Film forming method, film forming apparatus, and article manufacturing method

Abstract

A film formation method includes: an arrangement step in which a plurality of droplets of a curable composition are discretely arranged on a substrate, the curable composition comprising a polymeric compound of a non-volatile component and a solvent of a volatile component; an analysis step in which an image obtained by capturing images of each of the plurality of droplets on the substrate connected to adjacent droplets is analyzed to form a continuous liquid film on the substrate; an evaporation step in which solvent contained in the liquid film is evaporated by enhancing solvent evaporation compared to the liquid film formation process; and a formation step in which a cured film is formed by curing the liquid film, wherein if the analysis results obtained in the analysis step satisfy predetermined conditions indicating that the liquid film formation state is sufficient, the process proceeds to the evaporation step and then to the formation step.

Description

Film forming method, film forming apparatus, and article manufacturing method The present invention relates to a film forming method, a film forming apparatus and an article manufacturing method. With the increasing demand for miniaturization of semiconductor devices, not only traditional photolithography techniques but also microfabrication technologies that use a mold to mold an uncured composition onto a substrate and then cure it to form a pattern of the composition on the substrate are attracting significant attention. This technology is called imprint technology and can form fine patterns on a substrate at the scale of several nanometers. One type of imprinting technology, for example, is a photocuring method. Imprinting equipment employing the photocuring method uses a mold to mold a photocurable composition supplied to a projection area on a substrate, cures the composition through light irradiation, and separates the mold from the cured composition, thereby forming a pattern on the substrate. Japanese Patent Publication No. 2010-530641 discloses an imprint method using a composition containing a solvent and a polymerizable material. The imprint method includes forming a liquid film on a substrate surface by continuously supplying the composition to the substrate, evaporating the solvent from the composition, and polymerizing the polymerizable material in the composition to form a cured film. In the method described in Japanese Patent Publication No. 2010-530641, if the process proceeds to the solvent evaporation step while the liquid film is not fully formed, air gaps remain between the compositions, and defects appear in the solid layer formed on the substrate. To address this issue, the process waits a predetermined time, sufficient to form a liquid film without air gaps, before proceeding to the solvent evaporation step. However, even if liquid film formation is completed within this time, production throughput is reduced due to the predetermined waiting time. For example, the present invention provides a film formation method that is advantageous in simultaneously suppressing defects and achieving throughput. The present invention provides, in its first aspect, a film forming method, comprising: an arranging step of discretely arranging a plurality of droplets of a curable composition on a substrate, the curable composition containing a polymerizable compound as a non-volatile component and a solvent as a volatile component; an analyzing step of analyzing, after the arranging step, an image obtained by photographing a process in which each of the plurality of droplets on the substrate is connected to an adjacent droplet, thereby forming a continuous liquid film on the substrate; a volatilization step of volatilizing the solvent contained in the liquid film by enhancing the solvent volatilization effect compared to the process of forming the liquid film; and a forming step of forming a cured film by curing the liquid film, wherein, if the analysis result obtained in the analyzing step satisfies a predetermined condition indicating that the formation state of the liquid film is sufficient, the process proceeds to the volatilization step and then to the forming step. Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings). Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments are not intended to limit the scope of the claimed invention. While various features are described in the embodiments, they are not intended to limit the invention to include all of them, and these features may be appropriately combined. Furthermore, in the drawings, identical or similar components are given the same reference numerals, and any repetitive description thereof will be omitted. <First Embodiment> A film-forming apparatus according to an embodiment will now be described. This film-forming apparatus is used to manufacture a device, such as a semiconductor device, which is an article. The film-forming apparatus deposits an uncured composition on a substrate and molds the deposited composition using a mold, thereby forming a film of the composition on the substrate. In this embodiment, the film-forming apparatus may be a film-forming apparatus employing a photocuring method. Because of the use of a photocuring method, the composition is a photocurable and moldable material. Assuming that it is used in mass production equipment of semiconductor devices or the like, it is known that the pattern transfer method and equipment of the imprint photolithography technology using a photocuring method are applied. The imprint method of the photocuring method is generally performed as follows. First, a supply mechanism (distributor) of an inkjet nozzle or the like is used to supply a composition to be cured by ultraviolet light to the projection area of ​​the imprint target on the wafer. Then, a mold with a device pattern drawn thereon is brought into contact with the composition. When the composition is fully filled into the pattern of the mold, light (ultraviolet light (UV)) is applied to cure the composition. Afterwards, the mold is separated from the composition. Therefore, a fine pattern with good line width variation can be formed on the wafer. Therefore, in the example, the film forming apparatus 1 can be an imprint apparatus that transfers the pattern of the mold as described above to the composition on the substrate. In the EUV photolithography process, the depth of field (hereinafter referred to as "DOF") of the projected image formed with fine circuit patterns has been gradually decreasing in recent years as the NA has increased. In recent examples, the allowable DOF of EUV photolithography equipment with NA=0.33 is 300 nm to 110 nm (depending on the irradiation mode). The allowable DOF of EUV photolithography equipment with NA=0.55 is 160 nm to 40 nm (depending on the irradiation mode). However, it has been found that the method of applying the SOC film by a conventional spin coater is difficult to achieve sufficient surface flattening performance that meets the above-mentioned allowable range. In particular, in the case of spin coating, due to the viscosity of the SOC coating agent dripped onto the wafer and the centrifugal force generated by the rotation, a layer with a uniform film thickness is formed on the wafer. Therefore, if there is an area where the wiring density of the lower pattern of the processed wafer varies by 5μm or more over a long period, the boundary of the wiring density variation will remain intact and appear on the surface of the SOC film. In recent years, the use of the aforementioned imprint technology for planarization has been under scrutiny. In this method, a cover plate, devoid of patterned components, is pressed against a liquid composition supplied to a wafer. After the composition has spread, it is cured by UV exposure, and the cover plate is then separated. It is worth noting that the term "imprint" is often used to refer to the transfer of a pattern drawn on a mold by pressing the pattern, but in the planarization process, no pattern is drawn on the cover plate. The outline of a planarization process using imprint technology based on a photocuring method will be described with reference to Figures 12A to 12D. In the planarization process using imprint technology based on a photocuring method, a substrate (wafer) can be planarized through a supply step shown in Figure 12A, a contact step shown in Figure 12B, a curing step shown in Figure 12C, and a separation step shown in Figure 12D. In Figures 12A to 12D, a circuit pattern has been formed on the surface of a substrate W clamped by a substrate chuck C, and there may be concave / convex portions caused by the pattern, for example, approximately 80 nm to 100 nm. The planarization requirement according to this embodiment is to flatten the surface concave / convex portions caused by the pattern. In the supply step shown in Figure 12A, the composition ML as a flattening material is supplied from a dispenser DP to the surface of the substrate W clamped by the substrate chuck C. The dispenser DP is arranged on a bridge member (not shown) suspended above a base, which also acts as a Z-direction guide for the substrate stage holding the substrate chuck C. By scanning and driving the substrate W clamped by the substrate chuck C one or more times below the dispenser DP, the composition ML is supplied to the entire surface of the substrate. The dispenser DP can be a spray module for supplying the composition ML in a droplet state. The dispenser DP can supply the composition ML while applying a supply amount distribution of the composition ML according to the arrangement of the concave / convex pattern formed on the surface of the substrate W, etc. More specifically, the composition ML can be supplied so that the portion with a high proportion of concave portions of the pattern on the substrate surface has a high droplet density, while the portion with a low proportion of concave portions has a low droplet density. For this reason, when the composition ML is supplied through the dispenser DP, substrate alignment measurement can be performed to preliminarily match the position of the pattern formed on the substrate W with the position of the density pattern of the composition ML to be supplied. In the contact step shown in FIG12B , a superstrate SS (also referred to as a "flat template") is brought into contact with the composition ML and pressed against the entire surface area of ​​the substrate W. The superstrate SS is a member having a flat surface without a pattern formed thereon and having an outer diameter equal to or larger than the outer diameter of the substrate W. As a result, the composition ML is diffused in the layer (hereinafter referred to as "filling" or "diffusion"). 12C , while the superstrate SS is in contact with the composition ML on the substrate W, ultraviolet light from the light source IL is applied collectively (or through repeated partial exposure) to the entire surface of the substrate W. Thus, the composition ML diffused in the layer is cured. In the separation step shown in FIG12D , the cover plate SS is separated from the cured composition ML on the substrate W. Consequently, the concave / convex portions of the substrate W resulting from the pattern are flattened. It should be noted that the goal here is not to correct the flatness of components with low spatial frequencies, which could, for example, distort the contour of the entire substrate relative to an absolute plane. For such components, non-planar components are compensated for by focus tracking control of the exposure apparatus in the subsequent patterning step. In this way, the flattening process using imprint technology is a process that provides a composition according to the steps of the substrate, brings a thin flat member called a cover plate into contact with the provided composition, and solidifies the composition to perform nanoscale flattening. It should be noted that the use of a cover plate is not essential in the flattening process. If a solvent is added to the composition, flattening can be performed without using a cover plate. Therefore, there may be a type of flattening process that does not bring the cover plate into contact with the composition, but waits until the composition is naturally diffused for flattening, and then solidifies the composition. Therefore, in an example, the film forming apparatus may be a planarization apparatus using an imprint technique. Hereinafter, a detailed description will be given assuming that the film forming apparatus is a planarization apparatus as an example. FIG1 is a schematic diagram illustrating the configuration of a film-forming apparatus 1 according to this embodiment. In the figure, the Z axis is arranged in the vertical direction, and the mutually orthogonal X and Y axes are arranged in a plane orthogonal to the Z axis. Hereinafter, directions parallel to the X, Y, and Z axes will be referred to as the X, Y, and Z directions, respectively. 1 , a film-forming apparatus 1 may include a composition placement unit 2, a liquid film formation unit 3, a composition curing unit 4, and a controller 5. A substrate 6 is transported to each of the composition placement unit 2, the liquid film formation unit 3, and the composition curing unit 4 through a transport device (not shown). The composition placement unit 2, the liquid film formation unit 3, and the composition curing unit 4 may be stored in separate chambers or may be stored in one chamber. The composition placement unit 2 includes a substrate stage 7 that holds and moves a substrate 6 (wafer); and a placement unit 8 (dispenser) that places a composition in a droplet state on the substrate 6. The placement unit 8 can place a composition 9 containing a solvent and a polymerizable material on the substrate 6 while moving in the X and Y directions. Alternatively, the placement unit 8 can place the composition 9 on the substrate 6 while the substrate stage 7 moves the substrate 6 in the X and Y directions. Thus, the composition 9 is placed on the substrate 6. This composition is a curable composition that is cured by receiving curing energy. Examples of the curing energy used include electromagnetic waves, heat, and the like. For example, infrared light, visible light, and ultraviolet light selected from a wavelength range of 10 nm to 1 mm are used as electromagnetic waves. A curable composition is a composition that cures by light irradiation or heating. A photocurable composition that cures by light irradiation contains at least a polymerizable compound and a photopolymerization initiator and, if necessary, may also contain a non-polymerizable compound or solvent. The non-polymerizable compound is at least one type of material selected from the group consisting of a sensitizer, a hydrogen donor, an internal mold release agent, a surfactant, an antioxidant, and a polymer component. The viscosity of the curable composition (viscosity at 25°C) is, for example, 1 mPa·s to 100 mPa·s. Glass, ceramics, metals, semiconductors, resins, and the like are used as substrates, and, if necessary, a component made of a material different from that of the substrate may be formed on the surface of the substrate. More specifically, examples of substrates include silicon wafers, semiconductor compound wafers, and silica glass. In this embodiment, composition 9 is a curable composition that cures upon exposure to light of a specific wavelength. The curable composition contains at least a polymerizable compound as a non-volatile component and a solvent as a volatile component. The solvent is a solvent for dissolving the polymerizable compound. Examples of solvents include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and nitrogen-containing solvents. In this specification, a cured film refers to a film of composition 9 that has been polymerized and cured on a substrate. The liquid film forming unit 3 includes a substrate stage 10 that holds and moves the substrate 6; a gas supply port 12 that supplies gas to the space above the substrate 6 in the liquid film forming unit 3; and an exhaust port 13 that exhausts gas from the liquid film forming unit 3. The liquid film forming unit 3 also includes a gas controller 14 that controls the gas supply port 12 and the exhaust port 13. An opening 11 is formed above the substrate stage 10 in the liquid film forming unit 3. A light source unit 15 for illuminating the substrate 6, an imaging unit 16 for observing the state of the liquid film on the substrate 6, and an optical system 17 are arranged above the opening 11. The optical system 17 illuminates the substrate 6 placed on the substrate stage 10 with light from the light source unit 15 and directs the reflected light from the substrate 6 to the imaging unit 16. For example, a light emitting diode (LED) or a vertical cavity emitting laser (VCSEL) can be used as the light source unit 15. However, another light source device can also be used. For example, a CCD camera or a CMOS camera can be used as the imaging unit 16. However, another imaging device can also be used. Light emitted from the light source unit 15 is transmitted to the opening 11 via the optical system 17. The light emitted from the light source unit 15 has a wavelength that does not cure the composition 9, and the lower portion of the opening 11 is sealed by a light-transmissive cover glass 18. In the liquid film forming unit 3, the state of the liquid film formed by the composition 9 on the substrate 6 is observed by the imaging unit 16. The composition curing unit 4 includes: a substrate stage 19 that holds the substrate 6 and moves; a mold 21 (a cover plate or a flattening plate) that contacts the liquid film 20 on the substrate 6; a mold holding unit 22 that holds the mold 21; and an irradiation unit 23 that irradiates the composition 9 with light to cure it. The irradiation unit 23 may include a light source. The light source may be formed of a lamp such as a mercury lamp, but is not limited to a specific light source as long as it emits light with a wavelength that passes through the mold 21 and cures the composition 9. The mold 21 is made of a material that propagates the light emitted from the irradiation unit 23. The mold holding unit 22 adsorbs and holds the mold 21. In a state where the mold 21 (the flat surface of the mold 21) is in contact with the liquid film 20 on the substrate 6, the irradiation unit 23 uses light to irradiate the liquid film 20 on the substrate 6, thereby curing the liquid film 20 and forming a cured film (flattening film). The controller 5 controls the entire film-forming apparatus 1. More specifically, it controls the conveyor device (not shown), the placement unit 8, the light source unit 15, the imaging unit 16, the gas controller 14, the mold holding unit 22, the irradiation unit 23, and the substrate stages 7, 10, and 19. The controller 5 also functions as a processing unit that analyzes images obtained through imaging. The controller 5 can be implemented by a general-purpose computer or a dedicated computer with a program installed, or by a combination of some or all of these. A chuck (a vacuum chuck or an electrostatic chuck) (not shown) is mounted on each of the substrate stages 7 , 10 , and 19 , and the substrate 6 can be fixed by the chuck. The film forming method of the film forming apparatus 1 will be described with reference to the flowchart shown in FIG2 . Step S101 is a placement step for placing the composition 9 on the substrate 6. The substrate 6 loaded into the composition placement unit 2 by the conveyor device is placed on the substrate stage 7 and secured by the chuck. The controller 5 controls the placement unit 8 to discretely place the composition 9 on the substrate 6. The conveyor device unloads the substrate 6 with the composition 9 placed thereon from the composition placement unit 2. Step S102 is a step of forming a liquid film on a substrate. Step S102 is also an analysis step of analyzing the image obtained by the imaging unit 16. The imaging unit 16 shoots the following processing procedure, wherein each of the multiple droplets of the composition 9 is connected (merged) with the adjacent droplets on the substrate 6, thereby forming a continuous liquid film on the substrate 6. The substrate 6 arranged with the composition 9 is loaded into the liquid film forming unit 3 by a conveying device, placed on the substrate stage 10, and fixed by a chuck. The multiple droplets of the composition 9 discretely arranged on the substrate 6 by the arrangement unit 8, after being arranged on the substrate, immediately begin to spread on the surface of the substrate 6. Figure 3 is a view showing the diffusion of multiple droplets of the composition 9 on the surface of the substrate 6. First, multiple droplets of the composition 9 through discrete arrangement begin to diffuse on the substrate 6. As the multiple droplets of the composition 9 diffuse, adjacent droplets connect to each other. Finally, the gap 24 (gap between droplets) between the composition is filled and a liquid film 20 is formed. When the intercomposition gaps 24 are filled up to the step of forming a cured film to be described later, the occurrence of defects on the cured film can be suppressed. On the other hand, the solvent contained in the composition 9 begins to volatilize immediately after the composition 9 is arranged on the substrate 6. Therefore, over time, the viscosity of the composition 9 increases, and the diffusion rate on the substrate 6 decreases. Therefore, in the step S102 of forming the liquid film, a processing procedure for suppressing the volatilization of the solvent can also be added. In the example, after the arrangement step, the controller 5 controls the gas controller 14 to supply the vapor of the solvent from the gas supply port 12 to the space above the substrate 6, so that the volatilization of the solvent contained in the composition 9 (liquid film 20) is suppressed (first supply step). This suppresses the volatilization rate of the solvent. Furthermore, in step S102, the formation state of the liquid film formed by the composition 9 is observed using the imaging unit 16. The controller 5 performs image analysis on the image data obtained by the imaging unit 16. Thereafter, in step S103, the controller 5 determines whether the result of the image analysis satisfies a predetermined condition indicating that the formation state of the liquid film is sufficient (hereinafter referred to as the "formation condition"), thereby determining whether the liquid film 20 is formed. An example of the image analysis in step S102 and the determination processing in step S103 will be described with reference to Figures 4 and 5. Figure 4 shows an example of composition 9 discretely arranged on substrate 6, while Figure 5 shows signal intensity distributions 26, 27, and 28 of the image data at the position of line 25 in Figure 4. The image data obtained by imaging unit 16 may include a signal intensity distribution according to the characteristics of substrate 6, light source unit 15, optical system 17, and imaging unit 16. To this end, signal intensity distributions 26, 27, and 28 are obtained by subtracting the signal intensity distribution of substrate 6 obtained before composition 9 is arranged. This can be performed using the same substrate 6, or the measurement of the signal intensity distribution before composition 9 is arranged can be performed using another substrate that has undergone a similar processing procedure. At position 29 where composition 9 is placed, the illumination decreases because composition 9 absorbs a portion of the light emitted from light source unit 15. On the sides of composition 9, the illumination further decreases because the amount of light reflected in the direction of imaging unit 16 is small. As composition 9 spreads on substrate 6, the surface of substrate 6 exposed between discrete droplets of composition 9 narrows, and signal intensity distribution 26 changes to signal intensity distribution 27. Furthermore, if liquid film 20 is formed from composition 9, the exposed portions of the substrate 6 surface are eliminated, the illumination in areas where composition 9 is not placed decreases, and signal intensity distribution 27 changes to signal intensity distribution 28. If signal intensity 31 in liquid film formation area 30 is lower than a predetermined threshold value in signal intensity distribution 28, controller 5 can determine that liquid film 20 has been formed at the position of line 25. In this example, the "formation condition" described above can be the condition that signal intensity 31, obtained from image data acquired by imaging unit 16, is lower than a predetermined threshold value in all liquid film formation areas 30 on substrate 6. If the analysis result satisfies the formation condition, that is, if the signal intensity 31 in all the liquid film formation regions 30 on the substrate 6 is lower than the predetermined critical value, the controller 5 determines that the liquid film 20 is formed on the substrate 6, and the processing procedure proceeds to step S104. It should be noted that the fourth embodiment and subsequent embodiments describe an example of a handling method when the analysis result does not satisfy the formation condition. The volatilization step in step S104 is as follows: Compared to the process of forming composition 9 (liquid film 20) in step S102, the solvent contained in liquid film 20 is volatilized by enhancing the solvent volatilization effect. The volatilization step can be understood as a waiting step in which a predetermined time is allowed for the solvent contained in liquid film 20 to volatilize. During this waiting period, environmental adjustments are performed to enhance the solvent volatilization effect compared to the process of forming composition 9 (liquid film 20) in step S102. In this example, before the volatilization step begins, controller 5 stops the supply of solvent vapor from gas supply port 12 as a first supply step. In other words, the volatilization suppression process for the solvent contained in liquid film 20 is stopped. Therefore, in volatilization step S104, the volatilization effect of the solvent contained in liquid film 20 is enhanced compared to the process of forming liquid film 20. In order to further enhance the solvent volatilization effect during the volatilization step, the controller 5 can control the gas controller 14 to supply clean dry air (CDA) from the gas supply port 12 to the space above the substrate (second supply step). At this time, the gas in the liquid film forming unit 3 can be discharged from the exhaust port 13. As another method, decompression and baking can be performed in the liquid film forming unit 3. Thereafter, the conveying device loads the substrate 6 from the liquid film forming unit 3. It should be noted that the gas supplied to the space above the substrate is not limited to CDA. For example, a gas selected from the group consisting of CDA, oxygen, nitrogen, helium, etc. can be supplied. By supplying gas, the composition is prompted to fill the unconnected portion. Step S105 is a step for forming a cured film by curing the liquid film 20 formed on the substrate 6. The substrate 6, having the liquid film 20 formed by the liquid film forming unit 3 on its surface, is loaded into the composition curing unit 4 by a conveyor device, placed on the substrate stage 19, and secured by a chuck. The controller 5 drives at least one of the mold holding unit 22 and the substrate stage 19 to bring the liquid film 20 on the substrate 6 into contact with (the flat surface of) the mold 21. While the liquid film 20 and the mold 21 are in contact, the controller 5 controls the irradiation unit 23 to irradiate the composition 9 with light to cure the composition. This forms a cured film (solid layer) on the substrate 6. After the cured film (solid layer) is formed, the controller 5 controls at least one of the mold holding unit 22 and the substrate stage 19 to separate the cured film from the mold 21. Note that if the composition curing unit 4 performs flattening without using the mold 21, the controller 5 waits until the composition 9 spreads naturally and flattens. Thereafter, the controller 5 controls the irradiation unit 23 to irradiate the composition 9 with light to cure it. As described above, in the film-forming apparatus 1 according to this embodiment, during the step of forming the liquid film, the state of liquid film formation on the substrate 6 is detected by the imaging unit 16, and based on the detected state of liquid film formation, the process is advanced to the volatilization step at an appropriate time. According to this embodiment, since the process can advance to the volatilization step at the time when liquid film formation is confirmed, it has an advantage in terms of throughput compared to conventional techniques, in which the process advances to the volatilization step after waiting for a predetermined time that is unrelated to the state of liquid film formation. It should be noted that volatilization of the solvent contained in the composition 9 begins immediately after the composition 9 is placed on the substrate 6. If it is known that volatilization will be completed within the period of step S102, there is no need to provide a volatilization step such as step S104. In this case, in response to the image analysis results satisfying the formation conditions, the process can proceed to the formation step instead of the waiting step. According to the above embodiment, a film formation method is provided that is advantageous for both suppressing defects and improving throughput. Second Embodiment In the second embodiment, in step S102, the controller 5 performs frequency analysis on the image data obtained by the imaging unit 16. In step S103, if the frequency component of the arrangement of the composition 9 is lower than a predetermined critical value, the controller 5 determines that the liquid film 20 is formed. If a frequency analysis is performed on the illuminance distribution at the position of line 25 of composition 9 discretely arranged on substrate 6, analysis result 32 is obtained, as shown in Figure 6. Figure 6 is a semi-logarithmic graph, with frequency plotted on the abscissa and illuminance plotted on the ordinate, with the frequency on the abscissa expressed as a logarithm. Analysis result 32 includes components of the discretely arranged composition 9 and components based on the characteristics of substrate 6, light source unit 15, optical system 17, and imaging unit 16. In analysis result 32, the components of the discretely arranged composition 9 are shown as curve 33. In this embodiment, frequency component 34 is the frequency component of the arrangement of composition 9, and frequency component 35 is the harmonic component of the arrangement of composition 9. As composition 9 diffuses over time, curve 32 changes to curve 36, where frequency component 34 based on the arrangement of composition 9 is minimal. If the illuminance 37 of frequency component 34 in Figure 6 is below a predetermined critical value, controller 5 can determine that liquid film 20 has formed at the position of line 25. Therefore, in this embodiment, the "formation condition" may be the following condition: the illuminance 37 of the frequency component 34 obtained from the frequency analysis results of the image data obtained by the imaging unit 16 is lower than a predetermined critical value in all the liquid film formation areas 30 on the substrate 6. If the analysis results satisfy the formation condition in step S103, that is, if the illuminance 37 of the frequency component 34 obtained from the frequency analysis results of the image data is lower than the critical value in all the liquid film formation areas 30 on the substrate 6, the controller 5 determines that the liquid film 20 has been formed. <Third Embodiment> Next, a film-forming apparatus according to a third embodiment will be described with reference to FIG7 . FIG7 is a diagram showing the configuration of the liquid film-forming unit in the film-forming apparatus according to the third embodiment. The configuration of the composition placement unit 2 , the composition solidification unit 4 , etc. is the same as in the first embodiment ( FIG1 ). The liquid film forming unit 38 shown in FIG7 includes an illumination unit 39 above the opening 11, which illuminates a portion of the substrate 6, and an imaging unit 40, which observes the state of liquid film formation in the area of ​​the substrate 6 illuminated by the illumination unit 39. Furthermore, the liquid film forming unit 38 may include an optical system 41 that illuminates the substrate 6 with light emitted from the illumination unit 39 and guides reflected light from the substrate 6 (the composition 9 thereon) to the imaging unit 40. The liquid film forming unit 38 may also include a drive unit 42. The drive unit 42 includes the illumination unit 39, the imaging unit 40, and the optical system 41, and is driven in a direction parallel to the surface of the substrate 6. The drive unit 42 can be driven within the range in which the imaging unit 40 can observe the entire area of ​​the substrate 6. In addition to the units described in the first embodiment, the controller 5 can also control the drive of the drive unit 42. Next, a film forming method according to this embodiment will be described. Except for step S102 shown in FIG2 , the other steps are the same as those in the first embodiment. In step S102 of this embodiment, after substrate 6 is loaded onto liquid film forming unit 38, imaging unit 40 images composition 9 in an area narrower than substrate 6. This allows for observation of liquid film formation with higher resolution. Controller 5 also drives drive unit 42 to cause imaging unit 40 to observe as it scans relative to substrate 6. Furthermore, by driving drive unit 42, controller 5 can shorten the scanning drive time, allowing for selective observation of areas on substrate 6 where the liquid film is slowly forming. The image data thus obtained can be used to determine the formation state of the liquid film 20 using the same processing procedure as in the first embodiment. <Fourth Embodiment> Sometimes, due to factors such as the viscosity of the composition 9, the intercomposition gap 24 ( FIG. 3 ) may not be filled even after a predetermined time or longer, and the liquid film 20 may not be properly formed. FIG. 9 shows a state where unconnected portions 32 of the composition 9 are generated. In the fourth embodiment, a recovery process will be described in the case where the image analysis results in step S103 do not satisfy the above-described formation conditions after a predetermined time has elapsed. Fig. 8 is a flowchart of the film forming method according to the present embodiment. This flowchart is a modification of the flowchart of Fig. 2 described in the first embodiment, and steps S801 and S802 are added to the flowchart of Fig. 2 . If the image analysis result does not satisfy the formation condition in step S103, that is, if the signal intensity 31 in one of the liquid film formation areas 30 on the substrate 6 is not less than the predetermined critical value, it is determined that the liquid film 20 has not been fully formed on the substrate 6, and the processing procedure proceeds to step S801. In step S801, the controller 5 determines whether a predetermined time has passed since step S102. If the predetermined time has not passed, the processing procedure returns to step S102 to continue the analysis step. On the other hand, if the predetermined time has passed, it is determined that the liquid film 20 will not be fully formed even if waiting for a longer time (the unconnected portion will not be eliminated), and the processing procedure proceeds to step S802. Step S802 is a recovery step in which unconnected portions are detected and a recovery process is performed on the detected unconnected portions, wherein the unconnected portions are portions where adjacent droplets are not sufficiently connected in the formed film. In the example, in the recovery step S802, the controller 5 measures the position coordinates (X, Y) of the unconnected portions 32 of the composition 9 based on the image data obtained by the imaging unit 16. Figure 10 shows an example in which three unconnected portions 32a, 32b, and 32c are detected from the image data. The position coordinates of the unconnected portions 32a, 32b, and 32c on the substrate 6 are defined as (X1, Y1), (X2, Y2), and (X3, Y3), respectively. The controller 5 controls the conveying device to unload the substrate 6 from the liquid film forming unit 3 and load it into the composition arrangement unit 2. The substrate 6 is placed on the substrate stage 7 and fixed by the chuck. The controller 5 controls the arrangement unit 8 to arrange the composition 9 on each of the unconnected portions 32a, 32b, and 32c. For example, the arrangement unit 8 sequentially moves to positions corresponding to (X1, Y1), (X2, Y2), and (X3, Y3) on the substrate 6 to arrange the composition 9. Alternatively, the substrate stage 7 holding the substrate 6 can be moved below the arrangement unit 8 to arrange the composition 9. In addition, according to the size of each unconnected portion 32a, 32b, and 32c, the controller 5 can adjust the number of compositions 9 to be arranged. The number of compositions 9 can be obtained in advance based on the respective areas of the unconnected portions 32a, 32b, and 32c. After that, the controller 5 controls the transport device to unload the substrate 6 from the composition placement unit 2 and load it into the liquid film forming unit 3. The substrate 6 is placed on the substrate stage 10 and fixed by the chuck. The composition 9 placed on the unconnected portions 32a, 32b, and 32c by the placement unit 8 begins to spread on the surface of the substrate 6. Through the recovery process, the composition 9 diffuses to the unconnected portions 32a, 32b, and 32c, and generates the liquid film 20. After the recovery process is completed, the process proceeds to the volatilization step S104. <Fifth Embodiment> In the fourth embodiment, the substrate 6 was moved from the liquid film forming unit 3 to the composition placement unit 2, and the composition 9 was placed on each of the unconnected portions 32a, 32b, and 32c in the composition placement unit 2. In the fifth embodiment, on the other hand, the recovery process was performed in the liquid film forming unit 3 without moving the substrate 6 from the liquid film forming unit 3 to the composition placement unit 2. In this embodiment, the controller 5 drives the substrate stage 10 so that the unconnected portion 32a is positioned at the supply destination of the gas supply port 12. The controller 5 then controls the gas controller 14 to supply the solvent from the gas supply port 12. A similar process is performed sequentially for the unconnected portions 32b and 32c. Note that in this embodiment, CDA can be supplied instead of a solvent to the unconnected portion. The supplied gas is not limited to CDA; gases such as oxygen, nitrogen, or helium can also be supplied. By supplying the gas, the composition is forced to fill the unconnected portion. According to the present embodiment, at least since there is no need to move the substrate 6 from the liquid film forming unit 3 to the composition disposing unit 2 , there is an advantage in terms of throughput, unlike the fourth embodiment. <Sixth embodiment> The recovery treatment procedure according to the fourth and fifth embodiments is to supply a solvent or a gas to the unconnected portion. Another recovery treatment procedure is also possible. For example, another example of the recovery process can be to apply vibration to the substrate stage 10 (i.e., substrate 6). For example, a frequency that effectively diffuses the composition 9 is previously determined, and vibration of that frequency is applied to the substrate stage 10. This vibration causes the composition to fill the unconnected portion. Seventh Embodiment In the fourth embodiment ( FIG. 8 ), the recovery process is performed after the liquid film forming step S102 . However, the time point for performing the recovery process is not limited thereto. The recovery process can be performed at any time point before the start of the solidified film forming step S105 . For example, during the execution of the analysis step S102 (i.e., the liquid film forming step), the amount of change in droplet merging within a predetermined time period can be detected, the occurrence of unconnected portions can be predicted based on the amount of change, and the recovery process can be performed based on the prediction. Alternatively, the recovery process can be performed after the volatilization step S104 is performed. <Eighth Embodiment> In the fourth to seventh embodiments, the recovery process performed when the image analysis result does not satisfy the predetermined forming conditions after a predetermined time has elapsed in step S103 has been described. In the eighth embodiment, a process for unloading a substrate will be described as a method of handling the situation when the image analysis result does not satisfy the predetermined forming conditions after a predetermined time has elapsed in step S103. FIG11 is a flow chart showing a film-forming method according to this embodiment. This flow chart is a variation of the flow chart of FIG8 described in the fourth embodiment. It is assumed that the film-forming apparatus 1 according to this embodiment is of a type that uses a mold 21, that is, a type that solidifies the composition 9 while the liquid film 20 and the mold 21 are in contact. In this embodiment, if it is determined in step S801 that a predetermined time has elapsed since the start of step S102, it is determined that even if a longer wait is made, the liquid film 20 will not be sufficiently formed (unconnected portions will not be eliminated), and the process proceeds to step S104. In step S104, a volatilization step is performed. After the volatilization step is completed, the substrate 6 is transferred from the liquid film forming unit 3 to the composition curing unit 4 by the transport device. The processing procedure proceeds to step S901. In step S901, it is determined whether an unconnected portion exists. More specifically, if the image analysis result is determined to satisfy the formation conditions in step S103, then no unconnected portion exists. On the other hand, if the processing procedure proceeds to step S901 via step S801 because the image analysis result does not satisfy the formation conditions in step S103, then an unconnected portion exists. If there is no unconnected portion, the formation step S105 is performed. In the present embodiment, the formation step S105 may include a contact step S902, a curing step S903 and a separation step S904. In the contact step S902, the controller 5 drives at least one of the mold holding unit 22 and the substrate stage 19, so that the liquid film 20 on the substrate 6 contacts the mold 21 (flat portion). In the curing step S903, in a state where the liquid film 20 and the mold 21 are in contact, the controller 5 causes the irradiation unit 23 to perform light irradiation to cure the liquid film 20. Thus, a cured film (solid layer) is formed on the substrate 6. In the separation step S904, the controller 5 drives at least one of the mold holding unit 22 and the substrate stage 19, so that the cured film is separated from the mold 21. Afterwards, in the unloading step S905, the controller 5 controls the conveying device to unload the substrate 6 from the composition curing unit 4. If an unconnected portion exists ("Yes" in step S901), the process proceeds to step S906. In step S906, as in step S903, the controller 5 causes the irradiation unit 23 to irradiate light to cure the liquid film 20. Subsequently, in the unloading step S905, the controller 5 controls the transport device to unload the substrate 6 from the composition curing unit 4. Therefore, for substrates with unconnected portions, the liquid film 20 is cured without contact between the liquid film 20 and the mold 21, and then the substrate is loaded from the device. Since the liquid film 20 is already cured before the substrate is loaded, the substrate is never loaded while the solvent is evaporating from the liquid film 20, ensuring safety. The controller 5 stores execution information indicating that the contact step S902 has been executed on the substrate 6. The execution information can be used to distinguish whether the contact step has been executed or not executed on each substrate. The execution information can be transmitted from the controller 5 to the host system via a network. In the above example, the presence or absence of an unconnected portion is determined by the processing procedures of steps S102, S103, and S801. The timing of determining the unconnected portion is not limited thereto and may be any time before the completion of the contacting step S902. For example, a detection unit may be provided in the composition solidification unit 4, and detection of the unconnected portion may be performed simultaneously with the contacting step S902. Next, a method for manufacturing articles (semiconductor IC components, liquid crystal display components, color filters, MEMS, etc.) by using the above-mentioned planarization equipment will be described. The manufacturing method includes: using the above-mentioned film-forming equipment as a planarization equipment, a step of planarizing the composition by bringing the composition arranged on a substrate (wafer, glass substrate, etc.) and a mold into contact with each other, a step of curing the composition, and a step of separating the composition and the mold from each other. Thus, a planarization film is formed on the substrate. Then, the substrate with the planarization film formed thereon is subjected to processing such as pattern formation using a photolithography device, and the treated substrate is processed through other known processing steps to manufacture articles. Other known steps include etching, resist removal, cutting, bonding, packaging, etc. Compared with conventional methods, this manufacturing method can manufacture articles with higher quality. The film-forming apparatus described above can also be applied to an imprinting apparatus. The pattern of the cured product formed using the imprinting apparatus is permanently used for at least some of a variety of articles, or is temporarily used when manufacturing various articles. The articles include circuit components, optical components, MEMS, recording elements, sensors, molds, and the like. Examples of circuit components include volatile and non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, as well as semiconductor components such as LSIs, CCDs, image sensors, and FPGAs. Examples of molds include molds used for imprinting. The pattern of the cured product is directly used as at least some of the components of the above-mentioned article or temporarily used as a photoresist mask. After etching or ion implantation in the substrate processing step, the photoresist mask is removed. The following describes a method for manufacturing an article. As shown in step SA of Figure 13 , a substrate 1z, such as a silicon wafer, is prepared, having a treated material 2z, such as an insulator, formed on its surface. Next, an imprint material 3z is applied to the surface of the treated material 2z using an inkjet method or the like. This diagram shows the imprint material 3z being applied to the substrate in the form of multiple droplets. As shown in step SB of Figure 13 , one side of a mold 4z, used for imprinting a concave-convex pattern, is oriented so as to face the imprint material 3z on the substrate. As shown in step SC of Figure 13 , the substrate 1z, to which the imprint material 3z is applied, is brought into contact with the mold 4z, and pressure is applied. The gap between the mold 4z and the treated material 2z is filled with the imprint material 3z. In this state, when curing energy is irradiated onto the imprint material 3z through the mold 4z, the imprint material 3z is cured. As shown in steps SD in Figure 13 , after the imprint material 3z is cured, the mold 4z is separated from the substrate 1z. A pattern of the cured product of the imprint material 3z is then formed on the substrate 1z. In this pattern of the cured product, the concave portions of the mold correspond to the convex portions of the cured product, and vice versa. In other words, the concave-convex pattern of the mold 4z is transferred to the imprint material 3z. As shown in step SE of FIG13 , when etching is performed using the pattern of the cured product as an etch-resistant mask, portions of the surface of the treated material 2z where no cured product is present or a thin layer of the cured product remains are removed to form recesses 5z. As shown in step SF of FIG13 , when the pattern of the cured product is removed, an article having recesses 5z formed in the surface of the treated material 2z can be obtained. In this case, the pattern of the cured product is removed. However, instead of processing or removing the pattern of the cured product, it can be used as an interlayer dielectric film, for example, in semiconductor devices, i.e., a component of an article. While the present invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments and that the appended claims are to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 1: Film-forming device 2: Composition arrangement unit 3: Liquid film forming unit 4: Composition curing unit 5: Controller 6: Substrate 7: Substrate stage 8: Arrangement unit 9: Composition 10: Substrate stage 11: Opening 12: Gas supply port 13: Exhaust port 14: Gas controller 15: Light source unit 16: Imaging unit 17: Optical system 18: Cover glass 19: Substrate stage 20: Liquid film 21: Mold 22: Mold holding unit 23: Irradiation unit 24: Intercomposition gap 25: Line 26: Signal intensity distribution 27: Signal intensity distribution 28: Signal intensity distribution 29: Arrangement position 30: Liquid film formation area 31: Signal intensity 32: Analysis result 32: Curve 32: Unconnected portion 32a: Unconnected portion 32b: Unconnected portion 32c: Unconnected portion 33: Curve 34: Frequency component 35: Frequency component 36: Curve 37: Illumination 38: Liquid film forming unit 39: Illumination unit 40: Camera unit 41: Optical system 42: Drive unit DP: Dispenser ML: Composition W: Substrate C: Substrate chuck SS: Cover plate IL: Light source 1z: Substrate 2z: Treated material 3z: Imprint material 4z: Mold 5z: Groove SA: Step SB: Step SC: Step SD: Step SE: Step SF: Step S101: Step S102: Step S103: Step S104: Step S105: Step S801: Step S802: Step S901: Step S902: Step S903: Step S904: Step S905: Step S906: Step [FIG. 1] is a view showing the configuration of a film-forming apparatus according to a first embodiment; [FIG. 2] is a flow chart of a film forming method according to the first embodiment; [Fig. 3] is a diagram showing a process for forming a liquid film; [FIG. 4] is a view showing a state where a composition is arranged on a substrate; [Fig. 5] is a view showing an example of signal intensity distribution in a liquid film forming step; [FIG. 6] is a diagram showing an example of a frequency analysis result of a signal intensity distribution; [FIG. 7] is a view showing the configuration of a liquid film forming unit according to a third embodiment; [FIG. 8] is a flow chart of a film forming method according to a fourth embodiment; [Fig. 9] is a view showing a state where an unconnected portion of a composite is produced; [FIG. 10] is a view showing an example of detected unconnected portions; [FIG. 11] is a flowchart of a film forming method according to an eighth embodiment; [FIG. 12A] to [FIG. 12D] are views for explaining an outline of a flattening processing procedure; and [Fig. 13] is a view for explaining a method of manufacturing an article. 1: Film formation equipment 2: Combination layout unit 3: Liquid film formation unit 4: Composition curing unit 5: Controller 6:Substrate 7:Substrate table 8: Layout Unit 9: Composition 10:Substrate table 11: Opening 12: Air supply port 13: Exhaust port 14: Gas controller 15: Light source unit 16: Camera unit 17: Optical system 18: Cover glass 19:Substrate table 20: Liquid film 21:Mold 22: Mold holding unit 23: Irradiation unit

Claims

1. A method for forming a membrane, comprising: The arrangement step involves discretely arranging multiple droplets of a curable composition on a substrate, the curable composition containing a polymeric compound of a non-volatile component and a solvent of a volatile component; The analysis step involves analyzing an image obtained by capturing a photograph after the arrangement step, in which each of the plurality of droplets on the substrate is connected to an adjacent droplet, thereby forming a continuous liquid film on the substrate. The evaporation step, compared to the processing procedure for forming the liquid film, involves evaporating the solvent contained in the liquid film by enhancing the solvent evaporation effect; The process includes a forming step, in which a cured film is formed by solidifying the liquid film. If the analysis results obtained in the analysis step meet predetermined conditions indicating that the liquid film is in a sufficient state of formation, the process proceeds to the evaporation step and then to the forming step. If the analysis results do not meet the predetermined conditions within a predetermined time after the arrangement step, the liquid film is solidified without contacting the liquid film with the flat surface of the mold, and then the substrate is unloaded.

2. The membrane formation method as described in claim 1, wherein, If the analytical results obtained in the analytical step do not meet the predetermined conditions, the processing procedure will not perform the evaporation step and will return to the analytical step.

3. The membrane formation method as described in claim 1 further includes: After the arrangement step, the solvent vapor is supplied to the space above the substrate, wherein the supply of the vapor is stopped before the evaporation step, thereby enhancing the evaporation effect.

4. The membrane formation method as described in claim 3 further includes: During the evaporation step, a gas selected from the group consisting of clean, dry air, oxygen, nitrogen, and helium is supplied to the space above the substrate.

5. The membrane formation method as described in claim 1, wherein, The predetermined condition is as follows: in all liquid film formation regions on the substrate, the signal strength of the image is below a predetermined critical value.

6. The membrane formation method as described in claim 5, wherein, The signal strength of the image is the signal strength obtained by photographing the substrate after the plurality of droplets are arranged in the arrangement step, minus the signal strength of the image obtained by photographing the substrate before the plurality of droplets are arranged in the arrangement step.

7. The membrane formation method as described in claim 1, wherein, The analysis steps include performing frequency analysis on the image, and the predetermined condition is that the illuminance of the frequency components obtained from the frequency analysis in all liquid film formation areas on the substrate is lower than a predetermined critical value.

8. The membrane formation method as described in claim 1, wherein, The image is a picture captured by the camera unit when it scans the camera unit and the substrate in a relative manner.

9. The membrane formation method as described in claim 2, further comprising: If the analysis results do not meet the predetermined conditions within a predetermined time after the arrangement step, unconnected portions are detected, and a recovery process is performed on the detected unconnected portions, which are the portions in the formed membrane where adjacent droplets are not sufficiently connected.

10. The membrane formation method as described in claim 9, wherein, The restoration process includes applying the curable composition to the unconnected portion.

11. The membrane formation method as described in claim 9, wherein, The recovery process includes supplying the solvent to the unconnected portion.

12. The membrane formation method as described in claim 9, wherein, The recovery process includes supplying a gas selected from a group consisting of clean, dry air, oxygen, nitrogen, and helium to the unconnected portion.

13. The membrane formation method as described in claim 9, wherein, The recovery process includes applying vibrations at a predetermined frequency to the substrate.

14. The membrane formation method as described in claim 9, wherein, After the recovery process is performed, the process proceeds to the formation step.

15. The membrane formation method as described in claim 1, wherein, The forming step includes: a curing step, after the contact step, curing the liquid film while it is in contact with the flat surface of the mold to form a cured film; and a separation step, after the curing step, separating the cured film from the mold.

16. A membrane forming apparatus, comprising: A placement unit, configured to discretely place a plurality of droplets of a curable composition on a substrate, the curable composition containing a polymeric compound of a non-volatile component and a solvent of a volatile component; and a camera unit, configured to capture a process in which each of the plurality of droplets on the substrate is connected to an adjacent droplet, thereby forming a continuous liquid film on the substrate. A processing unit, configured to analyze the images acquired by the camera unit; The system includes a forming unit configured to form a cured film by solidifying a liquid film from which the solvent evaporates. If the analysis results satisfy predetermined conditions indicating that the liquid film formation state is sufficient, an evaporation process is performed as follows: compared to the liquid film formation process, the solvent contained in the liquid film is evaporated by enhancing the solvent evaporation effect, and then the forming unit forms the cured film. If the analysis results do not satisfy the predetermined conditions within a predetermined time after the arrangement step, the liquid film is solidified without contacting the liquid film with the flat surface of the mold, and then the substrate is unloaded.

17. A method for manufacturing an article, comprising: The forming step involves forming a film of a curable composition on a substrate using a film forming method as described in any one of claims 1 to 15; The processing step involves processing the substrate with the film, wherein the film is formed on the substrate in the formation step; And the manufacturing steps, which involve manufacturing articles from the treated substrate.

Images