Imprinting method, imprinting apparatus and article manufacturing method

Abstract

To provide a technique advantageous for improving the uniformity of a plurality of patterns formed on a substrate by using an imprint technique.SOLUTION: An imprint method is to cure an imprint material on a substrate while the imprint material and a mold are in contact with each other, and the method includes a curing step of irradiating the imprint material with first light by using a first light source and irradiating the imprint material with second light by using a second light source to cure the imprint material, and forming a plurality of patterns formed of the cured product of the imprint material. The intensity distribution of the second light is adjusted, with which the imprint material is irradiated by the second light source in the curing step so that the distribution of evaluation values of the plurality of patterns formed through the curing step satisfies a target distribution.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] An imprinting method is known in which a mold is brought into contact with an imprinting material on a substrate, and the imprinting material is cured by irradiating the imprinting material with light, thereby forming a pattern made of the cured product of the imprinting material. Patent Document 1 describes a method for forming a pattern on a region of a substrate using a template, in which a moldable material is exposed with a spatial distribution of exposure amounts in which an inner exposure amount applied to the inside of the region is greater than a sidewall exposure amount incident on a mesa sidewall of the template. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-198428 Summary of the Invention [Problem to be solved by the invention]

[0004] If an imprint material (moldable material) is exposed with a non-uniform exposure dose distribution, the pattern height and pattern line width formed after the curing process may become non-uniform. Furthermore, in semiconductor processes, an etching process may be performed after forming a pattern by an imprint method, and the result of exposing the imprint material with a non-uniform exposure dose distribution may result in non-uniformity in the pattern height and pattern line width after the etching process.

[0005] An object of the present invention is to provide an advantageous technique for improving the uniformity of multiple patterns formed on a substrate using imprint technology. [Means for solving the problem]

[0006] One aspect of the present invention relates to an imprinting method for curing an imprinting material on a substrate while the imprinting material is in contact with a mold, the imprinting method including a curing step of irradiating the imprinting material with first light using a first light source and irradiating the imprinting material with second light using a second light source to cure the imprinting material, thereby forming a plurality of patterns consisting of the cured product of the imprinting material, and the intensity distribution of the second light irradiated onto the imprinting material by the second light source in the curing step is adjusted so that the distribution of evaluation values ​​of each of the plurality of patterns formed through the curing step satisfies a target distribution. [Effects of the Invention]

[0007] SUMMARY OF THE INVENTION In accordance with the present invention, advantageous techniques are provided for improving the uniformity of multiple patterns formed on a substrate using imprint technology. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram schematically showing the configuration of an imprint apparatus according to a first embodiment. [Figure 2] FIG. 4 is a diagram schematically showing the configuration of a second light source unit. [Figure 3] FIG. 10 is a diagram illustrating an example of a light-shielding film provided on a mold. [Figure 4] 3 is a diagram illustrating an example of the exposure amount distribution of the imprint material on the substrate by the first light from the first light source unit 1 (first light source). FIG. [Figure 5] FIG. 3 is a diagram schematically showing exposure by a first light source unit and a second light source unit. [Figure 6] 10 is a diagram illustrating the relationship between the exposure amount of the first light source unit and the pattern height change amount (line width change amount). [Figure 7] FIG. 1 is a diagram showing the flow of imprint processing. [Figure 8] FIG. 10 is a diagram schematically showing the protrusion of uncured imprint material. [Figure 9] FIG. 10 is a diagram schematically showing the configuration of an imprint apparatus according to a second embodiment. [Figure 10] 10 is a diagram illustrating an example of the exposure dose distribution of the imprint material on the substrate by the second light from the second light source unit (second light source). FIG. [Figure 11] FIG. 10 is a diagram schematically showing the imprint material flowing under the peripheral region of the pattern region. [Figure 12] FIG. 10 is a diagram schematically showing the imprint material flowing under the peripheral region of the pattern region. [Figure 13] 1A to 1C are diagrams for explaining an article manufacturing method. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. 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.

[0010] FIG. 1 schematically illustrates the configuration of an imprint apparatus 100 according to a first embodiment. The imprint apparatus 100 can be used to manufacture articles such as semiconductor devices. The imprint apparatus 100 hardens the imprint material R on the substrate W while the imprint material R is in contact with a mold M. This allows multiple patterns to be formed on the substrate W, each made of the hardened imprint material R. In this specification and the drawings, directions are described according to an XYZ coordinate system. The substrate W can be positioned parallel to the XY plane. The XY plane is a horizontal plane, and the negative direction of the Z axis can be the vertical direction.

[0011] The imprint material used is a curable composition (sometimes referred to as an uncured resin) that cures upon exposure to light. The wavelength of the light can be selected from the range of 10 nm to 1 mm. The curable composition 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 sensitizers, hydrogen donors, internal mold release agents, surfactants, antioxidants, and polymer components. The imprint material can be disposed on the substrate in the form of droplets, islands formed by connecting multiple droplets, or a film. Alternatively, the imprint material can be applied to the substrate in the form of a film using a spin coater or slit coater. The viscosity of the imprint material (at 25°C) can be, for example, 1 mPa·s to 100 mPa·s. Examples of materials that can be used for the substrate include glass, ceramics, metals, semiconductors (e.g., Si, GaN, SiC), and resins. If necessary, a member made of a material different from the substrate may be provided on the surface of the substrate. The substrate may be, for example, a silicon wafer, a compound semiconductor wafer, or quartz glass. The mold M has a pattern region Mp corresponding to the shot region S of the substrate W, and the pattern region Mp may include a device pattern region having a device pattern to be transferred and a peripheral region located outside the device pattern region and including the mark 10 to be transferred. The mold M is made of quartz or the like, which is capable of transmitting light.

[0012] The imprint apparatus 100 may include, for example, a mold driving mechanism 6, a substrate driving mechanism 80, a first light source unit 1, and a second light source unit 4. The imprint apparatus 100 may also include an alignment optical system 2, an observation optical system 3, and a dispenser 7.

[0013] The mold driving mechanism 6 may include a mold chuck that holds the mold M by vacuum suction force, electrostatic force, or the like, and a mold driving actuator that drives the mold chuck. The mold driving mechanism 6 may also include a mold shape correction mechanism 34 that deforms the mold M in the X-axis and Y-axis directions to correct distortion of the pattern to be transferred to the imprint material R. The mold shape correction mechanism 34 can correct the shape of the pattern region Mp by applying force to the side surface of the mold M using the correction actuator to deform the shape of the pattern region Mp into a target shape. The correction actuator may include, for example, a piezoelectric actuator. The correction actuator of the mold shape correction mechanism 34 is controlled by the control unit 140 and can adjust the distortion of the pattern region Mp on the order of nm or sub-nm, for example.

[0014] The operation of bringing the imprint material R on the substrate W into contact with the mold M and the operation of separating the hardened imprint material R from the mold M may be achieved by moving the mold M in the Z-axis direction, but may also be achieved by moving the substrate W in the Z-axis direction, for example. Alternatively, these operations may be achieved by driving both the mold M and the substrate W.

[0015] The substrate driving mechanism 80 may include a substrate stage 81 having a substrate chuck that holds the substrate W by vacuum suction or the like, and a substrate driving actuator 82 that drives the substrate stage 81. The substrate driving actuator 82 may drive the substrate stage 81, for example, in the X-axis direction, the Y-axis direction, and rotation around the Z-axis. The substrate driving actuator 82 may further drive the substrate stage 81 in at least one of rotation around the X-axis, rotation around the Y-axis, and Z-axis direction.

[0016] The first light source unit 1 can be controlled by the control unit 140 to irradiate light such as ultraviolet light onto the imprint material R in order to harden the imprint material R after a contact step of bringing the imprint material R on the substrate W into contact with the transfer region of the mold M. The first light source unit 1 can include, as a first light source 91, for example, at least one of a high-pressure mercury lamp, an excimer lamp, an excimer laser, a light-emitting diode, or a laser diode.

[0017] In one example, the first light source unit 1 may include a high-pressure mercury lamp as the first light source 91. The high-pressure mercury lamp may generate light having peak intensities at at least two wavelengths. More specifically, the high-pressure mercury lamp may generate light including an emission line at a wavelength of 313 nm and an emission line at a wavelength of 365 nm. The light intensity (peak intensity) at the wavelength of 313 nm may be equivalent to the light intensity (peak intensity) at the wavelength of 365 nm. The imprint material R is preferably configured to absorb both light at wavelengths of 313 nm and 365 nm and cause a curing reaction. In this case, the illuminance contributing to the curing reaction is approximately twice that of a single wavelength. This reduces the time required to cure the imprint material R and significantly improves the throughput of the imprint apparatus 100. Furthermore, in optical design, a multi-wavelength lens group generally has inferior aberration performance compared to a lens group designed for a single wavelength. However, in the case of the imprint apparatus 100, the role of the exposure light is to harden the imprint material R, so the deterioration of pattern transfer performance due to this increased aberration is small. The first light source unit 1 can include a plurality of optical elements in addition to the first light source 91. The plurality of optical elements can define the illuminance distribution in the pattern region of the mold M.

[0018] A light-shielding unit 33 may be provided to define an irradiation area of ​​the substrate W with light from the first light source unit 1. The light-shielding unit 33 may be understood as a component of the first light source unit 1, or as a component separate from the first light source unit 1. The light-shielding unit 33 may include a light-shielding member that defines an opening through which light from the first light source 91 of the light source unit 1 passes, and an actuator that drives the light-shielding member. The irradiation area by the first light source unit 1 defined by the light-shielding unit 33 (light-shielding member) may be measured using an optical sensor 89 mounted on the substrate stage 81. The optical sensor 89 may also be used to measure the irradiation area by the second light source unit 4. The optical sensor 89 may be, for example, an integrating light intensity sensor that measures light that has passed through a pinhole, or an image sensor such as a CCD or CMOS sensor.

[0019] Here, the irradiation area by the first light source unit 1, which is defined by the light-shielding unit 33 (light-shielding member), will be described in more detail. In the imprint apparatus 100, uncured imprint material R is placed on the substrate W, and the mold M is pressed against the imprint material R to fill the pattern of the pattern area Mp of the mold M with the imprint material R. During this filling, as shown in FIG. 8, a portion 61 of the uncured imprint material R protruding outside the pattern area Mp (hereinafter, referred to as the protruding portion) may be formed. If the protruding portion 61 of the imprint material R is exposed to light, an unnecessary cured material is formed outside the pattern area Mp. The cured material in the protruding portion 61 may come into contact with the mold M when a pattern is formed in an adjacent shot area. Furthermore, the cured material in the protruding portion 61 may cause an etching process to be improperly performed in a subsequent etching process. Therefore, in the imprint apparatus 100, it is necessary to prevent the uncured imprint material R from protruding outside the pattern area Mp.

[0020] Therefore, to prevent the protruding portion 61 from hardening, a light-shielding film 51 that blocks the exposure light may be disposed outside the pattern region Mp of the mold M, as illustrated in FIG. 3 . The light-shielding film 51 is made of a material that does not transmit the exposure light or a material that attenuates the light by 50% or more. The light-shielding film 51 may be, for example, a Cr film. By providing the Cr light-shielding film 51 outside the pattern region Mp of the mold M, the exposure light can be blocked. However, the film stress generated by the light-shielding film 51 may reduce the IP (Image Placement) accuracy of the pattern region Mp. Therefore, to prevent the IP from being reduced, the light-shielding film 51 may be formed only in the minimum necessary area. In one example, the length of the Cr light-shielding film 51 in the X-axis direction shown in FIG. 4 may be approximately 100 μm, but this dimension may be changed as needed.

[0021] 4 illustrates an exposure dose distribution 52 of the imprint material R on the substrate W due to the first light from the first light source unit 1 (first light source 91). The exposure dose distribution 52 may be understood as a light intensity distribution formed on the imprint material R by the first light from the first light source unit 1. The exposure dose distribution 52 (light intensity distribution) of the imprint material R on the substrate W due to the first light from the first light source unit 1 has a shape that reflects optical blur, in which the exposure dose (light intensity distribution) decreases toward the outside of the pattern region Mp. In this specification, the distance 55 of the portion where the exposure dose changes on the left or right side of the exposure dose distribution 52 (or light intensity distribution) is defined as the amount of optical blur.

[0022] In the imprint apparatus 100, the first light generated by the first light source unit 1 (first light source 91) is light for curing the imprint material R, and therefore does not require an optical design that suppresses aberrations, as is the case with projection optical systems used in projection exposure apparatuses. Therefore, even if the amount of optical blur is on the order of several millimeters, it does not affect the performance of curing the imprint material R. However, as described above, problems may occur if the imprint material R in the protruding portion outside the pattern area Mp is cured. To prevent the imprint material R in the protruding portion from curing, for example, it is necessary to reduce the amount of exposure of the protruding portion by the first light generated by the first light source unit 1. To prevent the imprint material R in the protruding portion from curing, for example, it is necessary to set the amount of exposure of the protruding portion to 10% or less of the amount of exposure required for curing. Accordingly, the position of the tail of the light intensity distribution of the first light from the first light source unit 1 can be adjusted so that the amount of exposure at the position of the light-shielding film 51 is 10% or less of the amount of exposure required for curing. The light amount sensor 141 can be used to adjust the light blocking unit 33 so that such an exposure amount distribution 52 is formed.

[0023] The imprint material R in the protruding portion 61 that is shielded by the light-shielding film 51 remains unhardened even after the imprint process is completed, and therefore may volatilize over time. In this way, the problem of the protruding imprint material R is solved.

[0024] The alignment optical system 2 is responsible for measurements for aligning the mold M and the substrate W. The alignment optical system 2 is an optical device for optically detecting the relative positions of the mark 10 on the mold M and the mark 11 on the substrate W. The alignment optical system 2 may also have multiple drivable scopes 2a. The multiple scopes 2a can be driven in the X-axis and Y-axis directions depending on the position of the mark 10 on the mold M or the mark 11 on the substrate W. The multiple scopes 2a may also be configured to be drivable in the Z-axis direction to focus on the position of the marks. The alignment optical system 2 may also include a common optical system 21 and optical members 31, 22, and 23. The common optical system 21 and the optical members 31, 22, and 23 may include, for example, optical members constituting a relay optical system. The common optical system 21 and the optical members 31, 22, and 23 may, for example, constitute an optical system that forms a plane conjugate with the surface of the substrate W at position C.

[0025] A wide variety of materials are formed on the substrate W in the form of a multilayer film, and the marks 11 on the substrate W can be formed on any layer of the multilayer film. Therefore, if the wavelength band of the light used in the alignment optical system 2 is narrow and satisfies the interference condition that weakens the light intensity, the signal from the marks 11 on the substrate W will be weak, making alignment difficult. Therefore, it is desirable that the light used in the alignment optical system 2 has wavelengths to which the imprint material R is not photosensitive (cured), and covers as wide a band as possible. For example, it is desirable to cover a wavelength band of 400 to 2000 nm, and more desirably, at least a wavelength band of 500 to 800 nm. A lamp with a wide emission wavelength band is preferable as the light source used in the alignment optical system 2. Alternatively, a wide band may be discretely covered by combining multiple light sources (e.g., light-emitting diodes, laser diodes) with emission wavelength bands of several tens or several nanometers. The control unit 140 can generate control information for controlling the substrate stage 81, mold shape correction mechanism 34, second light source unit 4, etc. based on the relative position and shape difference between the mold M and the substrate W obtained using the alignment optical system 2.

[0026] The observation optical system 3 may be a scope capable of observing the entirety of at least one shot area S on the substrate W. The observation optical system 3 may be used to check the status of the imprint process. This may include, for example, the state of pressing the mold M against the imprint material R on the substrate W, the state of filling the imprint material R into the pattern of the mold M, the state of separation of the mold M from the cured imprint material R on the substrate W, and whether any foreign matter is trapped between the mold M and the substrate W. The light of the observation optical system 3 does not need to have as wide a bandwidth as the alignment optical system 2, and only needs to have a wavelength to which the imprint material R is not photosensitive (cured). Furthermore, to prevent the mold M or the substrate W from expanding due to heat generated by the observation light, which may result in misalignment or distortion of the pattern transferred to the imprint material R, it is desirable that the light intensity of the observation light be weak within an observable range.

[0027] FIG. 2 shows an example configuration of the second light source unit 4. The second light source unit 4 may employ light of a different wavelength from that of the first light source unit 1. The second light source unit 4 may generate light having a peak intensity at only one wavelength. From another perspective, it is preferable that the wavelength band of the second light generated by the second light source unit 4 is narrower than the wavelength band of the first light generated by the first light source unit 1. The second light source unit 4 may employ light of a wavelength of 405 nm, for example. The second light source unit 4 includes, as the second light source 101, a light source configured with a solid-state light-emitting element (or a semiconductor light-emitting element), such as a laser diode or a photodiode. In the exposure amount distribution 52 of the first light source unit 1 described with reference to FIG. 4, the exposure amount in the periphery of the pattern region Mp is smaller than that in the center of the pattern region Mp. In this way, the second light source unit 4 can compensate for the lack of exposure amount in the periphery.

[0028] The second light source unit 4 may include an adjuster 102 for forming a desired exposure dose distribution or light intensity distribution. The second light source unit 4 may, for example, irradiate the peripheral portion of the pattern region Mp with the second light. FIG. 10 illustrates an example of an exposure dose distribution 56 of the imprint material R on the substrate W due to the second light irradiated onto the imprint material R by the second light source unit 4. The exposure dose distribution 56 may also be understood as a light intensity distribution formed on the imprint material R by the second light from the second light source unit 4. To compensate for the lack of exposure dose in the peripheral portion of the pattern region Mp, the optical blur amount 57 of the second light source unit 4 may be kept equal to or less than the width of the light-shielding film 51. When the width of the light-shielding film 51 is 100 μm, the optical blur amount of the second light source unit 4 may be less than 100 μm. This configuration is advantageous for exposing the imprint material R in the shot region S with a uniform exposure dose.

[0029] In the peripheral part of the shot area S, the exposure amount of the imprint material R by the first light from the first light source unit 1 and the second light from the second light source unit 4 may be greater than in the central part of the shot area S (the area inside the peripheral part).

[0030] The amount of optical blur in the peripheral portion of the second light intensity distribution formed on the imprint material R by the second light from the second light source unit 4 is smaller than the amount of optical blur in the peripheral portion of the first light intensity distribution formed on the imprint material R by the first light from the first light source unit 1. This can be achieved, for example, by using a laser diode as the second light source 101 of the second light source unit 4. Because a laser diode generates light of a single wavelength, it is easy to suppress aberrations in optical design (i.e., it is easy to suppress the amount of optical blur). Furthermore, a laser diode is advantageous for obtaining high illuminance.

[0031] In order to make the amount of optical blur caused by the second light source unit 4 smaller than the amount of optical blur caused by the first light source unit 1, it is preferable that the NA (numerical aperture) of the second light irradiated onto the imprint material R is smaller than the NA of the first light irradiated onto the imprint material R. In one example, the NA of the light reaching the imprint material R (substrate W) from the first light source unit 1 is 0.18, and the NA of the light reaching the imprint material R (substrate W) from the second light source unit 4 is 0.05.

[0032] Of the first light source unit 1 and the second light source unit 4, it is possible to cure the imprint material R on the shot area S using only the second light source unit 4. However, in one typical configuration, the illuminance of the imprint material R by the second light from the laser diode of the second light source unit 4 is lower than the illuminance of the first light from the high-pressure mercury lamp of the first light source unit 1. One reason for this is that the second light from the laser diode of the second light source unit 4 is attenuated by the transmittance and reflectance of dichroic mirrors serving as optical members 31 and 32, which will be described later, and the half mirror serving as optical member 36. Furthermore, because the UV resistance of the adjuster 102, a component of the second light source unit 4, is limited, simply increasing the light output of the second light source unit 4 is difficult. For these reasons, it is difficult to cure the imprint material R using only the second light source unit 4 without reducing throughput.

[0033] Next, the configuration of the second light source unit 4 will be described. The light 105 emitted from the second light source 101, such as a laser diode, has its illumination area adjusted by the optical element 103 and illuminates the adjuster 102. The adjuster 102 reflects the spatially modulated light 105 according to a set illumination pattern. Of the light 105 incident on the adjuster 102, light unnecessary for spatial modulation is irradiated onto an optical attenuator (diffuser) (not shown) and does not reach the substrate W. The illumination magnification of the spatially modulated light 105 is adjusted by the optical element 104, and the modulated light illuminates the substrate W as second light. As described above, the amount of optical blur of the second light irradiated onto the imprint material R (substrate W) by the second light source unit 4 is smaller than that by the first light source unit 1. The amount of optical blur of the second light irradiated onto the imprint material R (substrate W) by the second light source unit 4 is set smaller than the width of the light-shielding film 51.

[0034] The adjuster 102 is controlled by the control unit 140 so that the shot area S is exposed with a target exposure amount (illuminance × time, or √(illuminance) × time) distribution. The adjuster 102 may be, for example, a liquid crystal device in which multiple liquid crystal elements are arranged on a light-transmitting surface and the illuminance distribution and irradiation time can be changed by individually controlling the voltages applied to the multiple liquid crystal elements. Alternatively, the adjuster 102 may be a digital mirror device (digital micromirror device) in which multiple mirror elements are arranged in an array on a light-reflecting surface and the illuminance distribution and irradiation time can be changed by individually adjusting the surface direction of each mirror element. Alternatively, the adjuster 102 may be a galvanometer mirror, a diffraction element such as a CGH, or other element. The adjuster 102 generates heat due to partial absorption of light 105, such as ultraviolet light, and its temperature may rise due to heat generated by its electrical circuit. Therefore, to ensure the performance and life of the adjuster 102, a cooling function such as air cooling or water cooling may be provided.

[0035] The control unit 140 can be configured to control multiple components of the imprint apparatus 100, such as the mold driving mechanism 6, the substrate driving mechanism 80, the first light source unit 1, the second light source unit 4, the alignment optical system 2, the observation optical system 3, and the dispenser 7. The control unit 140 can be configured, for example, by a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), an ASIC (abbreviation for Application Specific Integrated Circuit), a general-purpose or dedicated computer with an embedded program, or a combination of all or part of these. The control unit 140 can be configured integrally with other parts of the imprint apparatus 100 (in a common housing), or can be configured separately from other parts of the imprint apparatus 100 (in a different housing).

[0036] In the imprint apparatus 100 illustrated in FIG. 1 , the alignment optical system 2 includes a common optical system 21, which is also shared by the first light source unit 1, the observation optical system 3, and the second light source unit 4. In one aspect, the common optical system 21 is an optical system that forms a first light intensity distribution on the imprint material R by using a first light from the first light source unit 1, and forms a second light intensity distribution on the imprint material R by using a second light from the second light source unit 4. The optical member 31 reflects the alignment light and transmits the first light from the first light source unit 1, the observation light from the observation optical system 3, and the second light from the second light source unit 4. The common optical system 21 and the optical member 31 may be made of a material (e.g., quartz or fluorite) that has a sufficiently high transmittance for the first light from the first light source unit 1 and the second light from the second light source unit 4.

[0037] The optical member 31 may be, for example, a dichroic mirror, and may have characteristics such as high reflectance in a wavelength band of 500 to 2000 nm and high transmittance in a wavelength band of 200 to 500 nm. The wavelength band with high reflectance is not limited to 500 to 2000 nm, and although a wider range is preferable, it may be, for example, 600 to 900 nm or 500 to 800 nm due to manufacturing constraints, etc. Similarly, the wavelength band with high transmittance is not limited to 200 to 500 nm, and although a wider range is preferable, it may be, for example, 300 to 600 nm or 300 to 500 nm.

[0038] The optical member 32 reflects the first light from the first light source unit 1 and transmits the light from the observation optical system 3 and the second light from the second light source unit 4. In one example, the wavelength band of the first light from the first light source unit 1 can be 400 nm or less, and the wavelength band of the second light from the second light source unit 4 can be 400 nm or more and 500 nm or less. The optical member 32 can be, for example, a dichroic mirror. The optical member 32 can have, for example, high reflectance in a wavelength band of 400 nm or less (200 to 400 nm or 300 to 400 nm) and high transmittance in a wavelength band of 400 nm or more (400 to 500 nm or 400 to 600 nm). The wavelength threshold is not limited to 400 nm and may be, for example, 380 nm or 420 nm.

[0039] The optical member 35 is, for example, a half mirror, which shares part of the optical path of the observation optical system 3 with part of the optical path of the second light source unit 4. If the wavelength of the light used by the observation optical system 3 and the wavelength of the second light used by the second light source unit 4 are the same, similar, or partially overlap, a dichroic mirror cannot be used. The transmittance of the optical path of the observation optical system 3 and the optical path of the second light source unit 4 does not necessarily have to be evenly allocated, such as 50%:50%. As mentioned above, since the observation optical system 3 only needs to monitor the filling of the imprint material into the pattern of the mold M, for example, the optical path of the observation optical system 3 may transmit 40% and the optical path of the second light source unit 4 may reflect 60%.

[0040] The dispenser 7 applies or places the imprint material R on the substrate W. The dispenser 7 does not have to be a component of the imprint apparatus 100, and may be provided as an external device. If the dispenser 7 is provided as an external device, the substrate W on which the imprint material R has been placed by the dispenser 7 is provided to the imprint apparatus 100. With such a system configuration, it is no longer necessary to place the imprint material R on the substrate W inside the imprint apparatus 100, and therefore processing in the imprint apparatus 100 can be expedited. Furthermore, because the dispenser 7 is no longer necessary as a component of the imprint apparatus 100, the manufacturing costs of the imprint apparatus 100 as a whole can be reduced.

[0041] When the amount of optical blur of the first light source unit 1 is greater than the width of the light-shielding film 51, as illustrated in the exposure amount distribution 52 of Figure 4, a difference in exposure amount occurs between the center of the pattern area Mp and the peripheral area of ​​the pattern area Mp, and the exposure amount is insufficient particularly in the peripheral area.

[0042] FIG. 6 shows the results of comparing the pattern height (or line width) of imprint material R cured at a target exposure dose with that of imprint material R cured at several different exposure doses below the target exposure dose. The pattern height (or line width) when imprint material R is cured at the target exposure dose is used as a reference (Ref in FIG. 6). The vertical axis of FIG. 6 represents the pattern height reduction rate (or line width reduction rate) relative to the reference, which occurs due to differences in exposure dose. The horizontal axis represents the exposure dose from the first light source unit 1. It has been experimentally confirmed that the pattern height (or line width) decreases when the exposure dose from the first light source unit 1 is reduced from the reference. For example, at point C in FIG. 6, when the exposure dose is 10% of the reference, the pattern height is 5% lower than the reference. It can be seen that when the light-shielding film 51 and the light-shielding unit 33 are used to prevent the imprint material R from spilling outside the pattern region Mp, uniformity of the pattern height cannot be maintained within the shot region S. If the uniformity of the pattern height is disrupted by around 5%, problems such as the inability to perform etching correctly in subsequent processes may occur, although this depends on the process.

[0043] Although it is technically possible to compensate for the lack of exposure dose by extending the exposure time in accordance with the amount of exposure dose insufficiency, the throughput of the imprint apparatus 100 decreases in proportion to the amount of exposure time extension. Furthermore, excess heat is applied to the substrate W, which may reduce the overlay accuracy. In this embodiment, a technique is provided for suppressing changes in the pattern height and line width of the imprint material R due to the lack of exposure dose while suppressing overflow of the imprint material R.

[0044] In order to ensure uniformity of the pattern height or pattern line width after curing of the imprint material R, in this embodiment, the exposure amount of the second light from the second light source unit 4 is added to the exposure amount of the first light from the first light source unit 1. More specifically, the exposure amount according to the exposure amount distribution 54 (FIG. 5) of the second light from the second light source unit 4 is added to the exposure amount according to the exposure amount distribution 52 (FIG. 4) of the first light from the first light source unit 1.

[0045] Here, a method for determining the exposure dose distribution 54 by the second light will be described. As an example, the exposure dose by the first light from the first light source unit 1 is discretely reduced from 100% to 10%, and the pattern height (or line width) of the imprint material R cured at each exposure dose is created in a database.

[0046] Next, the exposure amount by the second light source unit 4 to be added to the exposure amount by the first light source unit 1 is determined so that a pattern height (or line width) equivalent to the reference (here, the pattern height (or line width) at 100% exposure by the first light from the first light source unit 1) is obtained at each exposure amount from 100% to 10% by the first light from the first light source unit 1. Because the wavelengths of light from the first light source unit 1 and the second light source unit 4 are different, the light absorption characteristics and curing reaction characteristics of the imprint material R are different between the two. For this reason, a database can be prepared according to combinations of the wavelengths of the first light source unit 1 and the second light source unit 4.

[0047] The control unit 140 uses the optical sensor 89 to acquire the exposure dose distribution 52 due to the first light from the first light source unit 1 irradiated onto the substrate W, and generates the first exposure dose distribution due to the first light source unit 1 within the shot area S.

[0048] Next, the control unit 140 determines the second exposure dose distribution of the second light source unit 4 by referring to the database, based on the first exposure dose distribution, so that the pattern height change (or line width change) falls within a target range (for example, within ±1%). Next, the control unit 140 adjusts the exposure dose of the second light source unit 4 onto the substrate W using the adjuster 102, based on the second exposure dose distribution. Through the above processing, it is possible to improve the uniformity of the pattern height (or line width) of the imprint material R without reducing throughput and without curing the imprint material R that extends outside the pattern region Mp.

[0049] In summary, the imprint method of this embodiment hardens the imprint material R on the substrate W while the imprint material R is in contact with the mold M. The imprint method includes a curing step of irradiating the imprint material R with first light using a first light source and irradiating the imprint material with second light using a second light source, thereby hardening the imprint material R and forming a plurality of patterns made of the cured product of the imprint material R. Here, the intensity distribution of the second light irradiated onto the imprint material R by the second light source in the curing step is adjusted so that the distribution of evaluation values ​​of each of the plurality of patterns formed through the curing step satisfies a target distribution. Here, the evaluation position is, for example, the pattern height or the pattern line width.

[0050] The imprint process by the imprint apparatus 100 will be described below with reference to FIG. 7. The process shown in FIG. 7 is controlled by the control unit 140. First, in step S1, a substrate (e.g., a wafer) W is transported to the substrate stage 81 by a substrate transport unit (not shown), and is held by a chuck of the substrate stage 81. Next, in step S2, the substrate stage 81 is driven so that the shot area S of the substrate W is moved to a coating position by the dispenser 7, and the imprint material R is deposited or coated on the shot area S by the dispenser 7. Next, in step S3, the substrate stage 81 is driven so that the shot S on which the imprint material R is deposited is positioned directly below the mold M. Next, in step S4, the mold driving mechanism 6 and / or the substrate driving mechanism 80 are controlled so that the imprint material R on the shot area S comes into contact with the mold M.

[0051] Next, in step S5, the imprint material R flows along the pattern region Mp of the mold M, filling the pattern (recesses) of the pattern region MP with the imprint material R. This is called the filling step. After the filling step in step S5, or in parallel with the filling step, steps S6 and S7 can be performed. In steps S6 and S7, the relative positions of the mark 10 on the substrate W and the mark 11 on the mold M are detected using the alignment optical system 2, and based on the detection results, the shot region of the substrate W is aligned with the pattern region of the mold M, and the shape of the mold M is corrected. The alignment can be performed, for example, by the substrate driving mechanism 80, but may also be performed by both the substrate driving mechanism 80 and the mold driving mechanism 6. The shape correction of the mold M is performed by the mold shape correction mechanism 34. Instead of or in addition to the shape correction of the mold M, the shape of the shot region of the substrate W may be corrected. The shape correction of the shot region can be performed, for example, by applying a heat distribution to the substrate W.

[0052] Next, in step S8, a curing step is performed in which the imprint material R on the shot area is cured using the first light source unit 1 and the second light source unit 4. Next, in step S9, the mold M is separated from the cured product of the imprint material R on the substrate W. In parallel with steps S4 to S9, in step S10, the substrate W, the imprint material R, and the mold M may be observed using the observation optical system 3.

[0053] In steps S5 to S8, the second light source unit 4 irradiates the peripheral region of the pattern region Mp with the second light so that the imprint material R does not extend beyond the outer edge of the pattern region Mp. This increases the viscosity or hardens the imprint material R. In this case, it may be understood that the hardening process starts from the point when the second light source unit 4 irradiates the imprint material R with the second light.

[0054] 11 schematically shows the imprint material R flowing under the peripheral region of the pattern region Mp. The pattern region Mp may include a device pattern region 72 and a peripheral region 73 outside the device pattern region 72. The device pattern region 72 may include a plurality of device patterns 13, and the peripheral region 73 may include at least one mark 10.

[0055] If the second light from the second light source unit 4 is irradiated onto the imprint material R through the region including the mark 10 while the mark 10 (recess) is being filled with the imprint material R, the filling of the mark 10 with the imprint material R may be hindered. This may increase the filling time or cause a filling failure. To avoid these problems, it is preferable that the timing for exposing the imprint material R through the peripheral region 73 (region including the mark 10) in the pattern region Mp by the second light source unit 4 be after the filling of the mark 10 with the imprint material R is completed. From another perspective, it is preferable that the timing for exposing the imprint material R through the peripheral region 73 (region including the mark 10) in the pattern region Mp by the second light source unit 4 be after the imprint material R has passed the mark 10. After this, the substrate W (shot region S) and the mold M are aligned in step S6, so exposure by the first light source unit 1 is not yet performed. Although the exposure by the second light source unit 4 increases the viscosity or hardens a portion of the imprint material R, this is only a small portion of the shot area S, and therefore the effect on alignment in step S6 is minimal.

[0056] Furthermore, as shown in FIG. 12 , there is generally no pattern in the region between the mark 10 and the outer edge of the pattern region Mp. In this case, it is not necessary to consider the filling behavior of the imprint material R in the region between the mark 10 and the outer edge of the pattern region Mp. Therefore, the exposure dose distribution 56 by the second light from the second light source unit 4 may be disposed outside the mark 10, as shown in FIG. 12 . In this case, in the curing process, the second light from the second light source unit 4 is irradiated onto the imprint material R only through the region of the pattern region Mp that is outside the mark 10. Therefore, exposure by the second light source unit 4 can be started before the completion of filling of the mark 10 with the imprint material R or the timing when the imprint material R passes over the mark 10. When the imprint material R flows into the exposure dose distribution 56 by the second light from the second light source unit 4, the viscosity of the imprint material R increases or the imprint material R hardens, preventing the imprint material R from spilling outside the pattern region Mp.

[0057] In the curing step, irradiation of the imprint material R with the first light by the first light source unit 1 may be started before irradiation of the imprint material with the second light by the second light source unit 4. Such control is advantageous when filling of the imprint material R in the region irradiated with the first light is completed earlier than filling of the imprint material R in the region irradiated with the second light.

[0058] In the curing step, the period during which the imprint material R is irradiated with the first light and the period during which the imprint material R is irradiated with the second light may at least partially overlap.

[0059] According to the above imprint process, the uniformity of the multiple patterns formed on the substrate W can be improved.

[0060] FIG. 9 schematically shows the configuration of an imprint apparatus 100 according to the second embodiment. Matters not mentioned in the second embodiment may follow those of the first embodiment. In the second embodiment, an optical member 36 (half mirror) that combines the first light from the first light source unit 1 and the second light from the second light source unit 4 is disposed between the first light source unit 1 and the optical member 32. In the second embodiment, the wavelength of the first light from the first light source unit 1 may be the same as the wavelength of the second light from the second light source unit 4. In the second embodiment, the member 35 in the first embodiment is not required. In the second embodiment, the amount of optical blur of the second light source unit 4 is preferably smaller than the amount of optical blur of the first light source unit 1 and equal to or smaller than the width of the light-shielding film 51.

[0061] By making the wavelengths of the light from the first light source unit 1 and the second light source unit 4 the same, the procedure for determining the exposure dose of the second light source unit 4 described in the first embodiment can be simplified. Because the wavelengths are the same, there is no need to consider differences in the light absorption characteristics and curing reaction characteristics of the imprint material R depending on the wavelength. Therefore, the exposure dose distribution from the second light source unit 4 can be determined to complement the exposure dose distribution 52 from the first light source unit 1 so as to obtain the exposure dose necessary to cure the imprint material R without considering the difference in wavelength. In other words, there is no need for a database that links each exposure dose and pattern height change (line width change) when light of different wavelengths is combined.

[0062] The pattern of the cured product formed using the imprinting apparatus 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 nonvolatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensors, and FPGAs. Examples of molds include molds for imprinting.

[0063] The pattern of the cured product may be used as it is as at least a part of a component of the article, or may be used temporarily as a resist mask, which is removed after etching or ion implantation in a substrate processing step.

[0064] Next, we will explain a method for manufacturing an article, in which a pattern is formed on a substrate using an imprinting apparatus, the substrate on which the pattern is formed is processed, and an article is manufactured from the processed substrate. As shown in Figure 13(a), a substrate 1z such as a silicon wafer having a workpiece 2z such as an insulator formed on its surface is prepared, and then an imprinting material 3z is applied to the surface of the workpiece 2z by an inkjet method or the like. Here, the state in which multiple droplets of the imprinting material 3z have been applied to the substrate is shown.

[0065] As shown in Figure 13(b), an imprinting mold 4z is placed with its side on which the concave-convex pattern is formed facing the imprinting material 3z on the substrate. As shown in Figure 13(c), the substrate 1z to which the imprinting material 3z has been applied is brought into contact with the mold 4z, and pressure is applied. The imprinting material 3z fills the gap between the mold 4z and the workpiece 2z. In this state, when light is irradiated through the mold 4z as hardening energy, the imprinting material 3z hardens.

[0066] 13(d), after the imprint material 3z is cured, the mold 4z and the substrate 1z are separated, forming a pattern of the cured imprint material 3z on the substrate 1z. In this cured material pattern, the recesses of the mold correspond to the protrusions of the cured material, and the protrusions of the mold correspond to the recesses of the cured material, i.e., the recess-protrusion pattern of the mold 4z is transferred to the imprint material 3z.

[0067] As shown in Figure 13(e), when etching is performed using the cured material pattern as an etching-resistant mask, portions of the surface of the workpiece 2z where no cured material or only a thin layer remains are removed, forming grooves 5z. As shown in Figure 13(f), when the cured material pattern is removed, an article is obtained in which grooves 5z are formed in the surface of the workpiece 2z. Here, the cured material pattern is removed, but it may also be used as an interlayer insulating film included in a semiconductor device or the like, i.e., a component of an article, without being removed after processing.

[0068] An article manufacturing method according to another embodiment will be described below. A manufacturing method for a device (such as a semiconductor integrated circuit element or a liquid crystal display element) as an article includes a step of forming a pattern on a substrate (such as a wafer, a glass plate, or a film-like substrate) using the imprint apparatus described above. Furthermore, the article manufacturing method may include a step of processing the substrate on which the pattern has been formed, such as an etching step. When manufacturing other articles such as patterned media (recording media) or optical elements, the manufacturing method may include other processes for processing the substrate on which the pattern has been formed, instead of etching. The article manufacturing method according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production costs of the article.

[0069] 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]

[0070] 100: Imprint device, 1: First light source unit, 4: Second light source unit, W: Substrate, M: Mold, 102: Adjuster

Claims

1. An imprinting method in which an imprinting material on a substrate is cured in a state in which the imprinting material is in contact with a mold, the method comprising: a curing step of irradiating the imprint material with first light using a first light source and irradiating the imprint material with second light using a second light source to harden the imprint material, thereby forming a plurality of patterns made of a hardened product of the imprint material; an intensity distribution of the second light irradiated onto the imprint material by the second light source in the curing step is adjusted so that a distribution of evaluation values ​​of each of the plurality of patterns formed through the curing step satisfies a target distribution; the mold has a pattern area corresponding to a shot area of ​​the substrate; In the curing step, the first light is irradiated onto the imprint material through the pattern area, and the second light is irradiated onto a peripheral portion of the pattern area, an amount of exposure of the imprint material by the first light and the second light in the peripheral portion is greater than an amount of exposure of the imprint material by the first light and the second light in a central portion inside the peripheral portion; An imprint method comprising:

2. An imprinting method comprising: curing an imprinting material on a substrate while the imprinting material is in contact with a mold, the method comprising: a curing step of irradiating the imprint material with first light using a first light source and irradiating the imprint material with second light using a second light source to harden the imprint material, thereby forming a plurality of patterns made of a hardened product of the imprint material; an intensity distribution of the second light irradiated onto the imprint material by the second light source in the curing step is adjusted so that a distribution of evaluation values ​​of each of the plurality of patterns formed through the curing step satisfies a target distribution; the mold has a pattern area corresponding to a shot area of ​​the substrate; In the curing step, the first light is irradiated onto the imprint material through the pattern area, and the second light is irradiated onto a peripheral portion of the pattern area, In the curing step, irradiation of the imprint material with the second light is started before irradiation of the imprint material with the first light. An imprint method comprising:

3. the pattern region includes a device pattern region and a peripheral region outside the device pattern region, the peripheral region including a mark; the second light is irradiated onto the imprint material through an area including the mark; In the curing step, the second light is irradiated onto the imprint material through the region including the mark after the imprint material has been filled into the mark.

3. The imprint method according to claim 1 or 2.

4. An imprinting method comprising: curing an imprinting material on a substrate while the imprinting material is in contact with a mold, the method comprising: a curing step of irradiating the imprint material with first light using a first light source and irradiating the imprint material with second light using a second light source to harden the imprint material, thereby forming a plurality of patterns made of a hardened product of the imprint material; an intensity distribution of the second light irradiated onto the imprint material by the second light source in the curing step is adjusted so that a distribution of evaluation values ​​of each of the plurality of patterns formed through the curing step satisfies a target distribution; the mold has a pattern area corresponding to a shot area of ​​the substrate; In the curing step, the first light is irradiated onto the imprint material through the pattern area, and the second light is irradiated onto a peripheral portion of the pattern area, the pattern region includes a device pattern region and a peripheral region outside the device pattern region, the peripheral region including a mark; In the curing step, the second light is irradiated onto the imprint material through only an area of ​​the pattern area that is outside the mark. An imprint method comprising:

5. In the curing step, irradiation of the imprint material with the first light is started before irradiation of the imprint material with the second light. The imprint method according to claim 1 .

6. An imprinting method comprising: curing an imprinting material on a substrate while the imprinting material is in contact with a mold, the method comprising: a curing step of irradiating the imprint material with first light using a first light source and irradiating the imprint material with second light using a second light source to harden the imprint material, thereby forming a plurality of patterns made of a hardened product of the imprint material; an intensity distribution of the second light irradiated onto the imprint material by the second light source in the curing step is adjusted so that a distribution of evaluation values ​​of each of the plurality of patterns formed through the curing step satisfies a target distribution; the mold has a pattern area corresponding to a shot area of ​​the substrate; In the curing step, the first light is irradiated onto the imprint material through the pattern area, and the second light is irradiated onto a peripheral portion of the pattern area, In the curing step, a period during which the first light is irradiated onto the imprint material and a period during which the second light is irradiated onto the imprint material at least partially overlap with each other. An imprint method comprising:

7. the first light is irradiated onto the imprint material with a first optical blur amount, and the second light is irradiated onto the imprint material with a second blur amount that is smaller than the first optical blur amount; 7. The imprint method according to claim 1, wherein the imprinting step is performed by applying a pressure to the imprinting layer.

8. An imprinting method comprising: curing an imprinting material on a substrate while the imprinting material is in contact with a mold, the method comprising: a curing step of irradiating the imprint material with first light using a first light source and irradiating the imprint material with second light using a second light source to harden the imprint material, thereby forming a plurality of patterns made of a hardened product of the imprint material; an intensity distribution of the second light irradiated onto the imprint material by the second light source in the curing step is adjusted so that a distribution of evaluation values ​​of each of the plurality of patterns formed through the curing step satisfies a target distribution; the mold has a pattern area corresponding to a shot area of ​​the substrate; In the curing step, the first light is irradiated onto the imprint material through the pattern area, and the second light is irradiated onto a peripheral portion of the pattern area, the first light is irradiated onto the imprint material with a first optical blur amount, and the second light is irradiated onto the imprint material with a second blur amount that is smaller than the first optical blur amount; the second blur amount is 100 μm or less; An imprint method comprising:

9. the first light is light having peak intensities at at least two wavelengths, and the second light is light having peak intensity at only one wavelength; The imprint method according to any one of claims 1 to 8.

10. the wavelength band of the second light is narrower than the wavelength band of the first light; The imprint method according to any one of claims 1 to 9.

11. The first light is generated by a high-pressure mercury lamp, and the second light is generated by a solid-state light emitting element.

11. The imprint method according to claim 9 or 10.

12. An imprinting method for curing an imprinting material on a substrate while the imprinting material is in contact with a mold, comprising: a curing step of irradiating the imprint material with first light using a first light source and irradiating the imprint material with second light using a second light source to harden the imprint material, thereby forming a plurality of patterns made of a hardened product of the imprint material; an intensity distribution of the second light irradiated onto the imprint material by the second light source in the curing step is adjusted so that a distribution of evaluation values ​​of each of the plurality of patterns formed through the curing step satisfies a target distribution; the mold has a pattern area corresponding to a shot area of ​​the substrate; In the curing step, the first light is irradiated onto the imprint material through the pattern area, and the second light is irradiated onto a peripheral portion of the pattern area, The NA of the second light is smaller than the NA of the first light. An imprint method comprising:

13. An imprinting apparatus that hardens an imprinting material on a substrate while the imprinting material is in contact with a mold, a first light source unit that generates a first light; a second light source unit that generates a second light; an optical system that forms a first light intensity distribution on the imprint material by the first light from the first light source unit and forms a second light intensity distribution on the imprint material by the second light from the second light source unit, the second light source unit includes an adjuster that adjusts the second light intensity distribution, an amount of optical blur in a peripheral portion of the second light intensity distribution is smaller than an amount of optical blur in a peripheral portion of the first light intensity distribution; the adjuster adjusts the second light intensity distribution so that a lack of exposure amount due to optical blur in a peripheral portion of the first light intensity distribution is compensated for by the second light intensity distribution; an amount of optical blur in a peripheral portion of the second light intensity distribution is 100 μm or less; An imprinting apparatus comprising:

14. The first light source unit generates light having peak intensities at at least two wavelengths, and the second light source unit generates light having peak intensities at only one wavelength. The imprinting apparatus according to claim 13 .

15. the wavelength band of the second light is narrower than the wavelength band of the first light; 15. The imprinting apparatus according to claim 13 or 14.

16. the first light source unit includes a high-pressure mercury lamp, and the second light source unit includes a solid-state light-emitting element; 16. The imprinting apparatus according to claim 14 or 15.

17. An imprinting apparatus for curing an imprinting material on a substrate while the imprinting material is in contact with a mold, comprising: a first light source unit that generates a first light; a second light source unit that generates a second light; an optical system that forms a first light intensity distribution on the imprint material by the first light from the first light source unit and forms a second light intensity distribution on the imprint material by the second light from the second light source unit, the second light source unit includes an adjuster that adjusts the second light intensity distribution, an amount of optical blur in a peripheral portion of the second light intensity distribution is smaller than an amount of optical blur in a peripheral portion of the first light intensity distribution; the adjuster adjusts the second light intensity distribution so that a lack of exposure amount due to optical blur in a peripheral portion of the first light intensity distribution is compensated for by the second light intensity distribution; The NA of the second light is smaller than the NA of the first light. An imprinting apparatus comprising:

18. forming a pattern on a substrate according to the imprinting method of any one of claims 1 to 12; a processing step of processing the patterned substrate to obtain an article; A method for manufacturing an article, comprising:

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