WO2017094225A1

WO2017094225A1 - Imprinting apparatus, measurement method, imprinting method, and article manufacturing method

Info

Publication number: WO2017094225A1
Application number: PCT/JP2016/004857
Authority: WO
Inventors: Hisashi Namba; Ken Katsuta
Original assignee: Canon Kabushiki Kaisha
Priority date: 2015-11-30
Filing date: 2016-11-10
Publication date: 2017-06-08
Also published as: TWI631599B; KR20180087382A; TW201720626A; KR102078954B1

Abstract

An embodiment of the present invention relates to an imprinting apparatus (100) that forms a pattern made of an imprint material (102) on a substrate (101) by bringing a mold (103) and the imprint material (102) into contact with each other and curing the imprint material (102). The imprinting apparatus (100) includes a moving unit (111) that moves the substrate (101), an ejecting unit (115) that ejects the imprint material (102), an acquiring unit (121) that acquires a landing position of the imprint material (102) ejected while the substrate (101) is moved in a predetermined direction by the moving unit (111), and a determining unit (122) that calculates a distance in a predetermined direction between a reference position and the landing position and determines a speed of ejection on the basis of the distance and information on a speed at which the substrate (101) is moved.

Description

IMPRINTING APPARATUS, MEASUREMENT METHOD, IMPRINTING METHOD, AND ARTICLE MANUFACTURING METHOD

The present invention relates to an imprinting apparatus, a measurement method, an imprinting method, and an article manufacturing method.

Known examples of an apparatus that forms a fine pattern on a substrate for the purpose of manufacturing a semiconductor device or the like include imprinting apparatuses that form patterns made of curable materials. In such an imprinting apparatus, an imprint material ejected from an ejecting unit toward a substrate and a mold having a relief pattern are brought into contact with each other, and curing energy is applied to the imprint material, whereby the relief pattern of the mold is transferred to the imprint material.

The ejecting unit that ejects the imprint material includes a plurality of nozzles each having an ejection port. The nozzles eject the imprint material with the aid of ejecting mechanisms such as piezoelectric devices. In general, an imprint material for forming a pattern is ejected toward a substrate that is being moved. Therefore, the ejecting unit ejects the imprint material before target positions reach positions exactly below the respective ejection ports. The timing of ejection of the imprint material is set on the basis of the length of time that the ejected imprint material remains in the air before landing on the substrate (the length of time is hereinafter referred to as "hang time").

PTL 1 relates to a method of correcting the offset in the landing position of an imprint material that is attributed to assembly tolerances of an ejecting unit. In other words, PTL 1 relates to a method of correcting the offset in the landing position of an imprint material attributed to errors in the arrangement of all of a plurality of nozzles. According to PTL 1, arrangement errors are measured as follows. An imprint material is ejected toward a substrate, and the offset between the actual landing position of the imprint material and the target landing position is calculated.

To measure arrangement errors as disclosed by PTL 1, the imprint material needs to be ejected toward a substrate that is stationary.

Japanese Patent Laid-Open No. 2011-222705

In view of the above, the present invention provides an imprinting apparatus, a measurement method, and an imprinting method in each of which one of ejection characteristics is measurable independently of the other ejection characteristics.

According to an aspect of the present invention, there is provided an imprinting apparatus that forms a pattern made of an imprint material on a substrate by bringing a mold and the imprint material into contact with each other and curing the imprint material. The imprinting apparatus includes a moving unit configured to move the substrate, an ejecting unit configured to eject the imprint material, an acquiring unit configured to acquire a landing position of the imprint material ejected toward the substrate from the ejecting unit while the substrate is being moved in a predetermined direction by the moving unit, a calculating unit configured to calculate a distance in the predetermined direction between a reference position and the landing position acquired by the acquiring unit, and a determining unit configured to determine a speed of ejection from the ejecting unit on the basis of the distance calculated by the calculating unit and on the basis of information on a speed at which the substrate is moved.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Fig. 1 illustrates an imprinting apparatus according to any of first to third embodiments. Fig. 2A is a diagram for describing the offset in the landing position of an imprint material. Fig. 2B is another diagram for describing the offset in the landing position of the imprint material. Fig. 3A is a diagram for describing a method of measuring the speed of ejection of the imprint material according to the first embodiment. Fig. 3B is another diagram for describing the method of measuring the speed of ejection of the imprint material according to the first embodiment. Fig. 4 is a flow chart illustrating the method according to the first embodiment. Fig. 5 is a diagram for describing a method of measuring the speed of ejection of the imprint material according to the second embodiment. Fig. 6 is a flow chart illustrating the method according to the second embodiment. Fig. 7 is a diagram for describing a method of measuring the angle of ejection of the imprint material according to a third embodiment. Fig. 8 is a diagram for describing the landing position of the imprint material that is measured in the method according to the third embodiment. Fig. 9 is a flow chart illustrating the method according to the third embodiment. Fig. 10A is a diagram for describing a method of measuring the angle of ejection of the imprint material according to a fourth embodiment. Fig. 10B is another diagram for describing the method of measuring the angle of ejection of the imprint material according to the fourth embodiment. Fig. 11 is a flow chart illustrating the method according to the fourth embodiment. Fig. 12A is a diagram for describing a method of measuring the angle of ejection of the imprint material according to a fifth embodiment. Fig. 12B is another diagram for describing the method of measuring the angle of ejection of the imprint material according to the fifth embodiment. Fig. 13 is a flow chart illustrating the method according to the fifth embodiment. Fig. 14A is a diagram for describing a method of measuring the speed of ejection of the imprint material according to a sixth embodiment. Fig. 14B is another diagram for describing the method of measuring the speed of ejection of the imprint material according to the sixth embodiment. Fig. 15 is a flow chart illustrating the method according to the sixth embodiment. Fig. 16A is a diagram for describing a method of measuring the speed of ejection of the imprint material according to a seventh embodiment. Fig. 16B is another diagram for describing the method of measuring the speed of ejection of the imprint material according to the seventh embodiment. Fig. 17 is a flow chart illustrating the method according to the seventh embodiment. Fig. 18 is a flow chart illustrating an imprinting method according to an eighth embodiment.

First Embodiment

Apparatus Configuration

Fig. 1 illustrates an imprinting apparatus 100 according to any of first to third embodiments. In Fig. 1, the vertical direction is represented by the Z axis, and two axes that are orthogonal to each other in a plane perpendicular to the Z axis are represented by the X axis and the Y axis, respectively. The imprinting apparatus 100 forms a pattern on a substrate 101 by using a mold 103. The pattern is formed by bringing the mold 103 into contact with a photo-curable imprint material 102 supplied onto the substrate 101 and curing the imprint material 102 with the mold 103 kept in contact therewith.

An applying unit 104 applies, to the substrate 101, ultraviolet light 105 for curing the imprint material 102 that is yet to be cured. The applying unit 104 includes a light source 106 that emits the ultraviolet light 105, and a mirror 107 that redirects the optical path of the ultraviolet light 105 toward the substrate 101.

The mold 103 has a rectangular contour and includes, at the center thereof, a rectangular pattern portion 103a having a relief pattern. The substrate 101 has a plurality of pattern areas 120 defined thereon. The pattern areas 120 each have substantially the same size as the pattern portion 103a. With a single motion of pressing the mold 103 into the imprint material 102 (the motion is hereinafter referred to as "mold-pressing motion"), the pattern of the pattern portion 103a is transferred to one of the pattern areas 120. The material forming the mold 103 is quartz or the like that transmits the ultraviolet light 105.

A chuck 108 holds the mold 103 by using a vacuum force or an electrostatic force. A driving mechanism 109 moves the mold 103 together with the chuck 108 in the Z direction. An open area 110 passes through the centers of the chuck 108 and the driving mechanism 109 so that the ultraviolet light 105 can reach the substrate 101. To make the mold-pressing motion or a motion for releasing the mold 103 from the imprint material 102 (the motion is hereinafter referred to as "mold-releasing motion"), the mold 103 is moved.

A substrate stage (moving unit) 111 includes a chuck 112a, a driving mechanism 112b, and a reference mark 112c and positions the substrate 101 in accordance with an instruction given by a control unit 122 to be described below. The chuck 112a holds the substrate 101 by using a vacuum force or an electrostatic force. The driving mechanism 112b moves the substrate 101 along an X-Y plane with the substrate 101 held by the chuck 112a. The reference mark 112c is used in measuring the position of the substrate 101 and is provided on the driving mechanism 112b.

The driving mechanism 109 and the driving mechanism 112b may each include a plurality of driving systems such as a coarse driving system and a fine driving system. The driving mechanism 109 may be capable of moving the mold 103 not only in the Z direction but also in the X direction, in the Y direction, and in the directions around the respective axes. The driving mechanism 112b may be capable of moving the substrate 101 not only in the X direction and in the Y direction but also in the directions of any other axes and in the directions around the respective axes.

The mold-pressing motion and the mold-releasing motion involving the mold 103 and the imprint material 102 can be made by moving at least one of the mold 103 and the substrate 101 in the Z direction.

A transmissive member 113 is provided above the mold 103, whereby a space 114 in which the pressure is adjustable is provided in the open area 110. When the pattern portion 103a is brought into contact with the imprint material 102, the pattern portion 103a is bent in such a manner as to be convex downward. Thus, entry of air between the mold 103 and the imprint material 102 is prevented, and the imprint material 102 is spread all over the pattern portion 103a.

An ejecting unit 115 ejects the imprint material 102 that is yet to be cured from a plurality of nozzles 116 (illustrated in Figs. 2A and 2B) aligned in the Y direction. The imprint material 102 is pushed out of the nozzles 116 with a piezoelectric effect produced by piezoelectric devices. The waveform of a voltage applied to each of the piezoelectric devices (the waveform is hereinafter referred to as "driving waveform") and the timing of voltage application conforming to the driving waveform are instructed by the control unit 122 to be described below.

In accordance with the instruction made by the control unit 122, ejection conditions such as the timing of ejection, the speed of ejection, and the amount of ejection of the imprint material 102 are adjusted.

A measurement unit 117 measures the relative positional difference between a mark 118 provided on the pattern portion 103a and a mark 119 provided in each of the pattern areas 120.

The imprinting apparatus 100 includes an image taking portion (image taking unit) 121 and the control unit 122 to be described below. The image taking portion 121 and the control unit 122 together serve as an acquiring unit that acquires the landing position of the imprint material 102 ejected by the ejecting unit 115 and landed on the substrate 101.

The image taking portion 121 emits light that is transmissive with respect to the mold 103 toward the substrate 101, and receives, with an image taking device such as a charge-coupled device (CCD), the light reflected by the substrate 101, thereby taking an image of the substrate 101. The image thus taken may be used for, for example, checking the state of contact between the mold 103 and the imprint material 102, the entry of any particles between the pattern portion 103a and the substrate 101, or the state of the imprint material 102 spread over the pattern portion 103a. The image taking portion 121 also takes an image of the imprint material 102 landed on the substrate 101 before imprinting is performed thereon. That is, the image taking portion 121 acquires an image indicating the landing position of the imprint material 102.

The control unit (serving as a calculating unit, a determining unit, and a correcting unit) 122 includes a central processing unit (CPU), a random access memory (RAM), and a read-only memory (ROM) and is connected to the applying unit 104, the driving mechanism 109, the substrate stage 111, the ejecting unit 115, the measurement unit 117, the image taking portion 121, and a storage unit 123 with communication lines. The control unit 122 generally controls the foregoing elements and thus executes the measurement of the speed of ejection in accordance with a program illustrated as a flow chart in Fig. 4 (to be described below) and also executes an imprinting process in accordance with a program illustrated as a flow chart in Fig. 18 (to be described below).

The control unit 122 has a function as a calculating unit (a second calculating unit) that calculates the landing position of the imprint material 102 by processing the image taken by the image taking portion 121. The control unit 122 also has a function as another calculating unit (a first calculating unit) that calculates the distance in a predetermined direction between a reference position and the calculated landing position. The control unit 122 also has a function as a determining unit that determines the speed of ejection on the basis of the calculated distance. Furthermore, the control unit 122 corrects an ejection condition of the ejecting unit 115 on the basis of the determined speed of ejection. That is, the control unit 122 also has a function as a correcting unit that corrects the landing position of the imprint material 102 by correcting the ejection condition.

The storage unit 123 includes a hard disk (a storage medium) that is readable by the control unit 122, and other associated elements. The storage unit 123 stores the programs illustrated as flow charts in Figs. 4 and 18 (to be described below), the distance between the substrate 101 and the ejecting unit 115 that is used in the measurement, the arrangement of the nozzles 116, and other associated pieces of information.

A base block 124 carries the substrate stage 111. A bridge block 125 that supports the driving mechanism 109 hung therefrom is supported by a post 126 provided on the base block 124.

Offset in Landing Position

Figs. 2A and 2B are diagrams for describing the offset in the landing position of the imprint material 102. The landing position refers to the position where the imprint material 102 ejected toward the substrate 101 lands on the substrate 101. The upper part of each of Figs. 2A and 2B illustrates the ejecting unit 115 seen from the -Z side thereof and illustrates some

nozzles

116a, 116b, and 116c among the plurality of nozzles 116. The lower part of each of Figs. 2A and 2B illustrates an image taken by the image taking portion 121 that illustrates the landing positions of droplets of the imprint material 102 on the substrate 101.

In the imprinting process, while the substrate stage 111 is moving at a seed Vs in the -X direction, the imprint material 102 is ejected from the ejecting unit 115. The ejecting unit 115 is fixed.

A broken line 201a extending in the X direction represents the virtual locus of movement of the nozzle 116a that is projected onto the substrate 101. Likewise,

broken lines

201b and 201c represent the respective virtual loci of movement of the

nozzles

116b and 116c that are projected onto the substrate 101. The intersections between the broken line 201a and each of broken lines 201_1, 201_2, ..., and 201_N extending in the Y direction represent the ideal landing positions of droplets of the imprint material 102 that are ejected in the first to N-th order from the nozzle 116a.

Fig. 2A illustrates the ideal arrangement of droplets of the imprint material 102 with no offsets in the landing positions thereof because there are no errors in the angle of ejection and in the speed of ejection. Fig. 2B illustrates an arrangement of droplets of the imprint material 102 with offsets in some landing positions because there are some errors, from respective predetermined values, in at least one of the angle of ejection and the speed of ejection from the

nozzles

116b and 116c.

In each of the first embodiment and other embodiments to be described below, the angle of ejection refers to the angle formed between the vertical direction and the direction of ejection of the imprint material 102. In each of the first embodiment and other embodiments to be described below, the speed of ejection corresponds to a value obtained by dividing the integral of the speed at which the droplet of the imprint material 102 moves in the air by a hang time Δt. This calculation is based on an assumption that the difference between the initial speed of the droplet of the imprint material 102 imparted by the ejecting unit 115 and the speed of the droplet immediately before the droplet lands on the substrate 101 after being decelerated with air resistance is corrected, and that the speed at which the droplet of the imprint material 102 falls is uniform.

Method of Measuring Speed of Ejection

In the first embodiment, the speed of ejection is measured as an ejection characteristic of the ejecting unit 115. In the first embodiment, the landing position of each droplet of the imprint material 102 ejected toward the substrate 101 that is stationary is defined as the reference position.

Figs. 3A and 3B are diagrams for describing a method of measuring the speed of ejection according to the first embodiment. Fig. 4 is a flow chart illustrating the method. The method according to the first embodiment will now be described with reference to Figs. 3A and 3B and Fig. 4. In the first embodiment, the distance in the X direction (a predetermined direction) between the landing position of a droplet of the imprint material 102 ejected toward the substrate 101 that is stationary and the landing position of a droplet of the imprint material 102 ejected toward the substrate 101 that is moving at a uniform speed in the X direction is calculated. The speed of ejection from the ejecting unit 115 is measured on the basis of the distance calculated by the control unit 122.

For convenience in description, defining the angle of ejection of the imprint material 102 from the ejecting unit 115 with respect to the vertical direction as 0 degrees and supposing that the ejecting unit 115 has only one nozzle 116, a method of measuring the speed of ejection will now be described.

In step S101, the substrate stage 111 sets the substrate 101 stationary at a position facing the ejecting unit 115. In step S102, the control unit 122 acquires a position 301 of the substrate 101 that faces the ejecting unit 115. The position 301 thus acquired is stored as the reference position in the storage unit 123.

The position facing the ejecting unit 115 is, in other words, the position facing the ejection port of the nozzle 116 for which the speed of ejection is to be measured. The position 301 is represented by the position in the X direction, the position in the Y direction, and the position in the Z direction.

In step S103, with the substrate stage 111 kept stationary, the ejecting unit 115 ejects the imprint material 102. The imprint material 102 ejected in step S103 and landed on the substrate 101 is referred to as a mark 302. That is, the mark 302 is a droplet of the imprint material 102. Since the angle of ejection is 0 degrees, the mark 302 is formed at the position 301. Step S102 and step S103 may be performed in the reverse order or simultaneously.

Subsequently, in step S104, the substrate stage 111 moves the substrate 101 to a position on the +X side with respect to the ejecting unit 115 and then moves the substrate 101 in the -X direction at a uniform speed (information on the speed of the substrate) Vs such that the position 301 passes through the position facing the ejecting unit 115.

In step S105, when the position 301 reaches the position facing the ejecting unit 115 as illustrated in Fig. 3A, the ejecting unit 115 ejects the imprint material 102. As illustrated in Fig. 3B, the imprint material 102 ejected in step S105 and landed on the substrate 101 is referred to as a mark 303. That is, the mark 303 is a droplet of the imprint material 102. Before the mark 303 is formed, the substrate stage 111 keeps moving the substrate 101 at the uniform speed Vs.

The image taking portion 121 takes an image of the mark 302 and the mark 303 landed on the substrate 101 and transmits the image to the control unit 122.

In step S106, the control unit 122 processes the image and acquires the position (landing position) 304 of the mark 303. The positions of the

marks

302 and 303 may be defined as, for example, the respective centers of the

marks

302 and 303. In each of the first embodiment and other embodiments to be described below, the landing position calculated by the control unit 122 is represented by at least the position in the X direction and may be represented by the position in the X direction and the position in the Y direction.

In step S107, the control unit 122 calculates a distance d between the position 301 acquired in step S102 and the position 304. The distance d calculated in step S107 is the distance in the direction in which the substrate 101 is moved in step S104.

Lastly, in step S108, the control unit 122 calculates the speed of ejection of the imprint material 102 on the basis of the distance d calculated in step S107, the speed Vs, and a distance L between the ejecting unit 115 and the substrate 101. The distance L is calculated from the position in the Z direction acquired in step S102.

How to calculate the speed of ejection will now be described. Letting the speed of ejection be Vr and the time elapsed from when the imprint material 102 is ejected until the imprint material 102 lands on the substrate 101 be t, the following holds:
t = L/Vr ... Equation (1)

The distance d between the position 301 and the position 304 is the length by which the substrate stage 111 moves during a period from when the imprint material 102 is ejected until the imprint material 102 lands on the substrate 101. Hence, the following holds:
d = Vs×t ... Equation (2)

The control unit 122 can calculate the speed of ejection Vr in accordance with Equation (3) given below. Equation (3) is obtained by solving Equations (1) and (2) for the speed of ejection Vr.
Vr = (Vs×L)/d ... Equation (3)

This is the end of the description of the method of measuring the speed of ejection illustrated as the flow chart in Fig. 4.

The speed of ejection from the ejecting unit 115 can be measured on the basis of the distance d between the position 301 as the reference and the position 304 of the mark 303 formed on the substrate 101 while the substrate stage 111 is moving the substrate 101 and on the basis of the information on the speed of the substrate 101. In the first embodiment, the information on the speed of the substrate 101 corresponds to the speed Vs of the substrate stage 111.

The mark 303 is formed while the substrate stage 111 is undergoing a uniform motion in which the variation in the driving operation is small. Therefore, the length by which the substrate 101 is moved during a period from when the imprint material 102 for forming the mark 303 is ejected until the imprint material 102 lands on the substrate 101 can be calculated accurately. Accordingly, in the imprinting apparatus 100, the speed of ejection Vr can be calculated accurately.

Since the state of the imprint material 102 falling from the ejecting unit 115 is observable sideways, the speed of ejection is measurable without providing a device dedicated to the observation of the speed of ejection. Therefore, the increase in the installation area that may be caused by providing such a dedicated device can be suppressed.

Furthermore, since the speed of ejection is measurable in one imprinting apparatus 100, the maintenance work for the ejecting unit 115 can be made less troublesome than in a case where the ejecting unit 115 needs to be taken out of the imprinting apparatus 100 for the measurement.

Even if the angle of ejection is not 0 degrees, the speed of ejection from the ejecting unit 115 is measurable according to the first embodiment. If the imprint material 102 is ejected obliquely at a certain angle of ejection in step S103, the mark 302 is formed at a position that is offset from the position 301 by a length corresponding to that angle. The mark 303 is also formed at a position that is offset by the same length corresponding to that angle. Hence, if the angle of ejection is unknown, the distance between the position where the mark 302 is actually formed and the position 304 where the mark 303 is formed only needs to be substituted for the distance d in Equation (3) in step S107.

Thus, according to the first embodiment, the speed of ejection can be measured regardless of the offset in the landing position that is attributed to an error in the angle of ejection. In other words, the speed of ejection as one of ejection characteristics can be measured independently of the other ejection characteristics.

Method of Correcting Offset in Landing Position 1

In the step of ejecting the imprint material 102 included in the imprinting process, if the speed of ejection changes from an ideal speed V0 to another speed V, the hang time of the imprint material 102 changes. Accordingly, the landing position is offset from the ideal position. Such an offset in the landing position can be corrected by correcting the timing of ejection of the imprint material 102 from the ejecting unit 115.

If the imprint material 102 is ejected from the ejecting unit 115 that is at the distance L from the substrate 101, a hang time Δt0 at the speed V0 equals L/V0, and a hang time Δt at the speed V equals L/V. Hence, if the speed V is lower than the speed V0, the timing of ejection is advanced by |Δt-Δt0| = L×(V-V0)/(V×V0). If the speed V is higher than the speed V0, the timing of ejection is delayed by L×(V-V0)/(V×V0).

Alternatively, instead of correcting the timing of ejection, the control unit 122 may change the driving waveform such that the speed of ejection from the nozzle 116 becomes close to the speed V0. In either case, different timings of ejection or different driving waveforms may be set for different nozzles 116. Both the timing of ejection and the driving waveform may be changed, as long as the landing position becomes close to the ideal landing position.

Thus, the control unit 122 can correct the offset in the landing position that is attributed to an error in the speed of ejection. Hence, the imprint material 102 can be made to land on the ideal position.

If there is a chance that the angle of ejection may change with aging of the ejecting unit 115 or any other like factor, the angle of ejection may also be measured in advance. If the offset in the landing position that is attributed to an error in the speed of ejection and the offset in the landing position that is attributed to an error in the angle of ejection are corrected simultaneously, the imprint material 102 can be made to land on a position much closer to the ideal position.

Second Embodiment

In a second embodiment, the speed of ejection is measured as an ejection characteristic of the ejecting unit 115, as in the first embodiment.

Fig. 5 is a diagram for describing a method of measuring the speed of ejection according to the second embodiment. Fig. 6 is a flow chart illustrating the method. Now, the second embodiment will be described with reference to Figs. 5 and 6.

The second embodiment relates to a method of measuring the speed of ejection on the basis of the position of a mark originally formed on the substrate 101 so as to indicate the reference position, and on the basis of the position of the imprint material 102 landed on the substrate 101 that is moving at a uniform speed.

The imprinting apparatus 100 according to the second embodiment differs from the imprinting apparatus 100 according to the first embodiment in that a program illustrated as the flow chart in Fig. 6 is stored in the storage unit 123 and in that the control unit 122 reads the program and thus executes the measurement of the speed of ejection.

The second embodiment also differs from the first embodiment in that the substrate 101 originally has a mark 401 indicating a known position serving as the reference position and is dedicated to the measurement of the speed of ejection. The mark 401 may be in any form, as long as the position thereof is detectable. For example, the mark 401 may have a three-dimensional shape or may be a concavity provided by engraving the substrate 101. Moreover, the mark 401 may be shared with another measurement.

In step S201, the position of the mark 401 is acquired from the position of the substrate stage 111 and a relative position of the mark 401 with respect to the substrate 101. The position of the mark 401 may be acquired through a measurement or may be the design value obtained in advance from the position of the mark 401 relative to the substrate 101 and the position of the substrate 101 relative to the substrate stage 111. The position of the mark 401 is represented by the position in the X direction, the position in the Y direction, and the position in the Z direction.

Subsequently, in step S202, the substrate stage 111 moves the substrate 101 such that the mark 401 is moved away from the ejecting unit 115 to a position on the +X side with respect to the ejecting unit 115.

Then, in step S203, the substrate stage 111 moves the substrate 101 in the -X direction at a uniform speed Vs. While the substrate 101 is moving at the uniform speed Vs, the mark 401 is made to pass through a position facing the ejecting unit 115.

In step S204, when the mark 401 reaches the position facing the ejecting unit 115, the ejecting unit 115 ejects the imprint material 102. As illustrated in Fig. 5, the imprint material 102 ejected in step S204 and landed on the substrate 101 is referred to as a mark 402. Before the mark 402 is formed, the substrate stage 111 keeps moving the substrate 101 at the uniform speed Vs.

The image taking portion 121 takes an image of the mark 401 and the mark 402 landed on the substrate 101 and transmits the image to the control unit 122. In step S205, the control unit 122 processes the image and thus acquires the position of the mark 401 and the position of the mark 402 (the landing position). Then, in step S206, the control unit 122 calculates a distance d between the mark 401 and the mark 402. The distance d calculated in step S206 is the distance in the direction in which the substrate 101 is moved in step S203.

Lastly, in step S207, the control unit 122 calculates the speed of ejection of the imprint material 102 on the basis of the distance d calculated in step S206, the speed Vs, and the distance L between the ejecting unit 115 and the substrate 101 that is calculated from the position of the mark 401 in the Z direction. The speed of ejection is calculated in the same manner as in the first embodiment.

This is the end of the description of the flow chart in Fig. 6.

The speed of ejection can be determined on the basis of the distance d in the X direction between the mark 402 formed on the substrate 101 while the substrate stage 111 is moving the substrate 101 in the X direction and the mark 401, and on the basis of the information on the speed of the substrate 101. In the second embodiment, the information on the speed of the substrate corresponds to the speed Vs of the substrate stage 111.

In the second embodiment, as in the first embodiment, the speed of ejection as one of ejection characteristics can be measured independently of the other ejection characteristics.

The imprint material 102 is ejected while the substrate stage 111 is undergoing a uniform motion in which the variation in the driving operation is small. Therefore, the length by which the substrate 101 is moved during a period from when the imprint material 102 for forming the mark 402 is ejected until the ejected imprint material 102 lands on the substrate 101 can be calculated accurately. Accordingly, in the imprinting apparatus 100, the speed of ejection Vr can be calculated accurately.

Since step S103 according to the first embodiment in which the substrate 101 is temporarily stopped to form the mark 302 is omitted, the time required for the measurement is shorter than in the first embodiment.

The reference position according to the second embodiment may not necessarily be visible and may be set to a predetermined position on the substrate 101, as long as the control unit 122 knows that position. That is, any position on the substrate 101 that is represented by (X, Y) coordinates may be defined as the reference position. The reference position may not necessarily be located on the substrate 101 and only needs to be located on a part that moves along with the substrate 101 in step S203. For example, the reference position may be defined on a part of the substrate stage 111 where the substrate 101 is not present.

In each of the first and second embodiments, if the ejecting unit 115 has a plurality of nozzles 116, the above process may be repeated so that the speed of ejection can also be calculated for each of the other nozzles 116. Alternatively, the imprint material 102 may be ejected from the plurality of nozzles 116 simultaneously, and the speeds of ejection for the respective nozzles 116 may be determined at a time. If there is a chance that the droplets of the imprint material 102 ejected from adjacent ones of the nozzles 116 may overlap each other on the substrate 101, the nozzles 116 that are used simultaneously for the ejection of the imprint material 102 may be selected at intervals of a predetermined number of nozzles 116.

In step S107 according to the first embodiment, the distance between the

marks

302 and 303 that are formed of the imprint material 102 ejected from one specific nozzle 116 is calculated. In the second embodiment, the substrate 101 may have a plurality of marks 401 provided in correspondence with a plurality of nozzles 116, so that the speeds of ejection for the plurality of nozzles 116 can be measured in a short time.

In step S105 or step S204, the imprint material 102 may be ejected when the ejecting unit 115 faces a position that is offset from the position 301 or the position of the mark 401 by a known length.

In step S107 according to the first embodiment, the control unit 122 may calculate the distance in the X direction between a position that is offset from the position 301 by a predetermined length and the position 304. In step S206 according to the second embodiment, the control unit 122 may calculate the distance between a position that is offset from the position of the mark 401 by a predetermined length and the position of the mark 402.

Thus, overlapping between the mark 302 and the mark 303 or between the mark 401 and the mark 402 can be prevented even if each droplet of the imprint material 102 landed on the substrate 101 tends to spread widely over the substrate 101.

In each of the first and second embodiments, the speed of the substrate stage 111 when the

mark

303 or 402 is formed may not necessarily be uniform. That is, the substrate stage 111 may be accelerated. For example, in the first embodiment, the speed of ejection may be calculated from the distance between the ideal position 301 where the ejected imprint material 102 ideally lands on the substrate 101 and the position 304 and from the distance between the mark 302 that is actually formed and whose position varies with the speed of ejection and the position 304.

The reference position only needs to be located on the substrate 101 or on a part that moves along with the substrate 101. For example, the reference position may be set to the position of the reference mark 112c or the like.

The positions of the mark 302 and the mark 303 in the Y direction or the positions of the mark 401 and the mark 402 in the Y direction may be staggered with respect to each other. Staggering the marks with respect to each other in the Y direction can suppress the reduction in the accuracy of measurement of the center position that may be caused by overlapping between the marks. In that case, however, the distance between the mark 302 and the mark 303 in the first embodiment or the distance between the mark 401 and the mark 402 in the second embodiment is defined as the distance in the direction in which the substrate 101 is moved (the predetermined direction), that is, the distance between the marks in the X direction in each of the first and second embodiments.

Method of Correcting Offset in Landing Position 2

A method of correcting the offset in the landing position that is attributed to an error in the speed of ejection according to the second embodiment is the same as that of the first embodiment, and description thereof is omitted. The control unit 122 can correct the offset in the landing position that is attributed to an error in the speed of ejection. Hence, the imprint material 102 can be made to land on the ideal position.

If the angle of ejection is known in advance, the speed of ejection is calculated by using, when the distance d is calculated, information that an error in the angle of ejection causes the imprint material 102 to land on the substrate 101 at a position offset by a sinθ component. If there is a chance that the angle of ejection may change with the aging of the ejecting unit 115, the angle of ejection may be measured in advance. To correct the offset in the landing position, the timing of ejection may be corrected such that the offset in the landing position that is based on the known or measured angle of ejection and the offset in the landing position that is based on the speed of ejection are corrected at a time.

Third Embodiment

A third embodiment relates to a method in which the angle of ejection and the speed of ejection are measurable as ejection characteristics of the ejecting unit 115.

Fig. 7 is a diagram for describing a method of measuring the angle of ejection according to the third embodiment. Fig. 8 is a diagram for describing the position of the imprint material 102 landed on the substrate 101. Fig. 9 is a flow chart illustrating the method. Now, the third embodiment will be described with reference to Figs. 7, 8, and 9.

The third embodiment relates to a method of measuring at least one of the angle of ejection and the speed of ejection from the ejecting unit 115. The imprint material 102 is ejected twice toward the substrate 101 that is moving at a first speed (information on the first speed) and twice toward the substrate 101 that is moving at a second speed (information on the second speed). At least one of the angle of ejection and the speed of ejection is measured on the basis of the positions of

marks

501, 502, 503, and 504 formed of the imprint material 102, the information on the first speed, and the information on the second speed.

For convenience in description, a method of measuring the angle of ejection will first be described.

The imprinting apparatus 100 according to the third embodiment differs from the imprinting apparatus 100 according to the first embodiment in that a program illustrated as a flow chart in Fig. 9 is stored in the storage unit 123 and in that the control unit 122 reads the program and thus executes the measurement of the angle of ejection.

For convenience in description, a method of measuring the angle of ejection from an ejecting unit 115 having only one nozzle 116 will be described. Suppose that the speed of ejection has been found by performing the measurement method according to the first embodiment.

In step S301, the substrate stage 111 moves the substrate 101 at a uniform speed Vs1 in the -X direction (a first direction) such that the substrate 101 passes through a position facing the ejecting unit 115. In step S302, the ejecting unit 115 ejects one droplet of the imprint material 102 first and ejects another droplet of the imprint material 102 after a time period t1 from the first ejection. The droplet of the imprint material 102 firstly ejected and landed on the substrate 101 is referred to as the mark 501. The droplet of the imprint material 102 secondly ejected and landed on the substrate 101 is referred to as the mark 502.

Fig. 7 illustrates the

marks

501 and 502 formed at positions P1 and P2, respectively. Fig. 7 illustrates a case where the ejecting unit 115 ejects the imprint material 102 obliquely toward the -X side at an angle θ with respect to the vertical direction.

Subsequently, in step S303, the substrate stage 111 moves the substrate 101 at another uniform speed Vs2 in the -X direction (a second direction) such that the substrate 101 passes through the position facing the ejecting unit 115. The speed Vs1 and the speed Vs2 are different. In step S304, the ejecting unit 115 ejects one droplet of the imprint material 102 first and ejects another droplet of the imprint material 102 after a time period t1 from the first ejection. The droplet of the imprint material 102 firstly ejected and landed on the substrate 101 is referred to as the mark 503. The droplet of the imprint material 102 secondly ejected and landed on the substrate 101 is referred to as the mark 504.

The image taking portion 121 takes an image of the

marks

501, 502, 503, and 504 landed on the substrate 101 and transmits the image to the control unit 122.

In step S305, the control unit 122 processes the image and acquires a first group of landing positions, which are the position P1 of the mark 501 and the position P2 of the mark 502, and a second group of landing positions, which are a position P3 of the mark 503 and a position P4 of the mark 504.

Fig. 8 illustrates the substrate 101 observed from the +Z side by the image taking portion 121 and illustrates a distance D1 in the X direction between the position P1 and the position P2 (a first distance in the first direction between at least two of the first group of landing positions) and a distance D2 in the X direction between the position P3 and the position P4 (a second distance in the second direction between at least two of the second group of landing positions). In step S306, the control unit 122 calculates the distance D1 and the distance D2 on the basis of the landing positions acquired in step S305.

Lastly, in step S307, the control unit 122 determines the angle of ejection of the imprint material 102 on the basis of the following: the distances D1 and D2 acquired in step S306, the speeds Vs1 and Vs2, and the distance L between the ejecting unit 115 and the substrate 101.

Letting the speed of ejection be Vr and the X-direction component and the Z-direction component of the speed be Vx and Vz, respectively, Vx = Vr×sinθ and Vz = Vr×cosθ hold.

Here, the distance D1 is expressed by Equation (4), and the distance D2 is expressed by Equation (5). From Equations (4) and (5), Equation (6) is derived.
D1 = (Vx+Vs1)×t = (Vx+Vs1)×(L/Vz) ... Equation (4)
D2 = (Vx+Vs2)×t = (Vx+Vs2)×(L/Vz) ... Equation (5)
Vx = {(D1×Vs2)-(D2×Vs1)}/(D2-D1) ... Equation (6)

The right side of Equation (6) equals Vr×θ, because the angle θ is very small. Hence, the angle θ of ejection is obtained by solving the equation based on Equation (3) and Vx = Vr×sinθ.

This is the end of the description of the flow chart illustrated in Fig. 9. The speed of ejection can also be obtained by solving Equations (4), (5), and (6) for Vz and calculating tanθ = Vx/Vz. That is, in the third embodiment, each of the angle of ejection and the speed of ejection as ejection characteristics are measurable independently of the other ejection characteristics. The speed of ejection may be calculated before the angle of ejection is calculated.

As described above, the positions of the

marks

501, 502, 503, and 504 formed by ejecting the imprint material 102 at different timings in the two cases where the substrate 101 is moved at the uniform speed Vs1 and at the uniform speed Vs2. Thus, in the imprinting apparatus 100, at least one of the angle of ejection and the speed of ejection from the nozzle 116 can be measured (determined) on the basis of the positions P1, P2, P3, and P4 and the speeds Vs1 and Vs2.

The substrate used in step S302 and the substrate used in step S304 may be different. If the same substrate is used in steps S302 and S304, the

marks

501, 502, 503, and 504 are all observable through the image taking portion 121 in one field of view. Consequently, the measurement time is reduced.

The direction of movement of the substrate 101 in step S301 and the direction of movement of the substrate 101 in step S303 may not necessarily be the same.

Method of Correcting Offset in Landing Position 3

When the imprint material 102 is supplied to the substrate 101 in the imprinting process, the landing position is offset in the X direction by (L×θ) because of an error in the angle of ejection in the X-Z plane. To correct the offset in the landing position, the control unit 122 corrects the timing of ejection of the imprint material 102.

Specifically, the control unit 122 changes the timing of ejection by Δt = (L×θ)/V with respect to the timing of ejection from a nozzle whose angle of ejection θ is 0 degrees. Here, V denotes the speed at which the substrate stage 111 moves in the step of supplying the imprint material 102 to the substrate 101.

"To change the timing of ejection" means "to change the timing of voltage application to the piezoelectric device." Note that the period of the driving waveform of the voltage to be applied to the piezoelectric device is unchanged from the period of the driving waveform that is set for the angle of ejection measured before the timing of voltage application is changed.

Specifically, if the direction of ejection is tilted toward the -X side (toward the leading side of the substrate stage 111), the timing of ejection is delayed by (L×θ)/V. If the direction of ejection is tilted toward the +X side (toward the trailing side of the substrate stage 111), the timing of ejection is advanced by (L×θ)/V. Different timings of ejection may be set for different nozzles 116.

Thus, the offset in the landing position from the target position that is attributed to an error in the angle of ejection can be corrected (reduced). Now, modifications that can be made to any of the first to third embodiments will be described.

The control unit 122 may correct the driving waveform of the voltage to be applied to the ejecting unit 115 as an ejection condition. Correcting the driving waveform corrects the speed of ejection. Alternatively, the landing position of the imprint material 102 may be corrected by correcting both the angle of ejection and the speed of ejection.

Before the landing position of the imprint material 102 is measured with the image taking portion 121, the ultraviolet light 105 may be applied to the substrate 101 so that the imprint material 102 can be cured. Thus, the accuracy in the measurement of the landing position of the imprint material 102 that is performed by using the image processed by the control unit 122 can be improved.

The substrate 101 used in the measurement of the speed of ejection or the angle of ejection may be a substrate that is dedicated to the measurement and that is made of such a material or is given such a process that the angle of contact with the imprint material 102 becomes large. For example, the substrate 101 may be coated with a fluorocarbon-based material.

The substrate 101 used in the measurement of the speed of ejection or the angle of ejection may be either the substrate 101 on which a pattern is to be formed in the imprinting process or a dedicated substrate on which no pattern is to be formed. If the substrate 101 on which a pattern is to be formed is used, the imprint material 102 may be ejected on a scribe line between adjacent ones of the pattern areas 120 so as not to land on any of the pattern areas 120.

The control unit 122 may be provided in a housing together with the other elements of the imprinting apparatus 100 or on the outside of the housing. The control unit 122 may be a combination of different control boards provided for respective elements to be controlled or for respective functions (for example, a function as a calculating unit, and a function as a determining unit).

The control unit 122 may compare the measured angle of ejection with a threshold angle θ' or the measured speed of ejection with a threshold speed V'. If the measured angle of ejection is larger than the threshold angle θ' or if the measured speed of ejection is higher than the threshold speed V', the user may be notified that it is time to replace the ejecting unit 115 with a new one.

While the third embodiment relates to a case where the angle of ejection or the speed of ejection is calculated from the speed of uniform motion of the substrate stage 111, the angle of ejection or the speed of ejection may be calculated from the acceleration of the substrate stage 111 (information on the speed of the substrate) that correlates with the speed of the substrate 101.

Fourth Embodiment

Method of Measuring Angle of Ejection

In a fourth embodiment, the angle of ejection from the nozzle 116 is measured by using a stepped substrate 211 having surfaces at different heights. A method of measuring the angle of ejection in the X-Z plane will now be described.

Figs. 10A and 10B are diagrams for describing a method of measuring the angle of ejection according to the fourth embodiment. Fig. 10A illustrates the substrate 211 seen from the +X side. Fig. 10B is a top view of the substrate 211 on which the imprint material 102 has landed.

The substrate 211 includes a first area 211a forming a surface at a higher position, and a second area 211b forming a surface at a lower position than the first area 211a by Δh. The first area 211a is positioned by the substrate stage 111 to be at a height H1 (a first height) that is at a distance h1 from the ejecting unit 115. In this state, the second area 211b is positioned at a height H2 (a second height) that is at a distance h2 from the ejecting unit 115. The distance h2 between the ejecting unit 115 and the second area 211b equals h1+Δh.

For accurate calculation of the angle of ejection, Δh may be set such that an offset Δd in the X direction between the landing position at the height H1 and the landing position at the height H2 becomes about several microns. For example, Δh of the substrate 211 can be set to 80 to 200 μm.

Fig. 11 is a flow chart illustrating the measurement method according to the fourth embodiment. For convenience in description, a case where the imprint material 102 is ejected from one nozzle 116 will be described.

In step S401, in a first state where the ejecting unit 115 faces the first area 211a, the ejecting unit 115 ejects a droplet 102a of the imprint material 102 toward the first area 211a. Subsequently, in step S402, the substrate stage 111 is moved in the Y direction (a predetermined direction) with the position thereof in the X direction (a direction intersecting the predetermined direction) fixed, whereby the ejecting unit 115 is made to face the second area 211b. In step S403, in a second state where the ejection port of the ejecting unit 115 faces the second area 211b, the ejecting unit 115 ejects a droplet 102b of the imprint material 102 toward the second area 211b.

In step S404, the image taking portion 121 takes an image of the droplet 102a ejected and landed on the substrate 211 in the first state and the droplet 102b ejected and landed on the substrate 211 in the second state. The image taking portion 121 transmits the image to the control unit 122.

The control unit 122 processes the image and calculates the position of the droplet 102a and the position of the droplet 102b (the landing positions of the

droplets

102a and 102b ejected in the respective states). The landing position of each of the

droplets

102a and 102b is represented by, for example, the position in the X direction and the position in the Y direction. Furthermore, in step S405, the control unit 122 calculates the offset Δd (see Fig. 10B) in the X direction between the

droplets

102a and 102b. Letting the angle of ejection be θ, if θ ≠ 0, Δd ≠ 0 holds.

In step S406, the control unit 122 determines the angle of ejection from the values of Δd and Δh. Here, tanθ = Δd/Δh holds (see Fig. 10A), because the droplet 102b ejected at an angle θ is also offset in the X direction while falling down by Δh. The angle θ is very small. Therefore, the angle of ejection can be determined by calculating an equation θ = Δd/Δh.

If the steps S401 to S406 are performed for each of the other nozzles 116 aligned in the Y direction, the angles of ejection from the respective nozzles 116 are obtained.

In the fourth embodiment, the substrate stage 111 is stationary when the

droplets

102a and 102b are ejected. Therefore, even if there is an error in the speed of ejection from the nozzle 116 with respect to a predetermined value, such an error in the speed of ejection does not affect the result of the measurement.

As described above, the angles of ejection from the ejecting unit 115 in the first and second states can be measured (determined) on the basis of the positions of the

droplets

102a and 102b ejected in the first and second states that are different from each other in the distance between the ejection port of the nozzle 116 and the substrate 101. Since the ejecting unit 115 ejects the imprint material 102 while the substrate stage 111 is stationary, the error in the speed of ejection with respect to the predetermined value does not need to be considered. Hence, by the measurement method using the imprinting apparatus 100 according to the fourth embodiment, the angle of ejection can be measured independently of the other ejection characteristics such as the speed of ejection.

Specifically, the substrate stage 111 is moved in the Y direction in step S402, and the angle of ejection is then measured on the basis of the X-direction positions of the

droplets

102a and 102b. Since the substrate stage 111 is moved, the

droplets

102a and 102b are prevented from overlapping each other. Hence, the control unit 122 can calculate the positions of the

droplets

102a and 102b without difficulties. Accordingly, the angle of ejection can be measured accurately.

Since the ejecting unit 115 is observable sideways, the angle of ejection is measurable in one imprinting apparatus 100 without providing a device dedicated to the observation of the angle of ejection. Therefore, the increase in the installation area that may be caused by providing such a dedicated device can be suppressed, and the maintenance work can be made less troublesome than in a case where the ejecting unit 115 needs to be taken out of the imprinting apparatus 100 for the measurement.

Method of Correcting Offset in Landing Position 4

In the step of supplying the imprint material 102 to the substrate 101 in the imprinting process, the landing position is offset in the X direction by (h1×θ) because of an error in the angle of ejection. To correct the offset in the landing position, the control unit 122 corrects the timing of ejection of the imprint material 102. Specifically, the control unit 122 changes the timing of ejection by Δt = (h1×θ)/Vs with respect to the timing of ejection from a nozzle 116 whose angle of ejection θ is 0 degrees. "To change the timing of ejection" means "to change the timing of voltage application to the piezoelectric device provided in the ejecting unit 115." Note that the period of the driving waveform of the voltage to be applied to the piezoelectric device is unchanged from the period of the driving waveform that is set for the angle of ejection measured before the timing of voltage application is changed.

Specifically, if the direction of ejection is tilted toward the -X side (toward the leading side of the substrate stage 111), the timing of ejection is delayed by (h1×θ)/Vs. If the direction of ejection is tilted toward the +X side (toward the trailing side of the substrate stage 111), the timing of ejection is advanced by (h1×θ)/Vs. Different timings of ejection may be set for different nozzles 116.

Thus, the offset in the landing position that is attributed to an error in the angle of ejection can be corrected, and the imprint material 102 can be made to land on the ideal position.

Fifth Embodiment

In a fifth embodiment, the angle of ejection is measured by ejecting the imprint material 102 in a first state where the substrate 101 is positioned at a height H1 (a first height) and in a second state where the substrate 101 is positioned at a height H2 (a second height) that is different from the height H1. The height H1 is at a distance h1 from the ejecting unit 115. The height H2 is at a distance h2 = h1+Δh from the ejecting unit 115.

The fifth embodiment differs from the fourth embodiment in that the substrate stage 111 of the imprinting apparatus 100 is movable in the Z direction and in that a program illustrated as a flow chart in Fig. 13 is stored in the storage unit 123. Referring to Figs. 12A and 12B illustrating a method of measuring the angle of ejection and Fig. 13 illustrating a flow chart of the method, the fifth embodiment will now be described.

The control unit 122 reads the program illustrated as a flow chart in Fig. 13 from the storage unit 123 and thus executes the program. In step S501, the ejecting unit 115 ejects a droplet 102a of the imprint material 102 toward the substrate 101 positioned at a height H1. Subsequently, in step S502, the substrate 101 is moved in the X direction. Furthermore, in step S503, the substrate stage 111 is moved in the Z direction by Δh, whereby the substrate 101 is positioned at a height H2. Then, in step S504, the ejecting unit 115 ejects a droplet 102b of the imprint material 102 toward the substrate 101. Steps S505 to S507 are the same as steps S404 to 406 illustrated in Fig. 11, and description thereof is omitted.

Step S502 and step S503 may be performed in the reverse order. The length by which the substrate 101 is moved in step S502 is set to such a value (for example, 80 to 200 μm) that the droplet 102a and the droplet 102b landed on the substrate 101 do not overlap each other.

Thus, the angle of ejection from the ejecting unit 115 can be measured (determined) on the basis of the positions of the

droplets

102a and 102b ejected toward the substrate 101 when the substrate 101 is in the first state and in the second state in which the substrate 101 is at the respective distances from the ejection port. Furthermore, the angle of ejection is measurable without using the dedicated stepped substrate 211 employed in the fourth embodiment. In the measurement method performed by using the imprinting apparatus 100 according to the fifth embodiment, the angle of ejection is measurable independently of the other ejection characteristics, such as the speed of ejection, for the same reason as in the fourth embodiment.

A method of correcting the offset in the landing position that is attributed to an error in the angle of ejection is the same as in the fourth embodiment, and description thereof is omitted.

Sixth Embodiment

In a sixth embodiment, the speed of ejection of the imprint material 102 from the nozzle 116 is measured by using the substrate 211 employed in the fourth embodiment. While the substrate stage 111 is moving, the ejecting unit 115 ejects the imprint material 102 in first and second states that are different from each other in the distance between the ejection port and the substrate 211.

For convenience in description, a case where the angle of ejection θ obtained in any of the third to fifth embodiments is 0 degrees will be described. The sixth embodiment differs from the fourth embodiment in that a program illustrated as a flow chart in Fig. 15 is stored in the storage unit 123 of the imprinting apparatus 100 and in that the control unit 122 has a function as a second determining unit that determines the speed of ejection.

The sixth embodiment will now be described with reference to Figs. 14A and 14B illustrating the method of measuring the speed of ejection and Fig. 15 illustrating the flow chart of the method. In the following description, the speed at which the substrate stage 111 is moved is denoted by Vs, and the speed of ejection of each of

droplets

102b and 102b' of the imprint material 102 from a nozzle 205b is denoted by V.

In step S601, while the substrate stage 111 is moving in the X direction (the predetermined direction), particularly in the -X direction, at a speed Vs with the ejecting unit 115 facing the first area 211a, the ejecting unit 115 regularly ejects the imprint material 102 toward the substrate 211.

The imprint material 102 is ejected from at

least nozzles

205a and 205b simultaneously among a plurality of nozzles 116. At time t, the nozzle 205a ejects a droplet 102a of the imprint material 102 toward the first area 211a, and the nozzle 205b ejects a droplet 102b of the imprint material 102 toward the first area 211a. At time t', the nozzle 205a ejects a droplet 102a' of the imprint material 102 toward the first area 211a, and the nozzle 205b ejects a droplet 102b' of the imprint material 102 toward the second area 211b.

In step S602, the image taking portion 121 takes an image of the

droplets

102a, 102a', 102b, and 102b' landed on the substrate 211 and transmits the image to the control unit 122.

The control unit 122 processes the image and calculates the positions of the

droplets

102a, 102a', 102b, and 102b'. Furthermore, in step S603, the control unit 122 calculates an offset Δx in the X direction between the droplet 102a and the droplet 102b. The offset Δx thus calculated contains the arrangement error in the X direction between the nozzle 205a and the nozzle 205b and the offset between the landing positions of the

droplets

102a and 102b that is attributed to the difference between the speed of ejection from the nozzle 205a and the speed of ejection from the nozzle 205b.

Subsequently, in step S604, the control unit 122 calculates an offset Δds in the X direction between the droplet 102a' ejected toward the first area 211a and the droplet 102b' ejected toward the second area 211b.

Subsequently, the control unit 122 calculates the offset in the landing position that is attributed to the height difference Δh. Specifically, in step S605, the control unit 122 calculates Δds' = Δds-Δx. Thus, the influence of the arrangement error in the X-direction position between the nozzle 205a and the nozzle 205b and the influence of the speed of ejection from the nozzle 205a are eliminated.

Lastly, in step S606, the control unit 122 calculates the speed of ejection V from the nozzle 205b. A time period Δt elapsed while the droplet 102b' falls down by the height difference Δh is expressed as Δt = Δh/V. Since the substrate 211 moves at the speed Vs during the time period Δt, Δt = Δds'/Vs also holds. Using the two equations, the speed of ejection V can be obtained by calculating an equation V = (Δh×Vs)/Δds'.

The above measurement is repeated while the position of the substrate 211 relative to the ejecting unit 115 is changed in the Y direction, whereby the speed of ejection V for each of the nozzles 116 that are at respective positions that are to face the second area 211b can be obtained.

If the angle of ejection θ measured in the X-Z plane in any of the third to fifth embodiments is not 0 degrees, the offset Δds' and the speed of ejection V may be calculated with consideration for the fact that the landing position is offset by θ×h1 when the imprint material 102 is ejected toward the substrate 101 that is at the distance h1 from the ejecting unit 115.

Hence, the speed of ejection from the ejecting unit 115 can be measured (determined) on the basis of the landing positions of the

droplets

102a, 102a', 102b, and 102b' ejected toward the substrate 211 in the first state and in the second state. Since the ejecting unit 115 is observable sideways, the speed of ejection is measurable in one imprinting apparatus 100 without providing a device dedicated to the observation of the speed of ejection. Therefore, the increase in the installation area that may be caused by providing such a dedicated device can be suppressed, and the maintenance work can be made less troublesome than in a case where the ejecting unit 115 needs to be taken out of the imprinting apparatus 100 for the measurement.

Steps S605 and S604 may be performed in the reverse order. Furthermore, the offset Δx may be obtained by measuring the actual positions of the

nozzles

205a and 205b.

Method of Correcting Offset in Landing Position 5

In the step of supplying the imprint material 102 to the substrate 101 in the imprinting process, if the speed of ejection changes from the predetermined speed V0 to another speed V, the landing position of the imprint material 102 is offset from the predetermined position because the hang time of the imprint material 102 changes. The control unit 122 can correct such an offset in the landing position by correcting the timing of ejection of the imprint material 102 from the ejecting unit 115.

If the imprint material 102 is supplied to the substrate 101 that is at a distance h1 from the ejecting unit 115, a hang time Δt0 at the speed V0 equals h1/V0, and a hang time Δt at the speed V equals h1/V. Hence, if the speed V is lower than the speed V0, the timing of ejection is advanced by |Δt-Δt0| = h1×(V-V0)/(V×V0). If the speed V is higher than the speed V0, the timing of ejection is delayed by h1×(V-V0)/(V×V0).

Alternatively, instead of correcting the timing of ejection, the control unit 122 may change the driving waveform such that the speed of ejection from the nozzle 116 becomes close to the speed V0. In either case, different timings of ejection or different driving waveforms may be set for different nozzles 116.

Thus, the control unit 122 can correct the offset in the landing position that is attributed to the error in the speed of ejection and can allow the imprint material 102 to land on the ideal position.

Seventh Embodiment

In a seventh embodiment, the speed of ejection is measured by ejecting the imprint material 102 in a state where the substrate 101 is positioned at a height H1 and in a state where the substrate 101 is positioned at a height H2.

The seventh embodiment differs from the fourth embodiment in that the substrate stage 111 of the imprinting apparatus 100 is capable of moving the substrate 101 in the Z direction and in that a program illustrated as a flow chart in Fig. 17 is stored in the storage unit 123. The control unit 122 has a function as a second determining unit that determines the speed of ejection.

Referring to the Figs. 16A and 16B illustrating a method of measuring the speed of ejection and Fig. 17 illustrating the flow chart of the method, the seventh embodiment will now be described. Figs. 16A and 16B illustrate a case where six nozzles 116 are provided in the Y direction. For convenience, the following description relates to a method of measuring the speed of ejection from a nozzle 205 among the six nozzles 116 and in a case where the angle of ejection θ obtained in any of the third to fifth embodiments is 0 degrees.

In step S701, while the substrate 101 that is at the height H1 is being moved in the -X direction at a speed Vs, droplets 102a of the imprint material 102 are ejected regularly from the nozzle 205. In this step, the relative positions of the nozzle 205 and the substrate 101 at the moment the droplets 102a start to be ejected are stored.

In step S702, the substrate stage 111 is moved in the Z direction by Δh, whereby the substrate 101 is positioned at the height H2. Then, in step S703, the substrate stage 111 is further moved in the X and Y directions, not in the Z direction, so that the substrate 101 and the nozzle 205 are set relative to each other at the respective positions stored in step S701.

In step S704, while the substrate stage 111 that is at the height H2 is being moved in the -X direction at the speed Vs again, droplets 102b of the imprint material 102 are ejected regularly from the nozzle 205 (step S704).

In step S705, the image taking portion 121 takes an image of the

droplets

102a and 102b landed on the substrate 101 and transmits the image to the control unit 122.

The control unit 122 processes the image and thus calculates the positions of the

droplets

102a and 102b. Furthermore, in step S706, the control unit 122 calculates an offset Δds1 (see Fig. 16B) in the X direction between the droplet 102a and the droplet 102b.

The control unit 122 calculates the speed of ejection on the basis of the offset Δds1. The speed of ejection V can be obtained by calculating an equation V = (Δh×Vs)/Δds1. Likewise, the speed of ejection for each of the nozzles 116 excluding the nozzle 205 can be obtained by calculating offsets Δds2 to Δds6.

Thus, the speed of ejection from each of the nozzles 116 can be measured on the basis of the positions of the

droplets

102a and 102b ejected toward the substrate 101 in the two states that are different from each other in the distance between the substrate 101 and the ejecting unit 115.

Since the speed of ejection from one nozzle 205 can be calculated by using only the nozzle 205, there is no need to consider the relationship with the other nozzles 116 that are only for reference in the measurement, unlike the case of the calculation of the offset Δx according to the sixth embodiment.

Since the ejecting unit 115 is observable sideways, the speed of ejection is measurable in one imprinting apparatus 100 without providing a device dedicated to the observation of the speed of ejection. Therefore, the increase in the installation area that may be caused by providing such a dedicated device can be suppressed, and the maintenance work can be made less troublesome than in a case where the ejecting unit 115 needs to be taken out of the imprinting apparatus 100 for the measurement.

The period of ejection in step S701 and the period of ejection in step S704 may be made the same. If the offset Δds1 between the droplet 102a and the droplet 102b ejected toward the substrate 101 at the height H1 and at the height H2, respectively, is calculated for a plurality of times, i.e., first to N-th times, and the average of the results is calculated, an accurate offset Δds1 can be obtained.

If the offset Δds1 is small and the droplet 102a and the droplet 102b overlap each other, step S701 and step S704 may be performed by using different substrates 101, respectively.

The method of correcting the offset in the landing position that is attributed to an error in the speed of ejection is the same as that described in the sixth embodiment, and description thereof is omitted.

In the imprinting apparatus 100 according to each of the fourth and fifth embodiments, the angle of ejection from the ejecting unit 115 is measurable independently of the other ejection characteristics. In the imprinting apparatus 100 according to each of the sixth and seventh embodiments, the speed of ejection from the ejecting unit 115 is also measurable. Furthermore, since the control unit 122 can correct the ejecting condition of the ejecting unit 115, the imprint material 102 can be made to land on the target position. The control unit 122 may correct ejection conditions on the basis of at least one of the angle of ejection determined by the control unit 122 and the speed of ejection determined by the control unit 122. Thus, the landing position of the imprint material 102 can be corrected.

Modifications that can be made to any of the fourth to seventh embodiments will now be described.

The control unit 122 may correct, as an ejection condition, the driving waveform of the voltage to be applied to the ejecting unit 115. Correcting the voltage corrects the speed of ejection. Alternatively, the control unit 122 may correct the landing position of the imprint material 102 by correcting both the angle of ejection and the speed of ejection.

Before the landing position of the imprint material 102 is measured with the image taking portion 121, the ultraviolet light 105 may be applied to the substrate 101 so that the imprint material 102 can be cured. Thus, the accuracy in the detection of the landing position of the imprint material 102 that is performed by using the image processed by the control unit 122 can be improved.

The substrate 211 may be one solid body with a portion thereof cut off for forming the second area 211b, or may be a combination of a plurality of parts.

The control unit 122 may compare the measured angle of ejection with a threshold angle θ' or the measured speed of ejection with a threshold speed V'. If the measured angle of ejection is larger than the threshold angle θ' or the measured speed of ejection is higher than the threshold speed V', the user may be notified that it is time to replace the ejecting unit 115 with a new one.

In each of the fourth, fifth, and seventh embodiments, the positions of at least two droplets of the imprint material 102 ejected in two states that are different from each other in the distance between the substrate 101 (211) and the ejecting unit 115 only need to be measured. In the sixth embodiment, the positions of at least four droplets of the imprint material 102 that are ejected by two each from two nozzles and in two states that are different from each other in the distance between the substrate 211 and the ejecting unit 115 only need to be measured.

In each of the fourth and sixth embodiments, the step of ejecting the imprint material 102 may be performed while the substrate stage 111 is moving. In that case, the control unit 122 calculates the offset Δd or Δds with consideration for the fact that the landing position is offset with the movement of the substrate stage 111.

The control unit 122 may be provided in a housing together with the other elements of the imprinting apparatus 100 or on the outside of the housing. The control unit 122 may be a combination of different control boards provided for respective elements to be controlled or for respective functions (for example, a function as a calculating unit, a function as a determining unit, and a function as a correcting unit).

The imprint material 102 is a curable composite that is cured when curing energy is applied thereto (an uncured composite is occasionally referred to as resin). Examples of curing energy include electromagnetic waves, radiation, heat, and so forth. Exemplary electromagnetic waves include light, such as infrared light, visible light, and ultraviolet light, selected from a wavelength band ranging from 10 nm to 1 mm, inclusive.

Curable composites are cured when light, radiation, heat, or the like is applied thereto. Among various curable composites, a photo-curable composite that is cured with light contains at least a polymerizable compound and a photo-polymerization initiator and may also contain non-polymerizable compounds or solutions, according to need. Such non-polymerizable compounds include at least one compound selected from the group consisting of a sensitizer, a hydrogen donor, an internal mold release agent, a surfactant, an antioxidant, a polymeric component, and the like.

The imprint material 102 may be supplied to the substrate in the form of a droplet, or in an island pattern or in the form of a film made of a plurality of droplets that are connected to one another. The viscosity of the imprint material 102 (at 25°C) is, for example, 1 millipascal-second or higher and 100 millipascal-second or lower.

Imprinting Method

Fig. 18 is a flow chart illustrating an imprinting method according to an eighth embodiment. The method includes a step of measuring the angle of ejection or the speed of ejection (step S801), a step of correcting the timing of ejection of the imprint material 102 such that the offset in the landing position is corrected (step S802), and steps of performing an imprinting process (steps S803 to S806). Step S801 is performed as described in any of the above embodiments, for example.

The steps of performing the imprinting process will now be described. In step S803, the imprint material 102 is supplied to a pattern area 120 at the timing of ejection determined in step S802 such that the offset in the landing position is corrected. Subsequently, in step S804, the pattern portion 103a is pressed into the imprint material 102. Subsequently, in step S805, the imprint material 102 is cured with the ultraviolet light 105. Lastly, in step S806, the pattern portion 103a is released from the imprint material 102. Thus, a transfer pattern having fewer defects than in a case where steps S801 and S802 are not performed is obtained.

Article Manufacturing Method

The cured pattern that is formed in the imprinting apparatus 100 is used permanently at least as a part intended for various articles or temporarily in manufacturing various articles.

Articles referred to herein include electric circuit devices, optical devices, microelectromechanical systems (MEMS's), storing devices, sensors, molds, and so forth. Electric circuit devices include volatile or nonvolatile semiconductor memories such as dynamic random access memories (DRAM's), static random access memories (SRAM's), flash memories, and magneto-resistive random access memories (MRAM's); and semiconductor devices such as large-scale integrated circuits (LSI's), charge-coupled devices (CCD's), image sensors, and field-programmable gate arrays (FPGA's). Molds include imprinting molds and the like. The cured pattern is used as it is at least as one of members included in any of the above articles or is used temporarily as a resist mask.

If the cured pattern is used temporarily as a resist mask, the resist mask is removed from a substrate after any processing work, such as etching or ion injection, is performed on the substrate. In addition, any other known processing work (such as development, oxidization, film forming, deposition, planarization, releasing of the imprint material, dicing, bonding, and packaging) may be performed.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2015-234319, filed November 30, 2015 and Japanese Patent Application No. 2015-234320, filed November 30, 2015, which are hereby incorporated by reference herein in their entirety.

Claims

An imprinting apparatus that forms a pattern made of an imprint material on a substrate by bringing a mold and the imprint material into contact with each other and curing the imprint material, the imprinting apparatus comprising:
a moving unit configured to move the substrate;
an ejecting unit configured to eject the imprint material;
an acquiring unit configured to acquire a landing position of the imprint material ejected toward the substrate from the ejecting unit while the substrate is being moved in a predetermined direction by the moving unit;
a calculating unit configured to calculate a distance in the predetermined direction between a reference position and the landing position acquired by the acquiring unit; and
a determining unit configured to determine a speed of ejection from the ejecting unit on the basis of the distance calculated by the calculating unit and on the basis of information on a speed at which the substrate is moved.
The imprinting apparatus according to Claim 1, wherein the reference position is defined on the substrate or on a part that moves along with the substrate when the substrate is moved.
The imprinting apparatus according to Claim 1 or 2, wherein the reference position is a landing position of the imprint material ejected toward the substrate that is stationary.
The imprinting apparatus according to any of Claims 1 to 3, wherein the speed at which the substrate is moved is uniform.
The imprinting apparatus according to any of Claims 1 to 4, further comprising a correcting unit configured to correct, on the basis of the speed of ejection, the landing position of the imprint material to be ejected toward the substrate.
The imprinting apparatus according to Claim 5, wherein the correcting unit corrects at least one of a timing of ejection from the ejecting unit and a voltage to be applied to the ejecting unit.
An imprinting apparatus that forms a pattern made of an imprint material on a substrate by bringing a mold and the imprint material into contact with each other and curing the imprint material, the imprinting apparatus comprising:
a moving unit configured to move the substrate;
an ejecting unit configured to eject the imprint material;
an acquiring unit configured to acquire a first group of landing positions of droplets of the imprint material that are ejected at different timings while the substrate is being moved by the moving unit in a first direction at a first speed and a second group of landing positions of droplets of the imprint material that are ejected at different timings while the substrate is being moved by the moving unit in a second direction at a second speed different from the first speed;
a calculating unit configured to calculate a first distance in the first direction between adjacent ones of the first group of landing positions acquired by the acquiring unit and a second distance in the second direction between adjacent ones of the second group of landing positions acquired by the acquiring unit; and
a determining unit configured to determine at least one of an angle of ejection and a speed of ejection from the ejecting unit on the basis of the first distance and the second distance calculated by the calculating unit and on the basis of information on the first speed and information on the second speed.
The imprinting apparatus according to Claim 7, wherein the first speed and the second speed are each uniform.
The imprinting apparatus according to Claim 7 or 8, further comprising a correcting unit configured to correct, on the basis of at least one of the angle of ejection and the speed of ejection, the landing positions of the droplets of the imprint material to be ejected toward the substrate.
The imprinting apparatus according to Claim 9, wherein the correcting unit corrects at least one of a timing of ejection from the ejecting unit and a voltage to be applied to the ejecting unit.
The imprinting apparatus according to Claim 7 or 8,
wherein the calculating unit is a first calculating unit, and
wherein the acquiring unit includes an image taking unit configured to take an image of the droplets of the imprint material landed on the substrate; and a second calculating unit configured to calculate the first group of landing positions and the second group of landing positions by processing the image taken by the image taking unit.
A method of measuring a speed of ejection at which an ejecting unit ejects an imprint material, the method comprising:
ejecting the imprint material while the substrate is being moved in a predetermined direction;
acquiring a landing position of the ejected imprint material;
calculating a distance in the predetermined direction between a reference position and the landing position; and
calculating the speed of ejection from the ejecting unit on the basis of the distance and on the basis of information on a speed at which the substrate is moved.
A method of measuring at least one of an angle of ejection and a speed of ejection at which an ejecting unit ejects an imprint material, the method comprising:
ejecting first droplets of the imprint material at different timings toward a substrate that is moving at a first speed in a first direction;
ejecting second droplets of the imprint material at different timings toward the substrate that is moving at a second speed in a second direction, the second speed being different from the first speed;
acquiring at least two of landing positions of the first droplets of the imprint material and at least two of landing positions of the second droplets of the imprint material;
calculating a first distance in the first direction between the at least two of the landing positions of the first droplets of the imprint material and a second distance in the second direction between the at least two of the landing positions of the second droplets of the imprint material; and
calculating at least one of an angle of ejection and a speed of ejection from the ejecting unit on the basis of the first distance, the second distance, information on the first speed, and information on the second speed.
An imprinting method comprising:
correcting, on the basis of the speed of ejection obtained by the method according to Claim 12, a condition for ejecting the imprint material from the ejecting unit;
ejecting the imprint material toward the substrate under the corrected condition;
bringing a mold and the ejected imprint material into contact with each other; and
releasing the mold from the imprint material.
An imprinting method comprising:
correcting, on the basis of at least one of the angle of ejection and the speed of ejection obtained by the method according to Claim 13, a condition for ejecting the imprint material from the ejecting unit;
ejecting the imprint material toward the substrate under the corrected condition;
bringing a mold and the ejected imprint material into contact with each other; and
releasing the mold from the imprint material.
An imprinting apparatus that forms a pattern made of an imprint material on a substrate by bringing a mold and the imprint material into contact with each other and curing the imprint material, the imprinting apparatus comprising:
an ejecting unit having an ejection port and configured to eject the imprint material from the ejection port toward the substrate;
an acquiring unit configured to acquire landing positions of droplets of the imprint material that are ejected from the ejecting unit in a first state and in a second state, respectively, the first state and the second state being different from each other in a distance between the ejection port and the substrate; and
a determining unit configured to determine an angle of ejection from the ejecting unit on the basis of the landing positions acquired by the acquiring unit.
The imprinting apparatus according to Claim 16,
wherein the substrate has surfaces at different heights,
wherein, in the first state, the ejection port faces one of the surfaces that is at a higher height, and
wherein, in the second state, the ejection port faces another one of the surfaces that is at a lower height.
The imprinting apparatus according to Claim 16,
wherein the substrate is positioned at a first height in the first state, and
wherein the substrate is positioned at a second height in the second state, the second height being different from the first height.
The imprinting apparatus according to any of Claims 16 to 18, further comprising:
a moving unit configured to move the substrate,
wherein the moving unit moves the substrate such that the landing position of the droplet of the imprint material ejected from the ejecting unit in the first state and the landing position of the droplet of the imprint material ejected from the ejecting unit in the second state are offset from each other in a predetermined direction, and
wherein the determining unit determines the angle of ejection on the basis of a distance between the landing positions of the droplets of the imprint material in a direction intersecting the predetermined direction.
The imprinting apparatus according to any of Claims 16 to 19, further comprising:
a moving unit configured to move the substrate,
wherein the determining unit is a first determining unit,
wherein the landing positions of the droplets of the imprint material that are acquired by the acquiring unit are landing positions of the droplets of the imprint material that are ejected while the moving unit is moving the substrate in a predetermined direction, and
wherein the imprinting apparatus further includes a second determining unit configured to determine a speed of ejection from the ejecting unit on the basis of an offset in the predetermined direction between the landing position of the droplet of the imprint material ejected from the ejecting unit while the moving unit is moving the substrate in the predetermined direction in the first state and the landing position of the droplet of the imprint material ejected from the ejecting unit while the moving unit is moving the substrate in the predetermined direction in the second state.
The imprinting apparatus according to any of Claims 16 to 20, wherein the acquiring unit includes an image taking unit configured to take an image of the droplets of the imprint material that are ejected in the first state and in the second state, respectively; and a calculating unit configured to calculate the landing positions by processing the image taken by the image taking unit.
The imprinting apparatus according to any of Claims 16 to 21, further comprising a correcting unit configured to correct, on the basis of the angle of ejection determined by the determining unit, the landing positions of the droplets of the imprint material to be ejected toward the substrate.
The imprinting apparatus according to Claim 20, further comprising a correcting unit configured to correct, on the basis of at least one of the angle of ejection determined by the first determining unit and the speed of ejection determined by the second determining unit, the landing positions of the droplets of the imprint material to be ejected toward the substrate.
The imprinting apparatus according to Claim 22 or 23, wherein the correcting unit corrects at least one of a timing of ejection from the ejecting unit and a voltage to be applied to the ejecting unit.
A method of measuring an angle of ejection at which an ejecting unit ejects an imprint material, the method comprising:
ejecting droplets of the imprint material from the ejection unit toward a substrate in a first state and in a second state, respectively, the first state and the second state being different from each other in a distance between an ejection port of the ejecting unit and the substrate;
acquiring landing positions of the ejected droplets of the imprint material; and
determining the angle of ejection on the basis of the acquired landing positions.
An imprinting method comprising:
determining an ejection condition for correcting, on the basis of the angle of ejection obtained by the method according to Claim 25, the landing positions of the droplets of the imprint material to be ejected toward the substrate;
ejecting the droplets of the imprint material toward the substrate under the determined ejection condition;
bringing the ejected imprint material and a mold into contact with each other; and
releasing the mold from the imprint material.
An article manufacturing method comprising:
forming a pattern on a substrate by the imprinting method according to any of Claims 14, 15, and 26; and
processing the substrate after the forming of the pattern.