JP5581017B2 - Exposure method and exposure apparatus - Google Patents

Description

  The present invention relates to an exposure method for aligning and forming colored pixels with a black matrix pattern formed on a substrate by, for example, slit exposure, and in particular, imaging that images a registration mark and adjusts the position. The present invention relates to an exposure method that does not cause a phenomenon that alignment is not satisfactorily performed at the end portion in the moving direction of an exposure region even when an exposure apparatus provided with a camera is used.

  In a display device such as a liquid crystal display device, it is a useful means to use a color filter for purposes such as color display, reflectance reduction, contrast adjustment, and spectral characteristic control. In many cases, the color filter used in this display device is formed and used as a pixel. As a method for forming a pixel of a color filter used in a display device, a printing method, a photolithography method, and the like can be given as methods that have been practically used.

  FIG. 1 is an enlarged plan view illustrating an example of a pixel of a color filter used in a liquid crystal display device. 2 is a cross-sectional view taken along line XX of the pixel of the color filter shown in FIG. As shown in FIGS. 1 and 2, the color filter used in the liquid crystal display device has a black matrix (21), a colored pixel (22), and a transparent conductive film (23) on a glass substrate (50) sequentially. It is formed.

  As a method of manufacturing the color filter used in the liquid crystal display device, first, a black matrix (21) is formed on a glass substrate (50), and then black on the glass substrate on which the black matrix (21) is formed. A method of forming a colored pixel (22) in alignment with a matrix pattern (opening) and further forming a transparent conductive film (23) is widely used.

  The black matrix (21) has a light-shielding property, determines the position of the colored pixels on the glass substrate at the opening, makes the size uniform, and is not preferable when used in a display device. It has a function of blocking light and making an image of a display device a uniform image with no unevenness and an improved contrast. The black matrix (21) is formed by, for example, providing a black photoresist coating film on a glass substrate (50), and forming the black matrix by exposing and developing the coating film through a photomask. Lithography is used.

The colored pixel (22) has a function of, for example, red, green, and blue color reproduction filters, and pigments and other pigments are dispersed on a glass substrate (50) on which a black matrix is formed. A photolithographic method is employed in which a coating film of a negative type colored photoresist is provided, and colored pixels are formed by exposure and development to the coating film through a photomask.
The transparent conductive film (23) is formed by forming a transparent conductive film on a glass substrate on which colored pixels are formed, for example, by sputtering using ITO (Indium Tin Oxide).

  When a large number of color filters are manufactured, a color filter having a size corresponding to a single liquid crystal display device is often manufactured in a state of being multifaceted on a large glass substrate. For example, a 17-inch diagonal color filter is manufactured by attaching four faces to a large glass substrate of about 650 mm × 850 mm.

The exposure at this time is performed using a photomask in which, for example, a mask pattern for forming a color filter having a diagonal size of 17 inches is provided on a mask substrate having a size approximately equal to the size of the glass substrate. The method is widely adopted. This is a so-called batch exposure method in which the entire four screens of the four-sided mask pattern are collectively performed by one exposure.
In this case, for example, a plurality of color filters of the same type, i.e., the same color filter size and color filter finish size, are used.

  In order to solve the problem of high cost due to the increase in mask size and the problem of bending due to the mask's own weight, the exposure method is uniaxial from the batch exposure method from the fourth generation with a glass substrate size of, for example, about 730 mm × 920 mm. The step exposure method begins to be adopted, and the glass substrate size shifts from the fifth generation of, for example, about 1000 mm × 1200 mm to the XY (biaxial) step exposure method (so-called step-and-repeat method). ing.

FIG. 3 is a plan view for explaining an example of step exposure when a color filter is manufactured by an XY step exposure method.
The example shown in FIG. 3 is an example in which six exposures of the first exposure to the sixth exposure were performed on the large-sized glass substrate (50). Each exposure after the second exposure is performed every five step movements (Py, Px) counted from the first exposure. Reference numerals (1Ex to 6Ex) represent first to sixth exposure regions, respectively.

By shifting to such a step exposure method, an increase in cost due to an increase in mask size is suppressed, and the problem of bending due to its own weight has been solved.
However, as the size of the glass substrate shifts to, for example, the sixth generation of about 1500 mm × 1800 mm or the eighth generation of, for example, about 2100 mm × 2400 mm, the mask size increases. Accompanying, the high cost and the problem of deflection are rekindling.

  Therefore, in order to avoid the high cost of the accompanying photomask when the size of the glass substrate is further increased, the color filter is made by reducing the mask size rather than increasing the mask size. Various exposure methods have been tried to produce the above.

  FIG. 4 is a plan view for explaining an example of slit exposure when a color filter is manufactured by slit exposure. The example shown in FIG. 4 is an example in which two exposures of the first exposure and the second exposure are performed on a large glass substrate (50). 5A and 5B are cross-sectional views taken along line XX in FIG. FIG. 5A shows a state where the first exposure is started, and FIG. 5B shows a state where the first exposure is finished.

  As shown in FIGS. 4 and 5, a photomask (PM2) is arranged above the glass substrate (50) placed on the exposure stage (60). The photomask (PM2) is fixed in the exposure apparatus and does not move in the X, Y, and Z axis directions. The exposure stage (60) below the photomask (PM2) moves at a constant speed in the X-axis direction to the left in the figure with the glass substrate (50) placed thereon. Further, step movement is performed in the Y-axis direction.

In slit exposure, a slit (S) that is short in the length direction (X-axis direction) and long in the width direction (Y-axis direction) is provided in the exposure apparatus, and the slit (S) or the glass substrate is a glass substrate. This is an exposure method in which light through the slit (S) is applied to the coating film (54) on the glass substrate (50) while being moved in the length direction (X-axis direction), and the entire surface of the glass substrate is exposed.
Since the slit exposure at the time of manufacturing the color filter forms a stripe-shaped colored pixel, the slit (S) has a width (Wi) corresponding to the width of the stripe of the colored pixel as an opening (51), and others. This part is a light shielding part (52). The opening (51) is provided on the photomask (PM2) as a mask pattern corresponding to the formation of the colored pixels.

FIG. 6 is an enlarged plan view showing a slit (S) portion in an example of a photomask (PM2) used for slit exposure. This photomask (PM2) is an example corresponding to a negative photoresist.
As shown in FIG. 6, the longitudinal direction (Ls) of the slit (S) is parallel to the Y axis, and a large number of openings (51) are arranged in the longitudinal direction (Ls). The portion other than the opening (51) is a light shielding portion (52). Below the photomask (PM2), the light transmitted through the opening (51) is moved to the glass substrate (50) while moving the exposure stage (60) in the direction indicated by the white thick arrow in FIG. 6 (X-axis direction). The top coating (54) is irradiated continuously. Reference numeral (Pi) represents the pitch of the opening (51), reference numeral (Wi) represents the width of the opening (51), and reference numeral (Li) represents the length of the opening (51).

FIG. 5A shows a state in which the first exposure through the slit of the photomask (PM2) is started on the photoresist coating film (54) applied on the glass substrate (50). . Further, (b) shows a state in which the first exposure is completed. In FIG. 5, the exposure light (E) is continuously passed through the slit of the photomask (PM2) while moving the exposure stage (60) to the left in the figure (X-axis direction) as indicated by the thick white arrow. Then, the first exposure indicated by the oblique lines in FIG. The second exposure is performed after the step movement (Py) shown in FIG. 4 is given to the exposure stage (60).
As described above, the slit exposure is a method that enables exposure of a large area without increasing the mask size, but rather by reducing the mask size and extending in the X-axis direction.

  FIG. 7 is a plan view showing an example of a stripe pattern obtained by development processing after exposure. As shown in FIG. 7, a stripe pattern having a pitch (Pi) and a width (Wi), for example, a striped colored pixel (22) is formed on a glass substrate (50).

FIG. 8 is an explanatory view showing an example of a color filter manufactured by such slit exposure. As shown in FIG. 8, this color filter is in a state in which colored pixels (22R, 22G, 22B) of red, green, and blue are formed on a glass substrate on which a black matrix (21) is formed. .
The colored pixels of each color are continuous stripes without interruption between pixels in the X-axis direction in FIG. Further, in the Y-axis direction, each of the stripe-like colored pixel columns is repeatedly arranged in the order of red, green, and blue. That is, this is an example in which the slit exposure method is suitably applied.

FIG. 9 exemplifies an imposition state when a color filter having a size corresponding to one liquid crystal display device is manufactured in many ways on a large glass substrate by such slit exposure. . In FIG. 9, reference numerals (M1 to M6) denote first to sixth exposure regions in which color filters having a size corresponding to one liquid crystal display device are formed.
Reference numerals (m1 to m4) denote non-exposed areas between the first to sixth exposed areas and outside the exposed areas.

  In FIG. 9, the white arrow indicates the direction (X-axis direction) in which the glass substrate (50) placed on the exposure stage (60) is moved below the photomask. Accordingly, the striped colored pixels (22) shown in FIG. 7 are formed in parallel with the X-axis direction in FIG. A part of the colored pixels (22) formed in the first to sixth exposure regions is represented by a dotted line. Colored pixels (22) are not formed between the exposed areas and in the non-exposed areas (m1 to m4) outside the exposed areas.

At this time, the exposure of the coating film on the glass substrate (50) through the photomask is performed by moving the glass substrate (50) placed on the exposure stage (60) to each exposure region (M1 to M6). ) Are sequentially passed under the photomask, for example, the shutter provided above the photomask is opened and the exposure light from the light source is irradiated.
Further, a method is adopted in which the shutter is closed and the exposure light from the light source is shielded in synchronization with each non-exposure region (m1 to m4) sequentially passing under the photomask.

  Compared with the method of manufacturing by XY step exposure, the method of manufacturing a color filter by slit exposure as described above certainly has a striped pattern formed on the entire surface of a large glass substrate with a small photomask. It is possible to form with multiple faces.

FIG. 10 is an enlarged plan view showing the vicinity of the first exposure region (M1) shown in FIG. 9, but the black matrix (1) of the first exposure region (M1) already formed on the glass substrate (50). 21) When the colored pixel (22) is formed in alignment with the pattern (not shown), the front end (A) and the center (B) of the glass substrate (50) indicated by the white thick arrow are formed. ), The alignment is performed satisfactorily.
However, in FIG. 10, there is a problem that the color pixel (22) is not properly aligned with the pattern of the black matrix (21) at the end portion (C) represented by the oblique line in the moving direction. It has been observed that this phenomenon occurs similarly in other exposure regions other than the first exposure region (M1).

  FIG. 11 is a partial cross-sectional view of an example of an exposure apparatus that employs slit exposure. FIG. 11 is an explanatory diagram of a method for forming the colored pixels (22) by aligning with the pattern of the black matrix (21) formed on the glass substrate (50) using the exposure apparatus shown in this example. FIG. 11 shows a cross section taken along line X2-X2 in the central portion (B) in the moving direction of the glass substrate (50) shown in FIG. 10, and is between FIGS. 5 (a) and 5 (b). This corresponds to the moving state of the glass substrate.

As shown in FIG. 11, in this exposure apparatus, an imaging camera (CM) is provided above the photomask (PM2). The position of the imaging camera (CM) is the direction opposite to the moving direction of the glass substrate (X in FIG. 11) from the optical axis of the exposure light (E) irradiated onto the opening (51) from above the photomask (PM2). It is a position separated by a distance (L ₀ ) in the axial right direction.

  This imaging camera (CM) is formed on the lower glass substrate (50) from above the photomask (PM2) through the imaging opening (53) provided in the photomask (PM2). This is for imaging the black matrix alignment mark (K1) and the pattern of the black matrix (21).

As shown in FIG. 6, the photomask (PM2) has an imaging opening at a position away from the slit (S) provided with its longitudinal direction parallel to the Y-axis by a distance (L ₀ ) in the right direction of the X-axis. A part (53) is provided. The longitudinal direction of the imaging opening (53) is parallel to the Y axis in the same manner as the slit (S).
Similar to the opening (51), the imaging opening (53) is a translucent part where the surface of the photomask substrate is exposed. Exposure light (E) from above the photomask (PM2) irradiates the slit (S), but does not irradiate the imaging aperture (53).
The photomask (PM2) is provided with a photomask alignment mark (K2) for alignment (not shown).

As shown in FIG. 11, a black matrix (21) is already formed on the glass substrate (50) placed on the exposure stage (60), and colored pixels (21) are formed on the black matrix (21). A coating (54) for forming 22) is provided.
The black matrix (21) is provided with a black matrix alignment pattern (opening) and a black matrix alignment mark (K1) for alignment (not shown).

  The pattern of the photomask (PM2) with respect to the pattern of the black matrix (21) when the exposure light (E) is irradiated to the first exposure region (M1) through the opening (51) on the photomask (PM2). For example, when the imaging camera (CM) images the black matrix alignment mark (K1) on the glass substrate (50) moving under the photomask, the black matrix alignment mark is detected. (K1) and the alignment mark (K2) of the photomask are adjusted so that the predetermined positional relationship is set in advance, whereby the pattern of the black matrix (21) and the pattern of the photomask are changed. It is designed to be aligned.

The present inventor has scrutinized the phenomenon that the colored pixel (22) is not well aligned with the pattern of the black matrix (21) at the end portion (C) indicated by hatching in FIG. As a result, the cause could be found.
That is, in FIG. 12, the exposure stage (60) is moved in the direction indicated by the white thick arrow from the front end (A) to the end (C) in the moving direction of the first exposure region (M1) shown in FIG. However, it is sectional drawing explaining the state which irradiates continuously the exposure light (E) which permeate | transmitted the opening part (51) of the slit to the coating film (54) on a glass substrate (50).

FIG. 12A is a cross section taken along line X1-X1 in FIG. 10, and shows a state in which the exposure light (E) irradiates the tip (A) of the first exposure region (M1). It is. FIG. 12B is a cross section taken along the line X2-X2, and the state of the central portion (B) of the first exposure region (M1). FIG. 12C is a cross section taken along the line X3-X3. The state of the terminal part (C) of a 1st exposure area | region (M1) is represented.
As shown in FIG. 12 (a), the portion (a) of the tip (A) of the first exposure region (M1) where the irradiation with the exposure light (E) is started is caused by the movement of the exposure stage (60). , Has reached the lower part of the opening (51), and irradiation from the part (a) to the tip (A) is started.

  On the other hand, the imaging camera (CM) has a black matrix alignment mark (K1) (not shown) that passes below the imaging opening (53) before the part (a) reaches below the opening (51). 2), the black matrix alignment mark (K1) is imaged, and the position information of the black matrix alignment mark (K1) is acquired. By adjusting the position of the black matrix alignment mark (K1) and the photomask alignment mark (K2) so as to have a predetermined positional relationship, the black matrix ( The alignment of the photomask pattern with respect to the pattern 21) is performed.

  This alignment is completed before the part (a) where irradiation is started reaches below the opening (51). Accordingly, the photomask for the pattern of the black matrix (21) is shown at the left end portion (A) in FIG. 12 (a) after the portion (a) where the exposure light (E) irradiation is started. Pattern alignment is performed well, and exposure light (E) is irradiated. The black matrix alignment mark (K1) is appropriately provided over the entire first exposure region (M1) from the vicinity of the portion (a) where irradiation is started to the vicinity of the portion where irradiation is ended. It has been.

  As shown in FIG. 12B, in the central portion (B) of the first exposure region (M1), the position information of the black matrix alignment mark (K1) acquired by the imaging camera (CM) is used. The alignment of the photomask pattern with respect to the pattern of the black matrix (21) is always satisfactorily performed, and the exposure light (E) is irradiated.

  However, as shown in FIG. 12 (c), when reaching the end portion (C) of the first exposure region (M1), the imaging aperture (53) is located after the terminal portion (c) of the end portion (C). The black matrix alignment mark (K1) that passes below is lost, and the photomask pattern is not aligned with the black matrix (21) pattern based on the position information of the black matrix alignment mark (K1). It becomes.

That is, the end (C) is opened in a state where the position adjustment between the black matrix alignment mark (K1) and the photomask alignment mark (K2) is not performed based on the position information of the imaging camera (CM). Irradiation of exposure light (E) that has passed through the part (51) is performed. It has been observed that the region of the end portion (C) is substantially comparable to the distance (L ₀ ) between the optical axis of the exposure light (E) and the imaging camera (CM).

  As a result, in the terminal portion (C) indicated by the oblique lines in FIG. 10, the cause of the phenomenon that the colored pixel (22) is not properly aligned with the pattern of the black matrix (21) occurs. I was able to find it.

JP 2008-216593 A JP 2007-121344 A

The present invention has been made in order to solve the above-described problems. For example, exposure is performed when a colored pixel is aligned with a black matrix pattern already formed on a substrate by slit exposure. Even if an exposure apparatus provided with an imaging camera that images the black matrix alignment mark and adjusts the position to align the photomask pattern with the black matrix pattern is used as an apparatus on the substrate. An exposure method that does not cause the phenomenon that the colored pixels are not properly aligned with the black matrix pattern at the end of the exposure area on the substrate in the moving direction of the multi-faceted exposure area. The issue is to provide.
Another object of the present invention is to provide an exposure apparatus based on the above exposure method.

The present invention is an exposure method for aligning and forming a second pattern with respect to a first pattern already formed on a substrate by slit exposure,
1) As an exposure apparatus, a) a first pattern on a substrate at a position away from the optical axis of exposure light from a light source that irradiates a slit on the photomask from above the photomask by a fixed distance in the counter-movement direction A front imaging camera that captures the alignment mark of the first pattern and obtains position information of the alignment mark of the first pattern,
b) Further, the first pattern alignment mark on the substrate is imaged at a position away from the optical axis in the movement direction of the substrate by the predetermined distance, and the position information of the alignment mark of the first pattern is acquired. Using an exposure device provided with a rear imaging camera,
2) As a photomask, a) First on the substrate by a front imaging camera at a position away from the center in the length direction of the slit pattern (opening) on the photomask in the counter-movement direction of the substrate. A front imaging opening for imaging the pattern alignment mark is provided,
b) In addition, a rear imaging opening for imaging the alignment mark of the first pattern on the substrate by the rear imaging camera is provided at a position away from the center in the length direction by the predetermined distance in the moving direction of the substrate. Using a photomask
3) When the second pattern is aligned with the first pattern already formed on the substrate, a) the alignment of the first pattern on the substrate moving under the photomask The mark is imaged by the front imaging camera at the front end of each exposure area, is imaged by both the front imaging camera and the rear imaging camera at the center of each exposure area, and is captured by the rear imaging camera at the end of each exposure area. To obtain the position information of the alignment mark of the first pattern,
b) The position information of the obtained alignment mark of the first pattern and the alignment mark of the photomask are adjusted, thereby aligning the photomask pattern (opening) with respect to the first pattern, An exposure method is characterized in that exposure light from a light source is irradiated onto a slit on a photomask.

  According to the present invention, in the exposure method according to the above-described invention, the front imaging camera of the exposure apparatus is composed of a plurality of front imaging cameras provided at positions spaced apart from each other by a predetermined distance adjacent to each other in the counter-movement direction of the substrate. Further, the exposure method is characterized in that the rear imaging camera is composed of a plurality of rear imaging cameras provided at positions spaced apart from each other by a certain distance adjacent to each other in the moving direction of the substrate.

  In the exposure method according to the present invention, the first pattern is a black matrix constituting a color filter or a pattern of a pixel region on a substrate constituting a liquid crystal display device, and the second pattern is a color filter. The exposure method is characterized by being colored pixels to be configured.

  According to the present invention, in the exposure method according to the above invention, the first pattern is a pixel region on a substrate constituting a liquid crystal display device, and the second pattern is a photo-alignment film region provided in the pixel region, or The exposure method is a divided photo-alignment film region obtained by dividing the photo-alignment film region.

  In addition, the present invention is an exposure apparatus based on the exposure method according to claim 1 or 2.

In the present invention, as an exposure apparatus, a) a front imaging camera that acquires position information of the alignment mark of the first pattern is provided in the counter-movement direction of the substrate, and b) the first pattern in the movement direction of the substrate. An exposure apparatus provided with a rear imaging camera that acquires position information of the alignment mark is used. 2) As a photomask, a) a front imaging opening is provided, and b) a photomask provided with a rear imaging opening. 3) When the second pattern is aligned with the first pattern already formed on the substrate, a) the first pattern on the substrate moving below the photomask the alignment marks, the distal ends of the exposed areas captured by the front imaging camera, the center of each exposure area captured by both the front imaging camera and the rear imaging camera, rear shooting than at the end of each exposure region The position information of the alignment mark of the first pattern is acquired by imaging with the camera, and b) the position information of the alignment mark of the acquired first pattern and the alignment mark of the photomask are adjusted. Thus, the photomask pattern (opening) is aligned with the first pattern, and the exposure light from the light source is applied to the slit on the photomask. For example, the pattern of the black matrix already formed on the substrate On the other hand, when the colored pixels are aligned and formed by slit exposure, the colored pixels are aligned with respect to the black matrix pattern over the entire area from the front end to the end of the exposure area multifaceted on the glass substrate. The exposure method is performed well.

  In the present invention, the front imaging camera of the exposure apparatus is composed of a plurality of front imaging cameras provided at positions that are adjacent to each other at a certain distance adjacent to each other in the counter-movement direction of the substrate. Since it is composed of a plurality of rear imaging cameras provided adjacent to each other in the moving direction and spaced apart by a certain distance, alignment is performed not only in the X-axis and Y-axis directions but also in the Z-axis direction of the glass substrate. It is possible to adjust the alignment corresponding to the inclination (θ direction) of the glass substrate as the rotation axis. In addition, the alignment in the X-axis and Y-axis directions is more reliable.

  In addition, since the present invention is an exposure apparatus based on the above exposure method, when the second pattern is formed with respect to the first pattern already formed on the substrate by slit exposure, the alignment is performed well. Exposure apparatus.

It is a top view which expands and shows an example of the pixel of the color filter of a liquid crystal display device. It is sectional drawing in the XX line of the pixel of the color filter shown in FIG. It is a top view explaining an example of XY step exposure. It is a top view explaining an example of slit exposure. (A), (b) is sectional drawing in the XX of FIG. It is the top view to which the part of the slit of an example of the photomask for slit exposure was expanded. It is a top view which shows an example of the stripe pattern obtained by the image development process after exposure. It is explanatory drawing which shows an example of the color filter manufactured by slit exposure. This is an example of an imposition state when a color filter having a size corresponding to one liquid crystal display device is produced by applying many colors on a large glass substrate. FIG. 10 is an enlarged plan view showing the vicinity of a first exposure region shown in FIG. 9. It is a fragmentary sectional view of an example of the exposure apparatus which employ | adopted slit exposure. It is sectional drawing explaining the state which moves an exposure stage and irradiates a 1st exposure area | region. It is a fragmentary sectional view of an example of the exposure apparatus by this invention. 14 is a photomask used in the exposure apparatus shown in FIG. It is a fragmentary sectional view of an example of the exposure apparatus by the invention concerning Claim 2. It is a fragmentary sectional view of an example of the exposure apparatus by the invention concerning Claim 2. It is a photomask used for the exposure apparatus shown in FIG.15 and FIG.16.

The exposure method according to the present invention will be described in detail below based on the embodiment.
FIG. 13 is a partial sectional view of an example of an exposure apparatus according to the present invention. FIG. 13 illustrates a method for forming the colored pixels (22) by aligning with the pattern of the black matrix (21) formed on the glass substrate (50) using the exposure apparatus shown in this example. .

In this exposure apparatus, a front imaging camera (CM-A) and a rear imaging camera (CM-B) are provided above the photomask (PM3). The position of the front imaging camera (CM-A) is the reverse movement of the glass substrate from the optical axis of the exposure light (E) from the light source that irradiates the slit (S) on the photomask from above the photomask (PM3). This is a position (in the right direction of the X axis in FIG. 13) that is a certain distance (L ₀ ) apart in the direction. This front image pickup camera (CM-A) passes from above the photomask (PM3) to the lower glass substrate (50) through the front image pickup opening (53-A) provided in the photomask (PM3). The formed first pattern, for example, a black matrix alignment mark is imaged, and position information of the black matrix alignment mark is acquired.

Further, the position of the rear imaging camera (CM-B) is a position (X-axis left direction in FIG. 13) that is a fixed distance (L ₀ ) away from the optical axis of the exposure light (E) in the moving direction of the substrate. is there. This rear imaging camera (CM-B) passes from above the photomask (PM3) to the lower glass substrate (50) via the rear imaging opening (53-B) provided in the photomask (PM3). The formed black matrix alignment mark is imaged to obtain position information of the black matrix alignment mark.

FIG. 14 is a plan view of a photomask (PM3) exemplified as a photomask used in the exposure apparatus shown in FIG. As shown in FIG. 14, the photomask (PM3) is provided with a front imaging opening (53-A) and a rear imaging opening (53-B). From the center of the length (Li) of the opening (51) of the slit (S) provided with its longitudinal direction parallel to the Y-axis, the counter-moving direction of the glass substrate (X-axis right direction in FIG. 14) A front imaging opening (53-A) for imaging the black matrix alignment mark on the glass substrate by the front imaging camera (CM-A) is provided at a position separated by a distance (L ₀ ).

Further, the rear imaging is performed at a position away from the center in the length (Li) direction of the opening (51) of the slit (S) by a distance (L ₀ ) in the substrate movement direction (X-axis left direction in FIG. 14). A rear imaging opening (53-B) is provided for imaging a black matrix alignment mark on the glass substrate by the camera (CM-B).

The front imaging opening (53-A) and the rear imaging opening (53-B) have the longitudinal direction parallel to the Y-axis like the slit (S), and like the opening (51), It is the translucent part where the surface of the mask substrate is exposed. Exposure light (E) from above the photomask (PM3) irradiates the slit (S), but does not irradiate the front imaging opening (53-A) and the rear imaging opening (53-B). ing.
The photomask (PM3) is provided with a photomask alignment mark (K2) for alignment (not shown).

As shown in FIG. 13, a black matrix (21) has already been formed on the glass substrate (50) placed on the exposure stage (60), and colored pixels (21) have been formed on the black matrix (21). A coating (54) for forming 22) is provided.
The black matrix (21) is provided with a black matrix alignment pattern (opening) and a black matrix alignment mark (K1) for alignment (not shown).

  In the following, using the exposure apparatus according to the present invention illustrated in FIG. 13, from the tip (A) to the end (C) in the moving direction of the first exposure region (M1) shown in FIG. An exposure method for continuously irradiating the coating film (54) on the glass substrate (50) with the exposure light (E) transmitted through the opening (51) of the slit while moving the exposure stage (60) in the direction indicated by Will be explained.

  FIG. 13A is a cross section taken along line X1-X1 in FIG. 10, and shows a state in which the exposure light (E) irradiates the tip (A) of the first exposure region (M1). It is. FIG. 13B is a cross section taken along the line X2-X2, and the state of the central portion (B) of the first exposure region (M1). FIG. 13C is a cross section taken along the line X3-X3. The state of the terminal part (C) of a 1st exposure area | region (M1) is represented.

  The pattern of the photomask (PM3) with respect to the pattern of the black matrix (21) when the exposure light (E) is irradiated to the first exposure region (M1) through the opening (51) on the photomask (PM3). For example, when the front imaging camera (CM-A) images the black matrix alignment mark (K1) on the glass substrate (50) moving below the photomask, By adjusting the position of the alignment mark (K1) and the alignment mark (K2) of the photomask so as to have a predetermined positional relationship set in advance, the pattern of the black matrix (21) and the photomask The patterns are aligned.

As shown in FIG. 13 (a), the part (a) of the tip (A) of the first exposure region (M1) where irradiation of the exposure light (E) is started is caused by the movement of the exposure stage (60). , Has reached the lower part of the opening (51), and irradiation from the part (a) to the tip (A) is started.
On the other hand, the front imaging camera (CM-A) has a black matrix alignment mark that passes under the front imaging opening (53-A) before the part (a) reaches below the opening (51). In synchronization with (K1) (not shown), the black matrix alignment mark (K1) is imaged, and the position information of the black matrix alignment mark (K1) is acquired.

  By adjusting the position of the black matrix alignment mark (K1) and the photomask alignment mark (K2) so as to have a predetermined positional relationship, the black matrix ( The alignment of the photomask pattern with respect to the pattern 21) is performed.

This alignment is completed before the part (a) where irradiation is started reaches below the opening (51). Accordingly, the position of the photomask pattern relative to the pattern of the black matrix (21) at the tip (A) in FIG. 13 (a) after the part (a) where irradiation of the exposure light (E) is started. The alignment is performed well and the exposure light (E) is irradiated.
As shown in FIG. 13B, in the central portion (B) of the first exposure region (M1), the position of the black matrix alignment mark (K1) acquired by the front imaging camera (CM-A). According to the information, the alignment of the photomask pattern with respect to the pattern of the black matrix (21) is always satisfactorily performed and the exposure light (E) is irradiated.

  As shown in FIG. 13C, when the end portion (C) of the first exposure region (M1) passes below the front imaging opening (53-A), the rear is replaced by the front imaging camera (CM-A). Obtained by the imaging camera (CM-B). According to the position information of the alignment mark (K1) of the black matrix, the alignment of the photomask pattern with respect to the pattern of the black matrix (21) is satisfactorily performed up to the end portion (c) of the end portion (C). Exposure light (E) is irradiated.

  As described above, according to the exposure method of the present invention, at the front end portion (A) to the central portion (B) of the first exposure region (M1), by the operation of the front imaging camera (CM-A), At the end portion (C) of the first exposure area (M1), the operation of the rear imaging camera (CM-B), that is, over the entire surface of the first exposure area (M1), with respect to the pattern of the black matrix (21). The alignment of the photomask pattern is satisfactorily performed and the exposure light (E) is irradiated.

  When the exposure stage (60) further moves and the second exposure area (M2) on the glass substrate (50) reaches below the front imaging opening (53-A) (not shown), The above operation is repeated for the front end (A) to the end (C) of the two exposure area (M2).

  In the central portion (B) of the first exposure region (M1), for example, by operating both the front imaging camera (CM-A) and the rear imaging camera (CM-B), the black matrix (21). The alignment of the photomask pattern with respect to the pattern can be adjusted not only in the X-axis and Y-axis directions, but also in accordance with the tilt (θ direction) of the glass substrate with the Z-axis direction of the glass substrate as the rotation axis It becomes.

  15 and 16 are partial cross-sectional views of an example of an exposure apparatus according to the second aspect of the present invention. 15 and 16 show an example in which two front imaging cameras and two rear imaging cameras are provided, and a black matrix (on a glass substrate (50) formed on the glass substrate (50) using the exposure apparatus shown in this example. 21) A method for forming the colored pixels (22) in alignment with the pattern of 21) will be described.

As shown in FIGS. 15 and 16, the exposure apparatus includes a first front imaging camera (CM-A1) and a second front imaging camera (CM-A2) above the photomask (PM4), and a first rear. An imaging camera (CM-B1) and a second rear imaging camera (CM-B2) are provided. The first front imaging camera (CM-A1) and the second front imaging camera (CM-A2) are separated from the optical axis of the exposure light (E) by a certain distance (L ₀ ) in the counter-movement direction of the glass substrate. In addition, the first front imaging camera (CM-A1) is further provided at a position further apart by a certain distance (L ₀ ).

  The first front imaging camera (CM-A1) and the second front imaging camera (CM-A2) have a first front imaging opening (53-A1) and a second front imaging provided in the photomask (PM4), respectively. The black matrix alignment mark formed on the lower glass substrate (50) is imaged through the opening (53-A2), and the position information of the black matrix alignment mark is acquired.

In addition, the first rear imaging camera (CM-B1) and the second rear imaging camera (CM-B2) are separated from the optical axis of the exposure light (E) by a certain distance (L ₀ ) in the moving direction of the glass substrate. In addition, the first rear imaging camera (CM-B1) is further provided at a position further apart by a certain distance (L ₀ ).
The first rear imaging camera (CM-B1) and the second rear imaging camera (CM-B2) have a first rear imaging opening (53-B1) and a second rear imaging opening provided in the photomask (PM4), respectively. Through the section (53-B2), the black matrix alignment mark formed on the lower glass substrate (50) is imaged, and the position information of the black matrix alignment mark is acquired.

FIG. 17 is a plan view of a photomask (PM4) exemplified as a photomask used in the exposure apparatus shown in FIGS. As shown in FIG. 17, the photomask (PM4) includes a first front imaging opening (53-A1), a second front imaging opening (53-A2), and a first rear imaging opening (53-B1). ) And a second rear imaging opening (53-B2).

The first front imaging opening (53-A1) and the second front imaging opening (53-A2) have a certain distance in the counter-movement direction of the glass substrate from the center in the length (Li) direction of the opening (51). (L ₀₎ first forward image pickup opening to a position away (53-A1) has a second front image capturing openings (53-A2) is provided in the further predetermined distance (L ₀₎ away.
In addition, the first rear imaging opening (53-B1) and the second rear imaging opening (53-B2) are a certain distance in the moving direction of the glass substrate from the center in the length (Li) direction of the opening (51). (L ₀₎ first rear imaging opening at a position apart (53-B1) has a second rearward imaging opening (53-B2) is provided on the further constant distance (L ₀₎ away.

  Exposure light (E) from above the photomask (PM4) irradiates the slit (S), but does not irradiate the two front imaging openings and the two rear imaging openings. . The photomask (PM4) is provided with a photomask alignment mark (K2) for alignment (not shown).

  Hereinafter, using the exposure apparatus according to claim 2 exemplified in FIGS. 15 and 16, from the front end (A) to the end (C) in the moving direction of the first exposure region (M1) shown in FIG. Then, while moving the exposure stage (60) in the direction shown by the white arrow, the exposure light (E) transmitted through the opening (51) of the slit is continuously applied to the coating film (54) on the glass substrate (50). An exposure method for irradiation will be described.

  FIG. 15A is a cross section taken along line X1-X1 in FIG. 10 and shows a state in which the tip (A) of the first exposure region (M1) is irradiated with the exposure light (E). Is. FIG. 15B is a cross section taken along line X2-X2, and shows the state of the central portion (B) of the first exposure region M1, and FIG. 16 is a cross section taken along line X3-X3, showing the first exposure. This shows the state of the end portion (C) of the region (M1).

  As shown in FIGS. 15 and 16, this exemplary exposure method uses the first front imaging camera (CM-A1) at the front end (A) and the center (B) of the first exposure region (M1). And the black matrix (21) with the position information of the black matrix alignment mark (K1) acquired by the two imaging cameras of the second front imaging camera (CM-A2) and the alignment mark (K2) of the photomask. These patterns and the photomask pattern are aligned.

  Further, at the end portion (C) of the first exposure area (M1), the black acquired by the two imaging cameras of the first rear imaging camera (CM-B1) and the second rear imaging camera (CM-B2). The pattern of the black matrix (21) and the pattern of the photomask are aligned by the position information of the alignment mark (K1) of the matrix and the alignment mark (K2) of the photomask.

  Therefore, the alignment can be adjusted not only in the X-axis and Y-axis directions but also in alignment with the inclination (θ direction) of the glass substrate with the Z-axis direction of the glass substrate as the rotation axis. In addition, the alignment in the X-axis and Y-axis directions is more reliable.

  As shown in FIG. 15 (a), the part (a) of the tip (A) of the first exposure region (M1) where the irradiation of the exposure light (E) is started is caused by the movement of the exposure stage (60). , Has reached the lower part of the opening (51), and irradiation from the part (a) to the tip (A) is started.

On the other hand, the first front imaging camera (CM-A1) and the second front imaging camera (CM-A2)
Before this part (a) reaches below the opening (51), the black matrix that passes under the first front imaging opening (53-A1) and the second front imaging opening (53-A2) respectively. The black matrix alignment mark (K1) is imaged in synchronization with the alignment mark (K1) (not shown), and the position information of the black matrix alignment mark (K1) is acquired.

  The alignment of the photomask pattern with respect to the pattern of the black matrix (21) is completed before the part (a) where the irradiation is started reaches below the opening (51). Accordingly, the position of the photomask pattern relative to the pattern of the black matrix (21) at the tip (A) in FIG. 15 (a) after the part (a) where irradiation of the exposure light (E) is started. The alignment is performed well and the exposure light (E) is irradiated.

  As shown in FIG. 15 (b), the first front imaging camera (CM-A1) and the second front imaging camera (CM-A2) are acquired at the central portion (B) of the first exposure area (M1). According to the position information of the black matrix alignment mark (K1), the alignment of the photomask pattern with respect to the pattern of the black matrix (21) is always performed satisfactorily and the exposure light (E) is irradiated.

  As shown in FIG. 16, when the end portion (C) of the first exposure region (M1) passes below the first front imaging opening (53-A1) and the second front imaging opening (53-A2), Black obtained by the first rear imaging camera (CM-B1) and the second rear imaging camera (CM-B2) instead of the first front imaging camera (CM-A1) and the second front imaging camera (CM-A2) According to the position information of the alignment mark (K1) of the matrix, the alignment of the photomask pattern with respect to the pattern of the black matrix (21) is satisfactorily performed up to the end portion (c) of the end portion (C). (E) is irradiated.

As described above, according to the exposure method of the present invention, the position of the pattern of the photomask with respect to the pattern of the black matrix (21) over the entire front end portion (A) to the end portion (C) of the first exposure region (M1). For the alignment, adjustment corresponding to the inclination (θ direction) is performed, and the X-axis and Y-axis directions are more reliably performed, and the exposure light (E) is irradiated.
Since the invention according to claim 2 uses two front imaging cameras and two rear imaging cameras, there are various combinations using the acquired position information of the black matrix alignment mark (K1). The description is omitted.

On the other hand, in a liquid crystal display device, a contact rubbing method has been widely used so far in order to align liquid crystal molecules in one direction on a substrate surface and develop a pretilt angle. However, as the size of the glass substrate is increased to, for example, the eighth generation of about 2100 × 2400 mm, non-contact liquid crystal alignment is required.
In the conventional photo-alignment method as the non-contact type alignment method, it is necessary to irradiate UV light obliquely with respect to the substrate surface.

  In recent years, a technique has been proposed in which a pretilt angle of liquid crystal is expressed by light irradiation from a direction perpendicular to a glass substrate. For example, it is a technique for expressing linearly polarized light having a periodic intensity distribution by applying slit exposure while moving the glass substrate on the photo-alignment film. The invention according to claim 4 is different for each of the divided photo-alignment film regions (domains) when the pre-tilt angle is expressed in the photo-alignment film region provided in the pixel region on the substrate or the photo-alignment film region is divided. This is suitable as a light irradiation method for developing the pretilt angle.

As described above, the exposure method according to the present invention will be described using the color filter constituting the liquid crystal display device as an example, and the alignment film on the substrate constituting the liquid crystal display device is exposed to the pixel region corresponding to the pixel. However, the exposure method according to the present invention is not limited to the pattern (pixel) formation of the substrate constituting the liquid crystal display device, and is widely applied when aligning and exposing the pattern by slit exposure. This exposure method can be used.

21 ... Black matrix 22 ... Colored pixel 22R ... Red colored pixel 22G ... Green colored pixel 22B ... Blue colored pixel 23 ... Transparent conductive film 50 ... Substrate (glass substrate)
51... Slit opening 52... Shading part 53... Imaging opening 53 -A .. Front imaging opening 53 -B .. Back imaging opening 53 -A 1, 53 -A 2. 1st front imaging opening, 2nd front imaging opening 53-B1, 53-B2 ... 1st back imaging opening, 2nd back imaging opening 54 ... Coating film 60 ... Exposure stage A ... tip B of the first exposure area ... central part C of the first exposure area ... end CM of the first exposure area ... imaging camera CM-A ... front imaging camera CM-B ... rear imaging camera CM-A1, CM-A2 ... first front imaging camera, second front imaging camera CM-B1, CM-B2 ... first rear imaging camera, second rear imaging camera E ..Exposure light 1Ex to 6Ex... First exposure to sixth exposure Li... Opening length Ls. Longitudinal directions M1 to M6 of the first to sixth exposure regions PM, PM2, PM3, and PM4 in which color filters are formed Photomask S ... Slit Wi on the photomask ... Opening portion Width a ... Site of exposure light irradiation c ... Terminal end portions m1-m4 ... Non-exposure region Px ... Step movement in the X-axis direction Py ... Y-axis Step movement in direction

Claims (5)

An exposure method for aligning and forming a second pattern with respect to a first pattern already formed on a substrate by slit exposure,
1) As an exposure apparatus, a) a first pattern on a substrate at a position away from the optical axis of exposure light from a light source that irradiates a slit on the photomask from above the photomask by a certain distance in the counter-movement direction of the substrate. A front imaging camera that captures the alignment mark of the first pattern and obtains position information of the alignment mark of the first pattern,
b) Further, the first pattern alignment mark on the substrate is imaged at a position away from the optical axis in the movement direction of the substrate by the predetermined distance, and the position information of the alignment mark of the first pattern is acquired. Using an exposure device provided with a rear imaging camera,
2) As a photomask, a) First on the substrate by a front imaging camera at a position away from the center in the length direction of the slit pattern (opening) on the photomask in the counter-movement direction of the substrate. A front imaging opening for imaging the pattern alignment mark is provided,
b) In addition, a rear imaging opening for imaging the alignment mark of the first pattern on the substrate by the rear imaging camera is provided at a position away from the center in the length direction by the predetermined distance in the moving direction of the substrate. Using a photomask
3) When the second pattern is aligned with the first pattern already formed on the substrate, a) the alignment of the first pattern on the substrate moving under the photomask The mark is imaged by the front imaging camera at the front end of each exposure area, is imaged by both the front imaging camera and the rear imaging camera at the center of each exposure area, and is captured by the rear imaging camera at the end of each exposure area. To obtain the position information of the alignment mark of the first pattern,
b) The position information of the obtained alignment mark of the first pattern and the alignment mark of the photomask are adjusted, thereby aligning the photomask pattern (opening) with respect to the first pattern, An exposure method, wherein exposure light from a light source is irradiated to a slit on a photomask.   The front imaging camera of the exposure apparatus is composed of a plurality of front imaging cameras provided at positions that are adjacent to each other at a certain distance adjacent to the counter-movement direction of the substrate, and the rear imaging camera is in the direction of substrate movement. 2. The exposure method according to claim 1, comprising a plurality of rear imaging cameras provided adjacent to each other at a predetermined distance from each other.   The first pattern is a black matrix constituting a color filter or a pattern of a pixel region on a substrate constituting a liquid crystal display device, and the second pattern is a colored pixel constituting a color filter. The exposure method according to claim 1 or 2.   The first pattern is a pixel region on a substrate constituting a liquid crystal display device, and the second pattern is a photo-alignment film region provided in the pixel region, or a divided photo-alignment film region obtained by dividing the photo-alignment film region The exposure method according to claim 1 or 2, wherein   An exposure apparatus based on the exposure method according to claim 1.

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