Molding device, molding method, and article manufacturing method

Abstract

To provide a molding device that is advantageous for feedback-controlling the volume of droplets of imprint material discharged toward a substrate.SOLUTION: There is provided a molding device that molds a composition on a substrate by using a mold, the molding device having: a discharge unit that discharges droplets of the composition to arrange them on the substrate; a measurement unit that measures the film thickness of a film of the composition on the substrate that is formed by molding the droplets of the composition arranged on the substrate with the mold; and a control unit that determines the volume of the droplets of the composition discharged from the discharge unit based on the film thickness measured by the measurement unit, and controls the discharge unit so that a variation in the volume of the droplets of the composition discharged from the discharge unit falls within an allowable range based on the volume.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a molding apparatus, a molding method, and a method for manufacturing an article. [Background technology]

[0002] A microfabrication technology is known that forms a pattern on a substrate by an imprinting process in which an imprint material (composition) on the substrate is molded using a mold. This technology, also known as imprinting technology, is capable of forming nanometer-order patterns (structures) on the substrate.

[0003] One of the methods for hardening an imprint material in imprint technology is a photo-curing method. In an imprint device that employs the photo-curing method, the imprint material is placed (supplied) on a substrate, and the imprint material is brought into contact with a mold and irradiated with light to harden the imprint material. Then, the mold is separated from the hardened imprint material on the substrate, forming a pattern of the imprint material on the substrate. Another method for hardening an imprint material is, for example, a thermal hardening method, in which the imprint material is hardened by heat.

[0004] In imprinting devices, the imprint material is generally placed on a substrate using a dispenser. The dispenser is a component of a liquid ejection device, and is a mechanism that ejects droplets of the imprint material using, for example, an inkjet system, and its specific configuration is similar to that of an inkjet head generally used in inkjet printers.

[0005] In an imprinting apparatus, to accurately form a pattern on a substrate, it is necessary to keep the volume of the droplets of imprinting material discharged from the dispenser constant. However, in a dispenser, the condition of the part that discharges the imprinting material may change due to changes in the pressure inside the dispenser, deterioration of the driving parts such as piezo elements, or adhesion of foreign matter, which may cause the volume of the droplets of imprinting material discharged from the dispenser to fluctuate. Therefore, although it is a technology related to an exposure apparatus, there is a technology that is thought to be applicable to an imprinting apparatus, which measures the film thickness of a photosensitive agent on a substrate (see Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-31895 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technology disclosed in Patent Document 1 measures the film thickness of the photosensitive agent using a measurement device (external device) outside the exposure device, and it takes time to feed back (reflect) the measurement results in exposure conditions such as the integrated exposure dose. This problem also occurs when the technology disclosed in Patent Document 1 is applied to an imprinting device, for example, when the film thickness of the imprinting material is measured using a measurement device outside the imprinting device and the measurement results are fed back to the control of the dispenser.

[0008] The present invention has been made in consideration of the problems with the conventional technology, and has an exemplary object to provide a molding device that is advantageous for feedback control of the volume of droplets of imprint material ejected toward a substrate. [Means for solving the problem]

[0009] A molding apparatus according to one aspect of the present invention is a molding apparatus that molds a composition on a substrate using a mold in a process for manufacturing an article, the molding apparatus comprising: a discharge unit that discharges droplets of the composition and arranges them on the substrate; a measurement unit that measures the thickness of a film of the composition formed on the substrate by using the mold to mold the droplets of the composition arranged on the substrate; and a measuring unit that obtains a volume of the droplets of the composition discharged from the discharge unit based on the thickness measured by the measurement unit, thereby acquiring a transition of fluctuation in the volume of the droplets, and adjusting the volume of the droplets so that the fluctuation in the volume of the droplets discharged from the discharge unit falls within an allowable range. In the above step and a control unit that performs feedback control of the discharge unit.

[0010] Further objects and other aspects of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. [Effects of the Invention]

[0011] According to the present invention, for example, it is possible to provide a molding apparatus that is advantageous for feedback control of the volume of droplets of imprint material discharged toward a substrate. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing the configuration of an imprint apparatus according to one aspect of the present invention. [Figure 2] FIG. 2 is a diagram for explaining the detailed configuration and functions of a measurement unit. [Figure 3] 10 is a flowchart illustrating an example of an imprint process according to the present embodiment. [Figure 4] 10 is a flowchart illustrating an example of an imprint process according to the present embodiment. [Figure 5] 1A to 1C are diagrams for explaining a method for manufacturing an article. [Figure 6] FIG. 2 is a diagram illustrating a case where the imprint apparatus shown in FIG. 1 is used as a planarization apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0014] FIG. 1 is a schematic diagram showing the configuration of an imprinting apparatus 100 according to one aspect of the present invention. The imprinting apparatus 100 is a lithography apparatus employed in a lithography process, which is a manufacturing process for devices such as semiconductor elements, liquid crystal display elements, and magnetic storage media, and forms a pattern on a substrate. The imprinting apparatus 100 functions as a molding apparatus that uses a mold to mold an imprinting material, which is a composition, on a substrate. In this embodiment, the imprinting apparatus 100 brings the mold into contact with uncured imprinting material placed (supplied) on the substrate, and applies energy for curing to the imprinting material, thereby forming a pattern in a cured product to which the pattern of the mold has been transferred.

[0015] The imprint material is a material (curable composition) that hardens when curing energy is applied. The curing energy may be electromagnetic waves, heat, or the like. Electromagnetic waves include, for example, light having a wavelength selected from the range of 10 nm to 1 mm, specifically infrared rays, visible light, ultraviolet rays, and the like.

[0016] The curable composition is a composition that cures upon irradiation with light or heat. The photocurable composition that cures upon irradiation with light contains at least a polymerizable compound and a photopolymerization initiator, and may further contain a non-polymerizable compound or a solvent, as necessary. The non-polymerizable compound is at least one selected from the group consisting of a sensitizer, a hydrogen donor, an internal mold release agent, a surfactant, an antioxidant, a polymer component, and the like.

[0017] The imprint material may be applied to the substrate by a liquid jet head in the form of droplets, or in the form of islands or a film formed by connecting multiple droplets. The viscosity of the imprint material (at 25°C) is, for example, 1 mPa·s or more and 100 mPa·s or less.

[0018] The substrate may be made of glass, ceramics, metal, semiconductor, resin, etc., and may have a member made of a material different from the substrate formed on its surface as needed. Specifically, the substrate may be made of a silicon wafer, a compound semiconductor wafer, quartz glass, etc.

[0019] In this embodiment, the imprint apparatus 100 employs a photo-curing method as a method for curing the imprint material. However, the imprint apparatus 100 can also employ a curing method that uses other energy (for example, heat) to cure the imprint material.

[0020] In this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system in which the direction parallel to the surface of the substrate is the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are the X-direction, Y-direction, and Z-direction, respectively, and rotation around the X-axis, Y-axis, and Z-axis are θX, θY, and θZ, respectively.

[0021] The imprint apparatus 100 has an irradiation unit 7, a mold holding unit 2, a substrate stage 6, a dispenser 11, a measurement unit 13, and a control unit 20. The imprint apparatus 100 also has a transport mechanism (not shown) that has the function of loading the substrate 4 onto the substrate stage 6 and the function of unloading the substrate 4 from the substrate stage 6.

[0022] The irradiation unit 7 adjusts light 9 (e.g., ultraviolet light) emitted from a light source (not shown) to a state appropriate for the imprint process, and irradiates the light onto the imprint material 8 on the substrate through the mold 1. The light source may be, for example, a mercury lamp that emits i-rays or g-rays, but is not limited to this, and may be any light source that emits light that is transmitted through the mold 1 and has a wavelength that hardens the imprint material 8. Note that if the imprint apparatus 100 employs a thermal curing method, a heating unit for hardening the imprint material 8 may be provided, instead of the irradiation unit 7, for example, near the substrate stage 6.

[0023] The mold 1 is also called a mold and has a rectangular planar shape. The mold 1 has a three-dimensional fine concave-convex pattern in the center of the surface facing the substrate 4. The mold 1 is made of a material that can transmit the light 9 from the irradiation unit 7, such as quartz.

[0024] The mold holding unit 2 is supported by the structure 3. The mold holding unit 2 includes, for example, a mold chuck that holds the mold 1 and a mold driving mechanism that supports and drives the mold chuck. The mold chuck holds the mold 1 by attracting the outer circumferential region of the incident surface of the mold 1, onto which light 9 from the irradiation unit 7 is incident, using vacuum suction force or electrostatic force. The mold driving mechanism drives the mold 1 (the mold chuck that holds it) in the Z direction to bring the mold 1 into contact with the imprint material 8 on the substrate or to separate the mold 1 from the imprint material 8 on the substrate. Note that the operation of bringing the imprint material 8 on the substrate into contact with the mold 1 and the operation of separating the mold 1 from the imprint material 8 on the substrate may be achieved by driving the substrate 4 (the substrate stage 6 that holds it) in the Z direction. Alternatively, the operation of bringing the imprint material 8 on the substrate into contact with the mold 1 and the operation of separating the mold 1 from the imprint material 8 on the substrate may be achieved by driving both the mold 1 and the substrate 4 relatively in the Z direction.

[0025] In this embodiment, the substrate 4 is a substrate made of single crystal silicon. For applications other than semiconductor devices, such as manufacturing optical elements, the substrate 4 may be made of optical glass such as quartz, or for light-emitting elements, GaN or SiC.

[0026] The substrate stage 6 is a stage that holds the substrate 4 and can be driven within the XY plane on the stage base 5. The substrate stage 6 is used to position the substrate 4 relative to the mold 1, i.e., to align the mold 1 and the substrate 4, when bringing the imprint material 8 on the substrate into contact with the mold 1.

[0027] The dispenser 11 is supported by the structure 3 and supplies the imprint material 8 onto the substrate. The dispenser 11 functions as a discharge unit that discharges droplets of the imprint material 8 and arranges the droplets of the imprint material 8 in a desired drop pattern in a shot area (a partitioned area where a pattern is to be formed) on the substrate. The imprint material 8 is required to have fluidity when filled between the mold 1 and the substrate 4, and to be solid (retain its shape) after being molded by the mold 1. In this embodiment, the imprint material 8 is photocurable, meaning that it is cured by irradiation with light 9, but it can also be thermosetting or thermoplastic depending on various conditions such as the manufacturing process of the article.

[0028] The measurement unit 13 is provided inside the imprint apparatus 100 (hereinafter referred to as "inside the apparatus"). The measurement unit 13 measures the thickness of a film of imprint material 8 formed on a substrate by using a mold 1 to form droplets of imprint material 8, which are placed on the substrate from a dispenser 11. In this embodiment, the measurement unit 13 measures the thickness of the film of imprint material 8 inside the apparatus during the period after the film of imprint material 8 is formed on a substrate held by a substrate stage 6 and before the substrate 4 is carried out from the substrate stage 6. The configuration and function of the measurement unit 13 will be described in detail later.

[0029] The control unit 20 is configured as a computer including a CPU, memory, etc., and controls each unit of the imprint apparatus 100 in accordance with a program stored in the memory. The control unit 20 controls the operation and adjustment of each unit of the imprint apparatus 100 to perform an imprint process of forming a pattern of imprint material 8 on a substrate using the mold 1. In this embodiment, the control unit 20 also calculates the volume of the droplets of imprint material 8 discharged from the dispenser 11 (volume per droplet). Based on the calculated volume of the droplets of imprint material 8, the control unit 20 controls (feedback control) the dispenser 11 so that fluctuations in the droplets of imprint material 8 discharged from the dispenser 11 fall within an allowable range. The control unit 20 may be configured integrally with the other units of the imprint apparatus 100 (in a common housing), or may be configured separately from the other units of the imprint apparatus 100 (in a different housing).

[0030] A general operation of the imprint apparatus 100, i.e., the imprint process, will now be described briefly. First, the control unit 20 loads the substrate 4 into the imprint apparatus 100 via the transport mechanism and causes the substrate stage 6 to hold the substrate 4. Next, the control unit 20 drives the substrate stage 6 so that a shot area of ​​the substrate 4 (a shot area to be subjected to the imprint process) faces the dispenser 11. While driving the substrate stage 6 below the dispenser 11, the control unit 20 causes the dispenser 11 to eject a predetermined amount of droplets of imprint material 8, thereby disposing the droplets of imprint material 8 on the shot area of ​​the substrate 4 (disposing step).

[0031] Next, the control unit 20 drives the substrate stage 6 so that the shot area (the shot area where droplets of imprint material 8 are arranged) of the substrate 4 is positioned opposite the mold 1 (pattern). Next, the control unit 20 drives the mold holding unit 2 in the Z direction (downward) to bring the mold 1 and the substrate 4 close to each other, and in this state, detects the marks provided on the mold 1 and the substrate 4 with an alignment scope (not shown). Then, based on the detection result of the alignment scope, the control unit 20 drives the substrate stage 6 in the X direction and the Y direction to adjust the relative positions of the mold 1 and the substrate 4 (align the mold 1 and the substrate 4).

[0032] Next, the control unit 20 drives the mold holding unit 2 in the Z direction to narrow the gap between the mold 1 and the substrate 4, thereby bringing the (droplets of) imprint material 8 on the substrate into contact with (the pattern of) the mold 1 (contact step). Next, while the imprint material 8 on the substrate and the mold 1 are in contact, the control unit 20 irradiates the imprint material 8 with light 9 from the irradiation unit 7 to harden the imprint material 8 (hardening step). Then, the control unit 20 drives the mold holding unit 2 in the Z direction (upward) to widen the gap between the mold 1 and the substrate 4, thereby separating the mold 1 from the hardened imprint material 8 on the substrate (hardening step). As a result, a pattern corresponding to the pattern of the mold 1 is formed (transferred) on the imprint material 8 on the substrate. Thereafter, the control unit 20 transports the substrate 4 from the substrate stage 6 (imprint apparatus 100) via the transport mechanism, and the imprint process is completed.

[0033] 2(a), 2(b), and 2(c) are diagrams for explaining the detailed configuration and functions of the measurement unit 13. The measurement unit 13 is configured, for example, with a distance measuring sensor such as a spectroscopic interferometer, as shown in FIGS. 2(a) to 2(c). In this case, it is preferable that the wavelength of light emitted from the light source of the distance measuring sensor (measurement unit 13) toward the substrate 4 and the imprint material 8 is not a wavelength that hardens the imprint material 8.

[0034] 2(a) to 2(c), an example of a measurement process in which a measurement unit 13 configured with a distance measurement sensor measures the film thickness of the imprint material 8 formed on a substrate will be described. Note that the amount of droplets of the imprint material 8 discharged from the dispenser 11 varies depending on the drop pattern. Therefore, it is preferable to measure the film thickness of the imprint material 8 formed on the substrate for each drop pattern, or to set a reference drop pattern and measure it.

[0035] First, as shown in Fig. 2(a), the measurement unit 13 measures the distance (first distance) between the surface 4a of the substrate 4 before the imprint process, i.e., the surface 4a of the substrate 4 before the droplets of the imprint material 8 are placed, and the measurement unit 13. Next, as shown in Fig. 2(b), the measurement unit 13 measures the distance (second distance) between the surface 8a of the imprint material 8 on the substrate after the imprint process, i.e., the surface 8a of the film of the imprint material 8 formed on the substrate, and the measurement unit 13. Then, the difference between the measurement result for the surface 4a of the substrate 4 before the imprint process and the measurement result for the surface 8a of the imprint material 8 on the substrate after the imprint process, i.e., the difference between the first distance and the second distance, is determined to be the film thickness of the film of the imprint material 8 formed on the substrate.

[0036] 2(c), the measurement unit 13 can also measure the film thickness of the imprint material 8 formed on the substrate by simultaneously detecting reflected light from each of the front surface 8a and back surface 8b of the imprint material 8 on the substrate after the imprint process. Specifically, first, the measurement unit 13 measures the distance (first distance) between the measurement unit 13 and the back surface 8b (first surface), which is the surface facing the substrate of the film of imprint material 8 formed on the substrate. Next, the measurement unit 13 measures the distance (second distance) between the measurement unit 13 and the front surface 8a (second surface), which is the surface opposite to the surface facing the substrate of the film of imprint material 8 formed on the substrate. Here, the difference between the measurement result for the back surface 8b of the film of imprint material 8 and the measurement result for the front surface 8a of the film of imprint material 8, i.e., the difference between the first distance and the second distance, may be taken as the film thickness of the imprint material 8. However, when the reflected light from each of the front surface 8a and the back surface 8b of the imprint material 8 is detected simultaneously, the optical path length becomes longer than that in air due to the refractive index of the imprint material 8, and therefore it is advisable to correct the film thickness of the imprint material 8 taking the refractive index of the imprint material 8 into consideration. Therefore, it is advisable to calculate the film thickness of the imprint material 8 based on a first distance which is the distance between the back surface 8b of the imprint material 8 film and the measurement unit 13, a second distance which is the distance between the front surface 8a of the imprint material 8 film and the measurement unit 13, and the refractive index of the imprint material 8. Note that the refractive index of the imprint material 8 needs to be acquired in advance as refractive index information indicating the relationship between the type of imprint material 8 and the refractive index of the imprint material 8, for example, for each type of imprint material 8.

[0037] Furthermore, the film thickness of the imprint material 8 film formed on the substrate may be obtained from the measurement results of the measurement unit 13 for multiple locations (two or more points) on the substrate 4 or the imprint material 8. For example, first, the measurement unit 13 measures a first distance between the surface 4 a of the substrate 4 and the measurement unit 13 for multiple locations (first multiple locations) on the surface of the substrate 4. Next, the measurement unit 13 measures a second distance between the surface 8 a of the imprint material 8 film and the measurement unit 13 for multiple locations (second multiple locations) of the imprint material 8 film on the first multiple locations on the surface 4 a of the substrate 4. Then, the difference between the average value of the first distances at the first multiple locations on the surface 4 a of the substrate 4 and the average value of the second distances at the second multiple locations of the imprint material 8 film may be used as the film thickness of the imprint material 8 formed on the substrate. This makes it possible to measure the first distance and the second distance while suppressing (leveling out) variations in distance depending on the location, even if the substrate 4 has unevenness (such as an underlying pattern). The first plurality of locations on the surface 4a of the substrate 4 include, for example, a central location of the shot area, a peripheral location on the periphery of the shot area, and a location between the central location and the peripheral location.

[0038] On the other hand, the same applies when reflected light from each of the front surface 8a and the back surface 8b of the imprint material 8 is detected simultaneously. First, the measurement unit 13 measures a first distance between the measurement unit 13 and the back surface 8b of the film of imprint material 8 at multiple locations (first multiple locations) on the back surface 8b of the film of imprint material 8 formed on the substrate. Next, the measurement unit 13 measures a second distance between the measurement unit 13 and the front surface 8a of the film of imprint material 8 at multiple locations (second multiple locations) on the surface 8a on the first multiple locations on the back surface 8b of the film of imprint material 8. Then, the film thickness of the film of imprint material 8 is calculated based on the average value of the first distances at the first multiple locations on the back surface 8b of the film of imprint material 8, the average value of the second distances at the second multiple locations on the front surface 8a of the film of imprint material 8, and the refractive index of the imprint material 8.

[0039] Once the thickness of the film of imprint material 8 formed on the substrate has been measured in this manner, the control unit 20 determines the volume of the droplets of imprint material 8 dispensed from the dispenser 11 based on the film thickness of the film of imprint material 8 measured by the measurement unit 13. The volume of the droplets of imprint material 8 can be calculated from the number of droplets of imprint material 8 dispensed from the dispenser 11, the film thickness of the film of imprint material 8 measured by the measurement unit 13, and the area of ​​the shot region (the area of ​​the region where the film of imprint material 8 is formed). For example, let N [pcs] be the number of droplets of imprint material 8 dispensed from the dispenser 11, t [m] be the film thickness of the film of imprint material 8 measured by the measurement unit 13, and S [m 2 In this case, the volume of the droplet of the imprint material 8 is t [m] × S [m 2 ] / N[pcs].

[0040] The control unit 20 stores the volume of the droplets of the imprint material 8 calculated from the film thickness of the film of the imprint material 8 measured by the measurement unit 13, and grasps the fluctuation (progression) of the volume of the droplets of the imprint material 8 discharged from the dispenser 11. Then, the control unit 20 controls (feedback controls) the dispenser 11 so that the fluctuation of the volume of the droplets of the imprint material 8 discharged from the dispenser 11 falls within an allowable range. For example, if the amount of fluctuation of the droplets of the imprint material 8 discharged from the dispenser 11 with respect to the optimal volume of the droplets of the imprint material 8 exceeds ±5%, the control unit 20 controls (adjusts) the volume of the droplets of the imprint material 8 discharged from the dispenser 11. Specifically, if the volume of the droplets of the imprint material 8 discharged from the dispenser 11 decreases by 5% or more with respect to the optimal volume of the droplets of the imprint material 8, the control unit 20 increases the volume of the droplets of the imprint material 8 discharged from the dispenser 11 by the amount of the decrease. On the other hand, if the volume of the droplets of imprint material 8 discharged from the dispenser 11 increases by 5% or more with respect to the optimal volume of the droplets of imprint material 8, the volume of the droplets of imprint material 8 discharged from the dispenser 11 is reduced by the amount of the increase. Note that 5% is just an example, and any number can be set depending on the operating conditions of the imprint apparatus 100. One method for controlling the volume of the droplets of imprint material 8 discharged from the dispenser 11 is, for example, to change the voltage applied to a piezo element (not shown) that is driven when the droplets of imprint material 8 are discharged from the dispenser 11.

[0041] In this embodiment, a measurement unit 13 provided within the apparatus measures the thickness of the film of imprint material 8 formed on the substrate, and the volume of the droplets of imprint material 8 dispensed from the dispenser 11 is calculated based on the measured thickness, and the dispenser 11 is feedback-controlled. This eliminates the need to remove the substrate 4 on which the film of imprint material 8 has been formed from the imprint apparatus 100 and measure the thickness of the film of imprint material 8 using a measurement device (external device) outside the imprint apparatus. This allows the measurement results of the measurement unit 13 to be fed back to the dispenser 11 (to control the volume of the droplets of imprint material 8 dispensed from it) in a short time. In other words, this embodiment significantly reduces the time required for feedback control of the dispenser 11 compared to conventional techniques. Furthermore, it is possible to maintain a constant volume of the droplets of imprint material 8 dispensed from the dispenser 11, thereby suppressing (preventing) the formation of a good pattern on the substrate 4 from being hindered by fluctuations in the volume of the droplets of imprint material 8.

[0042] Note that the droplets of imprint material 8 dispensed from the dispenser 11 onto the substrate 4 partially volatilize over time, reducing their volume. Therefore, it is preferable to keep the variation in the volume of the droplets of imprint material 8 dispensed from the dispenser 11 within an acceptable range based on the amount of volatilization of the imprint material 8 from when the droplets of imprint material 8 are dispensed onto the substrate until a film of the imprint material 8 is formed. In particular, the change in the time from when the droplets of imprint material 8 are dispensed onto the substrate until a film of the imprint material 8 is formed is highly correlated with the change in the film thickness of the imprint material 8 formed on the substrate. Therefore, it is effective to control (correct) the volume of the droplets of imprint material 8 dispensed from the dispenser 11, taking into account the amount of volatilization of the imprint material 8. Specifically, for example, data indicating the relationship between the time from when the droplets of imprint material 8 are dispensed onto the substrate from the dispenser 11 until a film of the imprint material 8 is formed and the film thickness of the imprint material 8 formed on the substrate is obtained in advance. Then, when feedback controlling the dispenser 11, the volume of the droplets of the imprint material 8 discharged from the dispenser 11 is controlled based on this data. Note that factors other than the time from when the droplets of the imprint material 8 are placed on the substrate until when the film of the imprint material 8 is formed may also be taken into consideration.

[0043] An example of an imprint process including feedback control of the dispenser 11 in this embodiment will be described below with reference to Fig. 3. Here, the description will be made taking as an example a sequence for measuring a first distance between the surface 4a of the substrate 4 before the imprint process and the measurement unit 13, and a second distance between the surface 8a of the imprint material 8 on the substrate after the imprint process and the measurement unit 13, to determine the film thickness of the imprint material 8.

[0044] In S1, the substrate 4 is transported to the substrate stage 6 and held by the substrate stage 6. In S2, for the substrate 4 held by the substrate stage 6, the measurement unit 13 measures a first distance between the surface 4a of the substrate 4 and the measurement unit 13 before the droplets of the imprint material 8 are placed.

[0045] In S3, droplets of the imprint material 8 are ejected from the dispenser 11 to place the droplets of the imprint material 8 on the substrate (placement step). In S4, the imprint material 8 on the substrate is brought into contact with the mold 1 (contact step), the imprint material 8 on the substrate is hardened in that state (hardening step), and the mold 1 is separated from the hardened imprint material 8 on the substrate (mold release step). As a result, a pattern (film) of the imprint material 8 is formed on the substrate. The imprint process, which includes the placement step, contact step, hardening step, and mold release step, is performed on predetermined shot areas on the substrate, and a pattern of the imprint material 8 is formed in all of these shot areas.

[0046] In S5, for the substrate 4 on which the pattern of the imprint material 8 is formed, the measurement unit 13 measures a second distance between the surface 8a of the film of the imprint material 8 formed on the substrate and the measurement unit 13.

[0047] In S6, the thickness of the film of imprint material 8 formed on the substrate is calculated. Specifically, the difference between the first distance measured in S2 and the second distance measured in S5 is calculated as the thickness of the film of imprint material 8 formed on the substrate.

[0048] In S7, the volume of the droplets of imprint material 8 dispensed from the dispenser 11 is calculated based on the film thickness of the imprint material 8 calculated in S6. Specifically, the volume of the droplets of imprint material 8 is calculated from the number of droplets of imprint material 8 dispensed from the dispenser 11 in S3, the film thickness of the imprint material 8 calculated in S6, and the area of ​​the shot region in which the pattern of the imprint material 8 is formed in S4.

[0049] In S8, it is determined whether the variation in the volume of the droplets of imprint material 8 discharged from the dispenser 11 falls within the allowable range, based on the volume of the droplets of imprint material 8 calculated in S7. If the variation in the volume of the droplets of imprint material 8 discharged from the dispenser 11 falls within the allowable range, the process ends without changing the volume of the droplets of imprint material 8 discharged from the dispenser 11. On the other hand, if the variation in the volume of the droplets of imprint material 8 discharged from the dispenser 11 does not fall within the allowable range, the process proceeds to S9.

[0050] In S9, based on the volume of the droplets of imprint material 8 calculated in S7, the volume of the droplets of imprint material 8 discharged from the dispenser 11 is controlled (changed) so that fluctuations in the volume of the droplets of imprint material 8 discharged from the dispenser 11 fall within an allowable range. For example, if the dispenser 11 is a piezoelectric type, the volume of the droplets of imprint material 8 discharged from the dispenser 11 can be controlled by changing the voltage applied to the piezoelectric element. Note that the timing for controlling the volume of the droplets of imprint material 8 discharged from the dispenser 11 may be on a lot-by-lot basis or on a substrate-by-substrate basis.

[0051] The film thickness of the imprint material 8 formed on the substrate may be determined by simultaneously detecting reflected light from each of the front surface 8a and back surface 8b of the imprint material 8, as described in FIG. 2(c). In this case, as shown in FIG. 4, steps S10 and S11 are performed instead of steps S2, S5, and S6 shown in FIG. 3. In step S10, the measurement unit 13 measures a first distance between the back surface 8b of the imprint material 8 film and the measurement unit 13, and a second distance between the front surface 8a of the imprint material 8 and the measurement unit 13, for the substrate 4 held by the substrate stage 6 and on which the imprint material 8 film has been formed. In step S11, the film thickness of the imprint material 8 film formed on the substrate is calculated. Specifically, the film thickness of the imprint material 8 film formed on the substrate is calculated from the difference between the first distance and the second distance measured in step S10 and the refractive index of the imprint material 8.

[0052] As described above, according to this embodiment, by quickly feeding back the measurement results of the measuring unit 13 provided in the apparatus to the dispenser 11, it is possible to significantly reduce the time required for feedback control of the dispenser 11. Furthermore, in the imprint process, the volume of the droplets of the imprint material 8 discharged from the dispenser 11 is kept constant, and it is possible to prevent fluctuations in the volume of the droplets of the imprint material 8 from interfering with the formation of a good pattern on the substrate 4.

[0053] The pattern of the cured material formed using the imprint apparatus 100 is used permanently on at least a portion of various articles, or temporarily when manufacturing various articles. Examples of articles include electrical circuit elements, optical elements, MEMS, recording elements, sensors, and molds. Examples of electrical circuit elements include volatile or non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensors, and FPGA. Examples of molds include molds for imprinting.

[0054] The pattern of the cured product may be used as it is as at least a part of a component of the above-mentioned article, or may be used temporarily as a resist mask, which is removed after etching or ion implantation is performed in a substrate processing step.

[0055] Next, a specific method for manufacturing the article will be described. As shown in Figure 5(a), a substrate such as a silicon wafer is prepared with a workpiece material such as an insulator formed on its surface. Then, an imprint material is applied to the surface of the workpiece by an inkjet method or the like. Here, the imprint material in the form of multiple droplets is shown applied to the substrate.

[0056] As shown in Figure 5(b), the imprinting mold is placed with the side on which the concave-convex pattern is formed facing the imprinting material on the substrate. As shown in Figure 5(c), the substrate on which the imprinting material has been applied is brought into contact with the mold, and pressure is applied. The imprinting material fills the gap between the mold and the workpiece. In this state, when light is irradiated through the mold as hardening energy, the imprinting material hardens.

[0057] As shown in Figure 5(d), after the imprint material is cured, the mold and substrate are separated, forming a pattern of the cured imprint material on the substrate. In this cured material pattern, the recesses of the mold correspond to the protrusions of the cured material, and vice versa. In other words, the recessed and protrusion patterns of the mold are transferred to the imprint material.

[0058] As shown in Figure 5(e), when etching is performed using the cured material pattern as an etching-resistant mask, the portions of the surface of the workpiece where no cured material is present or where only a thin layer remains are removed, forming grooves. As shown in Figure 5(f), when the cured material pattern is removed, an article with grooves formed on the surface of the workpiece can be obtained. Here, the cured material pattern was removed, but it may also be used as an interlayer insulating film included in semiconductor devices, i.e., a component of an article, without being removed after processing.

[0059] In this embodiment, the mold 1 has been described as a mold for transferring a circuit pattern on which a concave-convex pattern is formed. However, the mold 1 may also be a mold (planar template) having a flat portion on which no concave-convex pattern is formed. The planar template is used in a planarization device (molding device) that performs a planarization process (molding process) in which the flat portion is used to mold a composition on a substrate so as to flatten it. The planarization process includes a step of curing the curable composition by irradiating the flat portion of the planar template with light or by heating while the curable composition is supplied to the substrate. In this way, this embodiment can be applied to a molding device that molds a composition on a substrate using a planar template.

[0060] The underlying pattern on a substrate has a roughness profile resulting from the pattern formed in the previous process. In particular, with the recent trend toward multilayer structures for memory devices, substrates (process wafers) can have steps of approximately 100 nm. Steps resulting from the gentle waviness of the entire substrate can be corrected using the focus tracking function of the exposure equipment (scanner) used in the photolithography process. However, fine-pitch irregularities that fit within the exposure slit area of ​​the exposure equipment consume the depth of focus (DOF) of the exposure equipment. Conventional techniques for planarizing the underlying pattern on a substrate include techniques for forming a planarization layer, such as spin-on carbon (SOC) and chemical mechanical polishing (CMP). However, as shown in Figure 6(a), these conventional techniques only achieve a roughness suppression rate of 40% to 70% at the boundary between the isolated pattern region A and the dense (repeated line and space) pattern region B, which does not provide sufficient planarization performance. Furthermore, in the future, the unevenness of the underlying pattern will tend to increase further due to the increasing number of layers.

[0061] As a solution to this problem, U.S. Patent No. 9,415,418 proposes a technology for forming a continuous film by applying a resist that serves as a planarization layer using an inkjet dispenser and imprinting it with a flat template. Furthermore, U.S. Patent No. 8,394,282 proposes a technology for reflecting the results of topography measurement on the substrate in the shading information for each position that is instructed to be applied by an inkjet dispenser. The imprinting apparatus IMP can be used, in particular, as a flattening (planarization) device that presses a flat template, instead of a mold 1, against previously applied, uncured resist to locally planarize the substrate surface.

[0062] Figure 6(a) shows the substrate before flattening. In isolated pattern region A, the area of ​​the convex pattern portions is small. In repeated dense pattern region B, the area occupied by the convex pattern portions and the area occupied by the concave pattern portions are 1:1. The average heights of isolated pattern region A and repeated dense pattern region B differ depending on the proportion of the convex pattern portions.

[0063] 6(b) shows a state in which a resist that forms a planarization layer has been applied to a substrate. While FIG. 6(b) shows a state in which the resist has been applied using an inkjet dispenser based on the technology proposed in U.S. Pat. No. 9,415,418, a spin coater may also be used to apply the resist. In other words, the imprint apparatus 100 is applicable as long as it includes a step of pressing a planar template against previously applied, uncured resist to planarize it.

[0064] As shown in Figure 6(c), the flat template is made of glass or quartz that transmits ultraviolet light, and the resist hardens when irradiated with ultraviolet light from a light source. The flat template follows the profile of the substrate surface for any gentle irregularities across the entire substrate. After the resist hardens, the flat template is separated from the resist, as shown in Figure 6(d).

[0065] The present invention is not limited to molding devices including imprinting devices and planarizing devices, but can be widely applied to devices having a mechanism for ejecting droplets, including industrial equipment such as manufacturing devices for producing semiconductor elements and liquid crystal display elements, and consumer products such as printers.

[0066] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0067] 100: Imprinting device 1: Mold 4: Substrate 8: Imprinting material 11: Dispenser 20: Control unit

Claims

1. A molding apparatus for molding a composition on a substrate using a mold in a process for manufacturing an article, comprising: a discharge unit that discharges droplets of the composition and places them on the substrate; a measuring unit that measures a thickness of a film of the composition formed on the substrate by molding a droplet of the composition placed on the substrate with the mold; a control unit that obtains a transition of fluctuation in the volume of the droplets by calculating the volume of the droplets of the composition discharged from the discharge unit based on the film thickness measured by the measurement unit, and that feedback-controls the discharge unit in the process so that fluctuation in the volume of the droplets discharged from the discharge unit falls within an allowable range; A molding apparatus comprising:

2. The molding apparatus described in claim 1, characterized in that the measurement unit measures a first distance between the surface of the substrate before the droplet of the composition is placed and the measurement unit, and a second distance between the surface of the film of the composition formed on the substrate and the measurement unit, and the difference between the first distance and the second distance is defined as the film thickness.

3. The measurement unit measuring the first distance for a first plurality of locations on a surface of the substrate; measuring the second distance to a second plurality of locations of the film of the composition on the first plurality of locations; The molding apparatus according to claim 2 , wherein the film thickness is a difference between an average value of the first distances at the first plurality of locations and an average value of the second distances at the second plurality of locations.

4. The molding apparatus described in claim 1, characterized in that the measurement unit measures a first distance between a first surface of the composition film formed on the substrate facing the substrate and the measurement unit, and a second distance between a second surface of the composition film opposite the first surface and the measurement unit, and calculates the film thickness based on the first distance, the second distance, and the refractive index of the composition.

5. The measurement unit measuring the first distance for a first plurality of locations on the first surface; measuring the second distances to second plurality of locations on the second surface on the first plurality of locations; The molding apparatus according to claim 4, characterized in that the film thickness is calculated based on an average value of the first distances at the first plurality of locations, an average value of the second distances at the second plurality of locations, and a refractive index of the composition.

6. The molding device according to any one of claims 1 to 5, characterized in that the control unit controls the volume of the droplets of the composition ejected from the ejection unit so that the fluctuation in the volume of the droplets of the composition ejected from the ejection unit falls within an acceptable range.

7. The molding apparatus according to any one of claims 1 to 5, characterized in that the control unit controls the volume of the droplets of the composition ejected from the ejection unit so that the fluctuation in the volume of the droplets of the composition ejected from the ejection unit falls within an acceptable range, also based on the amount of evaporation of the composition from the time the droplets of the composition are placed on the substrate to the time a film of the composition is formed on the substrate.

8. The control unit pre-acquires data showing the relationship between the time from placing droplets of the composition on the substrate to forming a film of the composition on the substrate and the thickness of the film of the composition formed on the substrate, and controls the volume of the droplets of the composition ejected from the ejection unit based on the data so that the fluctuation in the volume of the droplets of the composition ejected from the ejection unit falls within an acceptable range.

9. a stage for holding the substrate and positioning the substrate relative to the mold; 9. The molding apparatus according to claim 1, wherein the measurement unit measures a film thickness of the composition film formed on the substrate while the substrate is held on the stage.

10. The molding apparatus according to claim 9, characterized in that the measurement unit measures the thickness of the film of the composition during a period after the film of the composition is formed on the substrate held by the stage and before the substrate is removed from the stage.

11. the mold includes a pattern; The molding apparatus according to any one of claims 1 to 10, wherein the molding apparatus forms a pattern in the film of the composition on the substrate by contacting the pattern of the mold with a droplet of the composition on the substrate.

12. the mold includes a flat portion; The molding apparatus according to any one of claims 1 to 10, wherein the molding apparatus flattens a film of the composition on the substrate by bringing the flat portion of the mold into contact with a droplet of the composition on the substrate.

13. 1. A method for manufacturing an article, comprising: a first step of discharging droplets of the composition from a discharge unit and disposing them on a substrate; a second step of measuring a thickness of a film of the composition formed on the substrate by molding the droplet of the composition placed on the substrate with a mold; a third step of treating the substrate on which the film of the composition has been formed to obtain the article; a fourth step of determining the volume of the droplets of the composition discharged from the discharge unit in the first step based on the film thickness measured in the second step, thereby grasping the progress of fluctuation in the volume of the droplets, and feedback-controlling the discharge unit so that the fluctuation in the volume of the droplets discharged from the discharge unit falls within an allowable range; A method for manufacturing an article, comprising:

Images