Foreign substance inspection device, nano-imprint lithography device, and article manufacturing method

Abstract

To provide a foreign substance inspection device that can detect a foreign substance with a high height on a substrate to improve productivity in a molding device that transfers a pattern of an original plate to a substrate.SOLUTION: A foreign substance inspection device detects a foreign substance on a substrate in a molding device that transfers a pattern of an original plate to a substrate. The foreign substance inspection device has: a confocal optical system in which a light source, a surface to be inspected, and a pinhole are in conjugation with each other; a sensor that detects the quantity of light passing through the pinhole in the confocal optical system; and a control unit that determines the presence or absence of a foreign substance on the substrate, on the basis of the light quantity detected by the sensor in a state where the surface to be inspected is set at a predetermined height higher than the height of the substrate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a foreign object inspection apparatus, a nanoimprint lithography apparatus, and a method for manufacturing an article.

Background Art

[0002] With the increasing demand for miniaturization of semiconductor devices, MEMS, etc., in addition to the conventional photolithography technology, a microfabrication technology that forms an imprint material on a substrate (wafer) with a mold (mask) and forms a pattern of the imprint material on the substrate has attracted attention. This technology, also called imprint technology, can form fine structures on the order of several nanometers on the substrate. In the imprint technology, a process of directly contacting and peeling the mold with the imprint material on the substrate is involved. Therefore, the life of the mold has become a major issue.

[0003] When pressing the mold onto the substrate, if there are particles attached to the substrate, the fine pattern of the mold may be damaged during pressing, or foreign substances such as particles may adhere to the mold, resulting in defects in the pattern on the substrate.

[0004] In particular, since the handling of the substrate in various semiconductor manufacturing processes is performed at the edge and bevel of the substrate, foreign substances are more likely to adhere to these edges and bevels of the substrate than to the central part of the substrate. Therefore, a technology for detecting foreign substances existing on the substrate in advance before pressing is important.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] When imprinting a so-called edge shot including the edge of the substrate, height information such as the edge of the substrate, foreign matter, dirt, and processing marks existing on the bevel is important. Even if the intensity of scattered light from the edge and bevel of the substrate is large in the conventional inspection method, if the height is lower than the height allowed in the imprinting operation, it does not necessarily cause a defect in the pattern on the substrate and become a problem. Conversely, even if the intensity of this scattered light is small, if the height is higher than the height allowed in the imprinting operation, there is a risk of occurrence of defects in the mold and damage to the fine pattern of the mold. Therefore, an object of the present invention is to provide a foreign matter detection device that can detect foreign matter with a high height on a substrate and improve productivity in a forming device that transfers a pattern of a master plate to the substrate.

Means for Solving the Problems

[0007] A foreign matter inspection device for detecting foreign matter on the substrate in a molding device that transfers a pattern of a master plate to the substrate, as one aspect of the present invention for solving the above problems, includes a confocal optical system in which a light source, a surface to be inspected, and a pinhole are conjugate, a sensor that detects the amount of light of the light that has passed through the pinhole of the confocal optical system, and a control unit that determines the presence or absence of foreign matter on the substrate based on the amount of light detected by the sensor in a state where the surface to be inspected is set at a predetermined height higher than the height of the substrate.

Effects of the Invention

[0008] According to the present invention, in a forming device that transfers a pattern of a master plate to a substrate, it is possible to provide a foreign matter detection device that can detect foreign matter with a high height on the substrate and improve productivity.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] As the demand for miniaturization of semiconductor devices, MEMS, etc. progresses, in addition to conventional photolithography technology, a microfabrication technology that forms a pattern of an imprint material on a substrate (wafer) by molding (masking) the imprint material on the substrate and pressing it has attracted attention. This technology is also called imprint technology and can form fine structures on the order of several nanometers on the substrate.

[0012] For example, as one of the imprint technologies, there is a photocuring method. In an imprint apparatus adopting this photocuring method, first, a photocurable imprint material is applied to a shot region which is an imprint region on the substrate. Next, while aligning the pattern portion of the mold and the shot region, the pattern portion of the mold and the imprint material are brought into contact (pressed), and the imprint material is filled into the pattern portion. Then, after irradiating light to cure the imprint material, the pattern portion of the mold and the imprint material are separated from each other, so that a pattern of the imprint material is formed in the shot region on the substrate (pattern forming process).

[0013] Thus, in the imprint technology, there is a step of directly contacting and peeling the mold with the resin on the substrate. Therefore, the lifetime of the mold has become a major issue. One of the major factors affecting the lifespan is the cleanliness of the substrate being transported within the imprint apparatus. When imprinting the mold onto the substrate, if there are particles (foreign substances) adhering to the substrate, the fine pattern of the mold may be damaged during imprinting, or particles may adhere to the mold, resulting in defects in the pattern on the substrate.

[0014] In particular, since the handling of the substrate in various semiconductor manufacturing processes is performed at the edges and bevels of the substrate, foreign substances such as particles are more likely to adhere to these edges and bevels of the substrate than to the central part of the substrate.

[0015] When imprinting a shot (partial field shot) on the outer periphery of the substrate with an imprint apparatus, the mold approaches the edges and bevels of this substrate. In this case, depending on the size of the foreign substance, there is a risk that the foreign substance may be trapped between the substrate and the mold, causing locally excessive stress to be applied to the substrate and the mold, leading to damage to the fine pattern of the mold.

[0016] Therefore, a technique for detecting foreign substances existing on the substrate in advance before imprinting becomes important. Conventionally, for detecting foreign substances at the edges and bevels of the substrate, the mainstream method is to irradiate light obliquely onto the foreign substances on the substrate and detect the scattered light with a light detection unit.

[0017] With these techniques, by using the scattered light intensity from standard particles with a known particle size in advance as a reference, the approximate size of the foreign substance can be determined from the scattered light intensity from the actual foreign substance. However, since the substrate is carried into the imprint apparatus after undergoing various semiconductor processes, there are not only particle adhesions but also dirt, processing marks, and minute peeling during film formation on the edges and bevels of the substrate. With the conventional techniques, the approximate size has been determined from the scattered light generated by irradiating obliquely incident light on these defects other than particles.

[0018] When performing so-called edge shots including the edges of the substrate, height information such as the edges of the substrate, particles, dirt, and processing marks present on the bevel is important. Even if the intensity of scattered light is high in the conventional inspection method, it does not necessarily pose a problem if the height is lower than the height allowed in the imprinting operation. Conversely, even if the intensity of this scattered light is low, if the height is higher than the height allowed in the imprinting operation, mold defects will occur and the fine pattern of the mold will be damaged. Therefore, an object of the present invention is to provide a technique for determining the height of particles, dirt, and processing marks present near the edges and bevels of a substrate in an imprint apparatus and controlling the operation of the imprint apparatus based on that information. In this specification, for the sake of simplicity of description, particles, dirt, processing marks, etc. on the substrate are collectively referred to as "foreign matter".

[0019] <First Embodiment> Using FIG. 2, the device configuration of the imprint apparatus according to the first embodiment will be described. The imprint apparatus 1 is a device that brings an imprint material supplied onto a substrate (wafer) 101 into contact with a mold (original plate, mask) 100 and forms the uneven pattern of the mold 100 on the substrate 101 by applying energy for curing to the imprint material.

[0020] Here, as the imprint material, a curable composition (sometimes also referred to as an uncured resin) that cures when energy for curing is applied is used. As the energy for curing, electromagnetic waves, heat, etc. are used. The electromagnetic wave is, for example, light such as infrared rays, visible light, and ultraviolet rays selected from the range where its wavelength is 150 nm or more and 1 mm or less.

[0021] The curable composition is a composition that cures by light irradiation or by heating. Among these, the photocurable composition that cures by light contains at least a polymerizable compound and a photoinitiator, and may 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 release agent, a surfactant, an antioxidant, a polymer component, and the like.

[0022] The imprint material is applied in a film form on the substrate 101 by a spin coater or a slit coater, or may be applied on the substrate 101 in the form of droplets or in an island or film form formed by connecting a plurality of droplets by a liquid injection head. The viscosity of the imprint material (viscosity at 25°C) is, for example, 1 mPa·s or more and 100 mPa·s or less.

[0023] The substrate 101 is made of glass, ceramics, metal, resin, etc., and a member made of a material different from that of the substrate 101 may be formed on its surface as necessary. Specifically, the substrate 101 is a silicon wafer, a compound semiconductor wafer, a glass wafer containing quartz as a material, etc.

[0024] The mold has a rectangular outer peripheral shape and has a pattern portion provided with a three-dimensionally formed pattern (concavo-convex pattern such as a circuit pattern to be transferred to the substrate 101) on the surface (pattern surface) facing the substrate 101. The mold is made of a material that can transmit light, for example, quartz.

[0025] In this embodiment, the imprint apparatus 1 will be described as adopting a photocuring method for curing the imprint material by light irradiation. Further, the direction parallel to the optical axis of the irradiation optical system described later is defined as the Z-axis direction, and two directions orthogonal to each other in the plane perpendicular to the Z-axis direction are defined as the X-axis direction and the Y-axis direction.

[0026] 104 is a mold chuck that attracts and holds the mold 100 by vacuum adsorption force or electrostatic force. 105 is a moving mechanism that holds the mold chuck 104 and moves the mold 100. The mold chuck 104 and the mold moving mechanism 105 have an opening at the central part (inside) so that the light from the light irradiation unit 111 irradiates the imprint material on the substrate 101. The mold moving mechanism 105 moves the mold 100 in the Z-axis direction so as to press (imprint) the mold 100 against the imprint material on the substrate 101 or to separate (release) the mold 100 from the imprint material on the substrate 101. The mold moving mechanism 105 may be composed of a plurality of drive systems such as a coarse drive system and a fine drive system in order to position the mold 100 with high precision.

[0027] The alignment optical system 114 can include the light irradiation unit 111, the spread camera 110, the bending mirror 108, etc. In the imprint process, the light irradiation unit 111 irradiates the imprint material on the substrate 101 with light (for example, ultraviolet light) via the bending mirror 108 and the mold 100. The light irradiation unit 111 includes a light source and optical elements (lenses, mirrors, light shielding plates, etc.) for adjusting the light from the light source to an appropriate light state (light intensity distribution, illumination area, etc.) for the imprint process.

[0028] The alignment scopes 107a and 107b measure the positional deviation in the X-axis direction and the Y-axis direction between the alignment marks formed on the substrate 101 and the alignment marks formed on the mold 100. The alignment scopes 107a and 107b are configured in the imprint head unit 106. Also, the alignment scopes 107a and 107b can measure the shape of the pattern part of the mold 100 and the shape of the shot area formed on the substrate 101. Therefore, the alignment scopes 107a and 107b also function as a measurement unit that measures the alignment state between the area of the substrate 101 to be imprinted and the pattern part of the mold 100.

[0029] The spread camera 110 can observe the filling process of the imprint material supplied therebetween and the release process in which the mold 100 separates from the substrate 101 when the mold 100 is imprinted on the substrate 101.

[0030] The liquid ejection device 116 supplies an imprint material onto the substrate 101 based on preset supply amount information. Further, the supply amount of the imprint material supplied from the liquid ejection device 116 (i.e., the supply amount information) is set according to, for example, the thickness of the pattern of the imprint material formed on the substrate 101 (the thickness of the remaining film) and the density of the pattern of the imprint material. The units described above are connected to the bridge surface plate 109.

[0031] The substrate chuck 102 attracts and holds the substrate 101 by means of a vacuum adsorption force or an electrostatic force. The substrate chuck 102 is mounted on the fine movement stage 103, and the fine movement stage 103 is mounted on the rough movement stage 117. The fine movement stage 103 and the rough movement stage 117 are movable within the XY plane. When pressing the mold 100 against the imprint material on the substrate 101, the positions of the fine movement stage 103 and the rough movement stage 117 are adjusted to align the position of the mold 100 and the position of the substrate 101 with each other. Further, the fine movement stage 103 and the rough movement stage 117 may be configured to have a tilt function for adjusting the position of the substrate 101 in the θ (rotation around the Z axis) direction and the inclination of the substrate 101.

[0032] The foreign matter inspection system for the substrate 101 of the present invention is composed of the foreign matter inspection optical system 115 and the foreign matter inspection stage 113. The foreign matter inspection optical system 115 is drivable in the Z-axis direction parallel to its optical axis and in the radial direction R of the substrate 101. The foreign matter inspection stage 113 is drivable in the rotation direction θ of the substrate 101. The foreign matter inspection optical system 115 drivable in the radial direction R of the substrate and the foreign matter inspection stage 113 drivable in the rotation direction θ constitute a substrate scanning means for scanning the invalid area of the outer peripheral portion of the substrate 101 to detect foreign matter. The robot hand 112 has a function of transporting the substrate 101 to the foreign matter inspection stage 113 and transporting the substrate 101 whose bevel inspection has been completed to the substrate stage of the imprint apparatus 1 according to the inspection result, or carrying it out of the apparatus.

Example

[0033] A first embodiment will be described. FIGS. 3 and 4 are diagrams for explaining an imprint method of an edge shot of a substrate 101 which is a problem in the present invention. FIG. 3 is a view of the overlapping state of a mold 100 and the substrate 101 when imprinting an edge shot, as seen from the mold side. FIG. 4 is a cross-section thereof. Before imprinting, a grid-like shot layout is defined on the substrate 101. On the other hand, the mold 100 has a mesa 120 which is convex toward the substrate 101 at the center, and a pattern is formed on its surface.

[0034] During imprinting, imprinting is performed in order according to this shot layout. At this time, an imprint process for a shot including the edge of the substrate 101 as shown in FIG. 3 always occurs. The substrate 101 shown in FIG. 4 includes a bare silicon wafer 122 on which no pattern is formed yet, and an organic film (processing layer) 121 previously formed thereon. During imprinting, an imprint material 123 is dropped onto the surface of this organic film, and the mesa 120 is pressed against the substrate 101, thereby transferring the pattern formed on the mesa 120 to the substrate 101.

[0035] Generally, the vicinity of the outer periphery of the substrate 101 is divided into a valid region suitable for semiconductor device manufacturing and an invalid region not suitable, as shown in FIG. 4. Further, the vicinity of the edge of the substrate 101 is divided into a rounded bevel portion and an edge end portion. The edge shot includes the edge end portion of the outermost periphery of the substrate, the bevel portion, and the end portion of the film formation portion. These regions are regions where mechanical contact occurs in order to handle the substrate 101 in various processes of semiconductor device manufacturing. Therefore, foreign matter, dirt, and scratches are likely to occur, and the end portion of the film formation portion is also likely to have film peeling.

[0036] Thus, a convex foreign matter 150a as shown in FIG. 4 is likely to adhere to the vicinity of the edge end portion and the bevel portion of the substrate 101. When the mesa 120 is pressed in this state during imprinting, the foreign matter 150a is sandwiched between the substrate 101 and the mesa 120. If the height of the foreign matter 150a is not acceptable in the imprinting operation, the mold pattern may be missing, and there is a risk that a pattern including defects will be continuously formed from the next imprint shot.

[0037] Thus, in the present invention, before pressing the substrate 101, a means is provided for inspecting the edge region of the substrate 101 using the foreign matter inspection system (foreign matter inspection apparatus) of the present invention to determine whether the substrate 101 is printable.

[0038] As shown in FIG. 1, the optical system of the foreign matter inspection system of the present invention is configured as a confocal optical system. In the confocal optical system, the point light source 130, the beam focus position (inspection surface) 137 set near the surface of the substrate 101, and the pinhole 135 at the image position are all in conjugate positions. That is, the light emitted from the point light source 130 is shaped by the point light source side optical system 131, enters the objective lens 134 through the beam splitter 132, and is focused on a single point at the beam focus position 137.

[0039] The light quantity sensor 136 detects the light quantity of the light that has passed through the pinhole 135. Since the pinhole 135 is conjugate with the beam focus position 137 by the pinhole side optical system 133 and the objective lens 134, when an object surface exists at the beam focus position 137, the light quantity received by the light quantity sensor 136 becomes maximum.

[0040] When an object surface exists at the beam focus position 137, the light reflected from the object surface returns along the same optical path, is separated by the beam splitter 132, shaped by the pinhole side optical system 133, and focused on the pinhole 135. Only the light that has passed through the pinhole 135 enters the light quantity sensor 136. Thus, the confocal optical system has the characteristic that the light quantity passing through the pinhole 135 becomes maximum when an object surface exists at the beam focus position 137.

[0041] Conversely, when there is no object surface at the beam focus position 137, most of the light is cut by the pinhole 135 and hardly any light enters the light quantity sensor 136. In FIG. 1, it shows that the beam focus position 137 of the optical system of the foreign matter inspection system is located on the surface of the region (the first region) where the organic film 121 formed in the invalid region of the substrate 101 is formed. The optical system of the foreign matter inspection system is integrally configured and corresponds to the foreign matter inspection optical system 115 in FIG. 2.

[0042] In this embodiment, using this foreign matter inspection system, first, the height position of the flat part in the invalid region of the substrate 101 is detected. In FIG. 5, the optical axis of the foreign matter inspection system is moved to the invalid region. At this time, the radial coordinate of the substrate 101 (the distance from the center of the substrate 101) is set as R = R0. The beam focus position of the foreign matter inspection optical system 115 is changed from below to above the expected flat surface position at this flat part.

[0043] As shown in FIG. 6, the amount of light incident on the light quantity sensor 136 becomes the maximum when the flat part of the invalid region enters within the depth of focus of the foreign matter inspection optical system. The detection of the peak position of the light quantity profile can be accurately detected by determining a threshold value I0 in advance and detecting a signal exceeding this value. The beam focus position Z of the foreign matter inspection optical system 115 at this time is defined as Z = Z0 as the height of the flat part of the invalid region.

[0044] Next, a method for detecting the height position of a foreign object existing near the bevel part of the substrate 101 will be described. As shown in FIG. 7, the beam focus position of the foreign matter inspection optical system 115 is set to the height Z = Z0 of the flat part of the invalid region of the substrate 101 detected above. The optical axis of the foreign matter inspection device is moved near the bevel part of the substrate 101 (R = R1), and the bevel part of the substrate 101 is scanned with the beam spot 138 by rotating the substrate 101 in the θ direction as shown in FIG. 8. Since the beam focus position is adjusted to Z = Z0 as shown in FIG. 7, in the state where there is no foreign object on the bevel part of the substrate 101, the amount of light received by the light quantity sensor 136 is at the background level, and the light quantity profile becomes a flat signal.

[0045] When foreign matter 150b adheres to the bevel of substrate 101, since the height of the foreign matter 150b is at a position lower than the beam focus position (Z = Z0), the sensor light quantity becomes a profile as shown in FIG. 9. That is, although a slight signal change is detected at the foreign matter coordinate θ1, the peak does not reach a predetermined threshold value I1. Therefore, a control unit (not shown) determines, based on the information of this detected value, that there are defects such as foreign matter at this coordinate (R1, θ1), but the height of its surface is not near Z = Z0. Therefore, even if an edge shot corresponding to this coordinate is imprinted, the pattern of mold 100 does not contact the foreign matter 150b.

[0046] On the other hand, FIG. 10 shows a case where foreign matter 150c adheres near the bevel portion of substrate 101 and its height is about the same as that of the invalid flat portion Z = Z0. The beam focus position of the foreign matter inspection optical system 115 is set to Z = Z0. The optical axis of the foreign matter inspection apparatus is moved to the edge end of substrate 101, near the bevel portion (R = R2), and substrate 101 is scanned in the θ direction with the beam spot 138.

[0047] In this case, as shown in FIG. 11, a peak exceeding the threshold value I1 is detected in the profile of the light quantity sensor 136. Therefore, it is detected that there are defects such as foreign matter at this coordinate (R2, θ2), and the height of its surface is near Z = Z0. When such foreign matter exists, if an edge shot corresponding to this coordinate is imprinted, the pattern of mold 100 contacts the foreign matter 150c. As a result, the pattern of mold 100 may be damaged, and continuous defects may occur on substrate 101 in subsequent imprint shots. Therefore, since this shot cannot be imprinted, substrate 101 is carried out from the imprint apparatus 1.

[0048] Next, a method for determining the presence or absence of foreign matter on substrate 101 in the imprint apparatus (molding apparatus) 1 of the present embodiment will be described with reference to FIG. 12. When substrate 101 is carried into the imprint apparatus, substrate 101 is once placed on the foreign matter inspection stage 113 (step 200). Next, the optical axis of the foreign object inspection optical system 115 moves to the flat portion (R = R0) of the invalid region of the substrate 101. The beam focus position is moved from a position lower than the expected flat portion height to a higher position to obtain a light quantity profile (first light quantity) incident on the light quantity sensor 136 (step 201, first detection step).

[0049] When the Z position (first height) corresponding to the peak with the maximum light quantity is detected from the profile, the Z position at that time becomes the height of the flat portion of the invalid region of the substrate 101. This value is stored as Z0 (step 202). Since the flat portion height of the invalid region of the substrate 101 has been detected, based on this height Z0 (second height), the position of the beam spot in the R direction (radial direction) of the substrate 101 is set to the position of the bevel portion of the substrate 101. While rotating the substrate 101 by the foreign object inspection stage 113, the beam spot is shifted in the +R direction. In this way, while scanning the bevel portion of the substrate 101 with the beam spot, a light quantity profile (second light quantity) is acquired (step 203, second detection step).

[0050] The acquired light quantity profile is processed to determine whether there is a signal peak equal to or higher than the threshold value I1 (step 204, determination step). If there is a signal peak equal to or higher than the threshold value I1, there is a foreign object with an unacceptable height on the bevel portion of this substrate 101. Therefore, imprinting on the substrate 101 is impossible and the substrate 101 is directly carried out of the imprint apparatus 1 (rejected from the production line for products) (step 206). Conversely, if there is no peak of a signal equal to or higher than the threshold value I1, since this substrate 101 is printable, it is passed on to the subsequent operation (step 205).

[0051] Note that, in this embodiment, it has been described that foreign matter which is a problem adheres near the bevel portion of the substrate 101. In this case, the maximum allowable height of the adhering foreign matter is near the height (Z = Z0) of the flat portion of the invalid region. However, it cannot be denied that foreign matter may also adhere to the flat portion of the invalid region adjacent to the bevel portion of the substrate 101. In that case, the allowable height of the foreign matter becomes even smaller. Specifically, it is the height based on the thickness and elastic modulus of the underlayer film of the substrate 101 and the residual layer thickness formed by imprinting.

[0052] For example, assuming that the thickness of the substrate underlayer film is 300 nm and the residual layer thickness formed by imprinting is about 30 nm, the allowable foreign matter size is about d = 30 nm. In this case, the maximum allowable height of the foreign matter is Z = Z0 + 30 nm with respect to the flat portion Z = Z0 of the invalid region. In such a case, in the present invention, the maximum allowable height of the foreign matter is set to Z = Z0 + d. And by including the flat portion of the invalid region in addition to the region of the bevel portion in the inspection region, the foreign matter height can be inspected using the same means.

[0053] In order to inspect foreign matter near the outer periphery of the substrate 101 in this way, the θ rotation mechanism of the foreign matter inspection stage 113 and the R direction movement mechanism of the foreign matter inspection optical system 115 are used. By this, it becomes possible to inspect the edge portion, bevel portion, and invalid region of the substrate 101 where convex defects such as foreign matter, dirt, processing residues, and film peeling are likely to occur.

[0054] In this embodiment, by further expanding the inspection region to the effective region of the substrate 101, it becomes possible to inspect the height of foreign matter over the entire surface of the substrate 101. In this case, since the inspection area becomes large, it is desirable to provide a plurality of sets of the foreign matter inspection optical system 115. Even in this case, the technology described in this embodiment can be used, and it becomes possible to perform the inspection of the entire surface of the substrate 101 in a shorter time.

Embodiment

[0055] A second embodiment will be described. In the first embodiment, when the foreign object height inspection area is near the bevel portion of the substrate 101, the allowable foreign object height is set to Z = Z0, and when the foreign object height inspection area is the flat portion of the invalid area of the substrate 101, Z = Z0 + d. However, although foreign objects tend to adhere to the vicinity of the bevel portion of the substrate 101, they may also adhere to the flat portion of the invalid area adjacent thereto. At the same time, there is also a possibility that foreign objects that are out of the depth of focus of the foreign object inspection optical system 115 may adhere.

[0056] In this embodiment, in order to cope with these various foreign object adhesion situations, the beam focus position 137 of the foreign object inspection optical system 115 is changed, and the invalid area and the bevel portion area are scanned multiple times to obtain a light quantity profile. This will be described with reference to FIG. 13. FIG. 13 shows an example in which a foreign object 150e adheres to the flat portion of the invalid area of the substrate 101 and a foreign object 150d adheres to the vicinity of the bevel portion of the substrate 101. However, on the substrate 101, the foreign objects 150d and 150e do not necessarily have the same θ coordinate. In this case, the beam focus position 137 of the foreign object inspection optical system 115 is set to Z = Z0 + d (d is the allowable foreign object size in the invalid flat portion), and the invalid area is inspected.

[0057] At this time, at the substrate coordinates (R3, θ3), if there is a non-allowable foreign object 150e, a light quantity profile as shown in FIG. 14 can be obtained. Further, the beam focus position 137 is moved in the +R direction to inspect the vicinity of the bevel portion. Although the foreign object 150d exists at R = R4, since its surface is out of the depth of focus of the foreign object inspection optical system 115, a signal exceeding the threshold value I1 cannot be obtained in the light quantity profile. At this point, it is impossible to determine whether the foreign object 150d has an allowable height.

[0058] In such a case, the beam focus position 137 is changed upward to Z = Z0 + h (where h is the predetermined depth of focus of the foreign object inspection optical system 115), and inspection is performed again. At this time, since the foreign object 150e is out of the depth of focus of the foreign object inspection optical system 115, a signal exceeding the threshold value I1 cannot be obtained in the light quantity profile. However, for the foreign object 150d, since its surface is within the depth of focus, a profile as shown in FIG. 15 can be obtained. From this, 150d is detected as an unacceptable foreign object.

[0059] Next, the operation steps of the nanoimprint process using this embodiment will be described with reference to the flowchart shown in FIG. 16. Steps 300 to 302 are the same as those in FIG. 12, and thus the description thereof will be omitted. In step 303, the beam focus position 137 of the foreign object inspection optical system 115 is set to Z1 = Z0 + ΔZ1 (the second height), and the invalid region and the bevel portion region of the substrate 101 are inspected. The initial value of ΔZ1 is preferably the allowable foreign object size d described above. The beam focus position 137 set for subsequent scans may define ΔZi for the i-th scan with the depth of focus of the foreign object inspection optical system 115 as a step. It is determined whether there is a signal equal to or higher than the threshold value I1 in the light quantity profile (the second light quantity) obtained by this detection (the second detection step) (the determination step). If there is a signal equal to or higher than the threshold value I1 (step 304), since this substrate 101 cannot be imprinted, it is carried out of the imprint apparatus 1 (step 307).

[0060] Even if there is no signal equal to or higher than the threshold value I1 in the light quantity profile in the scan at one beam focus position 137, it is not certain that there is no foreign object based solely on this. Through step 305, the focus position is changed again to Z2 = Z0 + ΔZ2, and the invalid region and the bevel portion region are scanned in the same manner. It is determined whether there is a signal equal to or higher than the threshold value I1 in the obtained light quantity profile.

[0061] Repeat steps 303, 304, and 305. The inspection ends when a signal equal to or greater than the threshold value I1 is detected in the light quantity profile. The method for setting the number of inspections N may be determined in advance according to the inspection throughput of the substrate 101, the frequency of foreign matter adhesion, and the number of foreign matters. For example, if N = 3 and no foreign matter with an unacceptable height is detected after three inspections, this substrate 101 is considered printable and the process proceeds to the imprint operation (step 308).

[0062] Even if the inspection is repeated N times and a signal equal to or greater than the threshold value I1 is not detected in the light quantity profile, if the light quantity of the peak at the same coordinates increases as the focus position is raised, it may be determined that there is an unacceptable foreign matter at that position. This is because it is considered to suggest the presence of a foreign matter surface at a position higher than the position of the surface to be inspected of the confocal optical system.

[0063] According to this embodiment, foreign matters of various heights can be inspected in the invalid region and the bevel portion region of the substrate 101.

Embodiment

[0064] A third embodiment will be described. In the previous embodiments, in the inspection of the invalid region of the substrate 101 of the present invention, when an unacceptable foreign matter is detected, this substrate 101 is not printable and is carried out of the imprint apparatus 1. However, since this directly leads to a significant decrease in the number of imprinted wafers, this embodiment will explain a means for avoiding this.

[0065] In FIG. 17, assume that three unacceptable foreign matters are detected at the shot positions 150f, 150g, and 150h during the foreign matter inspection of the substrate 101. If an edge shot corresponding to this position is imprinted, there is a risk of defects in the mold pattern. In this embodiment, for this region, it is characterized by performing a dummy imprint (dummy imprint process) using a dummy mold that is not intended to be a product.

[0066] If this area is not patterned and the process proceeds to the next etching step, the etching accuracy (such as LER: Line Edge Roughness, LWR: Line Width Roughness, etc.) near the boundary with the normally imprinted shots will change. Therefore, even if foreign matter is present, it is desirable to perform the imprint process and the dummy patterning process on these shots.

[0067] In this case, it is desirable to use a mold that has already exceeded its lifetime. For example, shots that cannot be imprinted due to the detection of foreign matter unacceptable by the method of the present invention are identified in advance, and their positions (coordinates) are stored in a storage unit (not shown). Thereafter, based on the stored positions, shots that can be imprinted as products (no foreign matter detected) are first imprinted using a mold within its lifetime. Thereafter, for example, using a mold that has exceeded its lifetime, a dummy imprint process is performed on shot positions that cannot be imprinted as products. For example, as shown in FIG. 18, shot positions 160a, 160b, and 160c are the targets of the dummy imprint process. By operating in this way, a decrease in the number of substrate processed sheets (product yield) can be suppressed.

[0068] <Embodiment of the method for manufacturing an article> A method for manufacturing a device (such as a semiconductor integrated circuit element, a liquid crystal display element, etc.) as an article includes a step of forming a pattern on a substrate (wafer, glass plate, film-like substrate) using the above-described imprint apparatus 1.

[0069] Furthermore, the manufacturing method may include a step of etching the substrate on which the pattern is formed. In the case of manufacturing other articles such as a patterned medium (recording medium) or an optical element, the manufacturing method may include other processes for processing the substrate on which the pattern is formed instead of etching.

[0070] The method for manufacturing an article of the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

[0071] <Other Embodiments> The present invention can also be implemented by supplying a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a recording medium, and causing one or more processors in a computer of the system or apparatus to read and execute the program. It can also be implemented by a circuit (for example, ASIC) that realizes one or more functions.

[0072] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0073] The disclosure of the present invention includes the following configurations and methods. (Configuration 1) A foreign matter inspection apparatus for detecting foreign matter on a substrate in a molding apparatus that transfers a pattern of an original plate to the substrate, a confocal optical system in which a light source, a surface to be inspected, and a pinhole are conjugate, a sensor that detects the amount of light of the light that has passed through the pinhole of the confocal optical system, and a control unit that determines the presence or absence of foreign matter on the substrate based on the amount of light detected by the sensor in a state where the surface to be inspected is set at a predetermined height higher than the height of the substrate. The foreign matter inspection apparatus is characterized by having these components. (Configuration 2) The surface of the substrate includes a first region provided with a treatment layer of an organic film, The foreign matter inspection apparatus according to Configuration 1, wherein the predetermined height is set based on the height of a specific position in the first region. (Configuration 3) The foreign matter inspection apparatus according to Configuration 1 or 2, wherein the control unit determines that foreign matter is present when the amount of light is greater than a predetermined threshold value. (Configuration 4) The foreign matter inspection apparatus according to any one of Configurations 1 to 3, further comprising a substrate scanning unit that scans a region including the outer peripheral portion of the substrate. (Configuration 5) The control unit acquires, as a first height, the height of the inspection surface at which the first light amount becomes maximum based on the first light amount detected by the sensor in a first region where the processing layer of the substrate is provided. The foreign matter inspection apparatus according to Configuration 2, wherein the control unit determines the presence of foreign matter based on a second light amount detected by the sensor with a second height higher than the first height as the inspection surface. (Configuration 6) The foreign matter inspection apparatus according to Configuration 5, wherein the control unit determines that foreign matter is present when the second light amount exceeds a threshold value. (Configuration 7) The shaping device is a nanoimprint lithography device. The foreign matter inspection apparatus according to any one of Configurations 1 to 6, wherein the predetermined height is set based on a height at which a defect occurs when the original plate is pressed against the substrate. (Configuration 8) The foreign matter inspection apparatus according to any one of Configurations 1 to 6, wherein the predetermined height is set based on at least any one of a thickness and an elastic modulus of an underlayer film applied to the substrate and a remaining film thickness formed on the substrate during a pattern formation process. (Configuration 9) The foreign matter inspection apparatus according to any one of Configurations 1 to 8, further comprising a storage unit that stores coordinates determined by the control unit to have foreign matter present. (Configuration 10) A nanoimprint lithography device having the foreign matter inspection apparatus according to any one of Configurations 1 to 9. (Configuration 11) The nanoimprint lithography device according to Configuration 10, wherein a shot position corresponding to the coordinates at which the foreign matter is detected is targeted for dummy imprint processing. (Configuration 12) The nanoimprint lithography device according to Configuration 10, wherein the substrate on which the foreign matter is detected has a function of rejecting it as a non-pressable substrate. (Method 1) A step of forming a pattern on a substrate using the nanoimprint lithography apparatus according to any one of configurations 10 to 12, And a step of processing the substrate on which the pattern is formed in the above step, A method for manufacturing an article, characterized by manufacturing an article using the processed substrate. (Method 2) A foreign matter inspection method for detecting foreign matter on a substrate using the foreign matter inspection apparatus according to any one of configurations 1 to 9, A first detection step of detecting a first light amount using the confocal optical system with respect to a first region where a processing layer of the substrate is provided, A step of obtaining the height of the inspection surface at which the first light amount is maximum as a first height, A step of setting a second height based on the first height, A second detection step of detecting a second light amount through the confocal optical system with the second height as the inspection surface, A determination step of determining that foreign matter is present when the second light amount exceeds a threshold value, A foreign matter inspection method having the above steps. (Method 3) The second height is the first height, The second detection step is performed on a second region where the processing layer of the substrate is not provided, and the foreign matter inspection method according to Method 2. (Method 4) The second height is at a position higher than the first height, The second detection step is performed on a region including a second region where the processing layer of the substrate is not provided, and the foreign matter inspection method according to Method 2. (Method 5) The forming apparatus is a nanoimprint lithography apparatus, The second height is set based on the height of the foreign matter where a defect occurred when the original plate was imprinted on the substrate, and the foreign matter inspection method according to Method 4. (Method 6) The shaping device is a nanoimprint lithography device, The second height is set based on at least any one of the thickness and elastic modulus of the base film applied to the substrate and the remaining film thickness formed on the substrate during the pattern formation process. The foreign object inspection method according to method 4 or 5. (Method 7) In the determination step, when the second light amount exceeding the threshold value is not detected, the method includes updating the second height to a position higher than the second height by the depth of focus of the confocal optical system. The foreign object inspection method according to any one of methods 4 to 6.

Explanation of symbols

[0074] 100 Master 101 Substrate 115 Optical system of foreign object inspection system (confocal optical system) 130 Point light source (light source) 135 Pinhole 136 Light amount sensor (sensor)

Claims

1. A foreign object inspection device for detecting foreign objects on a substrate in a molding apparatus that transfers an original pattern to the substrate, comprising: a confocal optical system in which a light source, a surface to be inspected, and a pinhole are conjugate; a sensor for detecting the amount of light that has passed through the pinhole of the confocal optical system; a control unit that determines the presence or absence of foreign objects on the substrate based on the amount of light detected by the sensor in a state where the surface to be inspected is set at a predetermined height higher than the height of the substrate. The foreign object inspection device is characterized by this.

2. The surface of the substrate includes a first region provided with a treatment layer of an organic film, The foreign object inspection device according to claim 1, wherein the predetermined height is set based on the height of a specific position in the first region.

3. The foreign object inspection device according to claim 1, wherein the control unit determines that a foreign object is present when the amount of light is greater than a predetermined threshold.

4. The foreign object inspection device according to claim 1, further comprising substrate scanning means for scanning a region including the outer peripheral portion of the substrate.

5. The control unit acquires, as a first height, the height of the surface to be inspected at which the first amount of light is maximized based on the first amount of light detected by the sensor in the first region where the treatment layer of the substrate is provided, The foreign object inspection device according to claim 2, wherein the control unit determines the presence of foreign objects based on the second amount of light detected by the sensor with a second height higher than the first height as the surface to be inspected.

6. The foreign object inspection device according to claim 5, wherein the control unit determines that a foreign object is present when the second amount of light exceeds a threshold.

7. The molding apparatus is a nanoimprint lithography apparatus, The foreign object inspection device according to claim 1, wherein the predetermined height is set based on the height at which defects occur when the original is imprinted on the substrate.

8. The foreign object inspection device according to claim 1, wherein the predetermined height is set based on at least any one of the thickness and elastic modulus of an underlayer film applied to the substrate and the remaining film thickness formed on the substrate during pattern formation processing.

9. The foreign object inspection device according to claim 1, further comprising a storage unit that stores the coordinates determined by the control unit to indicate the presence of the foreign object.

10. A nanoimprint lithography apparatus having the foreign object inspection device according to any one of claims 1 to 9.

11. The nanoimprint lithography apparatus according to claim 10, characterized in that a shot position corresponding to the coordinates at which the foreign matter is detected is made a target of dummy imprint processing.

12. The nanoimprint lithography apparatus according to claim 10, characterized in that the substrate on which the foreign matter is detected has a function of rejecting it as a substrate that cannot be imprinted.

13. A step of forming a pattern on a substrate using the nanoimprint lithography apparatus according to any one of claims 10 to 12, A step of processing the substrate on which the pattern has been formed in the above step, and A method for manufacturing an article, characterized in that an article is manufactured using the processed substrate.

14. A foreign matter inspection method for detecting foreign matter on a substrate using the foreign matter inspection apparatus according to any one of claims 1 to 9, A first detection step of detecting a first light amount using the confocal optical system with respect to a first region where a processing layer of the substrate is provided; A step of obtaining, as a first height, the height of a test surface at which the first light amount is maximum; A step of setting a second height based on the first height; A second detection step of detecting a second light amount through the confocal optical system with the second height as a test surface; A determination step of determining that foreign matter is present when the second light amount exceeds a threshold value; A foreign matter inspection method having the above steps.

15. The second height is the first height, The second detection step is performed with respect to a second region where the processing layer of the substrate is not provided, the foreign matter inspection method according to claim 14.

16. The second height is at a position higher than the first height, The second detection step is performed with respect to a region including a second region where the processing layer of the substrate is not provided, the foreign matter inspection method according to claim 14.

17. The shaping device is a nanoimprint lithography apparatus, The second height is set based on the height of foreign matter at which a defect occurred when the master was imprinted on the substrate, the foreign matter inspection method according to claim 16.

18. The shaping device is a nanoimprint lithography apparatus, The foreign matter inspection method according to claim 16, wherein the second height is set based on at least any one of the thickness and elastic modulus of the underlayer film applied to the substrate and the remaining film thickness formed on the substrate during the pattern formation process.

19. The foreign matter inspection method according to claim 16, further comprising, in the determination step, when the second light amount exceeding the threshold value is not detected, updating the second height to a position higher than the second height by the depth of focus of the confocal optical system.

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