Reduced pressure drying device

Abstract

A reduced-pressure drying apparatus is provided that can reduce variations in the exhaust flow rate of gas within a chamber within the surface of a coating film coated on a substrate. [Solution] The reduced pressure drying apparatus is provided in a chamber and comprises a support part 20 for supporting a substrate S and an exhaust port 30 for exhausting the air from inside the chamber, a rectifying plate 40 having an opening 40A is arranged above the substrate, and a side plate 50 is arranged to the side of the substrate to shield part of the gap between the support part and the rectifying plate, and when the pressure in the chamber is reduced, the area of ​​the opening provided in the rectifying plate and the area of ​​the gap between the support part and the rectifying plate that is not shielded by the side plate are adjusted so that the exhaust flow rate of gas becomes uniform in the space above the substrate.

Description

[Technical Field]

[0001] The present invention relates to a reduced pressure drying apparatus for drying a coating film formed on the surface of a substrate. [Background technology]

[0002] Perovskite solar cells, which use a perovskite film as the light-absorbing layer, can be manufactured inexpensively using a relatively low-temperature process because the perovskite film can be formed by coating.

[0003] A known method for forming a perovskite film involves applying a solution containing dissolved materials for the perovskite film onto a substrate using a spin coating method, then dropping a poor solvent for the perovskite compound to dry the applied film, and then annealing the applied film to form a crystallized perovskite film on the substrate (see Patent Document 1).

[0004] In the above method, the dropping of the poor solvent forms perovskite crystal nuclei in the coating film, and the subsequent annealing causes the perovskite to crystallize around the crystal nuclei. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 182058 Summary of the Invention [Problem to be solved by the invention]

[0006] In the method of drying a coating film by dropping a poor solvent, slight changes in the conditions for dropping the poor solvent can significantly change the formation of perovskite crystal nuclei, and therefore the crystalline state of the perovskite also changes significantly during subsequent annealing.

[0007] The crystalline state of perovskite films is an important factor that determines the photoelectric conversion efficiency of perovskite solar cells. Therefore, when a method of drying a coated film by dropping a poor solvent is used, it is possible to fabricate small cells with excellent crystallinity and high conversion efficiency at the laboratory level, but it has been difficult to fabricate large cells with excellent crystallinity and high conversion efficiency.

[0008] On the other hand, the formation of crystal nuclei in perovskite films varies greatly depending on the drying speed, so if the drying time is long, this leads to variations in the drying time, making it difficult to obtain a perovskite film with a stable crystal state.

[0009] Therefore, reduced-pressure drying is considered as a method for drying the coating film. In this method, the boiling point of the solvent in the coating film is lowered by reducing the pressure inside the chamber of the reduced-pressure drying device using a vacuum pump, which can speed up the drying speed of the coating film. A fast drying speed reduces variation in drying time, and it is expected that a perovskite film with a stable crystalline state can be obtained.

[0010] However, in conventional vacuum drying equipment, variations in the exhaust speed (exhaust flow rate) of the gas in the chamber occur within the plane of the coating film applied to the substrate, which also causes variations in the state of crystal nuclei formation in the perovskite film within the plane. This variation in the state of crystal nuclei formation within the plane leads to variations in the crystalline state of the perovskite film within the plane during subsequent annealing, making this a problem that must be solved in order to fabricate large cells with excellent crystallinity and high conversion efficiency.

[0011] The present invention has been made in consideration of the above points, and its main object is to provide a reduced-pressure drying apparatus that can reduce variations in the exhaust flow rate of gas within a chamber within the surface of a coating film applied to a substrate.

[0012] In particular, when a perovskite film is used as the coating film, the object is to provide a reduced-pressure drying apparatus that can form a uniform perovskite film with excellent crystallinity over a large area. [Means for solving the problem]

[0013] The reduced pressure drying apparatus of the present invention is a reduced pressure drying apparatus that dries a coating film formed on the surface of a substrate, and comprises a chamber that accommodates the substrate, a support part that is provided within the chamber and supports the substrate, and an exhaust port that is provided on the upper or lower wall of the chamber and is connected to an exhaust means that evacuates the inside of the chamber, a straightening plate having an opening in its center is arranged above the substrate supported by the support part, and a side plate that shields part of the gap between the support part and the straightening plate is arranged to the side of the substrate supported by the support part, and when gas in the chamber is exhausted from the exhaust port to reduce the pressure in the chamber, the area of ​​the opening provided in the straightening plate and the area of ​​the gap between the support part and the straightening plate that is not shielded by the side plate are adjusted so that the exhaust flow rate of the gas is uniform in the space above the substrate supported by the support part. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a reduced-pressure drying apparatus capable of reducing variations in the exhaust flow rate of gas within a chamber within the plane of a coating film coated on a substrate.

[0015] In particular, when a perovskite film is used as the coating film, it is possible to provide a reduced pressure drying apparatus that is capable of forming a uniform perovskite film with excellent crystallinity over a large area. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a reduced-pressure drying apparatus according to one embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the flow of gas in the space above the substrate when the pressure in the chamber is reduced. [Figure 3] FIG. 3 is a diagram illustrating a method for calculating the conductance at an arbitrary point in space on a substrate. [Figure 4]4(A) to 4(D) are graphs obtained by simulation of the relative values ​​of exhaust flow rates at various points from the edge to the center of the substrate when the gap between the support portion and the current plate is changed. [Figure 5] FIG. 5 is a graph showing the relative values ​​of the exhaust flow rate when only a straightening plate without an opening is provided and no side plate is provided. [Figure 6] FIG. 6 shows a method for evaluating the in-plane distribution of crystal size in a perovskite film. [Figure 7] 7(A) to 7(D) are diagrams showing the in-plane distribution of peak intensity after drying the perovskite film. [Figure 8] FIG. 8 is a diagram showing an example of the arrangement of the side plates. [Figure 9] FIG. 9 is a diagram showing another example of the arrangement of the side plates. [Figure 10] FIG. 10 is a diagram showing another example of the arrangement of the side plates. [Figure 11] FIG. 11 is a diagram showing another example of the arrangement of the side plates. [Figure 12] FIG. 12 is a diagram showing an example of adjusting the area of ​​the opening of the current plate. [Figure 13] FIG. 13 is a diagram showing another example of adjusting the area of ​​the opening of the current plate. DETAILED DESCRIPTION OF THE INVENTION

[0017] 1 is a cross-sectional view showing a schematic configuration of a reduced-pressure drying apparatus according to one embodiment of the present invention. The reduced-pressure drying apparatus according to this embodiment is an apparatus for drying a coating film formed on the surface of a substrate. The type of coating film is not particularly limited.

[0018] 1, the reduced-pressure drying apparatus 1 of this embodiment includes a chamber 10 that accommodates a substrate S, a support 20 that is provided within the chamber 10 and supports the substrate S, and an exhaust port 30 that is provided on a bottom wall 10a of the chamber 10 and is connected to an exhaust means P that evacuates the inside of the chamber 10. The support 20 is held to the bottom wall 10a of the chamber 10 by supports 22. The height of the substrate S is adjusted by a plurality of lift pins 21.

[0019] A rectifying plate 40 having an opening 40A in the center is disposed above the substrate S supported by the support part 20. The rectifying plate 40 is disposed so as to cover the entire surface of the substrate S in a plan view. The rectifying plate 40 is held to the upper wall 10b of the chamber 10 by supports 12.

[0020] A side plate 50 that shields part of a gap 60 between the support part 20 and the rectifying plate 40 is fixed to the support part 20 and disposed on the side of the substrate S supported by the support part 20. This leaves a gap 60A with a distance L between the support part 20 and the rectifying plate 40 that is not shielded by the side plate 50. Here, the gap 60 between the support part 20 and the rectifying plate 40 includes a gap 70 between the support part 20 and the substrate S and a gap 80 between the substrate S and the rectifying plate 40.

[0021] The chamber 10 is configured so that a first chamber 10A that holds the current plate 40 and a second chamber 10B that holds the support part 20 can be separated from each other. The inside of the chamber 10 is sealed by placing the first chamber 10A on the second chamber 10B via an O-ring 13.

[0022] 2, when the gas in the chamber 10 is exhausted by the exhaust means P through the exhaust port 30 to reduce the pressure in the chamber 10, the gas in the space above the substrate S is divided into two flows, one directed toward the exhaust port 30 through the opening 40A provided in the rectifying plate 40, and the other directed toward the exhaust port 30 through the gap 60A between the support part 20 and the rectifying plate 40 that is not shielded by the side plate 50, as shown by the arrows in the figure, and is then exhausted to the outside from the exhaust port 30. In the space above the substrate S, the exhaust flow rate of the gas at each point from the center to the edge of the substrate S (points indicated by black circles in the figure) is determined by these two gas flows.

[0023] The reduced pressure drying apparatus 1 in this embodiment is characterized in that, when exhausting gas from the chamber 10 through the exhaust port 30 and reducing the pressure in the chamber 10, the area of ​​the opening 40A provided in the straightening plate 40 and the area of ​​the gap 60A between the support part 20 and the straightening plate 40 that is not shielded by the side plate 50 are adjusted so that the gas exhaust flow rate is uniform in the space above the substrate S supported by the support part 20.

[0024] [Exhaust flow rate calculation] A method for obtaining a relative comparison of the exhaust flow rate of gas at each point (points indicated by black circles in FIG. 2) from the center to the edge of the substrate S in the space above the substrate S by simulation will be described. This simulation is performed by calculating, for each point indicated by black circles in FIG. 2, the conductance of the gas flow path toward the exhaust port 30 through the opening 40A provided in the current plate 40, and the conductance of the gas flow path toward the exhaust port 30 through the gap 60A between the support part 20 and the current plate 40 that is not shielded by the side plate 50, and then relatively comparing the total conductance at each point.

[0025] For example, as shown in FIG. 3, the conductance C at an arbitrary point A (indicated by a black circle) in the space on the substrate S is T is the three conductances C A , C B , and C C can be calculated as the combined conductance of

[0026] C T =1 / (C A +C B )+1 / C C where C A is the conductance in the flow path from point A through opening 40A to confluence point B (point indicated by a black circle) where the gas flowing from point A toward exhaust port 30 through opening 40A and the gas flowing from point A toward exhaust port 30 through gap 60A meet. B is the conductance in the flow path from point A through the gap 60A to the junction B. Also, the conductance C C is the conductance in the flow path from the junction B to the exhaust port 30.

[0027] In addition, the above conductance C A , C B , and C C The calculation of the conductance of a flow path and an opening of a given length can be performed based on the well-known formulas for calculating the conductance of a "rectangular tube" and the conductance of an "orifice", respectively.

[0028] Also, the above conductance C A and C B varies depending on the distance from point A to the opening 40A and gap 60A, the area of ​​the opening 40A and gap 60A, the distance between the rectifying plate 40 and the substrate S and the chamber upper wall 10b, and the like.

[0029] Using the above method, the conductances obtained at two adjacent points A1 and A2 at each point from the center to the edge of the substrate S shown in Figure 2 are calculated as C T1 , C T2 Then, the exhaust flow rates Q1 and Q2 at points A1 and A2 can be calculated using the following equations, respectively.

[0030] Q1=C T1 ×(P1-P0) Q2=C T2 ×(P2-P0) where P0 is the pressure of the vacuum source.

[0031] The pressure difference (P1-P2) between adjacent points A1 and A2 is sufficiently small compared to the pressure difference between each point A1, A2 and the vacuum source, so it can be ignored. Therefore, the ratio (Q1 / Q2) of the exhaust flow rates Q1 and Q2 at adjacent points A1 and A2 is T1 , C T2 The ratio (C T1 / C T2 )

[0032] In this way, the relative ratio (relative value) of the gas exhaust flow rate at each point (points indicated by black circles in Figure 2) from the center to the edge of the substrate S in the space above the substrate S can be determined from the relative ratio of the conductance determined at each point from the center to the edge of the substrate S.

[0033] [Evaluation of variation in exhaust flow rate within the substrate surface] 4(A) to 4(D) are graphs obtained by simulation of the relative ratios (relative values) of exhaust flow rates obtained at each point from the edge to the center of the substrate S when the opening 40A provided in the current vane 40 in the reduced-pressure drying apparatus 1 shown in Fig. 1 is a circle with a diameter φ of 200 mm and the distance L of the gap 60A between the support part 20 not shielded by the side plate 50 and the current vane 40 is changed to 0 mm, 3 mm, 6 mm, and 10 mm. The calculations were performed assuming that the size of the substrate S was a rectangle with a length of 370 mm and a width of 500 mm and the distance between the substrate S and the current vane 40 was 5 mm.

[0034] 4(A) to 4(D), the horizontal axis represents the distance (mm) from the edge of the substrate S, and the right end (250 mm) of the horizontal axis represents the center of the substrate S. For comparison, FIG. 5 shows a graph showing the relative values ​​of the exhaust flow rate when only the rectifying plate 40 without the opening 40A is provided and no side plate 50 is provided.

[0035] 4(A), when the distance L of the gap 60A is 0 mm, the gas in the space above the substrate S is blocked from flowing through the gap 60A toward the exhaust port 30, and only flows through the opening 40A toward the exhaust port 30. Therefore, the exhaust flow rate at the center of the substrate S is relatively larger than the exhaust flow rate at the edge of the substrate S, and the variation in the exhaust flow rate within the surface of the substrate S becomes large.

[0036] 4(D), when the distance L of the gap 60A is 10 mm, the flow passing through the gap 60a toward the exhaust port 30 is greater than the flow passing through the opening 40A toward the exhaust port 30. Therefore, the exhaust flow rate at the edge of the substrate S is relatively greater than the exhaust flow rate at the center of the substrate S, and the variation in the exhaust flow rate within the surface of the substrate S becomes greater.

[0037] 5, when only the rectifying plate 40 without the openings 40A is provided and the side plate 50 is not provided, the gas in the space above the substrate S flows only through the gap between the substrate S and the rectifying plate 40 toward the exhaust port 30. Therefore, the exhaust flow rate at the edge of the substrate S is relatively larger than the exhaust flow rate at the center of the substrate S, and the variation in the exhaust flow rate within the surface of the substrate S becomes large.

[0038] In contrast, as shown in Figures 4(B) and (C), when the spacing L of gap 60A is 3 mm or 6 mm, the flow through gap 60a toward exhaust port 30 and the flow through opening 40A toward exhaust port 30 are balanced, resulting in smaller variations in the exhaust flow rate within the surface of substrate S.

[0039] [Evaluation of the in-plane distribution of crystal size in perovskite films] To evaluate the effect of variations in exhaust flow rate within the substrate surface on the crystallinity of the coating film, a coating film made of a perovskite material was formed on the surface of substrate S, and the coating film was dried using reduced-pressure drying equipment 1. The in-plane distribution of the crystal size of the perovskite film was evaluated to evaluate the crystallinity of the perovskite film.

[0040] The inventors of the present application have disclosed in the specification of Japanese Patent Application No. 2024-023645 a method for evaluating the in-plane distribution of crystal size in a perovskite film, utilizing the fact that the peak intensity of the emission spectrum obtained by irradiating a perovskite film with excitation light serves as an index for evaluating the crystal size of the perovskite film.

[0041] FIG. 6 is a diagram showing a method for evaluating the in-plane distribution of crystal size of the perovskite film P.

[0042] As shown in Figure 6, the excitation light is irradiated onto the perovskite film P while a light source 90 that irradiates the excitation light is moved to multiple measurement positions M within the plane of the perovskite film P, and the peak intensity of the emission spectrum obtained from the perovskite film P is acquired, thereby enabling the in-plane distribution of crystal size in the perovskite film P to be evaluated.

[0043] 7(A) to 7(D) are diagrams showing the in-plane distribution of peak intensity of the perovskite film P obtained by the above-mentioned method after drying the perovskite film P using the reduced-pressure drying apparatus 1 shown in FIG. 1. Here, FIGS. 7(A) to 7(D) respectively show the in-plane distribution of peak intensity when the perovskite film P is dried under the same conditions as the side plate 50 arrangement shown in the graphs of FIGS. 4(A) to 4(D). In the in-plane distributions shown in FIGS. 7(A) to 7(D), the magnitude of the peak intensity at each measurement position M is displayed in patterns, with the pattern with a larger number indicating a larger crystal size.

[0044] Table 1 shows the relationship between the in-plane variation of the exhaust flow rate shown in FIGS. 4(A) to 4(D) and the in-plane variation of the crystal size shown in FIGS. 7(A) to 7(D).

[0045] [Table 1]

[0046] As shown in Table 1, it can be seen that the greater the in-plane variation in the exhaust flow rate, the greater the in-plane variation in the crystal size of the perovskite film. In other words, by adjusting the distance L (area) of the gap 60A between the support part 20 that is not shielded by the side plate 50 and the flow straightening plate 40, the in-plane variation in the exhaust flow rate can be reduced, and thereby the in-plane variation in the crystal size of the perovskite film can be reduced.

[0047] The relative value of the exhaust flow rate at each point from the edge to the center of the substrate S is calculated by the conductance C at any point A in the space above the substrate S shown above. T As can be seen from the calculation, it also varies depending on the diameter φ (area) of the openings 40A provided in the rectifying vane 40. Therefore, by adjusting the diameter φ (area) of the openings 40A provided in the rectifying vane 40, it is possible to reduce the in-plane variation in the exhaust flow rate, and thereby reduce the in-plane variation in the crystal size of the perovskite film.

[0048] That is, in this embodiment, by adjusting the area of ​​the opening 40A provided in the rectifying plate 40 and the area of ​​the gap 60A between the support part 20 and the rectifying plate 40 that is not shielded by the side plate 50, it is possible to reduce in-plane variations in the gas exhaust flow rate when reducing the pressure inside the chamber 10. This makes it possible to form a uniform perovskite film with excellent crystallinity over a large area, for example, when drying a coating film made of a perovskite material.

[0049] 1, when the pressure inside the chamber 10 is reduced, the flow of gas in the space above the substrate S toward the exhaust port 30, in other words, the conductance from the center to the edge of the substrate S, is also affected by the structure of the reduced-pressure drying apparatus 1, such as the distance between the upper wall 10b of the chamber 10 and the current rectifying plate 40, the distance between the substrate S supported by the support member 20 and the current rectifying plate 40, and the distance between the edge of the current rectifying plate 40 and the side wall 10c of the chamber 10. Therefore, it is preferable to adjust the area of ​​the opening 40A provided in the current rectifying plate 40 and the area of ​​the gap 60A between the support member 20 and the current rectifying plate 40 that is not shielded by the side plate 50, according to the above-mentioned setting conditions.

[0050] [Side panel placement] In the side plate 50 illustrated in Figure 1, one end of the side plate 50 is fixed to the support portion 20, and the area of ​​the gap 60A between the support portion 20 and the rectifying plate 40 that is not shielded by the side plate 50 is adjusted by the distance of the gap between the other end of the side plate 50 and the rectifying plate 40. However, as shown in Figure 8, one end of the side plate 50 may be fixed to the rectifying plate 40, and the area of ​​the gap 60A between the support portion 20 and the rectifying plate 40 that is not shielded by the side plate 50 may be adjusted by the distance of the gap between the other end of the side plate 50 and the support portion 20.

[0051] Also, as shown in Figure 9, a side plate 50 having an opening 50a may be fixed and positioned on the support part 20 or the rectifying plate 40, and the area of ​​the gap 60A between the support part 20 and the rectifying plate 40 that is not blocked by the side plate 50 may be adjusted by adjusting the area of ​​the opening 50a provided in the side plate 50.

[0052] In this case, as shown in FIG. 10, two side plates 50 each having a plurality of openings 50a arranged in a regular pattern may be prepared, and the area of ​​the openings 50a may be adjusted by sliding and positioning the two side plates 50.

[0053] 11, the side plate 50 may be composed of a first side plate 50A, one end of which is fixed to the rectifying plate 40 and the other end of which has a gap between it and the support part 20, and a second side plate 50B, one end of which is fixed to the support part 20 and the other end of which has a gap between it and the rectifying plate 40. In this case, the area of ​​the gap between the support part 20 and the rectifying plate 40 that is not shielded by the side plate 50 is adjusted by adjusting the width W of the overlapping region of the first side plate 50A and the second side plate 50B and the distance G between the first side plate 50A and the second side plate 50B.

[0054] 1, 8, and 9, when attempting to adjust the area of ​​gap 60A between support part 20 and rectifying plate 40 that is not shielded by side plate 50 using only one side plate 50, there is a risk that the distance of gap 60A will also change if the way O-ring 13 between first chamber 10A and second chamber 10B is compressed changes due to a decrease in pressure inside chamber 10. In particular, when the distance of gap 60A needs to be adjusted to about several millimeters, the way O-ring 13 is compressed not only significantly affects the conductance of gap A, but there is also a risk of interference between side plate 50 and support part 20 or rectifying plate 40.

[0055] To address this problem, as shown in Figure 11, side plate 50 is made up of two side plates 50A and 50B, and the overlap width W of the two side plates 50A and 50B and the distance G between them can be adjusted to the conductance required for gap A. By increasing the overlap width W of the two side plates 50A and 50B, the effect of the crushing of O-ring 13 on conductance can be reduced.

[0056] In the overlapping region of the two side plates 50A, 50B, the conductance is due to the rectangular tube, and is therefore greater than the conductance due to the orifice in gap A. In addition, the conductance provided by the two side plates 50A, 50B can be adjusted using two parameters: the overlap width W of the two side plates 50A, 50B, and the distance G between the two side plates 50A and 50B. This allows for more precise control of the exhaust flow rate in areas with large conductance (low exhaust speed areas).

[0057] [Adjusting the opening area of ​​the straightening plate] FIG. 12 is a diagram showing an example of adjusting the area of ​​the opening 40A of the current plate 40. In FIG.

[0058] 12, in a reduced-pressure drying apparatus 1 in which a rectifying plate 40 having openings 40A is disposed, the first chamber 10A holding the rectifying plate 40 is separated from the second chamber 10B holding the support part 20, and a rectifying plate 41 having openings 41A smaller in area than the openings 40A is slid between the first chamber 10A and the second chamber 10B and disposed on top of the rectifying plate 40. This allows the area of ​​the openings 40A of the rectifying plate 40 to be changed to the area of ​​the openings 41A of the rectifying plate 41. In this way, by preparing a plurality of rectifying plates 40 having openings 40A with different areas, the area of ​​the openings 40A can be easily adjusted.

[0059] Furthermore, with the first chamber 10A separated from the second chamber 10B, the rectifying plate 40 having the opening 40A may be replaced with a rectifying plate 41 having an opening 41A with a different area.

[0060] Alternatively, multiple openings 41A may be formed in the rectifying plate 41, and the area of ​​each opening may be changed for adjustment. Furthermore, in order to suppress a sudden change in the exhaust flow rate (exhaust speed) at the openings 40A, two rectifying plates 41 having openings 40A with different areas may be prepared and the two rectifying plates 41 may be arranged in double, spaced apart from each other. Alternatively, the outer periphery of the openings 40A may be made mesh-like.

[0061] 13, the flow straightening plate 41 may be made to protrude beyond the side plate 50 toward the side wall 10c of the chamber 10, and an opening 40B may be provided in the protruding portion, and the area of ​​the opening 40B may be adjusted to adjust the exhaust flow rate of the gas flowing between the flow straightening plate 31 and the upper wall 10b of the chamber 10. The area of ​​the opening 40B may be adjusted by the same method as that shown in FIG.

[0062] Furthermore, by adjusting or replacing the side plate 50 while the first chamber 10A is separated from the second chamber 10B, the area of ​​the gap 60A between the support portion 20 and the straightening plate 40 can be easily adjusted.

[0063] As described above, when the reduced-pressure drying apparatus 1 in this embodiment exhausts gas from the chamber 10 through the exhaust port 30 to reduce the pressure in the chamber 10, the area of ​​the opening 40A provided in the straightening plate 40 and the area of ​​the gap between the support part 20 and the straightening plate 40 that is not shielded by the side plate 50 are adjusted so that the gas exhaust flow rate is uniform in the space above the substrate S supported by the support part 20, thereby reducing the variation in the gas exhaust flow rate in the chamber 10 within the surface of the coating film applied to the substrate S.

[0064] In particular, in a reduced-pressure drying apparatus that dries a coating film made of a perovskite material, the in-plane distribution of the crystalline state of the perovskite film can be controlled by adjusting the area of ​​the opening 40A provided in the current plate 40 and the area of ​​the gap 60A between the support part 20 and the current plate 40 that is not blocked by the side plate 50. This makes it possible to form a uniform perovskite film with excellent crystallinity over a large area.

[0065] While the present invention has been described above with reference to preferred embodiments, these descriptions are not limiting and various modifications are possible. For example, although the exhaust port 30 is provided in the lower wall 10a of the chamber 10 in the above embodiment, it may also be provided in the upper wall 10b of the chamber 10. In this case, a current plate 40 having an opening 40A is disposed above the substrate S, and a side plate 50 is disposed to the side of the substrate S to block a portion of the gap between the support member 20 and the current plate 40. When the pressure in the chamber 10 is reduced, the area of ​​the opening 40A in the current plate 40 and the area of ​​the gap 60A between the support member 20 and the current plate 40 that is not blocked by the side plate 50 can be adjusted so that the exhaust flow rate of gas is uniform in the space above the substrate S. [Explanation of symbols]

[0066] 1. Vacuum drying device 10 Chambers 10A First Chamber 10B Second chamber 10a Lower wall of chamber 10b Upper wall of the chamber 10c Chamber side wall 11, 12 posts 13 O-ring 20 Support part 21 Lift pin 30 exhaust port 40, 41 Rectifier plate 40A, 40B, 41A Openings of the rectifier plate 50 Side panel 50A First side panel 50B Second side panel 50a opening 60 Gap between support and straightening plate 60A Gap between the support part not shielded by the side plate and the rectifier plate 70 Gap between support and substrate 80 Gap between the board and the rectifier plate 90 light source

Claims

1. A reduced pressure drying apparatus for drying a coating film formed on a surface of a substrate, a chamber containing the substrate; a support provided in the chamber and supporting the substrate; an exhaust port provided in an upper wall or a lower wall of the chamber and connected to an exhaust means for exhausting the inside of the chamber; Equipped with a current plate having an opening is disposed above the substrate supported by the support portion; a side plate that shields a part of a gap between the support portion and the rectifying plate is disposed on a side of the substrate supported by the support portion; A reduced-pressure drying apparatus in which, when the gas in the chamber is exhausted from the exhaust port to reduce the pressure in the chamber, the area of ​​the opening provided in the straightening plate and the area of ​​the gap between the support part and the straightening plate that is not shielded by the side plate are adjusted so that the exhaust flow rate of the gas is uniform in the space above the substrate supported by the support part.

2. 2. The reduced pressure drying apparatus of claim 1, wherein the area of ​​the opening provided in the rectifying plate and the area of ​​the gap between the support portion and the rectifying plate that is not shielded by the side plate are adjusted according to the distance between the upper wall of the chamber and the rectifying plate, the distance between the substrate supported on the support portion and the rectifying plate, and the distance between the end of the rectifying plate and the side wall of the chamber.

3. The side plate has an opening, 2. The reduced pressure drying apparatus according to claim 1, wherein the adjustment of the area of ​​the gap between the support portion and the straightening plate that is not shielded by the side plate is performed by adjusting the area of ​​an opening provided in the side plate.

4. The side plate is a first side plate having one end fixed to the current plate and the other end having a gap between it and the support portion; a second side plate having one end fixed to the support portion and the other end having a gap between it and the straightening plate; It is composed of 2. The reduced pressure drying apparatus according to claim 1, wherein the adjustment of the area of ​​the gap between the support portion and the straightening plate that is not shielded by the side plate is performed by adjusting the width of the area where the first side plate and the second side plate overlap and the distance between the first side plate and the second side plate.

5. the chamber is configured such that a first chamber that holds the current vane and a second chamber that holds the support portion are separable from each other, 2. The reduced pressure drying apparatus according to claim 1, wherein the adjustment of the area of ​​the opening provided in the straightening vane and the area of ​​the gap between the support portion and the straightening vane that is not shielded by the side plate is performed while the first chamber and the second chamber are separated from each other.

6. the coating film is a perovskite film, 2. The reduced-pressure drying apparatus according to claim 1, wherein the in-plane distribution of the crystalline state of the perovskite film is controlled by adjusting the area of ​​the opening provided in the current plate and the area of ​​the gap between the support portion and the current plate that is not shielded by the side plate.

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