Heating apparatus and heating method

Abstract

To provide a heating apparatus and a heating method which can stably produce a high-quality thin film.SOLUTION: A heating apparatus is used for heating a base material formed with a thin film on a surface, and comprises: a main heating unit capable of short-time heating of less than one second; a preliminary heating unit having a heating mechanism capable of long-time heating longer than the main heating unit; a transfer unit transferring the base material from a first region heated by the preliminary heating unit toward a second region heated by the main heating unit; a first chamber at least storing the preliminary heating unit; and an exhaust port exhausting an atmospheric gas in the first chamber.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a heating device and a heating method for heating a substrate having a thin film formed on its surface.

Background Art

[0002] In recent years, in fields such as solar cells, perovskite films have been actively studied because high photoelectric conversion efficiency can be expected. In addition, since a perovskite film can be composed of a material having high solubility in a solvent, film formation by a solution process is possible.

[0003] For example, Patent Document 1 below proposes instantaneously heating a perovskite film formed by a solution process such as spin coating in order to obtain a perovskite film having higher crystallinity with a flash lamp.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the inventors of the present invention have noticed that when a perovskite film is formed by a solution process and then heated by a flash lamp as shown in Patent Document 1, there may be a problem of deterioration in the film quality of the perovskite film after heating.

[0006] In view of the above, an object of the present invention is to provide a heating device and a heating method capable of stably manufacturing a thin film with high film quality.

Means for Solving the Problems

[0007] The heating device according to the present invention is A heating device for heating a substrate having a thin film formed on its surface, This heating unit capable of heating for a short time of less than 1 second, A preheating unit having a heating mechanism capable of heating for a longer time than the main heating unit, A transfer unit for transferring the substrate from a first region heated by the preheating unit to a second region heated by the main heating unit, A first chamber in which at least the preheating unit is accommodated, and an exhaust port for exhausting the atmospheric gas in the first chamber, which is characterized in that.

[0008] In this specification, the "thin film" refers to a film having a film thickness of about 1 nm to 10 μm formed by a solution process such as spin coating, dropwise method, inkjet method, etc. Note that the "thin film" in this specification is a concept including a state in which the solvent used during formation remains.

[0009] The main heating unit is capable of instantaneously heating a thin film made of, for example, a perovskite film. As an example, the main heating unit is composed of a flash lamp. By instantaneously heating a thin film made of, for example, a perovskite film with a flash lamp, the film quality of the thin film can be improved.

[0010] In this specification, the "perovskite film" refers to a film composed of crystals exhibiting a perovskite structure. The perovskite structure is represented by the structural formula ABX3, such as CH3NH3PbI3. As an example, in the case of an organometallic halogen compound, A is an organic group containing carbon, B is a metal element such as lead, and X is a halogen element such as iodine, chlorine, or bromine. Also, the perovskite structure includes a so-called double perovskite structure represented by the structural formula A2BB’X6, where B and B’ are two different metal elements.

[0011] By instantaneously heating the thin film, i.e., in a short time of less than 1 second, the crystals constituting the thin film instantaneously melt. After the crystals melt and are cooled to return to the solid state, the crystal size of the thin film becomes larger than before melting. Also, by being instantaneously heated, it is possible to enhance the crystallinity of the thin film while suppressing the deterioration of the thin film due to heating at a high temperature.

[0012] However, for this purpose, when heating is performed by a conventional method using a flash lamp, defects such as pinholes and cracks (hereinafter sometimes abbreviated as "pinholes, etc.") occur in the perovskite film after heating, and the film quality of the perovskite film may deteriorate more than expected. The reason for this is that the solvent remaining in the perovskite film instantaneously becomes a high temperature and boils due to heating by the flash lamp.

[0013] Therefore, the present inventors considered preheating before performing instantaneous heating by a flash lamp or the like to reduce the solvent in the perovskite film. Hereinafter, the instantaneous heating step by a flash lamp or the like is referred to as "main heating", and the heating step executed before the main heating is referred to as "preheating".

[0014] By performing preheating on the perovskite film before executing the main heating, the solvent in the perovskite film to be subjected to the main heating is reduced. As a result, it was considered that boiling of the solvent is less likely to occur in the perovskite film, and the generation of pinholes and the like in the main heating is suppressed.

[0015] However, as a result of the intensive studies by the present inventors, although the solvent in the perovskite film decreases due to preheating, it has been found that simply performing preheating makes the amount of solvent evaporated during preheating likely to fluctuate. If the amount of solvent evaporated during preheating is not stable, the amount of solvent in the perovskite film subjected to main heating varies, and for example, a perovskite film with high film quality in which the occurrence of pinholes and the like is suppressed cannot be stably manufactured. This problem is mainly caused by the variation in the amount of solvent remaining in the thin film after preheating, and it is considered that the same problem can occur not only in perovskite films but also in, for example, coating films made of metal nanoinks.

[0016] Before performing main heating, if preheating is carried out in a closed space such as a chamber, the vapor of the solvent evaporated from the thin film due to preheating may accumulate in the chamber. For example, when preheating is continuously carried out in the same chamber, the vapor derived from the solvent is likely to accumulate in the chamber.

[0017] When preheating is carried out with the vapor derived from the solvent accumulated in the chamber, it becomes difficult for the solvent to evaporate from the thin film. As a result, it is conceivable that a large amount of solvent remains in the thin film despite preheating. That is, the accumulation of the vapor derived from the solvent in the chamber can cause problems such as fluctuations in the amount of solvent evaporated during preheating or a large amount of solvent remaining in the thin film. In particular, when a large amount of solvent remains in the thin film, problems such as pinholes are likely to occur due to the solvent boiling over, and the film quality of the thin film deteriorates.

[0018] In contrast, according to the above configuration, the first chamber has an exhaust port for exhausting the atmosphere gas in the first chamber. Here, the first chamber houses a preheating unit, and this preheating unit has a heating mechanism capable of heating for a longer time than the main heating unit. That is, the first chamber is a chamber capable of performing preheating. By exhausting the vapor derived from the solvent contained in the atmosphere gas, the accumulation of the vapor derived from the solvent in the first chamber is suppressed. As a result, the amount of the solvent evaporated during preheating is stabilized, and the amount of the solvent in the thin film subjected to the main heating is less likely to vary. Therefore, according to the above heating device, defects such as pinholes in the thin film are suppressed, and a thin film with high film quality can be stably manufactured.

[0019] In the above, the case where the thin film is a perovskite film has been described as an example. However, the above heating device is not limited to the perovskite film and is preferably used, for example, for heating a coating film of metal nanoink.

[0020] For example, when sintering a coating film of metal nanoink, instantaneous heating (corresponding to "main heating") is performed by the main heating unit. At this time, if a large amount of the solvent in which the metal nanoparticles were dispersed is present in the coating film, the film quality of the coating film after sintering is likely to deteriorate due to the bumping of the solvent. In contrast, by performing preheating with the preheating unit before the main heating is executed, the solvent in the coating film is reduced, and as a result, the generation of pinholes and the like during the main heating is suppressed, and a thin film with high film quality can be obtained. Further, from the viewpoint of stabilizing the amount of the solvent evaporated during preheating, it is preferable to exhaust the vapor derived from the solvent in the first chamber where the preheating is performed, and in this regard, the same discussion as that for the above perovskite film is possible.

[0021] The main heating unit may include a light source that emits light with a pulse width of less than 1 second.

[0022] As the light source, a flash lamp can be preferably adopted. Other configuration examples of the main heating unit will be described in detail in the section "Mode for Carrying Out the Invention".

[0023] The first chamber houses both the preheating unit and the main heating unit, and has a partition wall that substantially partitions, while securing a transfer space for the base material, a first space in which the preheating unit is disposed and the first region is located inside, and a second space in which the main heating unit is disposed and the second region is located inside. The exhaust port may exhaust the atmospheric gas in the first space.

[0024] In the above configuration, the inside of the first chamber is substantially partitioned into a first space where preheating is performed and a second space where main heating is performed. By substantially partitioning the first space and the second space by a partition wall, it is possible to suppress the influence of the atmosphere in the second space on the first space. As a result, the temperature and the like in the first space are likely to be stabilized, and the amount of the solvent evaporated during preheating is stabilized, so that variations in the amount of the solvent in the thin film subjected to main heating are suppressed.

[0025] By suppressing variations in the amount of the solvent in the thin film subjected to main heating, it is possible to stably produce a thin film with high film quality.

[0026] Further, the heating device includes a second chamber that houses the main heating unit outside the first chamber. The transfer unit may transfer the base material from the first chamber toward the second chamber.

[0027] According to the above configuration, main heating is performed in a second chamber different from the first chamber where preheating is performed. By performing main heating in a second chamber different from the first chamber, it is difficult for the atmosphere in the second chamber to affect the atmosphere in the first chamber, and the temperature and the like in the first chamber are likely to be stabilized. As a result, the amount of the solvent evaporated during preheating is stabilized, and variations in the state of the thin film subjected to main heating are suppressed.

[0028] Further, the heating device It includes a connection area that closes the connection between the first chamber and the second chamber. The transfer unit may transfer the substrate from the first chamber to the second chamber through the connection area.

[0029] By closing the connection between the first chamber and the second chamber, when the transfer unit transfers the substrate toward the second chamber, it is possible to suppress the contact between the air existing in the space outside the first chamber and the second chamber and the thin film. By suppressing the deterioration of the thin film due to contact with air, it becomes easier to manufacture a thin film with high film quality, so the above configuration is suitable.

[0030] The heating method according to the present invention is a heating method for heating a substrate having a thin film formed on its surface, in the chamber, a step (a) of preheating the substrate to evaporate the residual components of the thin film; a step (b) of exhausting the atmosphere gas in the chamber from the exhaust port during or after the execution of step (a); and a step (c) of performing main heating on the area on the substrate that has been preheated in step (a) in a short time of less than 1 second.

[0031] Here, the "residual components" refer to the solvent remaining in the thin film when the thin film is formed by a solution process or the like.

[0032] As described above, it is preferable to perform preheating before performing main heating on the thin film. Furthermore, by exhausting the inside of the chamber during or after the execution of preheating, the accumulation of vapor such as solvent in the chamber is suppressed. As a result, the amount of solvent evaporated during preheating becomes stable, and variations in the amount of solvent in the thin film subjected to main heating are suppressed.

[0033] In the above heating method, Step (c) is carried out in a second space that is substantially partitioned by a partition wall from a first space in which the preliminary heating according to step (a) is performed within the chamber. In step (b), the atmosphere gas in the first space may be exhausted from the exhaust port.

[0034] Further, step (c) may be carried out using a light source that emits light with a pulse width of less than 1 second.

[0035] In the above heating method, The thin film may be a perovskite film.

[0036] Step (a) may be configured to raise the temperature of the substrate within a range of 30°C to 150°C.

[0037] The execution conditions of the preliminary heating can be appropriately adjusted according to the composition of the thin film. For example, for a perovskite film, considering the deterioration due to thermal decomposition of the material, the temperature rising range during the preliminary heating is preferably as described above.

[0038] The substrate may be a substrate, a film, or paper.

[0039] As an example, the substrate is mainly made of one selected from the group consisting of semiconductor, glass, metal, and resin. That is, available substrates include semiconductor substrates, glass substrates, metal substrates, and resin substrates. Also, available films include, for example, resin films mainly made of resin. Further, available papers include, in addition to synthetic papers mainly made of resin, high-quality papers, medium-quality papers, etc. Here, the "main material" refers to the material with the highest ratio among the materials constituting the substrate.

Advantages of the Invention

[0040] According to the present invention, a heating device and a heating method capable of stably manufacturing a thin film with high film quality are provided.

Brief Description of the Drawings

[0041]

Figure 1A

Figure 1B

Figure 1C

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0042] A configuration example of the heating device according to the present invention will be described with appropriate reference to the drawings. Note that each of the following drawings is schematically illustrated, and the actual dimensional ratio and the dimensional ratio on the drawing do not necessarily match. Also, the dimensional ratios do not necessarily match among the drawings.

[0043] [First Embodiment] Fig. 1A is a drawing schematically showing the structure of the first embodiment of the heating device. As shown in Fig. 1A, the heating device 1 includes a chamber 2a, a transfer unit 3 for transferring the substrate W1 to be processed in the chamber 2a, a heater 5, and a flash lamp 7.

[0044] In the following figures, an X - Y - Z coordinate system is appropriately referred to and described, where the direction perpendicular to the main surface of the base material W1 is the Z direction, and the plane perpendicular to the Z direction is the XY plane. The Z direction is typically the vertical direction.

[0045] In the following description, when distinguishing the positive and negative directions when expressing a direction, it is described with positive and negative signs, such as " +X direction" and " -X direction". When expressing a direction without distinguishing the positive and negative directions, it is simply described as "X direction". That is, in this specification, when simply described as "X direction", both " +X direction" and " -X direction" are included. The same applies to the Y direction and the Z direction. In this specification, when simply described as "X direction", both " +X direction" and " -X direction" are included. The same applies to the Y direction and the Z direction.

[0046] The heating device 1 is suitably used for heating the base material W1 on which the thin film W2 is formed on the surface.

[0047] The base material W1 is composed of, for example, a glass substrate, and as shown in FIG. 1A, the thin film W2 is formed on the surface. The thin film W2 is a perovskite film formed by a solution process such as spin coating.

[0048] As an example, the thickness of the base material W1 in the Z direction is 10 μm to 5 mm. Also, the film thickness of the thin film W2 is about 1 nm to 10 μm. Specific configuration examples of the base material W1 and the thin film W2 will be described later.

[0049] Hereinafter, after explaining the configuration of the heating device 1, a heating method that can be executed by the heating device 1 will be described.

[0050] [Chamber 2a] As shown in FIG. 1A, the chamber 2a houses the heater 5 and the flash lamp 7. In the internal space of the chamber 2a, the base material W1 is transferred by the transfer unit 3. FIG. 1B is a drawing showing the state in which the base material W1 is transferred by the transfer unit 3 from the state shown in FIG. 1A. In the present embodiment, as shown in FIGS. 1A and 1B, the base material W1 is transferred in the X direction.

[0051] As shown in FIG. 1A, the chamber 2a has a partition wall 10. The partition wall 10 is disposed in the internal space of the chamber 2a and functions to partition a first space R1 where the heater 5 is disposed and a second space R2 where the flash lamp 7 is disposed.

[0052] FIG. 1C is a cross-sectional view taken along line C-C of FIG. 1A. In FIG. 1C, for ease of understanding, the base material W1 is shown. As shown in FIG. 1C, the partition wall 10 has an opening 11 through which the base material W1 transferred by the transfer unit 3 can pass. The opening 11 is a narrow path with a separation distance D1 of 20 mm or less from the transfer unit 3 on the +Z side. That is, although the first space R1 and the second space R2 are connected through the opening 11, since the connection area is extremely narrow, it can be said that the partition wall 10 substantially partitions the internal space of the chamber 2a into the first space R1 and the second space R2.

[0053] For the sake of caution, it should be noted that the opening 11 is configured such that both the separation distance D2 from the transfer unit 3 on the -Z side and the separation distance D3 from the transfer unit 3 in the Y direction are smaller than the separation distance D1. That is, "substantially partition" may refer to a state where all of the separation distances D1 to D3 are 20 mm or less.

[0054] Also, as shown in FIG. 1A, the chamber 2a has an exhaust port 12 for exhausting the atmosphere gas G1 in the first space R1 on, for example, the wall surface 20a on the +Z side. The exhaust port 12 is connected to a pipe 14 in which an intake mechanism 13 such as a fan is disposed, and exhausts the atmosphere gas G1. The position of the exhaust port 12 is arbitrary as long as it exhausts the atmosphere gas G1 in the first space R1.

[0055] Further, the chamber 2a has an inlet 15 on the wall surface 20b related to the -X side, for example, through which a predetermined gas G2 can be introduced into the first space R1. The inlet 15 is provided from the viewpoint of introducing the gas G2 into the first space R1 in order to efficiently guide the atmospheric gas G1 to the exhaust port 12. The inlet 15 is connected to a gas introduction mechanism (not shown) via a pipe 16. As the gas G2, an inert gas such as nitrogen or clean dry air can be used, for example.

[0056] Furthermore, the chamber 2a has a carry-in port 17 on the wall surface 20b for carrying the substrate W1 into the first space R1, and a carry-out port 18 on the wall surface 20c related to the +X side for carrying the substrate W1 out of the second space R2. The carry-in port 17 is made into a narrow path similar to the opening 11 from the viewpoint of facilitating the stabilization of the temperature etc. in the first space R1. Similarly for the carry-out port 18, it is made into a narrow path from the viewpoint of facilitating the stabilization of the temperature etc. in the second space R2.

[0057] Also, the carry-in port 17 and the carry-out port 18 may be provided with an opening / closing mechanism (not shown) and may be in an open state only when the substrate W1 passes through.

[0058] The chamber 2a corresponds to the "first chamber".

[0059] [Transfer unit 3] The transfer unit 3 is constituted by, for example, a conveyor. The transfer unit 3 carries the substrate W1 into the first space R1 through the carry-in port 17. In FIG. 1A, the state where the substrate W1 is located in the first space R1 is shown.

[0060] Also, the transfer unit 3 transfers the substrate W1 to the second space R2 through the opening 11. In FIG. 1B, the state where the substrate W1 is located in the second space R2 is shown. Then, the transfer unit 3 carries the substrate W1 out of the second space R2 through the carry-out port 18.

[0061] [Heater 5] As shown in FIG. 1A, the heater 5 is disposed in the first space R1. The heater 5 is composed of a heating wire that radiates heat H1 when power is supplied, and forms a heating region A1 in the first space R1. The heater 5 corresponds to a "preheating unit". Also, the heating region A1 corresponds to the "first region".

[0062] In FIG. 1A, for the sake of illustration, the heater 5 is shown as being single, but a plurality of heaters 5 may be disposed in the first space R1. Also, in FIG. 1A, the heater 5 is disposed on the +Z side of the base material W1, but the installation position of the heater 5 is arbitrary as long as the base material W1 can be heated.

[0063] Note that, in FIG. 1A, the heater 5 is illustrated as the preheating unit, but the preheating unit may be composed of a light source such as a halogen lamp or an LED. In this case, heating light (hereinafter referred to as "heating light") is irradiated from the light source toward the base material W1, and a heating region A1 is formed.

[0064] By disposing the base material W1 in the heating region A1 by the transfer unit 3, the base material W1 is heated, and preheating of the base material W1 is performed. During the execution of the preheating, the base material W1 may be in a stationary state or a transfer state.

[0065] [Flash lamp 7] As shown in FIG. 1B, the flash lamp 7 is disposed in the second space R2. When the flash lamp 7 is lit by a lighting circuit (not shown), it emits a flash L1 toward the base material W1 and forms a heating region A2. Thereby, the flash L1 is irradiated onto the region on the base material W1 that has been preheated, and main heating is performed.

[0066] Specifically, the flash lamp 7 is, for example, a xenon flash lamp and emits light with a pulse width of less than 1 second. The pulse width is preferably 100 milliseconds or less, and more preferably 10 milliseconds or less.

[0067] The flash lamp 7 corresponds to the "main heating unit". Further, the heating region A2 corresponds to the "second region".

[0068] After the base material W1 is placed in the heating region A2 by the transfer unit 3, the base material W1 is irradiated with the flash L1 emitted by the flash lamp 7, and the main heating of the base material W1 is performed. In FIG. 1B, the flash L1 irradiated toward the base material W1 is schematically shown. During the execution of the main heating, the base material W1 may be in a stationary state or in a transfer state.

[0069] In the present embodiment, the heating device 1 has a light-transmitting window 8. This light-transmitting window 8 is disposed on the -Z side of the flash lamp 7 and transmits the flash L1. Due to the irradiation of the flash L1, although slightly, the material constituting the thin film W2 may sublime and scatter as a gas. Even in such a case, by disposing the light-transmitting window 8, the tube body of the flash lamp 7 is suppressed from being soiled by the scattered material or the like.

[0070] If dirt occurs on the tube surface of the flash lamp 7, when the flash lamp 7 is lit, the dirt absorbs the flash L1, and the region where the dirt exists is locally heated. When the tube body is locally heated, defects in the tube body are likely to occur. In view of the above, as shown in FIG. 1B, it is preferable to dispose the light-transmitting window 8 between the base material W1 and the flash lamp 7 to suppress the soiling of the tube body of the flash lamp 7.

[0071] [Heating method] Next, a heating method executable by the heating device 1 will be described.

[0072] FIG. 2 is a flowchart schematically showing an example of the execution procedure of the heating method M1. As shown in FIG. 2, the heating method M1 includes a base material preparation step S1, a thin film formation step S2, a preheating step S3, an evacuation step S4, a main heating step S5, and a post-treatment step S6.

[0073] [Base material preparation step S1] First, a substrate W1 is prepared. As the substrate W1, a substrate mainly made of a semiconductor such as silicon, glass such as quartz glass, metal such as copper or steel, or a resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) can be adopted. Further, the substrate W1 may be, for example, a sheet-like resin film mainly made of a resin. Furthermore, the substrate W1 may be synthetic paper mainly made of a resin, or may be high-quality paper, medium-quality paper, or the like. Note that the "main material" refers to the material with the highest ratio among the materials constituting the substrate W1.

[0074] The substrate W1 may have a film different from the thin film W2, such as a conductive layer formed of a transparent conductive film such as ITO. That is, in the thin film forming step S2 described later, the thin film W2 may be formed on the surface of the substrate W1 through the above-mentioned film.

[0075] [Thin Film Forming Step S2] Next, a thin film W2 is formed on the surface of the substrate W1. The thin film W2 is formed by a solution process such as spin coating, dropwise addition method, inkjet method, or the like.

[0076] As an example, the thin film W2 is a perovskite film composed of an organometallic halogen compound such as CH3NH3PbI3. Note that the material constituting the thin film W2 is not limited to an organometallic halogen compound, and a material showing a perovskite structure represented by the structural formula ABX3 can be appropriately used. For example, A is an organic group containing carbon or an inorganic element, and at least one of CH3NH3, CH(NH2)2, Cs, and Rb is selected. Also, B is, for example, a metal element, and at least one of Pb, Sn, Bi, and Sb is selected. Further, X is, for example, a halogen element, and at least one of iodine, chlorine, and bromine is selected.

[0077] Then, a solution containing the above material can be prepared using a solvent such as N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or N-methyl-2-pyrrolidone (NMP). When the solution is applied to the substrate W1 by a solution process, a perovskite film is formed.

[0078] Further, the thin film W2 may be formed by applying a metal nanoink in which metal nanoparticles such as gold or silver are dispersed by a solution process. Examples of the solvent in which the metal nanoparticles are dispersed include water, diethylene glycol butyl ether, and the like.

[0079] [Preheating Step S3] Next, the substrate W1 on which the thin film W2 is formed is transferred into the first space R1, and preheating is performed on the substrate W1 (see FIG. 1A). The preheating is performed for the purpose of evaporating the solvent contained in the thin film W2.

[0080] When the thin film W2 is a perovskite film, the preheating is to raise the temperature of the substrate W1 to a range of 30°C to 150°C. From the viewpoint of suppressing the deterioration of the perovskite film due to heating of the substrate W1, the temperature of the substrate W1 during preheating is preferably 150°C or lower, more preferably 130°C or lower, and particularly preferably 110°C or lower. Also, from the viewpoint of efficiently evaporating the solvent in the thin film W2, the temperature of the substrate W1 during preheating is preferably 40°C or higher, more preferably 50°C or higher, and particularly preferably 60°C or higher. As an example, the temperature of the substrate W1 during preheating is set to 70°C.

[0081] Also, when the thin film W2 is formed of a metal nanoink, the preheating is to raise the temperature of the substrate W1 to a range of 50°C to 150°C.

[0082] The temperature of the substrate W1 during preheating can be measured, for example, by attaching a thermocouple to the substrate W1. As the thermocouple, a K thermocouple can be used. For example, a test substrate W1 with a thermocouple attached may be prepared, and the heating conditions of the substrate W1 in the preheating step S3 may be set based on the temperature of the substrate W1.

[0083] The execution time of the preliminary heating is arbitrary, but as an example, it is 1 minute, which is made longer than the execution time of the main heating described later. Note that the execution time of the preliminary heating may be defined as the time during which the temperature of the base material W1 is equal to or higher than a predetermined temperature.

[0084] The preliminary heating step S3 corresponds to step (a).

[0085] [Exhaust step S4] After the preliminary heating step S3 is executed, the atmosphere gas G1 in the first space R1 is exhausted through the exhaust port 12. Since the gas containing the exhausted atmosphere gas G1 contains vapor derived from the solvent used in the thin film forming step S2, it is preferably recovered by a duct (not shown) having an arbitrary filter.

[0086] By executing the preliminary heating step S3, the solvent in the thin film W2 is evaporated. If the exhaust step S4 is not executed, the preliminary heating step S3 is repeated in the first space R1, so that the concentration of the solvent vapor increases in the first space R1. When the concentration of the vapor in the first space R1 becomes high, it becomes difficult for the solvent to evaporate from the thin film W2 during the preliminary heating step S3. As a result, the amount of the solvent evaporated in the preliminary heating step S3 fluctuates, and the amount of the solvent contained in the thin film W2 supplied to the subsequent main heating step S5 varies.

[0087] Therefore, as shown in FIG. 2, it is preferable to exhaust the first space R1 through the exhaust port 12 after the execution of the preliminary heating step S3. Note that the exhaust step S4 may be performed during the execution of the preliminary heating step S3.

[0088] Note that the atmosphere gas G1 may seem to flow out of the first space R1 through, for example, the carry-in port 17 or the opening 11. Here, the carry-in port 17 and the opening 11 are narrow paths as described above. Therefore, it can be said that the movement of the gas through the carry-in port 17 or the opening 11 is extremely small. That is, from the viewpoint of preventing the accumulation of the solvent vapor in the first space R1, the exhaust of the atmosphere gas G1 through the carry-in port 17 and the opening 11 is insufficient.

[0089] The exhaust process S4 corresponds to process (b).

[0090] [Main heating process S5] Next, as shown in FIG. 1B, the base material W1 is transferred to the second space R2, and main heating is performed on the base material W1.

[0091] As shown in FIG. 1B, the main heating is executed by lighting the flash lamp 7 in a state where the base material W1 is disposed in the heating region A2. Therefore, the execution time of the main heating is a short time of less than 1 second. The main heating process S5 is executed for the purpose of heating the thin film W2 in a short time and with a high energy density.

[0092] When the thin film W2 is a perovskite film, by heating to a high temperature in a short time of less than 1 second, the crystal size of the thin film W2 is increased. Further, since the main heating is instantaneous heating, deterioration of the thin film W2 due to heating to a high temperature and the thermal influence on the base material W1 are suppressed.

[0093] Since the thin film W2 instantaneously reaches a high temperature, when a large amount of solvent remains in the thin film W2, the solvent may boil suddenly, for example, pinholes or the like may occur in the thin film W2, and the film quality of the thin film W2 may be degraded. However, as shown in FIG. 2, before the main heating process S5 is executed, the preheating process S3 is executed, so that the solvent remaining in the thin film W2 of the base material W1 to be subjected to the main heating is reduced, and the degradation of the film quality of the thin film W2 in the main heating is suppressed.

[0094] Although not shown, while the main heating process S5 is being executed on the base material W1, the preheating process S3 may be executed on a base material different from the base material W1.

[0095] Also, even when the thin film W2 is a coating film of metal nanoink, the preheating process S3 and the exhaust process S4 are executed before the main heating process S5.

[0096] More specifically, the thin film W2 composed of the metal nanoink is more firmly sintered by the present heating step S5. However, if a large amount of the solvent in which the metal nanoparticles were dispersed is present in the thin film W2, the film quality of the thin film W2 after sintering is likely to deteriorate due to the bumping of the solvent. On the other hand, by performing the preliminary heating step S3 before executing the present heating step S5, the solvent in the thin film W2 can be reduced, and the deterioration of the film quality of the thin film W2 during the present heating step S5 can be suppressed.

[0097] Furthermore, from the viewpoint of stabilizing the state of the thin film W2 subjected to the present heating step S5, regarding the execution of the exhaust step S4, the same discussion as that for the above perovskite film is possible.

[0098] The present heating step S5 corresponds to step (c).

[0099] [Post-process S6] Thereafter, the substrate W1 is carried out from the chamber 2a, and a film different from the thin film W2, an electrode film for applying a voltage to the thin film W2, etc. are formed on the thin film W2 as appropriate.

[0100] [Second Embodiment] Hereinafter, regarding the second embodiment of the heating device, with reference to the drawings, the parts different from the first embodiment will be mainly described. FIG. 3 is a drawing schematically showing the structure of the second embodiment of the heating device.

[0101] In the present embodiment, the heating device 1a includes a chamber 2b, and the transfer unit 3 transfers the substrate W1 from the chamber 2a toward the chamber 2b, which is different from the first embodiment. In the present embodiment, the chamber 2a corresponds to the "first chamber", and the chamber 2b corresponds to the "second chamber".

[0102] As shown in FIG. 3, the chamber 2a forms a first space R1 that houses the heater 5. As shown in FIG. 3, the chamber 2b forms a second space R2 that houses the flash lamp 7. In FIG. 3, similar to FIG. 1B, the state in which the substrate W1 is located in the chamber 2b is illustrated.

[0103] The points that the heater 5 forms the heating region A1 in the first space R1 and that the flash lamp 7 forms the heating region A2 in the second space R2 are the same as those described with reference to FIGS. 1A and 1B.

[0104] The flash lamp 7 irradiates the base material W1 with the flash light L1 through the light-transmitting window 8 disposed in the chamber 2b, as described with reference to FIG. 1B. Thereby, the flash light L1 is irradiated to the region on the preheated base material W1, and the main heating is executed.

[0105] The chamber 2b has a carry-in port 27 for carrying the base material W1 into the second space R2 in the wall surface 21b on the -X side and a carry-out port 28 for carrying the base material W1 out in the wall surface 21c on the +X side.

[0106] After carrying out the base material W1 from the carry-out port 18 of the chamber 2a, the transfer unit 3 transfers the base material W1 into the chamber 2b through the carry-in port 27. Then, after the main heating for the base material W1 is executed, the transfer unit 3 carries out the base material W1 from the chamber 2b through the carry-out port 28.

[0107] As shown in FIG. 3, in the heating device 1a, the chamber 2a in which the heater 5 is accommodated and the preheating is executed and the chamber 2b in which the flash lamp 7 is accommodated and the main heating is executed are configured separately. Thereby, the atmosphere in the chamber 2b is less likely to affect the atmosphere in the chamber 2a, and the temperature etc. in the chamber 2a are likely to be stabilized. If the temperature etc. in the chamber 2a are stabilized, the amount of the solvent evaporated in the preheating is likely to be stabilized, and the variation in the amount of the solvent in the thin film W2 used for the main heating is suppressed.

[0108] Moreover, FIG. 4A is a drawing showing a modified example of the heating device 1a according to the second embodiment. The heating device 1a may have a cylindrical portion 30 connecting the chamber 2a and the chamber 2b as shown in FIG. 4A.

[0109] FIG. 4B is a cross-sectional view taken along line B-B of FIG. 4A. As shown in FIG. 4B, the cylindrical portion 30 is configured to cover the periphery of the transfer unit 3. That is, the cylindrical portion 30 closes the connection between the chamber 2a and the chamber 2b.

[0110] When the cylindrical portion 30 closes the connection between the chamber 2a and the chamber 2b, when the transfer unit 3 transfers the substrate W1 toward the chamber 2b, the contact between the air G3 existing in the space outside the chambers 2a and 2b and the thin film W2 can be suppressed. For example, from the viewpoint of suppressing the deterioration of the thin film W2 due to the contact between oxygen in the air G3 and the thin film W2, the chambers 2a and 2b may be connected in a closed manner.

[0111] [Alternative Embodiment] Hereinafter, an alternative embodiment of the heating device 1 will be described.

[0112] 〈1〉 In the above, the present heating unit has been described as being constituted by the flash lamp 7. However, the configuration of the present heating unit is arbitrary as long as it can instantaneously heat the thin film W2, that is, in a short time of less than 1 second. FIG. 5 is a drawing showing another configuration example of the present heating unit. In FIG. 5, the illustration of the configuration on the -X side of the chamber 2a is omitted.

[0113] As shown in FIG. 5, the present heating unit is constituted by, for example, a halogen lamp 9a and a slide mechanism 9b capable of moving the halogen lamp 9a in the X direction. The slide mechanism 9b moves the halogen lamp 9a at high speed from the +X side of the substrate W1 to the -X side of the substrate W1 in a state where the halogen lamp 9a emits the heating light L2 toward the -Z side. Thereby, the heating light L2 may be instantaneously irradiated onto the substrate W1 to heat the thin film W2 in a short time of less than 1 second.

[0114] Also, in FIG. 5, the light source of the heating light L2 has been described as being a halogen lamp, but the configuration of the light source is arbitrary. For example, the light source may be constituted by a high-pressure mercury lamp, an LED, or a laser light source.

[0115] In addition, the slide mechanism 9b may move the light source within the XY plane according to the irradiation range of the heating light L2 of the light source. Further, the slide mechanism 9b may move a plurality of times with respect to the base material W1 while varying the irradiation range of the heating light L2 on the base material W1.

[0116] 〈2〉 Further, in the above description, the light-transmitting window 8 is described as being disposed on the -Z side of the flash lamp 7. However, whether or not the light-transmitting window 8 is disposed can be appropriately selected in consideration of the configuration of the present heating unit and the distance between the flash lamp 7 and the base material W1. That is, in the heating device (1, 1a), whether or not the light-transmitting window 8 is disposed is arbitrary.

[0117] 〈3〉 FIG. 6 is a drawing showing another configuration example of the heating device 1 following FIG. 1A and the like. FIG. 6 illustrates a scene in which preheating is being performed on the base material W1.

[0118] In the above description, for example, as shown in FIGS. 1A and 1B, the heater 5 is disposed in the first space R1 and the flash lamp 7 is disposed in the second space R2, that is, the heater 5 and the flash lamp 7 are described as being disposed in different spaces from each other. However, as shown in FIG. 6, the heater 5 and the flash lamp 7 may be disposed in the same space within the chamber 2a. In this case, the preheating step S3 and the main heating step S5 are performed in the same space. That is, in FIGS. 1A and the like, whether or not the chamber 2a includes the partition wall 10 is arbitrary.

[0119] 〈4〉 FIG. 7 is a drawing showing yet another configuration example of the heating device 1 following FIG. 1A and the like. As shown in FIG. 7, the transfer unit 3 may be composed of a plurality of rollers 3a, and the base material W1 may be transferred due to the rotation of the rollers 3a. For example, when the base material W1 is composed of a film-like sheet, the base material W1 is preferably transferred by the rollers 3a.

[0120] Note that, although FIG. 7 is shown based on the heating device 1 according to FIGS. 1A and 1B, in the heating device 1a according to FIG. 3 or FIG. 4A, for example, the base material W1 may be transferred by the roller 3a.

[0121] 〈5〉 The configuration of the transfer unit 3 is arbitrary as long as the base material W1 can be transferred from the heating region A1 to the heating region A2. For example, the transfer unit 3 may be configured to include a transport mechanism such as a robot arm.

[0122] 〈6〉 The preheating unit may be a heat stage that contacts the -Z side surface of the base material W1. In this case, the transfer unit 3 is preferably configured to include a transport mechanism such as a robot arm that transfers the base material W1.

[0123] 〈7〉 In the above, heating of the perovskite film and the coating film of the metal nanoink was described. However, the present invention is not limited to the above, and is preferably used, for example, for heating in the formation of each film constituting the electron transport layer and the hole transport layer in a solar cell, a ferroelectric film, or a coating film of carbon ink.

[0124] 〈8〉 In the above, the preheating step S3, the exhaust step S4, and the main heating step S5 executed by the heating device (1, 1a) were described. The present invention does not exclude a configuration in which, for example, a chamber that executes the thin film formation step S2 is incorporated in the front stage of the heating device (1, 1a), or a configuration in which a chamber that executes the post-process step S6 is incorporated in the rear stage of the heating device (1, 1a).

[0125] 〈9〉 Embodiments of the heating device and the heating method are not limited to the above examples. Also, the configurations according to the above embodiments can be realized by appropriately combining them.

Explanation of reference numerals

[0126] 1, 1a: Heating device 2a, 2b: Chamber 3: Transfer unit 3a: Roller 5: Heater 7: Flash lamp 8: Translucent window 9a: Halogen lamp 9b: Slide mechanism 10: Partition wall 11: Opening 12: Exhaust port 13: Intake mechanism 14: Pipe 15: Inlet 16: Pipe 17,27: Loading entrance 18,28: Unloading exit 20a,20b,20c: Wall surface 21b,21c: Wall surface 30: Cylindrical part

Claims

1. A heating device for heating a substrate having a thin film formed on its surface, a main heating unit capable of heating for a short time of less than 1 second, a preheating unit having a heating mechanism capable of heating for a longer time than the main heating unit, a transfer unit for transferring the substrate from a first region heated by the preheating unit to a second region heated by the main heating unit, a first chamber in which at least the preheating unit is housed, and an exhaust port for exhausting the atmospheric gas in the first chamber, characterized in that it comprises a heating device.

2. The first chamber houses both the preheating unit and the main heating unit, and has a partition wall that substantially partitions, while securing a transfer space for the substrate, a first space in which the preheating unit is disposed and the first region is located inside, and a second space in which the main heating unit is disposed and the second region is located inside, The exhaust port exhausts the atmospheric gas in the first space, and the heating device according to claim 1 is characterized in that.

3. A second chamber for housing the main heating unit is provided outside the first chamber, The transfer unit transfers the substrate from the first chamber to the second chamber, and the heating device according to claim 1 is characterized in that.

4. A connection region for closing the connection between the first chamber and the second chamber is provided, The transfer unit transfers the substrate from the first chamber to the second chamber through the connection region, and the heating device according to claim 3 is characterized in that.

5. The main heating unit includes a light source that emits light with a pulse width of less than 1 second, and the heating device according to any one of claims 1 to 4 is characterized in that.

6. A heating method for heating a substrate having a thin film formed on its surface, comprising: In a chamber, a step (a) of preheating the substrate to evaporate residual components of the thin film; A step (b) of exhausting the atmosphere gas in the chamber from an exhaust port during or after the execution of the step (a); And a step (c) of performing main heating on a region on the substrate that has been preheated by the step (a) in a short time of less than 1 second. The heating method is characterized by this. **Claim 7** The step (c) is executed in a different second space that is substantially partitioned by a partition wall from a first space where the preheating by the step (a) is performed in the chamber, The step (b) is characterized by exhausting the atmosphere gas in the first space from the exhaust port. The heating method according to claim 6. **Claim 8** The step (c) is executed by a light source that emits light with a pulse width of less than 1 second. The heating method according to claim 6 or 7. **Claim 9** The thin film is a perovskite film. The heating method according to claim 6 or 7. **Claim 10** The step (a) is characterized by raising the temperature of the substrate to a range of 30°C to 150°C. The heating method according to claim 9. **Claim 11** The substrate is a substrate, a film, or paper. The heating method according to claim 10.

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