TWI649785B - Imprint apparatus, imprint method, and method of manufacturing article - Google Patents

Abstract

The present invention provides an imprint apparatus that performs an imprint process of forming a pattern of an imprint material on a substrate using a mold, the imprint apparatus including an image sense configured to sense at least one of the mold and the substrate and obtain an image a measuring unit, and a judging unit configured to determine a normal/abnormality of the imprinting process, wherein the imprinting process includes a first step of supplying the imprint material to the substrate, and contacting the imprint material on the mold and the substrate with each other a second step, and the determination unit changes the normal/abnormal reference for determining the imprint process for each step of the imprint process and determines the normal/abnormality of the imprint process based on the image sensed by the image sensing unit .

Description

Imprinting apparatus, imprinting method, and method of manufacturing the article

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

Imprint technology is a technology capable of forming a nano-scale fine pattern, and has attracted attention as a large-scale production of nanolithography technology for semiconductor devices and magnetic storage media. An imprinting apparatus using an imprint technique is performed on a substrate by curing a resin (imprint material) in a state in which a mold having a pattern formed thereon and a resin on the substrate are in contact with each other, and then releasing the mold from the cured resin. Form a pattern.

In the imprint apparatus, the normal/abnormality of the pattern formed on the substrate (that is, the normal/abnormality of the imprint process) is judged based on the image sensing information from the image sensing unit disposed above the substrate. It is effective (see Japanese Patent Laid-Open No. 2011-3616). Japanese Patent Laid-Open No. 2011-3616 discloses an image obtained by comparing a pattern formed on a substrate by sensing by an imprint process and by sensing in advance normally A technique of determining a normal/abnormal stamping process by forming a reference image prepared by a pattern on a substrate.

If the normal/abnormality of the imprint process is not determined after the pattern is formed on the substrate but during the imprint process (for example, when an abnormality is generated), the influence of the abnormality can be suppressed, thereby improving productivity. However, the state of the substrate during the imprint process is changed to, for example, a state in which the imprint material is supplied (applied), a state in which the mold and the imprint material are in contact with each other, and a state in which the mold is released to form a pattern. If the normal/abnormal judgment criterion of the imprint process is constant, the reference will become inappropriate depending on the substrate state, and the substrate state cannot be accurately grasped. That is, the normal/abnormality of the imprint process cannot be accurately judged in some cases. For example, when the pattern of the mold is filled with the imprint material on the substrate, the substrate state is sequentially changed according to the physical phenomenon (capillary phenomenon), and it is difficult to specify the time point at which the normal/abnormality of the imprint process is judged.

The present invention provides an imprint apparatus that is advantageous for judging the normal/abnormality of the imprint process.

According to an aspect of the present invention, there is provided an imprint apparatus performing an imprint process of forming a pattern of an imprint material on a substrate using a mold, the imprint apparatus comprising: configured to sense at least one of a mold and a substrate and obtain An image sensing unit of an image, and a judging unit configured to judge a normal/abnormality of the imprint process, wherein the imprint process includes a first step of supplying an imprint material onto the substrate, and causing the mold and the substrate Imprinted material a second step of contacting each other, and the determination unit changes the normal/abnormal reference for determining the imprint process for each step of the imprint process, and judges the imprint process based on the image sensed by the image sensing unit Normal / abnormal.

Further aspects of the present invention will become apparent from the following description of exemplary embodiments.

1‧‧‧Substrate chuck

2‧‧‧ substrate table

3‧‧‧Mold chuck

4‧‧‧Mold table

5‧‧‧Aligning the oscilloscope

6‧‧‧Alignment mark (substrate side mark)

7‧‧‧Alignment mark (mold side mark)

8‧‧‧Light source

9‧‧‧ observation unit

9a‧‧‧ Observation light source

9b‧‧‧Image Sensor

10‧‧‧Mirror

11‧‧‧Distributor

12‧‧‧Control unit

13‧‧‧ console unit

14‧‧‧Display unit

15‧‧‧Input device

16‧‧‧ force sensor

61‧‧‧孔口

62‧‧‧ scan direction

63‧‧‧孔口

64‧‧‧Area

65‧‧‧ dotted line

71‧‧‧ Section

72‧‧‧ Section

100‧‧‧imprint equipment

121‧‧‧Area

122‧‧‧Area

131‧‧‧ border

G‧‧‧ particles

G’‧‧‧ Section

M‧‧‧Mold

P‧‧‧ pattern

R‧‧‧Resin

W‧‧‧Substrate

AP‧‧ cycle

PP‧‧‧Preset period

PS‧‧‧Predetermined size

RL‧‧·reflected light

S101~S104‧‧‧Steps

S201~S207‧‧‧Steps

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the arrangement of an imprint apparatus as an aspect of the present invention.

2A and 2B are views showing an example of interference fringe observed by the observation unit of the imprint apparatus shown in Fig. 1.

Fig. 3 is a flow chart for explaining a general imprint process.

4A to 4F are views for explaining a general imprint process.

FIG. 5 is a flowchart for explaining an imprint process according to an embodiment.

6A to 6F are views for explaining the judgment of the normal/abnormality of the imprint process shown in Fig. 5 (step S202).

7A to 7D are views for explaining the judgment of the normal/abnormality of the imprint process shown in Fig. 5 (step S203).

FIG. 8 is a diagram for explaining a point in time at which the normal/abnormal determination (step S203) of the imprint process shown in FIG. 5 is performed.

FIG. 9 is a diagram for explaining a point in time at which the normal/abnormal determination (step S204) of the imprint process shown in FIG. 5 is performed.

10A to 10C are views for explaining points in time at which the judgment of the normal/abnormality of the imprint process shown in Fig. 5 (step S204) is performed.

11A and 11B are views for explaining the judgment of the normal/abnormality of the imprint process shown in Fig. 5 (step S206).

12A to 12C are views for explaining points in time at which the normal/abnormal judgment (step S206) of the imprint process shown in Fig. 5 is performed.

13A to 13D are views for explaining the judgment of the normal/abnormality of the imprint process shown in Fig. 5 (step S207).

14A to 14D are views for explaining the judgment of the normal/abnormality of the imprint process shown in Fig. 5 (step S205).

15A and 15B are views for explaining the judgment of the normal/abnormality of the imprint process shown in Fig. 5 (step S205).

Fig. 16 is a view for explaining the judgment of the normal/abnormality of the imprint process shown in Fig. 5 (step S205).

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It is to be noted that the same reference numerals are given to the same components throughout the drawings, and a repeated description thereof will not be given.

1 is a view showing an imprint apparatus 100 as an aspect of the present invention. Schematic diagram of the arrangement. The imprint apparatus 100 is a lithography apparatus that forms a pattern on an imprint material on a substrate using a mold. This embodiment will explain a case where an ultraviolet curable resin which is cured by irradiation with ultraviolet rays is used as an imprint material. However, the imprint material may be a thermoplastic or thermosetting resin.

The imprint apparatus 100 includes a substrate chuck 1 that holds the substrate W, a substrate stage that supports the substrate chuck 1 and moves, a mold chuck 3 that holds the mold M on which the pattern P is formed, and a mold chuck 3 that supports the mold Moving mold table 4. The imprint apparatus 100 further includes a dispenser 11 that supplies the resin R onto the substrate, and a control unit 12 that controls the entire imprint apparatus 100. Further, the imprint apparatus 100 includes a console unit 13 that generates an operation screen, a display unit 14 that displays an operation screen, an input device 15 that includes a keyboard and a mouse, and detects contact between the mold M and the resin R on the substrate. A force sensor 16 that generates force. When the substrate W to which the resin R has been supplied by the external device different from the imprint apparatus 100 is loaded into the imprint apparatus 100, the imprint apparatus 100 may not include the dispenser 11.

In a state where the mold M and the resin R on the substrate W supplied from the dispenser 11 are in contact with each other, the imprint apparatus 100 performs an imprint process of forming a pattern on the substrate by curing the resin R, and then, from curing The resin R releases the mold M. The imprint process includes a supply program, an imprint program, a curing program, and a release program. The supply procedure is a procedure for supplying the resin R onto the substrate (first step). The imprint process is a program (second step) of bringing the mold M into contact with the resin R on the substrate. By pressing the mold M and the resin R on the substrate with each other, that is, pressing the mold M against the resin R, the pattern P of the mold M is filled with the resin R. The curing procedure is a procedure of curing the resin R in a state where the mold M and the resin R on the substrate are in contact with each other. The release procedure is a procedure for releasing the mold M from the resin R cured on the substrate (third step).

A recessed portion larger than the area of the pattern P is formed on the surface of the mold chuck 3 opposite to the pattern surface of the mold M. The recessed portion is sealed by a mold M and a sealing glass (not shown) to define a closed space (cavity). A pressure control unit (not shown) is coupled to the chamber and controls the pressure of the chamber. When the mold M and the resin R on the substrate are brought into contact with each other, the pressure of the cavity is raised to deform the mold M into a shape protruding toward the substrate, thereby suppressing the retention of bubbles between the mold M and the resin R on the substrate. When the mold M and the resin R on the substrate are in contact with each other, the pressure of the cavity is restored, so that the mold M becomes parallel to the substrate W (completely contacting the resin R on the substrate).

The imprint apparatus 100 further includes an alignment oscilloscope 5 that detects an alignment mark (substrate side mark) 6 provided on the substrate W and an alignment mark (mold side mark) 7 provided on the mold M. The alignment oscilloscope 5 functions as an alignment detecting unit that detects the substrate side mark 6 formed in the shot region on the substrate W and the mold side mark 7 formed on the pattern P of the mold M, and generates alignment signal. As a method of detecting the substrate side mark 6 and the mold side mark 7, for example, a method of detecting a moire fringe (interference fringe) reflecting the relative positions of the two marks can be used. It is also possible to detect the images of the substrate side marks 6 and the mold side marks 7 and obtain the relative positions of the two marks.

The control unit 12 includes a CPU and a memory, and controls each unit of the imprint apparatus 100 to perform an imprint process. For example, the control unit 12 obtains the relative position (positional deviation) of the mold M and the substrate W based on the detection result of the substrate side mark 6 and the mold side mark 7 aligned with the oscilloscope 5. The control unit 12 moves the substrate stage 2 and the die stage 4 to correct the positional deviation between the mold M and the substrate W based on the relative positions of the mold M and the substrate W. The positional deviation between the mold M and the substrate W includes an offset component, an amplification component, a rotation component, and the like. In addition, by using, for example, a pressure finger (not shown) disposed around the mold M, the control unit 12 can correct the shape of the pattern P of the mold M according to the shape of the photographing area on the substrate W. In this embodiment, the control unit 12 functions as a judging unit that judges the normal/abnormality of the imprint process, which will be described later.

The imprint apparatus 100 further includes a light source 8 that emits ultraviolet rays, an observation unit 9 that observes at least one of the mold M and the substrate W, and a mirror 10. The mirror 10 includes a dichroic mirror and has a characteristic that the mirror 10 reflects ultraviolet rays from the light source 8 and transmits light (observation light) from the observation unit 9. The ultraviolet ray from the light source 8 is reflected by the mirror 10 to illuminate the resin R on the substrate via the mold M and cure the resin R, thereby forming the pattern P of the mold M on the substrate.

The observation unit 9 includes an observation light source 9a and an image sensor 9b, and functions as an image sensing unit that senses at least one of the mold M and the substrate W to obtain an image. The observation light from the observation light source 9a passes through the mirror 10 and the mold M, and illuminates the substrate W (photographing area). Image sensing The device 9b detects light reflected by the surface of the substrate W as observation light and light reflected by the pattern surface of the mold M. As described above, when the mold M and the resin R on the substrate are brought into contact with each other, the mold M is deformed into a shape protruding toward the substrate. Therefore, the gap between the mold M and the substrate W continuously changes from the portion where the mold M and the substrate W contact each other. The image sensor 9b senses interference fringes between the light reflected by the surface of the substrate W and the light reflected by the pattern surface of the mold M, a so-called Newton ring. 2A and 2B are views showing an example of interference fringes observed by the observation unit 9. 2A shows the gap between the mold M and the substrate W, and FIG. 2B shows the image sensed by the image sensor 9b.

A general imprint process will be described with reference to Fig. 3 and Figs. 4A to 4F. As shown in FIG. 3, the imprint process includes a supply program (step S101), an imprint process (step S102), a hardening process (step S103), and a release process (step S104). 4A to 4F are views showing changes in the state of the substrate W in the imprint process.

FIG. 4A shows the state of the substrate W before the start of the imprint process. As shown in FIG. 4A, the substrate W is not processed.

FIG. 4B shows the state of the substrate W that has undergone the supply process. In the supply process, the resin R is supplied to the substrate W by discharging the droplets of the resin R from the dispenser 11 onto the substrate. As shown in FIG. 4B, the droplets of the resin R are supplied to predetermined positions on the substrate, thereby forming a layout of droplets of the resin R on the substrate.

Fig. 4C shows the state of the substrate W in the imprint process. In the imprinting process, as shown in FIG. 4C, the mold M is deformed toward the substrate. In the state of the side protruding shape, the mold M is brought close to the substrate W, so that the mold M is gradually brought into contact with the resin R on the substrate from the center to the periphery of the mold M. In the imprint process, a gap is generated between the mold M and the substrate W, and interference fringes as shown in Fig. 2B are observed.

Fig. 4D shows the state of the substrate W in the curing process. In the curing step, the resin R is irradiated with ultraviolet rays from the light source 8 and is solidified in a state where the mold M and the resin R on the substrate are in contact with each other. In the curing step, as shown in FIG. 4D, the mold M and the resin R on the substrate are completely in contact with each other, and the pattern P of the mold M is filled with the resin R.

Fig. 4E shows the state of the substrate W in the release procedure. In the releasing procedure, as shown in FIG. 4E, while deforming the mold M into a shape protruding toward the substrate, the mold M is released from the substrate W to lower the release force for the slave substrate. The cured resin R releases the force of the mold M. In the releasing procedure, as in the imprinting process, a gap is generated between the mold M and the substrate W, and interference fringes as shown in Fig. 2B are observed.

Fig. 4F shows the state of the substrate W at the end of the imprint process. As shown in FIG. 4F, a pattern of the resin R corresponding to the pattern P of the mold M is formed.

In this manner, the state of the substrate W during the imprint process is changed in accordance with each of the processes in the imprint process. In the prior art, the normal/abnormality of the imprint process is judged after the pattern of the resin R corresponding to the pattern P of the mold M is formed on the substrate W (the state of the substrate W shown in FIG. 4F). In other words, the prior art is limited to The normal/abnormality of the imprint process is judged after the release process, and the normal/abnormality of the imprint process cannot be accurately judged in other processes of the imprint process.

In this embodiment, the normal/abnormality of the imprint process is judged during the imprint process, that is, it is judged in each process of the imprint process. At this time, the normal/abnormal judgment criterion of the imprint process is changed for each process of the imprint process, which will be described later. In other words, the normal/abnormal judgment of the imprint process is switched to be applied to the supply program (step S101), the imprint process (step S102), the hardening process (step S103), and the release process (step S104) as shown in FIG. The judgment of each of the programs, that is, the judgment for each state of the substrate W.

FIG. 5 is a flowchart for explaining an imprint process according to this embodiment. The imprint process according to this embodiment similarly includes a supply program (step S101), an imprint process (step S102), a hardening process (step S103), and a release process (step S104). These procedures have been described above and their detailed description will not be repeated. In Fig. 5, the imprint process (step S102) is divided into the start of the imprint process (step S102-1) and the end of the imprint process (step S102-2), at the beginning of the imprint process (step S102-1). In the middle, the operations of moving the mold M and the substrate W relatively close to each other are started, and at the end of the imprint process (step S102-2), the operation is ended. Similarly, the release program (step S104) is divided into the start of the release program (step S104-1) and the end of the release program (step S104-2), at the beginning of the release program (step S104-1), The operations of moving the mold M and the substrate W are relatively separated from each other, and at the end of the release program (step S104-2), the operation is ended.

In step S201, the state of the substrate W before the start of the imprint process is checked. For example, the observation unit 9 or the like is used to check whether or not particles (foreign matter or dust) or the like adhere to the substrate W.

In step S202, the normal/abnormality of the imprint process is judged based on the image sensed by the observation unit 9 (image sensor 9b) in the supply program (step S101). In the imprint apparatus 100, as shown in FIGS. 6A and 6D, the dispenser 11 has an arrangement in which a plurality of orifices 61 for discharging the droplets of the resin R are arranged in one row to shorten the cost of supplying the resin R to the substrate W. time. In the supply procedure (step S101), as shown in FIGS. 6B and 6E, by ejecting the droplets of the resin R from the plurality of orifices 61 of the dispenser 11 while moving the substrate stage 2 in the scanning direction 62, the resin R is It is supplied to the substrate W.

6B shows an image sensed by the image sensor 9b when the supply of the resin R to the substrate W is normally performed, and shows the liquid of the resin R on the substrate to which the dispenser 11 has supplied the resin R. The layout of the drops. Referring to FIG. 6B, it can be confirmed that the droplets of the resin R have been uniformly formed on the substrate, and the droplets of the resin R which should be supplied to the substrate are not missed.

Conversely, FIG. 6E shows that when the supply of the resin R to the substrate W is not normally performed, for example, when dust adheres to the orifice 63 in the plurality of orifices 61 of the dispenser 11 and the droplets of the resin R cannot be discharged An image sensed by the image sensor 9b. Referring to FIG. 6E, it can be confirmed that the droplet of the resin R is on the substrate corresponding to the region of the orifice 63 of the dispenser 11. 64 was missed.

In the judgment of the normal/abnormality of the imprint process in step S202, it is judged whether or not the droplet of the resin R which should be supplied to the substrate is missing. As a reference for judging the normal/abnormality of the imprint process, an image of the droplet of the resin R that is normally discharged from the dispenser 11 is used. At this time, an image sensed by the image sensor 9b in the supply program (the layout of the droplets of the resin R therein) and a reference pattern obtained when the dispenser 11 normally discharges the droplets of the resin R The comparison is made like (the reference layout of the droplets of the resin R).

The normal/abnormal determination of the imprint process in step S202 will be described in detail by taking as an example the case where the change in the brightness in the image sensed by the image sensor 9b is used. FIG. 6C is a diagram showing the brightness of the image shown in FIG. 6B along the broken line 65. In Figure 6C, the ordinate represents the brightness in the image and the abscissa represents the position in the image. When the supply of the resin R to the substrate W is normally performed, the brightness in the image sensed by the image sensor 9b is less changed, as shown in Fig. 6C. Fig. 6F is a view showing the luminance of the image (reference image) shown in Fig. 6E along the broken line 65. In Figure 6F, the ordinate represents the brightness in the image and the abscissa represents the position in the image. When the supply of the resin R to the substrate W is not normally performed, the luminance at the portion corresponding to the aperture 63 of the dispenser 11 is different from the luminance at the remaining portion as shown in FIG. 6F. The image sensed by the image sensor 9b in the supply program is compared with the reference image, and when the change in the brightness in the image exceeds a predetermined range, the resin R that should be supplied onto the substrate can be judged The droplets are missing, that is, The imprint process is abnormal.

In step S202, the normal/abnormality of the imprint process is judged. If it is judged that the imprint process is abnormal, the imprint process is stopped, and the occurrence of defects such as partial pattern missing on the substrate can be prevented. If the omission of the droplet of the resin R to be supplied onto the substrate is detected as an abnormality of the imprint process in step S202, the removal procedure for the dust attached to the dispenser 11 (orifice) is automatically performed, And the imprint process can continue.

In step S203, the normal/abnormality of the imprint process is judged based on the image sensed by the observation unit 9 (image sensor 9b) after the start of the imprint process (step S102-1). In the determination of the normal/abnormality of the imprint process in step S203, it is determined whether or not particles are attached to the substrate W.

The normal/abnormal judgment of the imprint process in step S203 will be explained in detail. Here, whether or not the particles are attached to the substrate W is at the same position between the image sensed by the image sensor 9b after the start of the reference image and the imprint process (step S102-1) The difference image of the difference in brightness of each pixel is judged. As a reference for judging the normal/abnormality of the imprint process, an image obtained when the imprint process is normally performed is used. The reference image is an image sensed by the image sensor 9b after the start of the imprint process (step S102-1) when the imprint process is normal.

Fig. 7B shows a difference image obtained when no particles are attached to the substrate W (as shown in Fig. 7A). The difference image shown in Figure 7B It is a difference image that does not change significantly and includes only low brightness values. This is because normal images are compared to each other. Fig. 7D shows a difference image obtained when the particle G is attached to the substrate W (as shown in Fig. 7C). The difference image shown in FIG. 7D is even a difference image including a high luminance value because a large portion is generated between the image and the reference image at the portion G' where the particle G attached to the substrate W exists. difference. When the difference image between the reference image and the image sensed by the image sensor 9b after the start of the imprinting program includes a luminance value exceeding a predetermined luminance value, it can be determined that the particle G is attached to the substrate. W, that is, the imprint process is abnormal.

If the imprinting process is continued in a state where the particles G are attached to the substrate W, the mold M and the particles G may come into contact with each other, thereby damaging the pattern P of the mold M. Therefore, the judgment as to whether or not the particles G are attached to the substrate W (step S203) is preferably performed at a time point when the mold M and the resin R on the substrate are in contact with each other. Therefore, it can be judged earlier that the particles G are attached to the substrate W (abnormality of the imprint process). When the particle G is attached to the substrate W, the imprint process is stopped and damage of the mold M can be avoided. It is not only determined that the particles G are attached to the substrate W, but it is also judged that the particles are attached to the mold M. In this way, the presence/absence of particles between the mold M and the substrate W can be judged (detected).

In order to detect the point in time when the mold M and the resin R on the substrate are in contact with each other, the force sensor 16 is used. FIG. 8 is a diagram for explaining a point in time at which the normal/abnormal determination (step S203) of the imprint process is performed. In FIG. 8, the ordinate represents the output of the force sensor 16 (the force detected by the force sensor 16) disposed on the substrate chuck 1, and the abscissa Represents the time from the start of the imprint process to the end of the imprint process. Figure 8 shows the change in force (imprint force) generated by the contact between the mold M and the resin R on the substrate in the imprint process. Referring to Fig. 8, the mold M and the resin R on the substrate are separated from each other at the beginning of the imprint process, so the output of the force sensor 16 is zero. As the imprinting process proceeds, and the mold M and the resin R on the substrate come into contact with each other, the output of the force sensor 16 gradually increases. At the time point when the force sensor 16 detects the force generated by the contact between the mold M and the resin R on the substrate, it is judged whether or not the particle G is attached to the substrate W. In some cases, after the mold M and the resin R on the substrate are in contact with each other, there is a time allowance before the mold M and the particles G attached to the substrate W are in contact with each other. In this case, whether or not the particles G are attached to the substrate W can be judged at a time point T1 when the output of the force sensor 16 exceeds the threshold Th. Note that the time point when the mold M and the resin R on the substrate are in contact with each other can also be detected without using the force sensor 16 but using an image sensed by the observation unit 9 (image sensor 9b). For example, the presence/absence of particles between the mold M and the substrate W is judged at a time point when the size (diameter) of the interference fringes sensed by the image sensor 9b becomes larger than the predetermined size PS.

In step S204 in parallel with step S203, the normal/abnormality of the imprint process is based on the image sensed by the observation unit 9 (image sensor 9b) after the start of the imprint process (step S102-1). To judge. As a reference for judging the normal/abnormality of the imprint process, an image of the interference fringes sensed by the image sensor 9b is used. In the steps In the normal/abnormal judgment of the imprint process in S204, the contact state between the mold M and the resin R on the substrate, and the mutual posture of the mold M and the resin R are judged based on the interference fringes as shown in FIG. 2B. . For example, information about at least any one of the position and the roundness of the sensed interference fringes as shown in FIG. 2B is obtained. Based on this information, it is judged whether or not the mold M contacts the resin R on the substrate in an inclined state. The interference fringe can be obtained by comparing the interference fringes sensed by the image sensor 9b after the start of the imprint process with the reference interference fringes obtained when the mold M and the resin R on the substrate are normally in contact with each other. Information on at least one of the position and the roundness. Note that the normal/abnormal judgment of the imprint process in step S204 and the normal/abnormal judgment of the imprint process (step S205) performed after the start of the release program (described later) (step S104-1) are The same, and will not repeat its detailed description.

The timing of performing the normal/abnormal determination of the imprint process (step S204) will be explained with reference to FIG. 9 and FIGS. 10A to 10C. FIG. 9 shows the alignment signals produced by the alignment oscilloscope 5. In Fig. 9, the ordinate represents the intensity of the alignment signal, and the abscissa represents the time from the start of the imprint process to the end of the imprint process.

Fig. 10A shows the state of the mold M and the substrate W at the time point T _A shown in Fig. 9. The alignment oscilloscope 5 detects the mold side mark 7 and the substrate side mark 6 by detecting the reflected light RL. When the mold side mark 7 and the substrate side mark 6 are separated from each other, as shown in FIG. 10A, they cannot be detected, and an alignment signal as shown in FIG. 9 is not generated.

Fig. 10B shows the state of the mold M and the substrate W at the time point T _B shown in Fig. 9. As shown in FIG. 10B, at the time point T _B , the mold M and the resin R on the substrate are in contact with each other, and the resin R starts to fill the pattern P of the mold M. As the mold side mark 7 and the substrate side mark 6 are close to each other, the mold side mark 7 and the substrate side mark 6 are detected. However, while the pattern P of the mold M is continued by the filling of the resin R, the reflected light RL fluctuates depending on the action of the resin R. Thereby, the alignment signal generated by the alignment oscilloscope 5 changes as shown in FIG.

Fig. 10C shows the state of the mold M and the substrate W at the time point T _C shown in Fig. 9. As shown in FIG. 10C, at the time point T _C , the pattern P of the mold M is sufficiently filled with the resin R on the substrate, so the resin R is no longer moved and the reflected light RL is stabilized. Therefore, the alignment signal generated by the alignment oscilloscope 5 is also stabilized as shown in FIG.

Thereby, whether or not the mold M contacts the resin R on the substrate in an inclined state is judged at a time point T _D when the alignment signal generated by the alignment oscilloscope 5 is stabilized in the preset period PP, as shown in the figure 9 is shown. By using the alignment oscilloscope 5, the time point at which the normal/abnormal determination of the imprint process (step S204) is performed can be specified. However, the present invention is not limited thereto, and the time point at which the normal/abnormal judgment (step S204) of performing the imprint process can be specified using the force sensor 16 as described above, instead of the alignment oscilloscope 5. In this case, whether the mold M contacts the resin R on the substrate in an inclined state is at a time point when the output of the force sensor 16 exceeds a threshold value, or when the force sensor 16 detects by the mold M The time point when the force generated by the contact with the resin R on the substrate is judged.

In the imprinting process, the alignment between the mold M and the substrate W is performed based on the detection result of the alignment oscilloscope 5 in the period AP shown in FIG. The normal/abnormality of the imprint process is judged at the time point T _C . If it is judged that the imprint process is abnormal, the imprint process is stopped, and unnecessary alignment between the mold M and the substrate W can be prevented.

In step S205 in parallel with steps S203 and S204, the normal/abnormality of the imprint process is based on the sensing by the observation unit 9 (image sensor 9b) after the start of the imprint process (step S102-1). The image is judged. In the judgment of the normal/abnormality of the imprint process in step S205, it is judged whether or not the droplet of the resin R which should be supplied from the dispenser 11 onto the substrate is missing.

In the imprint apparatus 100, as shown in FIGS. 14A and 14C, the dispenser 11 has an arrangement in which a plurality of orifices 61 for discharging droplets of the resin R are arranged in one row to shorten the cost of supplying the resin R to the substrate W. time. In the supply procedure (step S101), as shown in Figs. 14B and 14D, by ejecting the droplets of the resin R from the plurality of orifices 61 of the dispenser 11 while moving the substrate stage 2 in the scanning direction 62, the resin R is It is supplied to the substrate W.

14B shows an image sensed by the image sensor 9b during the imprinting process when the supply of the resin R to the substrate W is normally performed, and the pattern P of the mold M is displayed by the imprint process. The state in which the resin P is filled. Figure 14B shows the interference fringes at the time point after the embossing process continues, and the interference fringes observed in the imprint process (Fig. In 2A and 2B), the circle at the center of the interference fringe extends to the entire surface of the mold M (pattern P). Referring to FIG. 11B, it can be confirmed that the luminance of the pixel does not change in the region corresponding to the mold M (pattern P), and the droplet of the resin R that should be supplied onto the substrate is not missed.

In contrast, FIG. 14D shows an image sensed by the image sensor 9b during the imprinting process when the supply of the resin R to the substrate W is not normally performed. The case where the supply of the resin R to the substrate W is not normally performed is, for example, the case where the dust is adhered to the orifice 63 in the plurality of orifices 61 of the dispenser 11 and the droplets of the resin R cannot be discharged from the orifice 63. . Referring to FIG. 14D, it can be confirmed that the pixel luminance in the region 64 corresponding to the aperture 63 of the dispenser 11 on the substrate is different from the luminance of the pixel in the remaining region.

15A and 15B are views for explaining the interference fringes observed in Fig. 14D. Fig. 15A shows a gap between the mold M and the substrate W while the imprint process is being performed, and a state in which the pattern P of the mold M is filled with the resin R. Figure 15B shows a portion of the image sensed by image sensor 9b. Referring to Fig. 15B, the mold M and the resin R having a refractive index close to each other are in contact with each other in the region 121 where the droplets of the resin R are not missed, and therefore the reflectance at the interface between the mold M and the resin R is very low. Therefore, the reflected light in the region 121 where the droplets of the resin R are not missed becomes weak, and a dark image is obtained in the image sensor 9b.

In the region 122 where the droplets of the resin R are missing, there is a gap between the mold M and the resin R. The light reflected by the mold M and the light reflected by the resin R interfere with each other and are obtained in the image sensor 9b. Bright image. In other words, a region where a gap exists between the mold M and the resin R produces a bright image. Since the omission of the droplet of the resin R can be detected in a region having a size larger than that of one droplet of the actual resin R, the observation unit 9 having a lower resolution than that necessary for detecting one droplet of the resin R ( The image sensor 9b) can detect the omission of the droplets of the resin R.

In this way, whether or not the droplet of the resin R that should be supplied from the dispenser 11 onto the substrate is missing can be judged from the image in Fig. 14D obtained by the image sensor 9b. Note that the interference fringes include a case where there is a bright streak due to the omission of the droplet in one portion, as shown in FIG. 11D, and a plurality of variable densities due to the omission of the droplets in the plurality of portions. The streak is repeated.

As described above, in the judgment of the normal/abnormality of the imprint process in step S205, it is judged whether or not the droplet of the resin R which should be supplied from the dispenser 11 onto the substrate is missing. At this time, the image sensed by the image sensor 9b in the imprint process is compared with the reference image obtained when the dispenser 11 normally discharges the droplet of the resin R. By exemplifying the case where the presence/absence of vertical streaks (light/dark lines) in the scanning direction (moving direction) in the image sensed by the image sensor 9b is used, the pressure in step S205 is taken as an example. The normal/abnormal judgment of the printing process will be explained in detail.

Fig. 16 shows a difference image between the image shown in Fig. 14B and the image shown in Fig. 14D. Referring to FIG. 16, in the difference image, pixels having differences become white, and pixels having no difference become dark. From difference The image extracts a boundary 131 where the pixel brightness changes here. The presence/absence of vertical streaks in the scanning direction is judged based on whether the boundary 131 is parallel to the scanning direction 62 (that is, whether the boundary 131 approximates a straight line indicating the scanning direction 62).

In this embodiment, the judgment as to whether or not the droplet of the resin R is missing is also performed even in step S202. In step S202, the droplets of the resin R on the substrate are directly observed, and thus the brightness of each pixel changes depending on the presence/absence of the droplets in the image obtained by the image sensor 9b, as shown in the figure. Shown in 6B. In contrast, in step S205, the imprint process is started, and the interference fringes when the pattern P of the mold M is filled with the resin R are observed, and the luminance of each pixel is hardly changed as shown in Figs. 14B and 14D. In step S205, the low resolution of the image sensor 9b is allowed as compared with the step S202, and as a clearer vertical streak, the omission of the droplet of the resin R can be detected.

Note that the time point at which the normal/abnormal judgment (step S205) of performing the imprint process may be the time point when the pattern P of the mold M is filled with the resin R, like the time point T _D shown in FIG. The area 64 (vertical streak) detected when the droplet of the resin R is missed can be detected even during filling with the resin R, during which the interference fringes shown in Figs. 2A and 2B are obtained. Therefore, the time point at which the normal/abnormal judgment (step S205) of performing the imprint process is not limited to the time point T _D shown in FIG. 9, and may be any time when the region 64 shown in FIG. 14D can be detected. point.

In step S205, it is determined that the imprinting process is normal/different often. If it is judged that the imprint process is abnormal, the imprint process is stopped, and the occurrence of defects such as partial pattern missing on the substrate can be prevented. If the omission of the droplet of the resin R to be supplied onto the substrate is detected as an abnormality of the imprint process in step S205, the removal procedure for the dust attached to the dispenser 11 (orifice) is automatically performed, And the imprint process can continue.

In step S206, the normal/abnormality of the imprint process is judged based on the image sensed by the observation unit 9 (image sensor 9b) after the start of the release program (step S104-1). In the releasing procedure, if the resin R which is solidified from the substrate in the inclined state is released, as shown in FIG. 11A, the pattern of the resin R formed on the substrate may collapse or be damaged.

In the normal/abnormal determination of the imprint process in step S206, whether or not the mold M is released from the resin R which is solidified on the substrate in the inclined state is judged based on the interference fringes as shown in FIG. 2B or 11B. As a reference for judging the normal/abnormality of the imprint process, an image of the interference fringes sensed by the image sensor 9b is used. More specifically, the positions Pos X and Pos Y of the interference fringes and the roundness (ratio of the width to the height) are first obtained as shown in FIG. 11B. The position of the interference fringe can be obtained by comparing the interference fringes sensed by the image sensor 9b after the start of the release procedure with the reference interference fringes obtained when the mold M is normally released from the resin R on the substrate. And roundness. When the position and the roundness of the interference fringe exceed the threshold value, it is judged that the resin R solidified from the substrate in the inclined state by the mold M is released, that is, the imprint process is abnormal. In this way, even when The state of the substrate W is largely changed in a short period of time, and the normal/abnormality of the imprint process can also be judged with high accuracy by using the interference fringes sensed by the image sensor 9b.

The time point at which the normal/abnormal judgment (step S206) of the imprint process is performed will be explained with reference to FIGS. 12A to 12C. 12A to 12C show images (interference fringes) sensed by the image sensor 9b as time passes by the release procedure. In the releasing procedure, the mold M is deformed into a shape protruding toward the substrate to reduce the releasing force, which is a force for releasing the mold M from the resin R solidified on the substrate, as described above. Starting from the periphery of the mold M, the mold M is released from the resin R solidified on the substrate, and peeling of the resin R from the substrate W can be prevented. In the releasing procedure, as in the imprinting process, a gap is generated between the mold M and the substrate W, and interference fringes as shown in Figs. 12A to 12C are observed. Referring to FIGS. 12A to 12C, as the contact area between the mold M and the resin R cured on the substrate is reduced, the size of the interference fringes is gradually reduced. At a time point when the size (diameter) of the interference fringe becomes smaller than the predetermined size PS, it is judged whether or not the mold M is released from the resin R which is solidified on the substrate in an inclined state.

Since the release procedure is generally performed in a short time, it is difficult to specify a point in time at which it is judged whether or not the mold M is released from the substrate by the resin R in an inclined state. However, by using the size of the interference fringes sensed by the image sensor 9b, this embodiment can specify a point in time at which it is judged whether or not the mold M is released from the resin R which is solidified on the substrate in an inclined state.

In step S207, the normal/abnormality of the imprint process is judged based on the image sensed by the observation unit 9 (image sensor 9b) after the release procedure. As a reference for judging the normal/abnormality of the imprint process, an image of the interference fringes sensed by the image sensor 9b is used. In the normal/abnormal determination of the imprint process in step S207, it is judged whether or not the pattern has been normally formed on the substrate W, for example, whether or not the resin R has been peeled off from the substrate W.

The resin R having a pattern corresponding to the pattern P of the mold M is formed on the substrate W by releasing the mold M from the resin R solidified on the substrate. Fig. 13A shows an image sensed by the image sensor 9b when the releasing step has been normally performed. If the pattern P of the mold M is a periodic line-and-space pattern, an image in which the luminance is low at the portion where the resin R is formed on the substrate W and which is high at the remaining portion is obtained. As shown in Figure 13A. FIG. 13C shows an image sensed by the image sensor 9b when the releasing step is not normally performed, for example, when the resin R has been peeled off from the substrate W and attached to the mold M. In this case, an image in which the luminance is high at the portion 71 where the peeling of the resin R occurs is obtained as shown in Fig. 13C.

Thereby, whether or not the resin R is peeled off from the substrate W is judged using the difference image representing the same position between the reference image and the image sensed by the image sensor 9b after the release procedure The difference in brightness of each pixel. The reference image is an image sensed by the image sensor 9b after the release process when the imprint process is normal.

Fig. 13B shows when the resin R is not peeled off from the substrate W. The difference image obtained is as shown in Fig. 13A. The difference image shown in Fig. 13B is a difference image which does not largely change and includes only low luminance values. This is because normal images are compared to each other. Fig. 13D shows a difference image obtained when the resin R is peeled off from the substrate W, as shown in Fig. 13A. The difference image shown in Fig. 13D is a difference image including even a high luminance value because a large difference is generated between the image and the reference image at the portion 72 where the peeling of the resin R has occurred. When the difference image between the reference image and the image sensed by the image sensor 9b after the start of the release program includes the brightness value exceeding the predetermined brightness value, it can be judged that the resin R has been peeled off from the substrate W, That is, the imprint process is abnormal.

The normal/abnormal judgment of the imprint process using such a difference image is effective even when judging the normal/abnormality of the imprint process on the substrate having the underlayer on which the existing pattern is formed. . In this case, a baseline image needs to be prepared for each underlayer.

The imprint apparatus 100 according to this embodiment can accurately judge the normal/abnormality of the imprint process by grasping the state of the substrate W with high precision in each process of the imprint process. The imprint apparatus 100 can suppress the influence of abnormality of the imprint process and improve productivity.

The imprint apparatus 100 according to this embodiment uses a plurality of pieces of information from the alignment oscilloscope 5, the force sensor 16, and the observation unit 9 to specify a point in time at which the normal/abnormality of the imprint process is judged. Not at the time point when each process of the imprint process is switched, but a time point suitable for judging the normal/abnormality of the imprint process can be specified. In the imprint process or the like, the normal/abnormality of the imprint process may be different in the state corresponding to the substrate W. The time is judged.

Although, according to this embodiment, the normal/abnormality of the imprint process is judged in the supply program, the imprint process, and the release program, the present invention is not limited thereto. For example, the normal/abnormality of the imprint process may be judged in at least two of the supply program, the imprint process, and the release program, or in at least one of the supply step and the imprint step. The normal/abnormality of the imprint process can be judged even at intervals between the imprinting step and the curing step, or between the curing step and the releasing step.

When it is judged that the imprint process is abnormal, an error program corresponding to the abnormality is executed. For example, when it is judged in step S203 that the particle G is attached to the substrate W, a program for removing the particle G or a program for storing a position on the substrate on which the particle G is attached may be performed. When the particle G cannot be removed, the imprint process may be stopped, or the mold M may be prevented from coming into contact with the particle G (preventing the formation of a pattern).

This embodiment has been described as an example of a resin curing method by a photocuring method of curing a resin by irradiation with ultraviolet rays (light). However, the resin curing method is not limited to the photocuring method, and may be a heat cycle method. In the thermal cycle method, the thermoplastic resin is heated to a temperature equal to or higher than the glass transition temperature to enhance fluidity. In this state, the mold and the resin are brought into contact with each other, and the resin is cooled and solidified. The resin from which the mold is cured from the substrate is released, thereby forming a pattern on the substrate.

A method of manufacturing a device (for example, a semiconductor device, a magnetic storage medium, or a liquid crystal display element) as an article will be explained. This system The method includes the step of forming a pattern on a substrate (eg, a wafer, a glass plate, or a film substrate) using the imprint apparatus 100. This manufacturing method also includes the step of processing the substrate on which the pattern has been formed. The processing step may include the step of removing the residual film of the pattern. Additionally, the method can include other known steps, such as the step of etching the substrate using the pattern as a mask. The method of manufacturing an article according to this embodiment is advantageous over the prior art in terms of at least one of the performance, quality, productivity, and production cost of the article.

While the invention has been described with reference to the preferred embodiments thereof, it is understood that the invention is not limited to the illustrative embodiments disclosed. The scope of the following claims is to be accorded the breadth of the

Claims (19)

An imprint apparatus for performing an imprint process of forming a pattern of an imprint material on a substrate using a mold, the imprint apparatus comprising: an image sensing unit configured to obtain the mold during the imprint process is performed And an image of at least one of the substrates; and a determination unit configured to determine a normal/abnormality of the imprint process, wherein the imprint process includes a first step of supplying the imprint material to the substrate, And a second step of contacting the mold and the imprint material on the substrate with each other, and wherein the judging unit is based on the image sensing unit obtained after the imprint material is expanded to the entire surface of the mold The image judges normal/abnormality of the imprint process with respect to the first reference in the first step, and normality of the imprint process with respect to the second datum different from the first datum in the second step / abnormal, and during the imprint process, the determination unit performs the normal/abnormal determination while switching between the first reference and the second reference. An imprint apparatus according to claim 1, wherein the imprint process comprises a third step of releasing the mold from the imprint material solidified on the substrate, and in the third step, the judging unit The normal/abnormality of the imprint process regarding the third reference different from the first reference and the second reference is judged based on the image obtained by the image sensing unit. An imprint apparatus according to claim 1, wherein the image sensing unit obtains light reflected by the mold and An image of interference fringes between the lights reflected by the substrate, and in the second step, the determining unit determines the normal/abnormality of the imprint process based on the interference fringes. An imprint apparatus according to claim 3, wherein in the second step, the judging unit judges presence/absence of foreign matter between the mold and the substrate based on the interference fringes. An imprint apparatus according to claim 3, wherein the information based on at least one of a position and a roundness of the interference fringes included in the image obtained by the image sensing unit is The judging unit judges whether the mold contacts the imprint material on the substrate in an inclined state. An imprint apparatus as claimed in claim 3, further comprising a dispenser configured to supply droplets of the imprint material onto the substrate, wherein based on being included in the image sensing unit The interference fringes in the image, the judging unit judges whether or not the droplets to be supplied from the dispenser to the substrate are missing. An imprint apparatus as claimed in claim 6, wherein the judging unit compares the interference fringes included in the image obtained by the image sensing unit and when it should be supplied from the dispenser to the The reference interference fringes obtained when the droplets on the substrate are not missed, detecting the presence/absence of light/dark lines generated in the moving direction of the substrate when the dispenser supplies the droplets, and determining Whether or not the droplets that should be supplied to the substrate are missing. The imprint apparatus of claim 7, wherein the judging unit is based on being included in the image obtained by the image sensing unit Whether the boundary line of the interference fringes in the interference fringes approximates a line parallel to the moving direction to detect the presence/absence of the light/dark line in the interference fringes. An imprint apparatus as claimed in claim 3, further comprising a force sensor configured to detect a force generated by contact between the mold and the imprint material on the substrate, wherein the judging unit The normal/abnormality of the imprint process is judged at a point in time when the force detected by the force sensor exceeds a threshold. An imprint apparatus as claimed in claim 3, further comprising a force sensor configured to detect a force generated by contact between the mold and the imprint material on the substrate, wherein the judging unit The normal/abnormality of the imprint process is judged at the time point when the force sensor detects the force. An imprint apparatus as claimed in claim 3, further comprising an alignment detecting unit configured to detect a mark formed on the mold and a mark formed on the substrate and generate an alignment signal, wherein the determining unit is The alignment/signal generated by the alignment detecting unit determines the normal/abnormality of the imprint process at a time point when the preset period is stabilized. An imprint apparatus according to claim 3, wherein the judging unit at a time point when the size of the interference fringes included in the image obtained by the image sensing unit becomes larger than a predetermined size The normal/abnormality of the imprint process is judged. An imprinting apparatus as claimed in claim 2, wherein The image sensing unit obtains an image including interference fringes between light reflected by the mold and light reflected by the substrate, and in the third step, the determining unit determines based on the interference fringes This normal/abnormal of the imprint process. The imprint apparatus according to claim 13, wherein the judging unit judges the normal/abnormality of the imprint process at a time point when the size of the interference fringes becomes smaller than a predetermined size. An imprint apparatus according to claim 1, wherein the first reference or the second reference includes a reference for determining a normal/abnormality of an orifice provided in the supply unit, the supply unit being configured to apply the pressure The printing material is supplied onto the substrate. An imprint apparatus for performing an imprint process of forming a pattern of an imprint material on a substrate using a mold, the imprint apparatus comprising: an image sensing unit configured to obtain the mold during the imprint process is performed And an image of at least one of the substrates; and a determination unit configured to determine a normal/abnormality of the imprint process, wherein the imprint process includes a first step of supplying the imprint material to the substrate, a second step of bringing the mold and the imprint material on the substrate into contact with each other, and a third step of releasing the mold from the imprint material cured on the substrate, and the judging unit is based on expanding in the imprint material The image obtained by the image sensing unit after the entire surface of the mold determines the normal/abnormality of the imprint process with respect to the first reference in the first step, and the difference in the second step The imprint process on the second reference of the first reference Normal/abnormal, and normal/abnormal of the imprint process with respect to the third reference different from the first reference and the second reference in the third step, and during the imprint process, at the The determination unit performs the normal/abnormal determination while switching between a reference, the second reference, and the third reference. An imprint method for performing an imprint process of forming a pattern of an imprint material on a substrate using a mold, the imprint process including a first step of supplying the imprint material to the substrate, and the mold and the substrate a second step of contacting the embossed materials with each other, the embossing method determining based on an image obtained by sensing at least one of the mold and the substrate after the embossed material is extended to the entire surface of the dies a normal/abnormality of the imprint process with respect to the first reference in the first step, and a normal/abnormality of the imprint process with respect to the second datum different from the first datum in the second step, and During the imprint process, the imprint method performs the normal/abnormal determination while switching between the first reference and the second reference. A method of manufacturing an article, the method comprising: forming a pattern on a substrate using an imprint apparatus; and processing the substrate on which the pattern has been formed to fabricate the article, wherein the imprint apparatus is executed using a mold An imprint process of forming a pattern of an imprint material on the substrate, and the imprint apparatus includes: an image sensing unit configured to obtain at least one of the mold and the substrate during the imprint process being performed Image; a judging unit configured to determine a normal/abnormality of the imprint process, wherein the imprint process includes a first step of supplying the imprint material to the substrate, and the imprinting on the mold and the substrate a second step of contacting the materials with each other, and the judging unit judges the first reference in the first step based on the image obtained by the image sensing unit after the imprint material is expanded to the entire surface of the mold Normal/abnormality of the imprint process, and normal/abnormality of the imprint process with respect to the second datum different from the first datum in the second step, and during the imprint process, in the The determination unit performs the normal/abnormal determination while switching between the reference and the second reference. A method of manufacturing an article, the method comprising: forming a pattern on a substrate using an imprint apparatus; and processing the substrate on which the pattern has been formed to fabricate the article, wherein the imprint apparatus is executed using a mold An imprint process of forming a pattern of an imprint material on the substrate, and the imprint apparatus includes: an image sensing unit configured to obtain at least one of the mold and the substrate during the imprint process being performed And a determination unit configured to determine a normal/abnormality of the imprint process, wherein the imprint process includes a first step of supplying the imprint material to the substrate, causing the mold and the substrate a second step of contacting the embossed materials with each other, and a third step of releasing the dies from the embossed material cured on the substrate, and The judging unit judges the normal/abnormality of the imprint process with respect to the first reference in the first step based on the image obtained by the image sensing unit after the imprint material is expanded to the entire surface of the mold a normal/abnormality of the imprint process with respect to the second datum different from the first datum in the second step, and a difference from the first datum and the second datum in the third step a normal/abnormality of the imprint process of the third reference, and during the imprint process, the determination unit performs the normal/abnormal determination while switching the first reference, the second reference, and the third reference .