JP2009260010A - Resist film drying device, and resist film drying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist film drying device that suppresses variations in film thickness of a resist film without spoiling a circumferential environment. <P>SOLUTION: The resist film drying device has a heating plate 2 which heats a resist film 10 containing a solvent component applied over a substrate 9. Further, the resist film drying device includes a convection suppressing plate 3 disposed having its reverse surface opposed to a top surface of the resist film 10 to be close to the top surface of the resist film 10, and an outer exhaustion cover 5 having an exhaust port 5a formed outside above an outer circumference of the reverse surface of the convection suppressing plate 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resist film drying apparatus and a resist film drying method.

  Manufacturing processes of electronic devices such as inkjet recording heads often include a process of forming a resist film on a substrate. The resist film forming process usually includes an application process for applying a resist to the substrate and a drying process for drying the resist film applied to the substrate in the application process.

  In the coating process, a resist is applied to the substrate by a method such as spin coating. In the spin coating method, a liquid resist is dropped on the center of the substrate surface, and the resist is spread toward the outer periphery of the substrate surface by centrifugal force generated by rotating the substrate at a high speed. It is a method to apply to.

  In the drying process, the resist film applied to the substrate in the coating process is heated by a heating plate (hot plate) or a hot-air circulation furnace (oven) to remove the solvent component contained in the resist film, thereby Cure the film. Thereafter, the substrate and the resist film are cooled by a cooling plate (cold plate), and the drying process is completed.

  In the conventional drying process, the resist film is heated only from the lower side of the substrate by the heating plate, so that heat convection tends to occur in the space above the resist film. Therefore, in the drying process, drying unevenness and temperature unevenness may occur in the resist film.

  In the drying process, the solvent component contained in the resist film before drying evaporates in the drying process, and the viscosity of the resist film increases as the density of the resin component of the resist film increases. Removed and cured. On the other hand, at the same time, a softening action is caused by the viscosity of the resin component of the resist film being reduced by heating. Therefore, when the drying unevenness or temperature unevenness occurs in the resist film in the drying process, the resist film varies in hardness.

  In the drying process, if a variation in hardness occurs in the resist film, a variation in film thickness called a wind pattern or blown unevenness may occur after the drying process. This variation in film thickness is more noticeable as the resist film is thicker, and is particularly noticeable when a resist film of 30 μm or more is formed.

  Patent Document 1 describes a resist film drying apparatus configured to suppress the occurrence of variations in resist film thickness. In this resist film drying apparatus, the lower surface of the convection suppression plate is arranged at a position facing the surface of the resist film so that the convection suppression plate is close to the surface of the resist film applied to the substrate on the heating plate. .

In this resist film drying apparatus, the space between the surface of the resist film and the lower surface of the convection suppression plate is narrow, and a large temperature difference does not occur in this space during the drying process. Is unlikely to occur. Even if thermal convection occurs in the space above the convection suppression plate, the resist film is not easily affected by the thermal convection because the vicinity of the surface of the resist film is covered with the convection suppression plate. Thus, in this resist film drying apparatus, it can suppress that a resist film receives the influence of a thermal convection by arrange | positioning the convection suppression board.
JP 2003-305399 A

  However, since the resist film drying apparatus described in Patent Document 1 is used in the air, it is considered that the solvent component of the resist film evaporated during the drying process fills the surroundings. Moreover, the quality of the resist film may be deteriorated when dust or the like enters the gap between the resist film and the convection suppressing plate and adheres to the surface of the resist film.

  In order to suppress these, it is conceivable to provide an exterior and an exhaust mechanism that cover the periphery of the resist film drying apparatus. However, when an exterior and an exhaust mechanism are provided, a forced air flow due to exhaust is generated inside the exterior. Therefore, even if the resist film can be suppressed from being affected by thermal convection by arranging a convection suppression plate in the drying process, the resist film is affected by the flow of air due to exhaust, resulting in variations in film thickness. It is possible to do.

  Therefore, an object of the present invention is to provide a resist film drying apparatus and a resist film drying method that suppress the occurrence of variations in the film thickness of a resist film without deteriorating the surrounding environment.

  In order to achieve the above object, a resist film drying apparatus of the present invention is a resist film drying apparatus having a heating means for heating a resist film containing a solvent component applied to a substrate so as to be close to the surface of the resist film. And a plate member disposed at a position where the lower surface opposes the surface of the resist film, and an exhaust means for exhausting air from above the outer periphery of the lower surface of the plate member.

  ADVANTAGE OF THE INVENTION According to this invention, the resist film drying apparatus and resist film drying method which suppress that the dispersion | variation in the film thickness of a resist film generate | occur | produces without impairing the surrounding environment can be provided.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a top view showing the inside of a resist film coating / drying apparatus provided with a resist film drying apparatus according to an embodiment of the present invention. This resist film coating / drying apparatus includes a sender 6 for carrying a substrate 9, a spin coater 7 for coating a resist on the substrate 9, a resist film drying apparatus 1 for drying the resist film applied to the substrate 9, and a resist film. And a receiver 8 to which the processed substrate 9 is conveyed. The resist film drying apparatus 1 includes three heating plates 2 that heat and dry the resist film, and a cooling plate 4 that cools the substrate 9 on which the resist film is formed.

  In the resist film drying apparatus 1, three heating plates 2 are arranged side by side, and the temperature conditions of each heating plate 2 can be set individually. Therefore, in the resist film drying apparatus 1, the resist-coated substrate 9 is continuously transported to the respective heating plates 2 whose temperature conditions have been changed stepwise, thereby drying the resist film more stably. As a result, the quality of the resist film can be improved. Note that the resist film drying apparatus preferably includes a plurality of heating plates, but may have at least one heating plate.

  In this resist film coating and drying apparatus, first, the substrate 9 set on the sender 6 is transported to the cup of the spin coater 7 and vacuum chucked. Thereafter, a liquid resist is dropped on the central portion of the substrate 9 and the cup of the spin coater 7 is rotated at a high speed, so that the resist is uniformly spread over the entire surface of the substrate 9. Then, after the substrate 9 is conveyed to each heating plate 2 and heated to dry the resist film, the substrate 9 is conveyed to the cooling plate 4 to cool the substrate 9 and the resist film. Thereafter, the substrate 9 on which the resist film is formed is conveyed to the receiver 8, and the resist film forming step is completed.

  Next, details of the resist film drying apparatus according to the present embodiment will be described with reference to FIG.

  2A is a side sectional view of the heating plate portion of the resist film drying apparatus according to the present embodiment in the substrate transport direction, and FIG. 2B is orthogonal to the substrate transport direction of the heating plate portion of the resist film drying apparatus. FIG. 2A and 2B show a state in the drying process of the resist film drying apparatus 1 in which the resist film 10 applied on the substrate 9 is heated by the heating plate 2 and dried.

  The resist film drying apparatus 1 includes a heating plate 2 provided with a heater (not shown) therein, a convection suppression plate 3 that is a plate member, a heating plate box 2a that accommodates the heating plate 2, and an upper surface of the convection suppression plate 3. And an exterior exhaust cover 5 that covers the whole.

  At least three proxy pins 2b for supporting the substrate 9 are provided on the heating plate 2, and the substrate 9 on which the resist is applied is proximate from the cup of the spin coater 7 by a transport hand (not shown) or the like. It is conveyed on the pin 2b. When the substrate 9 and the resist film 10 are heated by the heating plate 2, the temperature of the resist film 10 applied to the substrate 9 rises and the solvent component contained in the resist film 10 evaporates.

  The distance between the heating plate 2 and the substrate 9 can be adjusted by changing the height of the proxy pin 2b. Thereby, by changing the temperature increase rate of the substrate 9, the speed of evaporating the solvent component of the resist film 10 can be adjusted to improve the quality of the resist film 10. In the resist film drying apparatus 1, the height of the proxy pin 2b is set to 0.2 mm.

  In the resist film drying apparatus 1, the lower surface of the convection suppression plate 3 is disposed at a position facing the surface of the resist film 10 so that the convection suppression plate 3 is close to the surface of the resist film 10. The convection suppression plate 3 is formed in a disk shape having a thickness of 1 mm so that the surface area is larger than the surface of the resist film 10, and the lower surface is disposed so as to cover the entire surface of the resist film 10.

  In the resist film drying apparatus 1, the convection suppression plate 3 is arranged so as to be close to the surface of the resist film 10, so that heat convection hardly occurs in the vicinity of the surface of the resist film 10 in the drying process, and the film of the resist film 10 Occurrence of thickness variations is suppressed. In addition, since the convection suppression plate 3 covers the entire surface of the resist film 10, the resist film 10 is suppressed from causing variations in film thickness to a portion closer to the outer periphery.

  In the resist film drying apparatus 1, the heating plate 2 is accommodated in the heating plate box 2a. In the heating plate box 2a, a wall member serving as a side wall is formed higher than the lower surface of the convection suppression plate 3, and an upper portion is opened. As a result, in the resist film drying apparatus 1, the gap space formed between the resist film 10 and the convection suppression plate 3 is surrounded by the side wall of the heating plate box 2 a. It is possible to suppress the adhesion of dust and the like.

  In addition, the resist film drying apparatus 1 is provided with an exterior exhaust cover 5 that is a cover member disposed to face the upper surface of the convection suppression plate 3 so as to cover the entire upper surface of the convection suppression plate 3. Thereby, it can prevent that dust etc. mix from the upper part by which the heating plate box 2a was opened.

  The exterior exhaust cover 5 has an exhaust port 5a in a region outside the portion facing the outer periphery of the convection suppression plate 3, and the solvent component evaporated from the resist film 10 is sucked from the exhaust port 5a. It is discharged outdoors through an exhaust pipe (not shown). Exhaust by the exterior exhaust cover 5 is started before the resist film 10 is heated by the heating plate 2 at the latest. Thereby, it is suppressed that the solvent component evaporated from the resist film 10 fills the surroundings.

  Further, in the resist film drying apparatus 1, the exhaust port 5 a is forcibly disposed on the outside of the outer periphery of the convection suppression plate 3 where the solvent component of the resist film 10 heated and evaporated is directed. The solvent component of the resist film 10 is exhausted without creating a simple air flow. Further, since the heating plate box 2a and the exterior exhaust cover 5 are arranged apart from each other and the inside of the heating plate box 2a is not sealed, convection is generated inside the heating plate box 2a by the flow of air due to exhaust. Hard to occur.

  Furthermore, an inclined surface that is inclined upward from the central region toward the exhaust port 5a is formed on the lower surface of the exterior exhaust cover 5. As a result, the heated and evaporated solvent component going upward is efficiently exhausted without creating a forced air flow.

  As described above, in the resist film drying apparatus 1, it is difficult for the air flow due to the exhaust to occur in the heating plate box 2 a, so that it is possible to suppress the occurrence of film thickness variations in the resist film 10.

  When the drying of the resist film 10 by the heating plate 2 is completed, the convection suppression plate support arm 3a supporting the convection suppression plate 3 is raised by the convection suppression plate elevating cylinder 3b, and the substrate 9 on which the resist film 10 is formed is formed. It is conveyed to the cooling plate 4 by a conveyance hand or the like.

  For comparison with the resist film drying apparatus 1 according to this embodiment, the resist film drying apparatus shown in FIGS. 3 and 4 was prepared.

  3A is a side sectional view of the heating plate portion of the comparative resist film drying apparatus in the substrate transport direction, and FIG. 3B is a side perpendicular to the substrate transport direction of the heating plate portion of the resist film drying apparatus. It is sectional drawing. The heating plate 12 of the resist film drying apparatus 11 is accommodated in a heating plate box 12a. In addition, an exhaust port 12b is formed in the central region of the heating plate box 12a above the heating plate 12, and the solvent component evaporated from the resist film 20 is sucked from the exhaust port 12b and is outdoors through an exhaust pipe or the like. To be discharged. In addition, parts other than the exhaust port 12b of the heating plate box 12a are sealed.

  The resist film drying apparatus 11 and the resist film drying apparatus 1 according to this embodiment are different in two points. First, the resist film drying apparatus 1 has the convection suppression plate 3 disposed so as to cover the entire surface of the resist film, whereas the resist film drying apparatus 11 has no convection suppression plate disposed. It is. The second point is that the resist film drying apparatus 1 exhausts air from the exhaust port 5a formed in the exterior exhaust cover 5, whereas the resist film drying apparatus 11 has a central region of the sealed heating plate box 12a. Exhaust is performed from the formed exhaust port 12b.

  4A is a side sectional view of the heating plate portion of the comparative resist film drying apparatus in the substrate transport direction, and FIG. 4B is a side orthogonal to the substrate transport direction of the heating plate portion of the resist film drying apparatus. It is sectional drawing. The resist film drying apparatus 11a is obtained by attaching the convection suppression plate 13 similar to the convection suppression plate 3 of the resist film drying apparatus 1 according to the present embodiment to the resist film drying apparatus 11 shown in FIG. The convection suppression plate 13 is disposed at a position where the lower surface of the convection suppression plate 13 faces the surface of the resist film 20a so as to be close to the surface of the resist film 20a.

  The resist film drying apparatus 11a and the resist film drying apparatus 1 according to this embodiment differ in one point. That is, while the resist film drying apparatus 1 exhausts air from the exhaust port 5a formed in the exterior exhaust cover 5, the resist film drying apparatus 11a is formed in the central region of the sealed heating plate box 12a. The exhaust gas is exhausted from the exhaust port 12b.

  FIG. 5 is a top view showing the inside of a resist film coating and drying apparatus provided with a comparative resist film drying apparatus. In this resist film coating and drying apparatus, as in the resist film coating and drying apparatus shown in FIG. 1, the substrate is continuously conveyed from the sender 16 to the spin coater 17, the heating plate 12, the cooling plate 14, and the receiver 18. A resist film is formed.

  Next, the result of comparing the resist film dried using the comparative resist film drying apparatuses 11 and 11a and the resist film dried using the resist film drying apparatus 1 according to the present embodiment will be described. In addition, all samples used resists having the same components, and were processed under the same conditions except for those shown below so that the average thickness of the resist film after drying was 75 μm. In any sample, a 6-inch Si substrate having a thickness of 0.625 mm is used as the substrate, and the substrate temperature is maintained at 90 ° C. for 15 minutes using only one heating plate in the drying process. The resist film applied to was dried. The film thickness distribution was evaluated at about 3800 points measured at a pitch of 2 mm except for the outer peripheral portion of the substrate 5 mm.

  FIG. 6 is a view showing a film thickness distribution of a resist film formed on a substrate using the comparative resist film drying apparatus shown in FIG. A wind pattern that can be visually confirmed is generated on the surface of the resist film 20, and it was confirmed that the resist film 20 was affected by thermal convection in the drying process. The difference between the maximum film thickness and the minimum film thickness was 15 μm, and the film thickness distribution was 20% of the average film thickness, indicating that the film was non-uniform.

  FIG. 7 is a view showing the film thickness distribution of the resist film formed on the substrate using the comparative resist film drying apparatus shown in FIG. In the resist film drying apparatus 11a, the distance between the surface of the resist film 20a applied to the substrate 19a and the lower surface of the convection suppression plate 13 was d = 6 mm. On the surface of the resist film 20a, although it was suppressed more than the resist film 20, a wind pattern was observed. Further, it was found that the difference between the maximum film thickness and the minimum film thickness was 10 μm or more and was not uniform.

  In the resist film drying apparatus 11a, although the convection suppressing plate 13 is disposed, the resist film 20a is affected by the air flow other than the thermal convection because the resist film 20a has a wind pattern. I understand that. That is, in the resist film drying apparatus 11a, it is considered that convection is generated in the sealed heating plate box 12a by generating an air flow toward the exhaust port 12b by being exhausted from the exhaust port 12b. .

  FIG. 8 is a view showing the film thickness distribution of the resist film formed on the substrate using the resist film drying apparatus 1 according to the present embodiment. The distance between the surface of the resist film applied to the substrate and the lower surface of the convection suppression plate 3 was d = 6 mm. No disturbance such as wind ripples was observed on the surface of the resist film. Further, the difference between the maximum film thickness and the minimum film thickness was 7 to 8 μm, and the film thickness distribution was within 10% of the average film thickness and was found to be uniform.

  This is because, in the resist film drying apparatus 1, the occurrence of thermal convection near the surface of the resist film is suppressed by the convection suppression plate 3, and the air flow caused by exhaust in the heating plate box 2 a is suppressed by the exterior exhaust cover 5. This is considered to be the effect of the occurrence being suppressed.

  In addition, the resist film drying apparatus 1 according to the present embodiment is used to form a resist film formed on the substrate with the distance between the surface of the resist film and the lower surface of the convection suppression plate 3 being d = 8 mm. It was found that the width was within about 10% of the thickness and was uniform.

  In addition, using the resist film drying apparatus 1 according to the present embodiment, a slight wind pattern is observed on the resist film formed on the substrate with the distance between the surface of the resist film and the lower surface of the convection suppression plate 3 being d = 10 mm. It was. Further, the difference between the maximum film thickness and the minimum film thickness was 10 μm or more and was non-uniform. This is because the effect of suppressing the thermal convection of the convection suppression plate 3 is weakened by increasing the distance between the surface of the resist film and the lower surface of the convection suppression plate 3, and thermal convection is generated near the surface of the resist film. it is conceivable that.

  FIG. 9 shows the film thickness distribution of the resist film formed on the substrate using the resist film drying apparatus 1 according to the present embodiment, with the distance between the surface of the resist film and the lower surface of the convection suppression plate 3 being d = 4 mm. It is a figure. Disturbances such as wind ripples were not confirmed on the surface of the resist film, and the effect of installing the convection suppression plate 3 and the exterior exhaust cover 5 was confirmed. However, the difference between the maximum film thickness and the minimum film thickness was 10 μm or more, and the film thickness was not uniform. This result is considered to suggest that when the surface of the resist film and the lower surface of the convection suppression plate 3 are brought closer to each other, it is necessary to further examine the temperature condition and the like.

  Table 1 summarizes the above results.

A: Good.
○: Disturbances such as wind ripples were not observed, but the difference between the maximum film thickness and the minimum film thickness was 10 μm or more.
Δ: Some wind ripples were observed.
X: Many wind ripples were seen.

  From this result, in the resist film drying apparatus 1, the effect of having installed the convection suppression board 3 and the exterior exhaust cover 5 has been confirmed. Moreover, in the resist film drying apparatus 1 according to the present embodiment, it is possible to suppress the variation in the film thickness of the resist film particularly when the distance between the surface of the resist film and the convection suppression plate is 6 mm or more and 8 mm or less. I understood.

  Further, using the resist film drying apparatus 1 according to the present embodiment, the film thickness distribution of the resist film formed on the substrate by changing the film thickness was evaluated in the same manner. As a result, in the resist film having an average film thickness after drying of 100 μm or less, the film thickness distribution was within about 10% of the average film thickness, and it was confirmed that a uniform film thickness was obtained. Therefore, according to the resist film drying apparatus according to the present embodiment, when a resist film having a thickness of 30 μm or more and 100 μm or less is formed, it is possible to suppress the variation in the thickness of the resist film particularly effectively.

  As described above, according to the resist film drying apparatus according to the present embodiment, it is possible to suppress the occurrence of wind ripples and the like and the variation in film thickness in the resist film without damaging the surrounding environment. can do.

It is the top view which showed the inside of the resist film application | coating drying apparatus provided with the resist film drying apparatus which concerns on one Embodiment of this invention. It is the side sectional view of the substrate conveyance direction of the heating plate part of the resist film drying apparatus concerning one embodiment of the present invention, and the side sectional view orthogonal to the substrate conveyance direction. It is the side sectional view of the substrate conveyance direction of the heating plate part of the resist film drying apparatus for comparison, and the side sectional view orthogonal to the substrate conveyance direction. It is the side sectional view of the substrate conveyance direction of the heating plate part of the resist film drying apparatus for comparison, and the side sectional view orthogonal to the substrate conveyance direction. It is the top view which showed the inside of the resist film application | coating drying apparatus provided with the resist film drying apparatus for a comparison. It is the figure which showed the film thickness distribution of the resist film formed in the board | substrate using the resist film drying apparatus shown in FIG. It is the figure which showed the film thickness distribution of the resist film formed in the board | substrate using the resist film drying apparatus shown in FIG. It is the figure which showed the film thickness distribution of the resist film formed in the board | substrate using the resist film drying apparatus shown in FIG. It is the figure which showed the film thickness distribution of the resist film formed in the board | substrate using the resist film drying apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resist film drying apparatus 2 Heating plate 2a Heating plate box 2b Proxy pin 2b
3 Convection Suppression Plate 3a Convection Suppression Plate Support Arm 3b Convection Suppression Plate Lifting Cylinder 4 Cooling Plate 5 Exterior Exhaust Cover 5a Exhaust Port 6 Sender 7 Spin Coater 8 Receiver 9 Substrate 10 Resist Film

Claims (13)

In a resist film drying apparatus having a heating means for heating a resist film containing a solvent component applied to a substrate,
A plate member having a lower surface disposed at a position facing the surface of the resist film so as to be close to the surface of the resist film; and an exhaust unit that exhausts air from outside the outer periphery of the lower surface of the plate member. A resist film drying apparatus.   The resist film drying apparatus according to claim 1, further comprising a wall member surrounding a periphery of a gap space formed between a surface of the resist film and a lower surface of the plate member.   The exhaust means has a cover member disposed to face the upper surface so as to cover the entire upper surface of the plate member, and is an area outside the portion of the cover member facing the outer periphery of the plate member The resist film drying apparatus according to claim 1, wherein an exhaust port is formed in the resist film drying apparatus.   The resist film drying apparatus according to claim 3, wherein an inclined surface that is inclined upward from a central region of the cover member toward the exhaust port is formed on a lower surface of the cover member.   The resist film drying apparatus according to claim 3, wherein the cover member and the wall member are disposed to be separated from each other.   The resist film drying apparatus according to claim 1, wherein a lower surface of the plate member covers the entire surface of the resist film.   The resist film drying apparatus according to any one of claims 1 to 6, wherein a distance between the surface of the resist film and a lower surface of the plate member is 6 mm or more and 8 mm or less. In a resist film drying method including an evaporation step of heating a resist film containing a solvent component applied to a substrate to evaporate the solvent component,
An arrangement step of disposing the plate member at a position where the lower surface of the plate member faces the surface of the resist film so as to be close to the surface of the resist film, and exhausting from above the outer periphery of the lower surface of the plate member. An exhaust process to be performed,
A resist film drying method, wherein the placement step and the exhaust step are started before the evaporation step is started at the latest.   The resist film drying method according to claim 8, wherein the disposing step includes disposing the plate member such that a lower surface of the plate member covers the entire surface of the resist film.   The resist film drying method according to claim 8 or 9, wherein the disposing step includes disposing the plate member such that a distance between a surface of the resist film and a lower surface of the plate member is 6 mm or more and 8 mm or less. .   The resist film drying method according to claim 8, wherein the evaporation step includes setting an average film thickness after drying of the resist film to 30 μm or more and 100 μm or less.   12. The method of drying a resist film according to claim 8, wherein the evaporation step is performed in a state in which a gap member formed between the resist film and the plate member is surrounded by a wall member.   13. The resist film drying method according to claim 8, wherein the evaporation step is performed in a state where the entire upper surface is covered with a cover member disposed to face the upper surface of the plate member.