JP2019009226A - Imprint method, imprint apparatus, program, and article manufacturing method - Google Patents

Abstract

To provide an imprint method which is advantageous for suppressing pattern defects.SOLUTION: The imprint method includes: applying an uncured imprint material on a substrate; and forming a pattern of a cured imprint material on the substrate by curing the uncured imprint material in a state where the uncured imprint material and a mold are in contact to each other. After applying the uncured imprint material to a shot area formed on the substrate and before contacting, a region for curing the uncured imprint material of a part of the shot region is set. A position of the cured imprint material in the set area and a position of a mark provided on the substrate or the mold are measured. On the basis of the position of the cured imprint material and the position of the mark, an irradiation region for curing the uncured imprint material of the partial region including a part of the shot region is set.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an imprint method, an imprint apparatus, a program, and an article manufacturing method.

  One of lithography methods for manufacturing articles such as semiconductor devices and liquid crystal display devices is an imprint method. The imprint method is a method of forming a fine pattern by bringing a mold into contact with an uncured imprint material on a substrate. In the imprint method, an uncured imprint material may spread in a region other than a region where a pattern is formed on the substrate. In this case, problems such as pattern defects and yield reduction may occur. In Patent Document 1, an uncured resist near the boundary between a pattern formation region on a substrate and an outer peripheral region where no pattern is formed is first cured to prevent the uncured resist from spreading on the back surface of the substrate.

JP2013-69919A

  However, if the uncured resist in the desired region cannot be cured as intended, the method of Patent Document 1 may cause the uncured imprint material to spread to a region other than the region where the pattern is formed.

  An object of the present invention is to provide an imprint method that is advantageous for suppressing pattern defects, for example.

  In order to solve the above problems, the present invention applies an uncured imprint material on a substrate, and cures the uncured imprint material in a state where the uncured imprint material and the mold are in contact with each other. An imprint method for forming a pattern of a cured imprint material on a substrate by applying an uncured imprint material to a shot area formed on the substrate and before performing contact Set the area to cure the uncured imprint material in a part of the area, measure the position of the cured imprint material in the set area and the position of the mark provided on the substrate or mold, and cure Based on the position of the imprint material and the position of the mark, an irradiation area for curing the uncured imprint material in a partial area including a part of the shot area is set.

  According to the present invention, for example, it is possible to provide an imprint method that is advantageous for suppressing pattern defects.

It is the schematic which shows the structure of the imprint apparatus using the imprint method which concerns on 1st Embodiment. It is a figure which shows an example of the board | substrate and shot area explaining the imprint method which concerns on 1st Embodiment. It is a figure which shows an example of the alignment mark detected by the alignment scope in the imprint method which concerns on 1st Embodiment. It is a flowchart which shows the imprint method which concerns on 1st Embodiment. It is a figure explaining partial field exposure concerning a 1st embodiment. It is a flowchart which shows the imprint method which concerns on 2nd Embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram illustrating a configuration of an imprint apparatus 100 that uses the imprint method according to the present embodiment. Here, as an example, an ultraviolet curable imprint apparatus that cures an uncured imprint material on a substrate by irradiation with ultraviolet rays was used as an imprint apparatus using a photocuring method. However, as a method for curing the imprint material, a method using light irradiation in another wavelength region or a method using other energy (for example, heat) may be used.

  The imprint apparatus 100 includes, for example, a curing unit 110, a mold holding unit 120, a mold deforming unit 130, a dispenser 140, a substrate holding unit 150, a measuring unit 160, a control unit 170, and a scope 180. May be included. The imprint apparatus 100 forms a pattern in a shot area on the substrate by repeating the imprint cycle. Here, the imprint cycle is a cycle in which a pattern is formed in one shot region of the substrate by curing the imprint material R in a state where the mold M is pressed against the imprint material R.

  The curing unit 110 irradiates the imprint material R with light through the mold M to cure the imprint material R. In this embodiment, the imprint material R is an ultraviolet light curable resin. The curing unit 110 includes, for example, a light source 111, an optical system 112 including a lens, a setting unit 113, and a half mirror 114. The light source 111 can include, for example, a light source such as a halogen lamp that generates ultraviolet light (for example, i-line or g-line), and an elliptical mirror that collects light generated by the light source.

  The optical system 112 includes a lens for irradiating the imprint material in the pattern formation region (shot region) on the substrate W with light for curing the imprint material R. The setting unit 113 is used for angle of view control and outer periphery light shielding control, and is, for example, a DMD, an aperture, a variable field stop, or the like. Only the target shot area can be illuminated by the angle of view control, and the irradiation of the ultraviolet light beyond the shot area of the substrate W can be limited by the outer periphery light shielding control. The curing unit 110 can illuminate an arbitrary area on the substrate W by using the setting unit 113. The half mirror 114 changes the optical path of the light from the setting unit 113 in the direction toward the substrate W. The optical system 112 may include an optical integrator in order to uniformly illuminate the substrate W (type M). The light whose energy (light) irradiation area is defined by the setting unit 113 is incident on the imprint material R on the substrate W through the imaging system (not shown) and the mold M.

  The mold holding unit 120 includes, for example, a mold chuck 121 that holds the mold M, a drive unit 122 that moves the mold M by driving the mold chuck 121, and a base 123 that supports the drive unit 122. The mold M is held by the mold chuck 121 by, for example, a vacuum suction force or an electrostatic force. The drive unit 122 controls the position of the mold M with respect to the six axes, brings the mold M into contact with the imprint material R on the substrate W, or peels (releases) the mold M from the cured imprint material R. Or Here, the six axes are rotations around the X axis, Y axis, Z axis and their respective axes in the XYZ coordinate system.

  For example, the mold M has a rectangular outer peripheral portion, a predetermined uneven pattern is formed in a three-dimensional manner on the surface facing the substrate W, and is made of a material (such as quartz) that transmits ultraviolet rays. An alignment mark AMM is formed on the mold M. The mold M can be transported by a mold transport device (not shown). The mold transfer device includes, for example, a transfer robot having a chuck such as a vacuum chuck.

  For example, the mold deforming unit 130 is mounted on the mold chuck 121 and can deform the mold M by pressurizing the mold M from the outer peripheral direction using a cylinder (actuator) that is operated by a fluid such as air or oil. The mold deforming unit 130 may further include a temperature control unit that controls the temperature of the mold M, and the mold M may be deformed by controlling the temperature of the mold M. The substrate W can be deformed (typically expanded or contracted) through a process such as heat treatment. The mold deforming unit 130 corrects the shape of the mold M so that the positions of the substrate W and the mold M are matched in accordance with the deformation of the substrate W. The imprint apparatus 100 may further include a temperature control unit that controls the temperature of the substrate W, and the substrate W may be intentionally deformed by controlling the temperature of the substrate W.

  The dispenser 140 may include, for example, a tank 141 that stores an imprint material, and a nozzle 142 (discharge port) that discharges the imprint material supplied from the tank through a supply path to the substrate. Furthermore, the dispenser 140 can include a valve (not shown) provided in the supply path and a supply amount control unit (not shown). The dispenser 140 may apply (supply) the imprint material to a plurality of shot areas of the substrate W at once, or may apply the imprint material for each shot area. In addition, you may apply | coat collectively on the surface of the board | substrate W with an external apparatus (coating apparatus), without using the dispenser 140 comprised in the apparatus. The supply amount control unit controls the supply amount of the imprint material to the substrate W by controlling the valve.

  The substrate holding unit 150 may include a substrate chuck 151 that holds the substrate W, a substrate stage 152 that moves the substrate W by driving the substrate chuck 151, and a drive mechanism (not shown). The substrate chuck 151 holds the substrate W by a vacuum suction pad or the like, for example. The substrate stage 152 holds the substrate chuck 151 and is driven by a driving mechanism (not shown) to move the substrate W to six axes so that the substrate W and the mold M are aligned. The substrate W can be transferred by a substrate transfer device (not shown).

  FIG. 2 is a diagram illustrating an example of the substrate and the shot area according to the present embodiment. The substrate W is a substrate onto which the concavo-convex pattern is transferred by the mold M, and includes, for example, a single crystal silicon substrate or an SOI (Silicon on Insulator) substrate. A plurality of shot regions S are formed on the substrate W, and a plurality of alignment marks AMW are formed in each shot region S. In the present embodiment, it is assumed that at least one pattern is already formed on the substrate W.

  Returning to FIG. 1, the measurement unit 160 may include an alignment scope 161 and an alignment stage 162. The alignment scope 161 may include an automatic adjustment scope (AAS) that aligns the mold M and the shot area on the substrate W. The alignment scope 161 detects the alignment mark AMM formed on the mold M and the alignment mark AMW formed on the substrate W through the mold M.

  FIG. 3 is a diagram illustrating an example of alignment marks detected by the alignment scope 161 in the present embodiment. The alignment mark AMM on the mold M and the alignment mark AMW on the substrate W are formed so as not to overlap each other when alignment (alignment) described later is performed. The alignment scope 161 can measure the relative position between the alignment mark AMM and the alignment mark AMW of the substrate W through the alignment mark AMM of the mold M. In this embodiment, alignment is performed by a die-by-die method. The alignment stage 162 positions the alignment scope 161.

  The control unit 170 in FIG. 1 controls the operation of each component of the imprint apparatus 100, adjustment processing, and the like. The control unit 170 is configured by, for example, a computer having a storage unit such as a magnetic storage medium connected to each component of the imprint apparatus via a line, or a sequencer (not shown). The method according to the present embodiment can be executed by a computer as a program. The control unit 170 may be provided in the imprint apparatus 100, or may be installed in a place different from the imprint apparatus 100 and controlled remotely. In this figure, only the connection relationship between main components and the control unit 170 is shown.

  The scope 180 is an imaging unit that observes the entire shot area, and confirms the imprint state and the progress of filling of the mold and the imprint material R. Although not shown, the imprint apparatus 100 includes a surface plate for holding the mold holding unit 120 and a vibration isolator (damper). The surface plate supports the entire imprint apparatus 100 and forms a reference plane when the substrate stage 152 moves. The vibration isolator removes vibration from the floor and supports the surface plate.

  FIG. 4 is a flowchart showing the imprint method according to this embodiment. Each flow is executed mainly by control of each unit by the control unit 170.

  FIG. 4A is a flowchart of the entire imprint method according to this embodiment. In step S410, the mold M is carried into the mold chuck 121 and positioned by a mold conveyance device (not shown). The positioned mold M is held by the mold chuck 121. In step S420, the substrate W is carried into the substrate chuck 151 by a substrate transfer device (not shown). The substrate chuck 151 holds the loaded substrate W. In step S430, the imprint material R is applied to the entire surface of the substrate W by the dispenser 140. Note that, as described above, batch application may be performed by an external apparatus without using the dispenser 140 configured in the apparatus.

  In step S440, the alignment stage 162 moves the alignment scope 161 to the position of the alignment mark AMM on the mold M. The alignment stage 162 positions the alignment scope 161.

  In step S450, a partial region that is an end portion of the shot region S formed on the substrate W is exposed. FIG. 5 is a diagram for explaining exposure of a partial area. For example, when the mold M and the substrate W are brought into contact with each other, in order to prevent the imprint material R from spreading into an undesired region, before the mold M and the substrate W are brought into contact with each other, as shown in FIG. As described above, the uncured imprint material in the partial region 501 that is the end of the shot region S is irradiated with light in advance. However, even if the setting unit 113 sets the light irradiation region to the partial region 501 and tries to cure the uncured imprint material R on the partial region 501, due to the installation error of the mold M or the setting unit 113, etc. The imprint material in this area may not be cured. For example, the imprint material R in a region deviated from the partial region 501 such as a cured region 502 illustrated in FIG. 5B can be cured. In the present embodiment, the partial area 501 is an area along the outline of the shot area S.

  FIG. 4B is a flowchart showing a partial area exposure method. In the present embodiment, in step S450, the imprint material R in a part of the shot area and part of the partial area 501 is cured, and the positional difference from the alignment mark AM is measured. By correcting the setting by the setting unit 113 according to the measurement result, the light irradiation region is prevented from being shifted from the partial region 501. In the present embodiment, step S450 includes steps S451 to S456. The region 503 is a region along the outline of the partial region in the partial region 501 and is a planar region having a certain area.

  The shape of the region 503 is not limited as long as the positional difference between the cured imprint material R and the alignment mark AMW can be measured, and may be, for example, a planar shape, a linear shape, or a dot (dot shape). By reducing the area of the region 503, for example, it is possible to reduce irradiation of light outside the partial region 501 in the following step S452.

  In step S451, as shown in FIG. 5C, the setting unit 113 is set to a part of the shot area and a part of the area 503 in the partial area 501. In step S452, the curing unit 110 irradiates the region 503 with light. By setting the partial region 503 in the partial region 501 in step S451, the irradiation region in step S452 can be prevented from protruding from the partial region 501. Since the installation error of the mold M and the setting unit 113 in the conventional imprint apparatus is 10 μm or less, the width 504 of the region 503 is preferably 10 μm or less.

  In step S453, the imprint material R on the region 503 cured by light irradiation in step S452 is observed as a latent image pattern with the alignment scope 161, and the positional difference between the cured imprint material and the alignment mark AMW is measured. FIG. 5D illustrates an example of a cured imprint material 505. For example, as shown in FIG. 5D, the position difference is measured in each of two directions perpendicular to the side forming the shot area from the reference point 506 of the alignment mark AMW placed on the substrate W. In the present embodiment, the distances L1 and L2 between the reference point 506 and the cured imprint material 505 are positional differences. The cured imprint material can be visually observed. For example, when the alignment mark AMW is provided in the vicinity of the corner of the shot region on the substrate and other than the partial region 501 as in the present embodiment, the alignment mark AMW formed in the vicinity of two or more corners. The positional difference between and may be measured. If all the alignment marks AMW formed near each corner are used, the accuracy is further improved. It is also possible to use an alignment mark AMM provided on the mold M as a reference for the position difference. For example, an alignment mark AMM provided outside the region corresponding to the partial region 501 on the mold M.

  In step S454, it is determined whether or not the position difference measured in step S453 is equal to or smaller than a predetermined threshold value. The predetermined threshold is determined by the mold M, the installation error of the setting unit 113, and the like. When it is determined that the position difference is equal to or smaller than the threshold (YES), step S455 is performed. In Step S454, when it is determined that the position difference exceeds the threshold (NO), Step S451 is performed again. When performing the process S451 again, the setting unit 113 sets a new area different from the area set in the previous process S451 based on the position difference, and until the position difference becomes equal to or smaller than the threshold, the process S451 to the process S453. repeat. Thereby, for example, the accuracy of irradiating light to a desired partial region is improved. Even if the position difference measured in step S453 is not less than or equal to the threshold value, the irradiation area of the partial area may be set in step S455 based on the measured position difference.

  In step S455, the control unit 170 controls the setting unit 113 set in the area 503 to be set in the entire partial area 501. In step S456, the curing unit 110 irradiates the entire partial region with light. Above, process S450 is completed. Thereby, for example, the imprint material R in the partial region can be cured without deviating from the partial region 501, and the imprint material R can be prevented from spreading in the undesired region.

  In step S460, the control unit 170 controls the drive unit 122 to bring the mold M and the imprint material R into contact with each other. Note that the controller 170 may control a driving mechanism (not shown) to raise the substrate W and bring the mold M and the imprint material R into contact with each other. The contact load can be controlled using, for example, a load sensor built in the drive unit 122.

  In step S470, the pattern formed on the mold M is filled with the imprint material R, and alignment is performed according to a die-by-die alignment method. In the alignment, the alignment scope 161 detects the image of the alignment mark AMM of the mold M and the alignment mark AMW of the substrate W, and images it. An image processing apparatus (not shown) measures the relative positions of the alignment mark AMM and the alignment mark AMW from the captured image. The control unit 170 measures a shot shape difference (coordinates, rotation, magnification, amount of platform formation, etc.) between the mold M and the substrate W based on the result of the relative position measurement of the alignment mark AM, and the mold M and the substrate W. And align. In step S480, control unit 170 determines whether filling is completed. If it is determined that the filling is not completed (NO), step S470 is repeated until the filling is completed. If it is determined that the process has been completed (YES), step S490 is performed.

  In step S490, the control unit 170 controls the curing unit 110 to irradiate the imprint material R with ultraviolet rays through the mold M and cure it. In step S491, the mold holding unit 120 or the substrate holding unit 150 is controlled to peel the mold M from the cured imprint material R. In step S492, the control unit 170 determines whether imprint processing has been completed for all shot regions on the substrate W. If not completed (NO), step S440 to step S492 are repeated. When completed (YES), in step S493, the control unit 170 controls the transfer device (not shown) to carry out the substrate W.

  In the present embodiment, the setting unit 113 is described as being able to use a DMD, an aperture, a variable field stop, or the like. However, the partial area may be irradiated with light so as to be painted using a scanable laser or the like. Even in such a case, a desired region can be cured by irradiating a part of the partial region with light with a scan laser, measuring the cured imprint material, and correcting the scanning location.

  Moreover, although the alignment using the measurement part 160 was described, you may align using the scope 180. FIG. Since the scope 180 can observe all the alignment marks in the shot, it does not need to be driven.

  In the present embodiment, as an example, a method of applying the imprint material R to a plurality of shot regions of the substrate W at once is used. However, a method of applying the imprint material R to each shot region may be used. . In this case, if it is determined in step S492 that the imprint process has not been completed for all shot regions on the substrate W (NO), steps S430 to S492 are repeated.

(Second Embodiment)
FIG. 6 is a flowchart showing an imprint method according to the second embodiment. Steps and configurations similar to those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, alignment is performed before the partial area exposure (step S450). In step S440, when positioning of the alignment scope 161 is completed, step S601 is performed.

  In step S601, alignment is performed according to a die-by-die alignment method. In the alignment, the relative positions of the alignment mark AMM and the alignment mark AMW are measured in the same manner as the measurement of the relative position in S470. In step S602, the mold M and the substrate W are aligned as in the alignment in step S470. Here, if necessary, the mold deforming unit 130 deforms and corrects the shape of the mold M in order to match the shape of the shot region S of the substrate W.

  In the shape correction of the mold M in step S602, a correction error may occur due to a driving error of the mold deforming unit 130 or the like. Therefore, in step S603, tolerance determination of the shape difference between the mold M and the shape of the shot region S of the substrate W is performed. When it is determined that the shape difference exceeds the predetermined tolerance (NO), control unit 170 repeats steps S601 to S602. When it is determined that the shape difference is equal to or less than the tolerance (YES), the control unit 170 performs step S4050.

  According to the present embodiment, for example, the alignment accuracy between the mold M and the substrate W is further improved. In step S453, the alignment mark AM that has already been aligned can be used.

(Product manufacturing method)
A method for manufacturing a device (semiconductor integrated circuit element, liquid crystal display element, etc.) as an article includes a step of forming a pattern on a substrate (wafer, glass plate, film-like substrate) by an imprint apparatus using the method described above. . Furthermore, the manufacturing method may include a step of etching the substrate on which the pattern is formed. When manufacturing other articles such as patterned media (recording media) and optical elements, the manufacturing method may include other processes for processing a substrate on which a pattern is formed instead of etching. The method for manufacturing an article according to 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.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 100 Imprint apparatus 110 Curing part 120 Type | mold holding part 130 Type | mold deformation | transformation part 140 Dispenser 150 Substrate holding part 160 Measuring part 170 Control part M type W board | substrate

Claims (11)

An imprint material cured on the substrate by applying an uncured imprint material on the substrate and curing the uncured imprint material in a state where the uncured imprint material and the mold are in contact with each other. An imprint method for forming a pattern of
After applying the uncured imprint material to the shot region formed on the substrate, and before performing the contact, a region for curing the uncured imprint material in a part of the shot region Set,
Measure the position of the cured imprint material in the set area and the position of the mark provided on the substrate or the mold,
Based on the position of the cured imprint material and the position of the mark, setting an irradiation region to cure the uncured imprint material of the partial region including the part of the shot region,
An imprint method characterized by the above.   2. The input according to claim 1, wherein the mark provided on the substrate is provided outside the partial region, and the mark provided on the mold is provided outside the region corresponding to the partial region. How to print.   3. The measurement according to claim 1, wherein the measurement is performed with respect to a plurality of positions of the cured imprint material and positions of a plurality of marks provided on the substrate or the mold. Imprint method.   Based on the result of the measurement, to determine the difference between the position of the cured imprint material and the position of the mark provided on the substrate or the mold, when it is determined that the difference exceeds a predetermined threshold, The imprint method according to any one of claims 1 to 3, wherein the setting and the measurement are performed for an area different from the part of the shot area.   The imprint method according to claim 1, wherein the partial area is an area along an outline of the shot area.   The imprint method according to claim 5, wherein the part is an area included in the partial area and along an outline of the partial area.   The imprint method according to claim 6, wherein a part of the shot area is planar, linear, or dotted.   The imprint according to any one of claims 1 to 7, wherein the substrate and the mold are aligned before the part of the uncured imprint material is cured. How to print.   A program for causing a computer to execute the method according to any one of claims 1 to 8. An imprint material cured on the substrate by applying an uncured imprint material on the substrate and curing the uncured imprint material in a state where the uncured imprint material and the mold are in contact with each other. An imprint apparatus for forming a pattern of
A curing portion for curing the uncured imprint material;
A setting unit for setting a region for curing the uncured imprint material by the curing unit;
A measurement unit for measuring the position of the mark provided on the substrate or the mold and the position of the cured imprint material,
The setting unit is configured to apply the uncured imprint material to the shot area formed on the substrate, and before performing the contact, the uncured imprint material in a part of the shot area. Set the area to cure,
The measurement unit measures the position of the imprint material and the position of the mark that the curing unit is cured by the setting,
The setting unit sets a region for curing the uncured imprint material of the partial region including the part of the shot region based on the measurement result.
An imprint apparatus characterized by that. Forming a pattern on a substrate using the imprint method according to any one of claims 1 to 8,
Processing the substrate on which the pattern has been formed in the step;
A method for producing an article comprising:

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