a light source (for example, an exposure flash lamp, an ultraviolet laser beam oscillator, etc.) 11a capable of intermittently emitting exposure light and a light emitted from the light source 11a capable of intermittently emitting the exposure light. And an optical system 11b for making a bundle of parallel light beams, which are disposed above the exposure mask 1, and the optical system 11b faces the exposure mask 1.
The light source 11a capable of intermittently emitting exposure light is connected to the control device 17, and when the color filter substrate W passes under the exposure mask 1 as will be described later, one pitch of the pixels 8 (see FIG. The light is emitted every P).
Hereinafter, the light source 11a capable of intermittently emitting exposure light is described as an exposure flash lamp for simplicity.

The exposure mask 1 is disposed in close proximity to the upper surface of the color filter substrate W that is transported with the surface 2a on which the light shielding film 3 is formed facing down. The mask driving means 16 causes the Y axis, Z axis, The position and orientation of the exposure mask 1 can be controlled on each of the θ axis and the α axis.
Further, the mask driving means 16 is connected to the control device 17, and the X, Y, Z (direction perpendicular to the paper surface of FIG. 1) axis and the θ axis (rotation around the Z axis) of the exposure mask 1 are provided. ), The posture of the exposure mask 1 can be controlled.

The transport device 12 is disposed below the exposure mask 1 and includes a stage 14, an imaging unit 13, and a transport unit 15.
The stage 14 has a large number of ejection holes for ejecting gas and a large number of suction ports for sucking gas on the upper surface. The stage 14 is connected to a compressed gas supply device and a gas suction device (not shown). The filter substrate W is floated on the stage 14, and a portion facing the exposure mask 1 is opened, and the opening portion 14 a is on the near side of the exposure position by the exposure mask 1. The image pickup means 13 for picking up an image of the color filter substrate W from the lower side at the position is provided toward the color filter substrate W.

The transport unit 15 holds the color filter substrate W in a predetermined direction (in FIG. 3) while gripping a part of the color filter substrate W (one of the edges parallel to the transport direction of the color filter substrate W) with a grip unit (not shown). Further, a color filter position sensor (not shown) for detecting the position of the color filter substrate W in the direction of the arrow A is provided.

The image pickup means 13 is a line sensor (FIG. 8) in which a large number of light receiving elements 13a are arranged in a line in a direction perpendicular to the transport direction (the direction of arrow A in FIG. 3). A predetermined range including the pixel 8 is imaged from the side, and as shown in FIG. 9, a line 8a perpendicular to the direction of the arrow A and a line 8b parallel to the direction of the arrow A are detected. is there.
Then, the imaging unit (hereinafter, simply referred to as "line sensor".) 13, predetermined light receiving element 13a1 is, light-transmitting hole 4 ₁ of line exposure mask 1 of a number of light receiving elements arranged in the single row Arranged so as to correspond to 4 ₁ b.

  The control device 17 includes a lamp driving unit 18 that drives the flash lamp 11a of the exposure light source 11, a mask control unit 19 that controls the mask driving unit 16, a transport controller unit 20 that controls the transport unit 15, and an image processing unit. 21 and a control unit 22 for controlling them. The control unit 22 is connected to the color filter position sensor and the external input means 23.

  The image processing unit 21 uses the luminance data obtained by processing the image data of the color filter substrate W picked up by the line sensor 13, the direction of the line 8 a perpendicular to the direction of the arrow 8 of the pixel 8 and the direction of the arrow 8 of the pixel 8. The line 8b is detected and the result is sent to the control unit 22.

The control unit 22 specifies the line 8a of the pixel 8 to be exposed based on the data signal of the line 8a from the image processing unit 21 and the position signal from the color filter position sensor, and the filter in which the specific line 8a is detected. From a position (detected by the color filter position sensor) of the substrate W in the transport direction (in the direction of arrow A in FIG. 3), a predetermined distance (translucent hole of the line sensor 13 and the exposure mask 1 measured in advance) 4 ₁ X-axis direction distance) L (FIG. 8) to send a luminous signal of the flash lamp 11a to the lamp driving unit 18 when the filter substrate W is conveyed with, fire the flash lamp 11a.
The specific line 8 a is a line 8 a detected for each pitch of the pixels 8.

Further, the control unit 22 sends a signal to the mask control unit 19 based on the data signal of the line 8b from the image processing unit 21, and the Y direction and the θ axis (FIG. 1) direction of the exposure mask 1 by the mask driving unit 16. adjust the position and orientation, always as line 8b of light-transmitting hole 4 ₁ line 4 _{1 b} and the pixel 8 of the exposure mask 1 overlap.
The external input means 23 adjusts the light intensity of the flash lamp 11a to the control unit 22 and exposes the same pixel 8 through _one light transmitting hole 4 (for example, the light transmitting hole 4 ₁ ). The setting of the number of flashes can be input from the outside.

Next, the exposure operation of the proximity exposure apparatus configured as described above will be described with reference to FIGS. 10, 1 to 9, and 11.
First, in step 1, the setting of the intensity of exposure light and the number of flashes of exposure light irradiated to the same pixel 8 through one light transmission hole 4 (for example, light transmission hole 4 ₁ ) are input from the external input means 23. After that, the color filter substrate W is set at a predetermined position of the transport device 12.

  Next, in step 2, the color filter substrate W is transported at a predetermined speed in the direction of the arrow A in FIG. Is captured, and the captured image data is sent to the control unit 22 via the image processing unit 21.

Next, in step 3, the control unit 22 specifies the line 8 a of the pixel 8 to be exposed, and determines whether the line 8 b is detected by the specific light receiving element 13 a 1 of the line sensor 13. When the line 8b is detected by a light receiving element 13a other than the specific light receiving element 13a1, a light transmitting hole is formed based on the number of light receiving elements between the specific light receiving element 13a1 and the light receiving element 13a actually detecting the line 8b. 4 and ₁ line 4b, the amount of deviation of the line 8b of pixels 8 is calculated.

In step 4, the line 4b of light-transmitting hole 4 _1, as the amount of deviation of the line 8b of pixels 8 is within a predetermined range (range differs depending on the thickness of the light shielding portions of the black matrix), control unit 22 signal to the mask control unit 19 is sent from it based on the mask drive unit 16 is operated, light-transmitting hole 4 ₁ of line 4b is, the exposure mask 1 as line 8b pixels 8 overlaps always driven Is done.

Next, in step 5, the detection position of the specified line 8a is detected by position data from the color filter position sensor, and the color filter substrate W is measured in advance on the transport device 12 from this detection position. When the distance L (FIG. 8) between the line sensor 13 and the exposure mask 1 is conveyed, the flash lamp 11a emits light. Whether or not the exposure mask 1 has been transported the distance L in the X-axis direction is determined from the position data of the color filter position sensor.

Next, in step 6, the line 8a of the pixel 8 after one pitch is specified, and the flash lamp 11a is emitted when the color filter substrate W is transported the distance L from the position.
Next, in step 7, the above step 6 is repeated, and all the pixels 8 to be exposed are exposed, and then the exposure operation is completed.

In the above-described embodiment, the light-transmitting hole 4 of the exposure mask 1 is described as having no light-shielding portion. However, as another embodiment, as shown in FIG. The light shielding part 4B may be provided inside. Hereinafter, the exposure mask 1A of FIG. 11 will be described.
The shape of the light shielding portion 4B of each of the light transmitting holes 4A _{1 to} 4A _{3 in} FIG. 11 is the same, and the light transmitting holes 4A _{1 to} 4A ₃ are stacked in the same direction and with the centroids aligned. Each light shielding part 4B is provided at a position of each light transmitting hole 4A _{1 to} 4A ₃ so as to overlap each other at the same position.

As a result, by applying the exposure mask 1A to the above-described proximity exposure apparatus 10 in place of the exposure mask 1, the exposure amount for the pixels 8 is distributed as shown in FIG. 12B. As a result, FIG. The film thickness of the color resist as in c) is formed.
That is, the outer edge of the picture element portion is formed with a taper having a gentle slope, while the steep edge is formed around the light shielding portion 4B.
Therefore, it is possible to expose an object to be exposed in which a gently inclined portion and a steeply inclined portion are mixed like a color filter substrate having a contact hole in the picture element portion.

As described above, the case where the object to be exposed is the color filter substrate W has been described. However, the present invention is not limited to this, and the exposure-generated film thickness is inclined by adjusting the exposure amount in the exposure target area of the object to be exposed. It may be an object to be exposed.
Further, the case where the exposure operation is performed while the color filter substrate W is being transported has been described. However, the present invention is not limited to this, and the exposure mask 1 or 1A is moved with respect to the color filter substrate W placed on the stage 14 and stationary. You may perform exposure, making it.
Furthermore, although the case where exposure is performed while continuously conveying the color filter substrate W has been described, the present invention is not limited to this, and the exposure may be performed by step-feeding the pixels 8 by one pitch.

The top view for demonstrating one Embodiment of the mask for exposure which concerns on this invention 1 is a schematic cross-sectional perspective view of the exposure mask of FIG. 1 is a conceptual diagram for explaining an embodiment of a proximity exposure apparatus according to the present invention. Conceptual diagram showing the plane of the object to be exposed Conceptual diagram for explaining the relationship between the size of light-transmitting holes and the relationship between pixels Explanatory drawing explaining the relationship between a light transmission hole, exposure amount, and film thickness It is a conceptual diagram which shows the pixel partial cross section of a color filter, Comprising: (a) shows a prior art example, (b) shows the example by this invention. Explanatory drawing which shows the positional relationship of the light transmission hole of an imaging means and exposure mask Explanatory drawing which shows the positional relationship of the light receiving element of an imaging means, and the pixel of a color filter substrate. FIG. 3 is a flowchart for explaining the operation of the proximity exposure apparatus according to the present invention. The top view for demonstrating other embodiment of the mask for exposure which concerns on this invention Explanatory drawing explaining the relationship between the exposure amount and film thickness at the time of using the exposure mask of FIG.

Explanation of symbols

1: Exposure mask 2: Transparent substrate 3: Light shielding film 4: Light projection hole 5: Light shielding film 6: Glass substrate 7: Black matrix 8: Pixel 10: Proximity exposure device 11: Exposure light source 12: Transport device 13: Line sensor 14: Stage 15: Conveying means 16: Mask driving means 17: Control device 21: Image processing section

Claims (2)

An exposure mask having a transparent substrate and a light shielding film formed on one surface of the transparent substrate, and an exposure pattern region formed on the light shielding film,
The exposure pattern region is a region composed of a plurality of light-transmitting holes having the same shape and disposed at a predetermined pitch on at least one line;
A region composed of a plurality of light-transmitting portions having a shape similar to the shape of the light-transmitting holes arranged at the predetermined pitch on at least one line parallel to the line. A mask for exposure. An exposure mask having a transparent base material, a light shielding film formed on one surface of the transparent base material, and an exposure pattern region formed on the light shielding film, wherein the exposure pattern region is predetermined on at least one line. The shape of the light-transmitting holes disposed at the predetermined pitch on the region composed of a plurality of light-transmitting holes having the same shape and arranged at a pitch of at least one line parallel to the line And an area composed of a plurality of light-transmitting portions having a shape having a predetermined similarity relationship.
An exposure light source disposed above the exposure mask and intermittently irradiating the exposure mask with exposure light;
A transport device that is disposed below the exposure mask and transports a plate-shaped object to which a photosensitive material is applied at a constant speed in the other direction of the exposure mask;
An imaging unit that images a position serving as a reference of an exposure target portion on the object to be exposed conveyed by the conveying unit;
Control means for controlling the timing of intermittent irradiation of the exposure light source based on data from the imaging means;
A proximity exposure apparatus comprising: