Reduced pressure drying device

Abstract

Provided is a reduced pressure drying device capable of reducing variation in an exhaust flow rate of a gas in a chamber in a plane of a coating film applied on a substrate. Specifically, the reduced pressure drying device is provided within a chamber and includes a support portion 20 for supporting a substrate S and an exhaust port 30 for exhausting air from the chamber. A rectifying plate 40 having an opening 40A is arranged above the substrate, a side plate 50 is arranged on a side of the substrate to shield part of a gap between the support portion and the rectifying plate, and when pressure within the chamber is reduced, 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 so that the exhaust flow rate of gas becomes uniform in a space above the substrate.

Description

Reduced pressure drying device

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

[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.

[0005] International Publication No. 2019 / 182058

[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 reduced-pressure drying apparatuses, 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 in 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.

[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.

[0014] According to the present invention, it is possible to provide a reduced-pressure drying apparatus that can reduce 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, a reduced-pressure drying apparatus can be provided that is capable of forming a uniform perovskite film with excellent crystallinity over a large area.

[0016] FIG. 1 is a cross-sectional view schematically illustrating the configuration of a reduced-pressure drying apparatus according to one embodiment of the present invention. FIG. 2 is a diagram illustrating the flow of gas in the space above the substrate when the pressure in the chamber is reduced. FIG. 3 is a diagram illustrating a method for calculating the conductance at any point in the space above the substrate. FIGS. 4A to 4D 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 member and the current plate is changed. FIG. 5 is a graph illustrating the relative values ​​of exhaust flow rates when only a current plate without an opening is provided and no side plate is provided. FIG. 6 is a diagram illustrating a method for evaluating the in-plane distribution of crystal size in a perovskite film. FIGS. 7A to 7D are diagrams illustrating the in-plane distribution of peak intensity after drying a perovskite film. FIG. 8 is a diagram illustrating an example of a side plate arrangement. FIG. 9 is a diagram illustrating another example of a side plate arrangement. FIG. 10 is a diagram illustrating another example of a side plate arrangement. FIG. 11 is a diagram illustrating another example of a side plate arrangement. Fig. 12 is a diagram showing an example of adjusting the area of ​​the opening of the current plate, and Fig. 13 is a diagram showing another example of adjusting the area of ​​the opening of the current plate.

[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 in a bottom wall 10a of the chamber 10 and is connected to an exhaust means P that exhausts 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 current plate 40 having an opening 40A in the center is disposed above the substrate S supported by the support portion 20. The current plate 40 is disposed so as to cover the entire surface of the substrate S in a plan view. The current plate 40 is held to the upper wall 10b of the chamber 10 by supports 12.

[0020] A side plate 50 that shields a 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 of 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, as shown by the arrows in the figure: one flow passing through the opening 40A in the current plate 40 toward the exhaust port 30, and the other flow passing through the gap 60A between the support part 20 and the current plate 40 that is not shielded by the side plate 50, toward the exhaust port 30, 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 becomes uniform in the space above the substrate S supported by the support part 20.

[0024] [Calculation of Exhaust Flow Rate] A method will be described below for obtaining, by simulation, a relative comparison of the exhaust flow rate of gas at each point (points indicated by black circles in FIG. 2) in the space above the substrate S from the center to the edge of the substrate S. This simulation is performed by calculating, for each point indicated by a black circle in FIG. 2, the conductance in the gas flow path toward the exhaust port 30 through the opening 40A provided in the current plate 40, and the conductance in 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 Ｔ is the following three conductances C Ａ , C Ｂ , and C Ｃ can be calculated as the combined conductance of

[0026] C Ｔ = 1 / (C Ａ +CＢ ) + 1 / C Ｃ Here, 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 at point B. Also, conductance C 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] The 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 determining the conductance of a "rectangular tube" and the conductance of an "orifice", respectively.

[0028] Moreover, the 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 current plate 40 and the substrate S and the chamber upper wall 10b, and the like.

[0029] By the above method, at each point from the center to the edge of the substrate S shown in FIG. 2, two adjacent points A １ , A ２ The conductance calculated in Ｔ１ , C Ｔ２ Then, point A １ , A ２ Exhaust flow rate Q １ , Q ２ can be calculated using the following formulas, respectively.

[0030] Q １ =C Ｔ１ × (P １ -P ０ ) Q ２ =C Ｔ２ × (P ２-P ０ ) where P ０ is the pressure of the vacuum source.

[0031] Adjacent point A １ , A ２ The pressure difference (P １ -P ２ ) is each point A １ , A ２ Since the pressure difference between the point A and the vacuum source is sufficiently small, it can be ignored. １ , A ２ Exhaust flow rate Q １ , Q ２ The ratio (Q １ / Q ２ ) is adjacent point A １ , A ２ Conductance C at 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] 4A to 4D are graphs obtained by simulation of the relative ratios (relative values) of the 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 that is 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] 4A to 4D, 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, a graph of the relative values ​​of the exhaust flow rate when only the flow rectifying plate 40 without the opening 40A is provided and no side plate 50 is provided is shown in FIG.

[0035] 4A, 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, if only the rectifying plate 40 without the openings 40A is provided and no side plate 50 is provided, the gas in the space above the substrate S will only flow toward the exhaust port 30 through the gap between the substrate S and the rectifying plate 40. Therefore, the exhaust flow rate at the edge of the substrate S will be 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 will be large.

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

[0039] [Evaluation of in-plane distribution of crystal size of perovskite film] In order 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 the substrate S, and the coating film was dried using the reduced-pressure drying apparatus 1. The in-plane distribution of the crystal size of the perovskite film was evaluated as an evaluation of the crystallinity of the perovskite film.

[0040] The present inventors 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-described 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 different patterns, with larger numbers indicating larger crystal sizes.

[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]

[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 exhaust flow rate of gas 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 portion 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 portion 20 and the current rectifying plate 40 that is not shielded by the side plate 50, according to the above-mentioned setting conditions.

[0050] [Arrangement of side plates] 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 straightening plate 40, and the area of ​​the gap 60A between the support part 20 and the straightening 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 Figure 10, two side plates 50 with multiple openings 50a arranged in a regular pattern may be prepared, and the area of ​​the openings 50a may be adjusted by sliding and positioning these two side plates 50.

[0053] 11 , the side plate 50 may be configured with a first side plate 50A having one end fixed to the current plate 40 and the other end having a gap between it and the support portion 20, and a second side plate 50B having one end fixed to the support portion 20 and the other end having a gap between it and the current plate 40. In this case, the area of ​​the gap between the support portion 20 and the current 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 in which O-ring 13 between first chamber 10A and second chamber 10B is compressed changes due to a reduction in pressure within chamber 10. In particular, when the distance of gap 60A needs to be adjusted to about several mm, the way in which 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 FIG. 11 , the side plate 50 is constructed from two side plates 50A and 50B, and the overlap width W of the two side plates 50A and 50B and the distance G between the two side plates 50A and 50B can be adjusted to the conductance required for the gap A. By increasing the overlap width W of the two side plates 50A and 50B, the effect of the crushing of the O-ring 13 on the 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 the gap A. 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] [Adjustment of Opening Area of ​​Straightening Plate] FIG. 12 is a diagram showing an example of adjusting the area of ​​the opening 40A of the straightening plate 40. In FIG.

[0058] 12 , in a reduced-pressure drying apparatus 1 having a current plate 40 with openings 40A, the first chamber 10A holding the current plate 40 is separated from the second chamber 10B holding the support part 20, and a current plate 41 having an opening 41A with an area smaller than that of the current plate 40A is slid between the first chamber 10A and the second chamber 10B and placed on top of the current plate 40. This allows the area of ​​the openings 40A of the current plate 40 to be changed to the area of ​​the openings 41A of the current plate 41. In this way, by preparing a plurality of current 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 current plate 40 having the opening 40A may be replaced with a current 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 a double layer at a distance from each other. Alternatively, the outer periphery of the openings 40A may be meshed.

[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 a method similar to 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, in the reduced pressure drying apparatus 1 of this embodiment, when the gas in the chamber 10 is exhausted from 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 shielded 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, in the above embodiment, the exhaust port 30 is provided in the lower wall 10a of the chamber 10, but 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.

[0066] REFERENCE SIGNS LIST 1 reduced pressure drying apparatus 10 chamber 10A first chamber 10B second chamber 10a lower wall of chamber 10b upper wall of chamber 10c side wall of chamber 11, 12 support 13 O-ring 20 support part 21 lift pin 30 exhaust port 40, 41 current rectifier 40A, 40B, 41A opening of current rectifier 50 side plate 50A first side plate 50B second side plate 50a opening 60 gap between support part and current rectifier 60A gap between support part and current rectifier not shielded by side plate 70 gap between support part and substrate 80 gap between substrate and current rectifier 90 light source

Claims

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

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

4. The reduced pressure drying apparatus of claim 1, wherein the side plates are composed of a first side plate having one end fixed to the straightening plate and the other end having a gap between it and the support part, and a second side plate having one end fixed to the support part and the other end having a gap between it and the straightening plate, and the area of ​​the gap between the support part and the straightening plate that is not shielded by the side plates is adjusted 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 reduced pressure drying apparatus of claim 1, wherein the chamber is configured such that a first chamber that holds the straightening plate and a second chamber that holds the support part are separable from each other, and the adjustment of 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 is performed with the first chamber and the second chamber separated from each other.

6. A reduced-pressure drying apparatus as described in claim 1, wherein the coating film is a perovskite film, and the in-plane distribution of the crystalline state of the perovskite film is controlled by adjusting 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.

Images