JP2005224741A - Method for heating and drying coating film, and heating and drying apparatus for coating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the peripheral edge part of a coating film is swelled in heating and drying the coating film. <P>SOLUTION: A method for drying the coating film is provided by which the swelling of the peripheral edge part of the coating film in heating and drying is prevented to obtain the coating film having uniform thickness by giving potential to the coating film surface and supplying a solvent during the drying. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coating film drying method and apparatus for heating and drying various liquid coating solutions such as a resist solution and a slurry coated on the surface of a plate-like workpiece such as a glass substrate or a semiconductor wafer.

  For example, a glass substrate by a spin coating method disclosed in JP-A-3-56163 (Patent Document 1), for example, a slit nozzle method disclosed in US Pat. No. 4,696,885 (Patent Document 2) or the like. As a method for drying a coating film of a liquid material such as a resist solution or an SOG solution applied to the surface of a plate-like substrate such as a semiconductor wafer or a semiconductor wafer, a furnace in which the substrate is installed in a heating furnace and the coating film is overheated and dried There are an internal drying method, a hot plate method in which a substrate is placed on a hot plate and a coating film is dried through the plate.

In the method of heating and drying the coating film such as in-furnace heating method or hot plate method, when the evaporated solvent component is likely to diffuse around, the peripheral edge of the coating film is the fastest evaporation, so the peripheral edge of the coating film Then, there is a problem that the coating film is raised by drying. To solve this problem, there is a method of suppressing evaporation of the coating film solvent as disclosed in Japanese Patent Application Laid-Open No. 2003-19558 (Patent Document 3). As another method, before the coating film as disclosed in JP-A-2000-107671 (Patent Document 4) is completely dried and solidified, an air current is blown onto the surface of the coating film to obtain a uniform film thickness. There is a way.
JP-A-3-56163 US Pat. No. 4,696,885 JP2003-19558 JP 2000-107671

  However, in the method described in Japanese Patent Application Laid-Open No. 2003-19558, since the distribution of the amount of solvent evaporated from the coating film cannot be made extremely non-uniform, the effect of suppressing the rise of the peripheral edge of the coating film is small. Further, the method described in JP-A-2000-107671 has a problem that the effect of completely suppressing the rising of the peripheral edge portion of the coating film is small and the film thickness unevenness due to the airflow tends to occur on the coating film surface.

  In order to solve the above-mentioned problems, the present invention provides a liquid from a coating head opening while moving a coating head having a slit-shaped opening and a substrate to be coated so as to be orthogonal to the longitudinal direction of the coating head opening. In a heating and drying method in which a coating film made of a solvent and a solute applied to a substrate to be printed is heated and dried to solidify by supplying the solvent, the solvent is supplied to the peripheral edge of the coating film applied to the substrate to be coated Heat drying method of providing a solvent supply unit and an electric field application terminal, supplying a solvent from the solvent supply unit to the substrate to be coated, and simultaneously applying a potential to the peripheral edge surface of the coating film applied by the electric field application terminal Is provided.

  The present invention also provides a heating and drying method in which the solvent supply unit moves vertically and horizontally with respect to the surface of the coating film.

  The present invention also provides a heat drying method for changing the amount of the solvent supplied according to the dry state of the peripheral edge portion of the coating film applied to the substrate to be coated.

  The present invention also provides a heat drying method in which the time for supplying the solvent is changed according to the dry state of the peripheral edge portion of the coating film applied to the substrate to be coated.

  The present invention also provides a heating and drying method in which a potential applied to the electric field application terminal is changed according to a dry state of the peripheral edge portion of the coating film applied to the substrate to be coated.

  The present invention also provides a coating head by discharging liquid from the coating head opening while relatively moving the coating head having the slit-shaped opening and the substrate to be coated so as to be orthogonal to the longitudinal direction of the coating head opening. In a heating and drying apparatus that heats and solidifies a coating film made of a solvent and a solute applied to a printed substrate, a solvent supply unit that supplies the solvent to a peripheral edge of the coating film applied to the substrate to be coated is provided. There is provided a heating and drying apparatus provided with an electric field application terminal for applying a potential to the peripheral edge surface of the coating film coated on the substrate to be coated.

  The present invention also provides a heating and drying apparatus in which the solvent supply unit moves vertically and horizontally with respect to the surface of the coating film.

  The present invention also provides a heating and drying apparatus in which the electric field application terminal is installed so as to face the upper surface of the coating film.

  The present invention also provides a heating and drying apparatus in which the electric field application terminal installed at a position facing the upper surface of the coating film moves vertically and horizontally with respect to the upper surface of the coating film.

  The present invention also provides a heating and drying apparatus in which the electric field application terminal is installed so as to face the side surface of the coating film.

  The present invention also provides a heating and drying apparatus in which the electric field application terminal installed at a position facing the side surface of the coating film moves vertically and horizontally with respect to the side surface of the coating film.

  In the heating and drying method of the present invention, a solvent is supplied to the surface of the peripheral edge of the coating film applied to the substrate to be coated, and a potential difference is created on the surface of the peripheral edge of the coating film in a direction opposite to the upper surface of the peripheral edge of the coating film. By holding the solvent supplied by applying an electric field to the film, there is an effect of suppressing the swell of the peripheral edge of the coating film.

  In addition, the solvent is supplied to the surface of the peripheral edge of the coating film applied to the substrate to be coated according to the dry state, and the potential difference applied to the surface of the peripheral edge of the coating film in the direction facing the upper surface of the peripheral edge of the coating film is in the dry state. By adjusting according to the above, there is an effect of suppressing the swell of the peripheral edge of the coating film.

  In addition, the solvent is supplied to the surface of the peripheral edge of the coating film applied to the substrate to be coated according to the dry state, and the potential difference applied to the surface of the peripheral edge of the coating film in the direction facing the upper surface of the peripheral edge of the coating film is in the dry state. And adjusting the potential difference applied to the surface of the peripheral edge of the coating film in the direction facing the side surface of the peripheral edge of the coating film according to the dry state, thereby suppressing the rise of the peripheral edge of the coating film. is there.

  The present invention solves the problem of rising at the peripheral edge of the coating film at the time of heating and drying, which is the above-mentioned problem, and by applying a potential to the coating film surface and supplying a solvent during drying, the present invention An object of the present invention is to provide a method for drying a coating film that can prevent the above-mentioned problem from rising at the peripheral edge of the coating film during heat drying and obtain a coating film having a uniform thickness.

  FIG. 1 is a schematic view of a drying method using a heat drying method in Example 1. FIG. A substrate 2 to be coated is placed on the hot plate 1 by vacuum suction (not shown). A coating film 3 is formed on the surface of the substrate to be coated 2 by the coating film forming method shown in FIG. An electric field application terminal 5 that can be arbitrarily moved is provided at a position facing the upper surface of the coating film peripheral edge 4 of the coating film 3. A DC voltage device 6 is connected to the substrate to be coated 2 and the electric field application terminal 5. A nozzle 7 that can supply the solvent 8 of the coating film 3 in an arbitrary amount and time from a solvent supply pump (not shown) is installed at a position facing the surface of the coating film peripheral edge 4 of the coating film 3.

  FIG. 2 is a schematic view of a coating film forming method by a slit nozzle method showing an embodiment of the first embodiment. As shown in FIG. 2A, the coating head 102 is stopped at a coating start position of the substrate to be coated 101 with a certain distance from the substrate to be coated 101. In a state in which the coating head 102 is stopped, the coating liquid 104 is discharged from the slit portion 103 to form a coating liquid pool 105. Next, as shown in FIG. 2B, the coated substrate 101 is moved 106 so that the coating head 102 moves relative to the coated substrate 101 while keeping the coated substrate 101 and the coating head 102 at a constant interval. Alternatively, the coating film 107 is formed on the substrate 101 by moving the coating head 102.

(Experimental example 1)
As the substrate to be coated, blue plate glass of 10 cm long × 10 cm wide × 0.5 cm thick was used. The coating solution viscosity was 4 Pa · sec. The coating solution solid content concentration was 60.6 wt%. The distance between the coating head and the substrate to be coated was 150 μm. The relative speed between the coating head and the substrate to be coated during the coating operation was 5 mm / sec. Electric field application terminals having a width of 2 mm were placed along the periphery of the coating film at intervals of 2 mm from the upper surface of the coating film. A voltage of 5 kV was set between the electric field application terminal and the substrate to be coated by a DC voltage device. The solvent is supplied from the nozzle at 0.05 ml / sec. The temperature distribution in the surface of the hot plate was set to a set temperature of 90 ± 1 ° C.

  As a result of heat drying for 7 minutes under the above conditions, the thickness of the dry film at the center of the substrate to be coated was 88.1 μm, and the thickest film at the edge of the dry film was 95.3 μm.

(Experimental example 2)
As the substrate to be coated, blue plate glass of 10 cm long × 10 cm wide × 0.5 cm thick was used. The coating solution viscosity was 4 Pa · sec. The coating solution solid content concentration was 60.6 wt%. The distance between the coating head and the substrate to be coated was 150 μm. The relative speed between the coating head and the substrate to be coated during the coating operation was 5 mm / sec. Electric field application terminals having a width of 2 mm were placed along the periphery of the coating film at intervals of 2 mm from the upper surface of the coating film. A voltage of 5 kV was set between the electric field application terminal and the substrate to be coated by a DC voltage device. The solvent is supplied from the nozzle at 0.05 ml / sec. The temperature distribution in the surface of the hot plate was set to a set temperature of 90 ± 1 ° C.

  Under the above conditions, heat drying was performed for 7 minutes. The solvent was supplied from the nozzle at 0.05 ml / sec for 4 minutes from the start of drying. From the start 4 minutes to 6 minutes, the solvent was supplied from the nozzle at 0.04 ml / sec, and the electric field application terminal was moved in the direction perpendicular to the upper surface of the coating film at 0.5 mm / min to approach the coating film. Thereafter, the solvent was continuously supplied from the nozzle at 0.02 ml / sec while the movement of the electric field application terminal was stopped until the end. As a result, the film thickness at the center of the substrate to be coated of the dry film was 89.3 μm, and the thickest film at the edge of the dry film was 93.5 μm.

  FIG. 3 is a schematic view of a drying method by a heat drying method in Example 2. A substrate 10 to be coated is placed on the hot plate 9 by vacuum suction (not shown). A coating film 11 is formed on the surface of the substrate 10 to be coated by the coating film forming method shown in FIG. An electric field application terminal 13 that can be arbitrarily moved is provided at a position facing the upper surface of the coating film peripheral edge 12 of the coating film 11. A DC voltage device 14 is connected to the substrate to be coated 10 and the electric field application terminal 13. An electric field application terminal 17 that can be arbitrarily moved is provided at a position facing the side surface of the coating film peripheral edge portion 12 of the coating film 11. A DC voltage device 14 is connected to the substrate to be coated 10 and the electric field application terminal 17. The substrate to be coated 10 is provided with a ground 19. A nozzle 15 capable of supplying the solvent 16 of the coating film 11 in an arbitrary time and amount from a solvent supply pump (not shown) is installed at a position facing the surface of the coating film peripheral edge 12 of the coating film 11.

(Experimental example 3)
As the substrate to be coated, blue plate glass of 10 cm long × 10 cm wide × 0.5 cm thick was used. The coating solution viscosity was 4 Pa · sec. The coating solution solid content concentration was 60.6 wt%. The distance between the coating head and the substrate to be coated was 150 μm. The relative speed between the coating head and the substrate to be coated during the coating operation was 5 mm / sec. An electric field application terminal having a width of 1 mm was placed along the periphery of the coating film at an interval of 2 mm from the upper surface of the coating film as an initial position. A voltage of 5 kV was set between the electric field application terminal and the substrate to be coated by a DC voltage device. An electrode having a width of 1 mm was placed along the periphery of the coating film at an interval of 2 mm from the coating side surface as an initial position. The temperature distribution in the surface of the hot plate was set to a set temperature of 90 ± 1 ° C.

  Under the above conditions, heat drying was performed for 7 minutes. The solvent was supplied from the nozzle at 0.05 ml / sec for 4 minutes from the start of drying. From the start 4 minutes to 6 minutes, the solvent was supplied from the nozzle at 0.03 ml / sec, and the electric field application terminal facing the upper and side surfaces of the coating film was brought closer to the coating film at 0.5 mm / min. Thereafter, the solvent was continuously supplied from the nozzle at 0.01 ml / sec while the movement of the electric field application terminal was stopped until the end. As a result, the film thickness at the center of the substrate to be coated of the dry film was 90.2 μm, and the thickest film at the edge of the dry film was 91.3 μm.

(Comparative Experimental Example 1)
FIG. 4 is a schematic view of a drying method using a heat drying method in a comparative experimental example. As shown in FIG. 4A, an exhaust device 27 and an air supply device 28 are installed in the chamber 29. A substrate 21 to be coated is placed on the hot plate 20 by vacuum suction (not shown) in the chamber 29. A coating film 22 is formed on the surface of the substrate to be coated 21 by the coating film forming method shown in FIG. A member 23 provided with through holes 24, 25, 26 is installed at a predetermined position with respect to the substrate 21 to be coated. FIG. 4B shows a plan view of the member 23.

  As the substrate to be coated, blue plate glass of 10 cm long × 10 cm wide × 0.5 cm thick was used. The coating solution viscosity was 4 Pa · sec. The coating solution solid content concentration was 60.6 wt%. The distance between the coating head and the substrate to be coated was 150 μm. The relative speed between the coating head and the substrate to be coated during the coating operation was 5 mm / sec. The holes provided in the 15 cm long × 15 cm wide × 0.5 cm thick member had diameters of 24, 16, and 8 mm. Supply / exhaust was performed at 0.5 mm / min so that the pressure in the chamber was 1 atm. The temperature distribution in the surface of the hot plate was set to a set temperature of 90 ± 1 ° C.

  Under the above conditions, heat drying was performed for 7 minutes. As a result, the film thickness at the center of the substrate to be coated of the dry film was 87.3 μm, and the thickest film at the edge of the dry film was 99.3 μm.

1 is a schematic cross-sectional view showing a heat drying method in Example 1. FIG. FIG. 2 is a schematic cross-sectional view illustrating a method for forming a coating film in Example 1. FIG. 3 is a schematic cross-sectional view showing a heat drying method in Example 2. FIG. 3 is a schematic cross-sectional view showing a heat drying method in Comparative Experimental Example 1.

Explanation of symbols

1, 9, 20 Hot plate 2, 10, 21, 101 Substrate to be coated 3, 11, 22, 107 Coating film 4, 12 Coating film peripheral edge 5, 13, 17 Electric field application terminal 6, 14, 18 DC voltage device 7, 15 Nozzle 8, 16 Solvent 19 Ground 23 Member 24, 25, 26 Through hole 27 Exhaust device 28 Air supply device 29 Chamber 102 Coating head 103 Slit 104 Coating solution 105 Coating solution reservoir 106 Moving direction

Claims (11)

  The coating head having a slit-shaped opening and the substrate to be coated were applied to the substrate to be printed by ejecting liquid from the coating head opening while relatively moving the coating head and the coating head in the longitudinal direction of the coating head opening. In a heating and drying method in which a coating film made of a solvent and a solute is dried by heating and solidified, a solvent supply unit for supplying the solvent and an electric field application terminal are provided at a peripheral edge of the coating film applied to the substrate to be coated, A heating and drying method, wherein a solvent is supplied from the solvent supply unit to the substrate to be coated, and at the same time, a potential is applied to a peripheral edge surface of the coating film applied by the electric field application terminal.   The heating method according to claim 1, wherein the solvent supply unit moves vertically and horizontally with respect to the surface of the coating film.   2. The heat drying method according to claim 1, wherein the amount of the solvent to be supplied is changed according to a dry state of the peripheral edge of the coating film applied to the substrate to be coated.   The heat drying method according to claim 1, wherein a time for supplying the solvent is changed according to a dry state of the peripheral edge portion of the coating film applied to the substrate to be coated.   2. The heat drying method according to claim 1, wherein a potential applied to the electric field application terminal is changed in accordance with a dry state of the peripheral edge portion of the coating film applied to the substrate to be coated.   The coating head having a slit-shaped opening and the substrate to be coated were applied to the substrate to be printed by ejecting liquid from the coating head opening while relatively moving the coating head and the coating head in the longitudinal direction of the coating head opening. In a heating and drying apparatus for heating and drying and solidifying a coating film composed of a solvent and a solute, a solvent supply unit for supplying the solvent is provided at a peripheral edge of the coating film applied to the substrate to be coated, and the solvent supply unit A heating and drying apparatus comprising an electric field applying terminal for applying a potential to a peripheral edge surface of the coating film coated on a substrate to be coated.   The heating apparatus according to claim 6, wherein the solvent supply unit moves vertically and horizontally with respect to the surface of the coating film.   The heat drying apparatus according to claim 6, wherein the electric field applying terminal is disposed so as to face the upper surface of the coating film.   The heat drying apparatus according to claim 6, wherein the electric field application terminal installed at a position facing the upper surface of the coating film moves vertically and horizontally with respect to the upper surface of the coating film.   The heat drying apparatus according to claim 6, wherein the electric field application terminal is disposed so as to face a side surface of the coating film.   The heat drying apparatus according to claim 10, wherein the electric field application terminal installed at a position facing the side surface of the coating film moves vertically and horizontally with respect to the side surface of the coating film.

Images