JP2008058898A - Exposure apparatus, exposure method and method for manufacturing display panel substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent decrease in printing accuracy of a pattern even when the temperature of a mask changes. <P>SOLUTION: A camera 23 acquires an image of a detection pattern 21 provided on a mask 2 and outputs an image signal. An image signal processor 30 processes the image signal outputted by the camera 23. A main controller 40 detects an expansion or contraction amount of the mask 2 from the processing result of the image signal processor 30 and sets a target temperature of a chuck 10 by a temperature controller 14. A heat exchanger 12 changes the temperature and amount of a secondary heat medium supplied to a heat medium passage 11 to change the temperature of the chuck 10. A temperature sensor 13 detects the temperature of the chuck 10, and the temperature controller 14 controls the heat exchanger 12 so that the temperature of the chuck 10 detected by the temperature sensor 13 reaches the target temperature. The temperature of the substrate 1 is adjusted with high accuracy through the chuck 10 and the substrate 1 is expanded or contracted according to the expansion or contraction of the mask 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exposure apparatus that exposes a substrate by a proximity method, an exposure method, and a method for manufacturing a display panel substrate using the same in manufacturing a display panel substrate such as a liquid crystal display device.

  Manufacturing of TFT (Thin Film Transistor) substrates, color filter substrates, plasma display panel substrates, organic EL (Electroluminescence) display panel substrates, etc. for liquid crystal display devices used as display panels is performed using an exposure apparatus, and photolithography. This is performed by forming a pattern on the substrate by a technique. As an exposure apparatus, a projection method in which a mask pattern is projected onto a substrate using a lens or a mirror, and a minute gap (proximity gap) is provided between the mask and the substrate to transfer the mask pattern to the substrate. There is a proximity method. The proximity method is inferior in pattern resolution performance to the projection method, but the configuration of the irradiation optical system is simple, the processing capability is high, and it is suitable for mass production.

  Conventionally, the exposure apparatus has a problem that the mask temperature rises due to the energy of exposure light, and the pattern printing accuracy decreases due to thermal expansion of the mask. The mask is generally made of quartz with a high light transmittance and a low coefficient of thermal expansion. However, as the size of the mask increases with the increase in size of the substrate, even a mask made of quartz has a thermal expansion. Has become a size that cannot be ignored.

Japanese Patent Application Laid-Open No. 2004-133260 discloses a technique for changing the imaging characteristics of a projection optical system by measuring the amount of thermal deformation of a mask in a projection type exposure apparatus. Japanese Patent Application Laid-Open No. 2004-228561 also discloses a technique for correcting the magnification or distortion of a projection pattern by calculating the amount of thermal expansion of a mask by calculation in the same projection type exposure apparatus.
JP-A-8-55780 Japanese Patent Laid-Open No. 10-163082

  Conventionally, in a projection-type exposure apparatus, as described in Patent Document 1 or Patent Document 2, even if the mask is thermally expanded, a reduction in pattern printing accuracy is prevented by adjusting the projection optical system. Was possible.

  On the other hand, in the proximity type exposure apparatus, since the mask pattern is transferred to the substrate on a one-to-one basis, it is not possible to prevent deterioration in pattern printing accuracy due to thermal expansion of the mask. Therefore, conventionally, there has been a countermeasure only by providing a mask cooling mechanism in the exposure apparatus to suppress the thermal expansion of the mask as much as possible.

  An object of the present invention is to prevent a pattern printing accuracy from being deteriorated in a proximity type exposure apparatus even if a mask expands or contracts due to a temperature change. Another object of the present invention is to manufacture a high-quality substrate by preventing a reduction in pattern printing accuracy.

  An exposure apparatus according to the present invention is an exposure apparatus for transferring a mask pattern to a substrate by providing a minute gap between the mask and the substrate, and detecting means for detecting an expansion / contraction amount due to temperature change of the mask, and detection And a substrate temperature adjusting means for adjusting the temperature of the substrate according to the detection result of the means and expanding and contracting the substrate in accordance with the expansion and contraction of the mask.

  The exposure method of the present invention is an exposure method in which a minute gap is provided between the mask and the substrate, and the mask pattern is transferred to the substrate. The amount of expansion and contraction due to the temperature change of the mask is detected, and the detection result Accordingly, the temperature of the substrate is adjusted in accordance with the expansion and contraction of the substrate in accordance with the expansion and contraction of the mask.

  Even if the mask expands and contracts due to temperature changes, the amount of expansion and contraction due to the temperature change of the mask is detected, the substrate temperature is adjusted according to the detection result, and the substrate is expanded and contracted according to the expansion and contraction of the mask. Does not drop. With regard to the temperature of the substrate, conventionally, there have been known techniques for controlling the temperature of the substrate before mounting the substrate on the exposure chuck, or cooling the substrate by providing a cooling mechanism in the exposure chuck itself. The purpose of each is to suppress thermal expansion due to temperature changes of the substrate. The present invention is greatly different from the conventional one in that the temperature of the substrate is adjusted to positively expand and contract the substrate.

  Furthermore, in the exposure apparatus of the present invention, the detection means acquires images of detection patterns provided at a plurality of locations on the mask, and outputs a plurality of image acquisition means, and the image signal output by the image acquisition means Detecting the position of each detection pattern from the processing result of the image signal processing apparatus, calculating the interval of the detection pattern from the position of each detection pattern, and masking from the interval of the detection pattern And a main control device for calculating the amount of expansion / contraction of.

  Also, the exposure method of the present invention provides detection patterns at a plurality of locations on the mask, acquires images of each detection pattern, processes the image signal of each detection pattern, and detects the position of each detection pattern. Then, the interval of the detection pattern is calculated from the position of each detection pattern, and the expansion / contraction amount of the mask is calculated from the interval of the detection pattern.

  Expansion and contraction due to changes in the temperature of the mask through simple processing of detecting the position of each detection pattern, calculating the interval between detection patterns, and calculating the amount of expansion and contraction of the mask from images of detection patterns provided at multiple locations on the mask The quantity is detected with high accuracy.

  Further, in the exposure apparatus of the present invention, the substrate temperature adjusting means supplies the heat medium to the chuck that contacts the substrate, the heat medium passage provided in the chuck, the heat medium passage, and the temperature and amount of the heat medium to be supplied. A heat exchanger that changes the temperature of the chuck by changing the temperature, a temperature sensor that detects the temperature of the chuck, and a temperature control device that controls the heat exchanger so that the chuck temperature detected by the temperature sensor becomes a target temperature The main control device calculates the target temperature of the chuck based on the calculated expansion / contraction amount of the mask, and sets the target temperature in the temperature control device.

  In the exposure method of the present invention, the heating medium passage is provided in the chuck that contacts the substrate, the heating medium is supplied to the heating medium passage provided in the chuck, and the temperature and amount of the supplied heating medium are changed to change the temperature of the chuck. The target temperature of the chuck is calculated based on the calculated amount of expansion and contraction of the mask, the chuck temperature is detected, and the detected chuck temperature is supplied to the heat medium passage provided in the chuck so as to reach the target temperature. The temperature and amount of the heat medium to be controlled are controlled.

  The target temperature of the chuck is calculated based on the amount of expansion and contraction of the mask, the temperature of the chuck is detected, and the temperature of the heat medium supplied to the heat medium passage provided in the chuck and the detected temperature of the chuck become the target temperature, and Since the amount is controlled, the temperature of the substrate is adjusted with high accuracy through the chuck, and the substrate is expanded and contracted in accordance with the expansion and contraction of the mask.

  The method for producing a display panel substrate of the present invention is to transfer the mask pattern onto the substrate using any one of the exposure apparatuses or exposure methods described above. By using the above exposure apparatus or exposure method, even if the mask expands and contracts due to temperature changes, the pattern printing accuracy does not decrease, and a high-quality substrate is manufactured.

  According to the exposure apparatus and the exposure method of the present invention, the amount of expansion / contraction due to the temperature change of the mask is detected, the temperature of the substrate is adjusted according to the detection result, and the substrate is expanded / contracted according to the expansion / contraction of the mask. In the Mitty exposure apparatus, even if the mask expands or contracts due to a temperature change, it is possible to prevent the pattern printing accuracy from being lowered.

  Furthermore, according to the exposure apparatus and the exposure method of the present invention, detection of the position of each detection pattern, calculation of the interval of the detection pattern, and expansion / contraction amount of the mask from the detection pattern images provided at a plurality of locations on the mask The amount of expansion and contraction due to the temperature change of the mask can be detected with high accuracy by a simple process of calculating.

  Further, according to the exposure apparatus and the exposure method of the present invention, the chuck target temperature is calculated based on the expansion / contraction amount of the mask, the chuck temperature is detected, and the detected chuck temperature is set to the target temperature. By controlling the temperature and amount of the heat medium supplied to the heat medium passage provided in the substrate, the temperature of the substrate can be adjusted with high accuracy through the chuck, and the substrate can be expanded and contracted in accordance with the expansion and contraction of the mask. it can.

  According to the method for manufacturing a display panel substrate of the present invention, even if the mask expands or contracts due to a temperature change, it is possible to prevent the pattern printing accuracy from being lowered, and thus it is possible to manufacture a high-quality substrate. .

  FIG. 1 is a view showing the schematic arrangement of an exposure apparatus according to an embodiment of the present invention. The exposure apparatus includes a base 3, an X guide 4, an X stage 5, a Y guide 6, a Y stage 7, a θ stage 8, a Z-tilt mechanism 9, a mask expansion / contraction amount detection unit, and a substrate temperature adjustment mechanism. Yes. The mask expansion / contraction amount detection unit includes a lens 22, a camera 23, an image signal processing device 30, and a main control device 40. The substrate temperature adjustment mechanism includes a chuck 10, a heat medium passage 11, a heat exchanger 12, and a temperature. A sensor 13 and a temperature control device 14 are included. In addition to these, the exposure apparatus includes an irradiation optical system that irradiates exposure light, a carry-in unit that carries in the substrate 1, a carry-out unit that carries out the substrate 1, a temperature control unit that manages the temperature in the apparatus, and the like. Yes.

  In FIG. 1, the chuck 10 is at an exposure position where the substrate 1 is exposed. The mask 2 is held by the mask holder 20 above the exposure position. The substrate 1 is mounted on the chuck 10 by a carry-in unit (not shown) at a delivery position away from the exposure position, and is recovered from the chuck 10 by a carry-out unit (not shown). The chuck 10 holds the substrate 1 by vacuum suction.

  The chuck 10 is mounted on the θ stage 8 via a Z-tilt mechanism 9, and a Y stage 7 and an X stage 5 are provided below the θ stage 8. The X stage 5 moves in the X direction (the horizontal direction in the drawing) along the X guide 4 provided on the base 3. As the X stage 5 moves in the X direction, the chuck 10 moves between the delivery position and the exposure position. The Y stage 7 moves in the Y direction (the drawing depth direction) along the Y guide 6 provided on the X stage 5. The θ stage 8 rotates in the θ direction, and the Z-tilt mechanism 9 moves and tilts in the Z direction (vertical direction in the drawing).

  At the exposure position, the substrate 1 is positioned by moving the X stage 5 in the X direction, moving the Y stage 7 in the Y direction, and rotating the θ stage 8 in the θ direction. Further, the gap control between the mask 2 and the substrate 1 is performed by the movement and tilt of the Z-tilt mechanism 9 in the Z direction.

  An irradiation optical system (not shown) is disposed above the mask 2 held by the mask holder 20, and exposure light from the irradiation optical system passes through the mask 2 and is irradiated onto the substrate 1 during exposure. The pattern of the mask 2 is transferred to the surface of the substrate 1 to form the pattern on the substrate 1.

  FIG. 2 is a diagram showing a substrate temperature adjusting mechanism. A heat medium passage 11 through which the heat medium passes is provided inside the chuck 10. The heat exchanger 12 exchanges heat between the primary heat medium and the secondary heat medium, supplies the secondary heat medium to the heat medium passage 11 provided in the chuck 10, and passes through the heat medium passage 11. Recover. The temperature of the chuck 10 contacting the substrate 1 is adjusted by the secondary heat medium supplied to the heat medium passage 11, and the temperature of the substrate 1 is adjusted via the chuck 10. The heat exchanger 12 changes the temperature of the chuck 10 by changing the temperature and amount of the secondary heat medium supplied to the heat medium passage 11 under the control of the temperature control device 14.

  In FIG. 1, detection patterns 21 for detecting the amount of expansion / contraction of the mask 2 are provided at a plurality of locations on the surface of the mask 2. In the present embodiment, the detection patterns 21 are provided at two locations on the surface of the mask 2, but the detection patterns 21 may be provided at three or more locations on the surface of the mask 2.

  A lens 22 and a camera 23 are arranged above the detection pattern 21 provided on the mask 2. The lens 22 collects the reflected light from the surface of the mask 2 and forms an image on the light receiving surface of the camera 23. The camera 23 acquires an image of the detection pattern 21 from the reflected light received by the light receiving surface, and outputs an image signal. The image signal processing device 30 processes the image signal output from the camera 23 under the control of the main control device 40. The main control device 40 detects the expansion / contraction amount of the mask 2 from the processing result of the image signal processing device 30.

  FIG. 3 is a flowchart showing the operation of the main controller. The main controller 40 stores the interval L of the detection pattern 21 at the reference temperature and the thermal expansion coefficient of the substrate 1 in order to start temperature adjustment of the substrate 1 (step 401). When temperature adjustment of the substrate 1 is started, the main control device 40 first detects the position of each detection pattern 21 from the processing result of the image signal processing device 30 (step 402). Next, main controller 40 calculates detection pattern interval L ′ from the position of each detection pattern (step 403), and subsequently, mask expansion / contraction amount ΔL = from detection pattern intervals L and L ′. L′−L is calculated (step 404).

  From the images of the detection patterns 21 provided at two locations on the mask 2, the mask is detected by simple processing of detecting the position of each detection pattern 21, calculating the interval between the detection patterns 21, and calculating the amount of expansion / contraction of the mask 2. The amount of expansion / contraction due to temperature change 2 is detected with high accuracy.

  Based on the calculated expansion / contraction amount of the mask 2, the main controller 40 uses the coefficient of thermal expansion of the substrate 1 so that the exposure area of the substrate 1 expands / contracts as much as the exposure area of the mask 2. Is calculated (step 405). Then, main controller 40 sets a target temperature in temperature controller 14 (step 406). 1 and 2, the temperature sensor 13 detects the temperature of the chuck 10, and the temperature control device 14 controls the heat exchanger 12 so that the temperature of the chuck 10 detected by the temperature sensor 13 becomes the target temperature. To do.

  The target temperature of the chuck 10 is calculated based on the expansion / contraction amount of the mask 2, the temperature of the chuck 10 is detected, and the detected temperature of the chuck 10 is supplied to the heat medium passage 11 provided in the chuck 10 so as to become the target temperature. Since the temperature and amount of the secondary heat medium to be controlled are controlled, the temperature of the substrate 1 is adjusted with high accuracy via the chuck 10, and the substrate 1 is expanded and contracted in accordance with the expansion and contraction of the mask 2.

  According to the embodiment described above, the expansion / contraction amount due to the temperature change of the mask 2 is detected, the temperature of the substrate 1 is adjusted according to the detection result, and the substrate 1 is expanded / contracted according to the expansion / contraction of the mask 2. In the proximity type exposure apparatus, even if the mask 2 expands or contracts due to a temperature change, it is possible to prevent the pattern printing accuracy from being lowered.

  Furthermore, according to the embodiment described above, the position of each detection pattern 21 is detected from the images of the detection patterns 21 provided at two locations of the mask 2, the interval between the detection patterns 21 is calculated, and the mask 2. By a simple process of calculating the amount of expansion / contraction, the amount of expansion / contraction due to temperature change of the mask 2 can be detected with high accuracy.

  Further, according to the embodiment described above, the target temperature of the chuck 10 is calculated based on the expansion / contraction amount of the mask 2, the temperature of the chuck 10 is detected, and the detected temperature of the chuck 10 becomes the target temperature. By controlling the temperature and amount of the secondary heat medium supplied to the heat medium passage 11 provided in the chuck 10, the temperature of the substrate 1 can be adjusted with high accuracy via the chuck 10, and the mask 2 can be expanded and contracted. The substrate 1 can be expanded and contracted according to the above.

  By transferring the mask pattern to the substrate using the exposure apparatus or the exposure method of the present invention, it is possible to prevent the pattern printing accuracy from being lowered even if the mask expands or contracts due to a temperature change. A quality substrate can be manufactured.

  For example, FIG. 4 is a flowchart showing an example of the manufacturing process of the TFT substrate of the liquid crystal display device. In the thin film formation step (step 101), a thin film such as a conductor film or an insulator film, which becomes a transparent electrode for driving liquid crystal, is formed on a glass substrate by sputtering, plasma chemical vapor deposition (CVD), or the like. In the resist coating process (step 102), a photosensitive resin material (photoresist) is applied by a roll coating method or the like to form a photoresist film on the thin film formed in the thin film forming process (step 101). In the exposure step (step 103), the mask pattern is transferred to the photoresist film using a proximity exposure apparatus, a projection exposure apparatus, or the like. In the development step (step 104), a developer is supplied onto the photoresist film by a shower development method or the like to remove unnecessary portions of the photoresist film. In the etching process (step 105), a portion of the thin film formed in the thin film formation process (step 101) that is not masked by the photoresist film is removed by wet etching. In the stripping step (step 106), the photoresist film that has finished the role of the mask in the etching step (step 105) is stripped with a stripping solution. Before or after each of these steps, a substrate cleaning / drying step is performed as necessary. These steps are repeated several times to form a TFT array on the glass substrate.

  FIG. 5 is a flowchart showing an example of the manufacturing process of the color filter substrate of the liquid crystal display device. In the black matrix forming step (step 201), a black matrix is formed on the glass substrate by processes such as resist coating, exposure, development, etching, and peeling. In the colored pattern forming step (step 202), a colored pattern is formed on the glass substrate by a dyeing method, a pigment dispersion method, a printing method, an electrodeposition method, or the like. This process is repeated for the R, G, and B coloring patterns. In the protective film forming step (step 203), a protective film is formed on the colored pattern, and in the transparent electrode film forming step (step 204), a transparent electrode film is formed on the protective film. Before, during or after each of these steps, a substrate cleaning / drying step is performed as necessary.

  In the TFT substrate manufacturing process shown in FIG. 4, in the exposure process (step 103), in the color filter substrate manufacturing process shown in FIG. 5, in the black matrix forming process (step 201) and the colored pattern forming process (step 202). In this exposure process, the exposure apparatus or the exposure method of the present invention can be applied.

1 is a diagram showing a schematic configuration of an exposure apparatus according to an embodiment of the present invention. It is a figure which shows a board | substrate temperature control mechanism. It is a flowchart which shows operation | movement of a main controller. It is a flowchart which shows an example of the manufacturing process of the TFT substrate of a liquid crystal display device. It is a flowchart which shows an example of the manufacturing process of the color filter board | substrate of a liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Mask 3 Base 4 X guide 5 X stage 6 Y guide 7 Y stage 8 θ stage 9 Z-tilt mechanism 10 Chuck 11 Heat medium passage 12 Heat exchanger 13 Temperature sensor 14 Temperature controller 20 Mask holder 21 Detection pattern 22 Lens 23 Camera 30 Image signal processor 40 Main controller

Claims (8)

An exposure apparatus for transferring a mask pattern to a substrate by providing a minute gap between the mask and the substrate,
Detection means for detecting the amount of expansion and contraction due to temperature change of the mask;
An exposure apparatus comprising: a substrate temperature adjusting unit that adjusts the temperature of the substrate in accordance with a detection result of the detecting unit and expands and contracts the substrate in accordance with the expansion and contraction of the mask. The detection means includes
A plurality of image acquisition means for acquiring images of detection patterns provided at a plurality of locations of the mask and outputting image signals;
An image signal processing apparatus for processing the image signal output by the image acquisition means;
Main control for detecting the position of each detection pattern from the processing result of the image signal processing device, calculating the interval of the detection pattern from the position of each detection pattern, and calculating the expansion / contraction amount of the mask from the interval of the detection pattern The exposure apparatus according to claim 1, further comprising: an exposure apparatus. The substrate temperature adjusting means includes
A chuck that contacts the substrate;
A heat medium passage provided in the chuck;
A heat exchanger for supplying a heat medium to the heat medium passage, and changing the temperature and amount of the supplied heat medium to change the temperature of the chuck;
A temperature sensor for detecting the temperature of the chuck;
A temperature control device for controlling the heat exchanger so that the temperature of the chuck detected by the temperature sensor becomes a target temperature;
The exposure apparatus according to claim 2, wherein the main control device calculates a target temperature of the chuck based on the calculated expansion / contraction amount of the mask, and sets the target temperature in the temperature control device. An exposure method for transferring a mask pattern to a substrate by providing a minute gap between the mask and the substrate,
Detects the amount of expansion / contraction due to the temperature change of the mask,
An exposure method characterized by adjusting the temperature of a substrate in accordance with a detection result, and expanding and contracting the substrate in accordance with expansion and contraction of a mask. Provide detection patterns at multiple locations on the mask,
Acquire an image of each detection pattern,
Process the image signal of each detection pattern to detect the position of each detection pattern,
Calculate the interval of the detection pattern from the position of each detection pattern,
5. The exposure method according to claim 4, wherein the expansion / contraction amount of the mask is calculated from the interval between the detection patterns. A heat medium passage is provided in the chuck that contacts the substrate,
Supply the heat medium to the heat medium passage provided in the chuck, change the temperature and amount of the supplied heat medium, change the temperature of the chuck,
Calculate the target temperature of the chuck based on the calculated expansion / contraction amount of the mask,
Detect chuck temperature,
6. The exposure method according to claim 5, wherein the temperature and amount of the heat medium supplied to the heat medium passage provided in the chuck are controlled so that the detected temperature of the chuck becomes a target temperature.   A method for manufacturing a display panel substrate, comprising: transferring a mask pattern onto the substrate using the exposure apparatus according to claim 1.   A method for manufacturing a display panel substrate, wherein a mask pattern is transferred to a substrate using the exposure method according to claim 4.

Images