JP2016111335A - Imprint device, imprint method and, manufacturing method of material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imprint device having an advantageous for determining a quality of an imprint processing.SOLUTION: An imprint device includes: an imaging part 9 that images at least one of a mold and a substrate W, and obtains an image; and a determination part 12 that determines a quality of an imprint processing. The imprint processing includes: a first step of supplying an imprint material onto the substrate; and a second step of allowing the mold and the imprint material on the substrate to contact each other. The determination part changes a reference for determining the quality of the imprint processing in each step of the imprint processing, and determines the quality of the imprint processing based on the image imaged by the imaging part.SELECTED DRAWING: Figure 1

Description

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

  The imprint technique is a technique that enables transfer of a nanoscale fine pattern, and has attracted attention as one of nanolithography techniques for mass production of semiconductor devices and magnetic storage media. The imprint apparatus using the imprint technology cures the resin in a state where the mold on which the pattern is formed and the resin (imprint material) on the substrate are in contact with each other, and pulls the mold away from the cured resin. A pattern is formed.

  In the imprint apparatus, it is effective to determine the quality of the pattern formed on the substrate, that is, the quality of the imprint process based on the imaging information from the imaging unit disposed above the substrate (Patent Document 1). reference). In Patent Document 1, an image obtained by imaging a pattern formed on a substrate by imprint processing is compared with a reference image prepared by previously imaging a pattern normally formed on the substrate. A technique for determining whether the imprint process is good or bad is disclosed.

JP 2011-3616 A

  Whether imprint processing is good or bad is not performed after the pattern is formed on the substrate, but during imprint processing, for example, when an abnormality occurs, it is possible to suppress the influence of the abnormality. It leads to improvement of productivity. However, the state of the substrate during the imprint process is such that the resin is supplied (applied), the mold is in contact with the resin, or the mold is pulled away to form a pattern according to the imprint process. It changes to the state. Accordingly, if the standard for determining whether the imprint process is good is constant, it becomes an inappropriate standard depending on the state of the substrate, and the state of the substrate cannot be grasped correctly, that is, the quality of the imprint process may not be correctly determined. . In addition, while the resin on the substrate is filled in the pattern of the mold, the state of the substrate sequentially changes due to a physical phenomenon (capillary phenomenon), so it is difficult to specify the timing for determining whether the imprint process is good or bad. .

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide an imprint apparatus that is advantageous for determining the quality of imprint processing.

  In order to achieve the above object, an imprint apparatus according to one aspect of the present invention is an imprint apparatus that performs an imprint process for forming a pattern using a mold on an imprint material on a substrate. An imaging unit that captures an image of at least one of the substrates and obtains an image; and a determination unit that determines whether the imprint process is acceptable. The imprint process supplies an imprint material on the substrate. A first step and a second step of bringing the mold and the imprint material on the substrate into contact with each other, and the determination unit determines whether the imprint process is good or bad in each step of the imprint process. The standard is changed, and the quality of the imprint process is determined based on the image captured by the imaging unit.

  Further objects and other aspects of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  According to the present invention, for example, it is possible to provide an imprint apparatus that is advantageous for determining whether the imprint process is good or bad.

It is the schematic which shows the structure of the imprint apparatus as 1 side surface of this invention. It is a figure which shows an example of the interference fringe observed by the observation part of the imprint apparatus shown in FIG. It is a flowchart for demonstrating a general imprint process. It is a figure for demonstrating a general imprint process. It is a flowchart for demonstrating the imprint process in this embodiment. FIG. 6 is a diagram for describing a quality determination (S202) of the imprint process illustrated in FIG. It is a figure for demonstrating the quality determination (S203) of the imprint process shown in FIG. FIG. 6 is a diagram for describing timing for performing quality determination (S203) of the imprint process illustrated in FIG. 5. FIG. 6 is a diagram for describing timing for performing quality determination (S204) of the imprint process illustrated in FIG. 5. FIG. 6 is a diagram for describing timing for performing quality determination (S204) of the imprint process illustrated in FIG. 5. FIG. 6 is a diagram for explaining a quality determination (S206) of the imprint process shown in FIG. FIG. 6 is a diagram for describing timing for performing quality determination (S206) of the imprint process illustrated in FIG. 5. FIG. 6 is a diagram for explaining quality determination (S207) of the imprint process shown in FIG. FIG. 6 is a diagram for explaining the quality determination (S205) of the imprint process shown in FIG. FIG. 6 is a diagram for explaining the quality determination (S205) of the imprint process shown in FIG. FIG. 6 is a diagram for explaining the quality determination (S205) of the imprint process shown in FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted.

  FIG. 1 is a schematic diagram illustrating a configuration of an imprint apparatus 100 according to one aspect of the present invention. The imprint apparatus 100 is a lithography apparatus that forms a pattern on an imprint material on a substrate using a mold. In this embodiment, a case where an ultraviolet curable resin that is cured by irradiating ultraviolet rays is used as the imprint material will be described. However, the imprint material may be a thermoplastic or thermosetting resin.

  The imprint apparatus 100 includes a substrate chuck 1 that holds a substrate W, a substrate stage 2 that moves while supporting the substrate chuck 1, a mold chuck 3 that holds a mold M on which a pattern P is formed, and a mold chuck 3. And a mold stage 4 that moves while being supported. In addition, the imprint apparatus 100 includes a dispenser 11 that supplies the resin R onto the substrate, and a control unit 12 that controls the entire imprint apparatus 100. The imprint apparatus 100 also includes a console unit 13 that generates an operation screen, a display unit 14 that displays the operation screen, an input device 15 such as a keyboard and a mouse, and a contact between the mold M and the resin R on the substrate. And a force sensor 16 for detecting the generated force. Note that when the substrate W supplied with the resin R is carried into the imprint apparatus 100 by an external apparatus different from the imprint apparatus 100, the imprint apparatus 100 may not include the dispenser 11.

  The imprint apparatus 100 cures the resin R in a state where the resin R on the substrate supplied from the dispenser 11 is in contact with the old 40, and forms a pattern on the substrate by separating the mold M from the cured resin R. The imprint process is performed. The imprint process includes a supply process, a stamp process, a curing process, and a release process. The supply process is a process (first step) for supplying the resin R onto the substrate. The stamping process is a process (second step) in which the mold M and the resin R on the substrate are brought into contact with each other. By bringing the mold M into contact with the resin R on the substrate, that is, pressing the mold M against the resin R, the resin R fills the pattern P of the mold M. The curing process is a process 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 mold release process is a process (third step) for separating the mold M from the cured resin R on the substrate.

  In the mold chuck 3, a recess having an area larger than the area of the pattern P is formed on the surface opposite to the pattern surface of the mold M. Such a recess is sealed by a mold M and a seal glass (not shown) to define a sealed space (cavity). A pressure control unit (not shown) is connected to the cavity, and the pressure of the cavity can be controlled. When the mold M and the resin R on the substrate are brought into contact with each other, bubbles are generated between the mold M and the resin R on the substrate by increasing the pressure of the cavity and deforming the mold M into a convex shape on the substrate side. Suppresses being caught. When the mold M and the resin R on the substrate come into contact with each other, the pressure of the cavity is returned so that the mold M becomes parallel to the substrate W (completely contacts the resin R on the substrate).

  The imprint apparatus 100 further includes an alignment scope 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 scope 5 functions as an alignment detection unit that generates an alignment signal by detecting the substrate-side mark 6 formed in the shot region of the substrate W and the mold-side mark 7 formed in the pattern P of the mold M. To do. As a method for detecting the substrate side mark 6 and the mold side mark 7, for example, a method of detecting moire fringes (interference fringes) reflecting the relative positions of the two marks can be used. Alternatively, the respective images of the substrate side mark 6 and the mold side mark 7 may be detected to determine the relative positions of the two marks.

  The control unit 12 includes a CPU, a memory, and the like, and controls each unit of the imprint apparatus 100 to perform imprint processing. For example, the control unit 12 obtains the relative position (position shift) between the mold M and the substrate W based on the detection result of the substrate side mark 6 and the mold side mark 7 by the alignment scope 5. Then, the control unit 12 moves the substrate stage 2 and the mold stage 4 so that the positional deviation between the mold M and the substrate W is corrected based on the relative position between the mold M and the substrate W. The positional deviation between the mold M and the substrate W includes a shift component, a magnification component, a rotation component, and the like. Further, the control unit 12 can correct the shape of the pattern P of the mold M according to the shape of the shot area of the substrate W using a pressure finger (not shown) arranged around the mold M. It is. Further, as will be described later, in the present embodiment, the control unit 12 functions as a determination unit that determines whether the imprint process is good or bad.

  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 reflects the ultraviolet rays from the light source 8 and has the characteristic of transmitting the light (observation light) from the observation unit 9. The pattern P of the mold M is formed on the substrate by reflecting the ultraviolet rays from the light source 8 by the mirror 10 and irradiating the resin R on the substrate through the mold M to cure the resin R.

  The observation unit 9 includes an observation light source 9a and an imaging element 9b, and functions as an imaging unit that captures an image of at least one of the mold M and the substrate W. Observation light from the observation light source 9a passes through the mirror 10 and the mold M, and illuminates the substrate W (shot region). The imaging element 9b detects light reflected on the surface of the substrate W and light reflected on the pattern surface of the mold M as observation light. As described above, when the mold M and the resin R on the substrate are brought into contact with each other, since the mold M is deformed in a convex shape toward the substrate, the mold M is moved from the portion where the mold M and the substrate W are in contact with each other. And the substrate W change continuously. Therefore, the image sensor 9b captures an image of 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, so-called Newton rings. 2A and 2B are diagrams illustrating an example of interference fringes observed by the observation unit 9. FIG. 2A illustrates a gap between the mold M and the substrate W, and FIG. 2B illustrates imaging. The image imaged with the element 9b is shown.

  A general imprint process will be described with reference to FIGS. 3 and 4A to 4F. As shown in FIG. 3, the imprint process includes a supply process (S101), a stamp process (S102), a curing process (S103), and a release process (S104). FIG. 4A to FIG. 4F are diagrams illustrating changes in the state of the substrate W in the imprint process.

  FIG. 4A shows the state of the substrate W before the imprint process is started. As shown in FIG. 4A, the substrate W is in an unprocessed state.

  FIG. 4B shows the state of the substrate W that has been supplied. In the supply process, the resin R is supplied to the substrate W by discharging droplets of the resin R from the dispenser 11 onto the substrate. As shown in FIG. 4B, droplets of the resin R are supplied to a predetermined position on the substrate, and an array of droplets of the resin R is formed on the substrate.

  FIG. 4C shows the state of the substrate W in the stamping process. In the stamping process, as shown in FIG. 4 (c), the mold M is brought close to the substrate W in a state where the mold M is deformed in a convex shape toward the substrate, so that the mold M gradually moves from the center to the periphery. To the resin R on the substrate. Therefore, in the stamping 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 cured by irradiating the resin R with ultraviolet rays from the light source 8 in a state where the mold M and the resin R on the substrate are in contact with each other. As shown in FIG. 4D, in the curing process, the mold M and the resin R on the substrate are in complete contact, and the pattern R of the mold M is filled with the resin R.

  FIG. 4E shows the state of the substrate W in the mold release process. In the release treatment, in order to reduce the release force, which is a force for separating the mold M from the cured resin R on the substrate, as shown in FIG. The mold M is separated from the substrate W while being deformed. Accordingly, in the mold release process, a gap is generated between the mold M and the substrate W as in the stamping process, 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 resin R corresponding to the pattern P of the mold M is formed on the substrate W.

  As described above, the state of the substrate W during the imprint process changes according to each process of the imprint process. However, in the related art, 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), the quality of the imprint process is determined. In other words, the prior art is specialized in determining whether the imprint process is good after the mold release process, and in other processes in the imprint process, the quality of the imprint process can be correctly determined. Can not.

  Therefore, in this embodiment, whether the imprint process is good or bad is determined during the imprint process, that is, in each process of the imprint process. At this time, as will be described later, the criteria for determining whether the imprint process is good or not is changed for each process of the imprint process. In other words, an imprint suitable for each of the supply process (S101), the stamp process (S102), the curing process (S103), and the release process (S104) shown in FIG. Switch to pass / fail judgment.

  FIG. 5 is a flowchart for explaining the imprint processing in the present embodiment. Similarly, the imprint process in this embodiment includes a supply process (S101), a stamp process (S102), a curing process (S103), and a release process (S104). Since these processes are as described above, a detailed description thereof is omitted here. However, in FIG. 5, the stamping process (S102) starts the stamping process (S102-1) for starting the operation of relatively moving the mold M and the substrate W relatively close, and ends the stamping process (S102) for ending the operation. -2). Similarly, in the mold release process (S104), the start of the mold release process (S104-1) for starting the operation of relatively moving the mold M and the substrate W away from each other, and the end of the mold release process (S104) for ending the operation. -2).

  In S201, the state of the substrate W before starting the imprint process is confirmed. For example, the observation unit 9 or the like is used to check whether particles (foreign matter, dust) or the like are attached to the substrate W.

  In S202, the quality of the imprint process is determined based on the image captured by the observation unit 9 (image sensor 9b) in the supply process (S101). In the imprint apparatus 100, in order to shorten the time required to supply the resin R to the substrate W, the dispenser 11 drops droplets of the resin R as shown in FIGS. 6 (a) and 6 (d). A plurality of discharge ports 61 for discharging are arranged in a line. In the supply process (S101), as shown in FIGS. 6B and 6E, while the substrate stage 2 is moved in the scanning direction 62, droplets of the resin R are discharged from the plurality of discharge ports 61 of the dispenser 11. The resin R is supplied to the substrate W by discharging.

  FIG. 6B shows an image captured by the image sensor 9b when the resin R is normally supplied to the substrate W. The resin R on the substrate to which the resin R is supplied by the dispenser 11 is shown. The arrangement of the droplets is shown. Referring to FIG. 6B, it can be confirmed that the droplets of the resin R are uniformly formed on the substrate, and the droplets of the resin R to be supplied onto the substrate are not missing.

  On the other hand, in FIG. 6E, when the resin R is not normally supplied to the substrate W, for example, dust adheres to some of the discharge ports 63 of the plurality of discharge ports 61 of the dispenser 11. For example, when the droplet of the resin R cannot be discharged, the image is captured by the image sensor 9b. Referring to FIG. 6 (e), it can be confirmed that the resin R droplets are missing in the region 64 on the substrate corresponding to the discharge port 63 of the dispenser 11.

  Therefore, in the determination of whether the imprint process is good or not in S202, it is determined whether or not there is a drop of resin R droplets to be supplied onto the substrate. Here, an image of a droplet of the resin R that has been normally ejected from the dispenser 11 is used as a reference for determining the quality of the imprint process. At this time, the image captured by the image sensor 9b in the supply process (the arrangement of the droplets of the resin R) and the reference image (the resin in the resin) obtained when the dispenser 11 normally ejects the droplets of the resin R are used. (Reference arrangement of R droplets).

  The determination of the quality of the imprint process in S202 will be specifically described by taking as an example the case where the variation in the luminance of the image captured by the image sensor 9b is used. FIG. 6C is a graph showing the luminance along the broken line 65 of the image shown in FIG. In FIG. 6C, the luminance in the image is adopted on the vertical axis, and the position of the image is adopted on the horizontal axis. When the resin R is normally supplied to the substrate W, as shown in FIG. 6C, the variation in luminance in the image captured by the image sensor 9b is reduced. FIG. 6F is a graph showing the luminance along the broken line 65 of the image (reference image) shown in FIG. In FIG. 6F, the vertical axis represents the luminance in the image, and the horizontal axis represents the position of the image. When the supply of the resin R to the substrate W is not normally performed, as shown in FIG. 6F, the luminance at the location corresponding to the discharge port 63 of the dispenser 11 is different from the luminance at other locations. Yes. Therefore, the image picked up by the image sensor 9b in the supply process is compared with the reference image, and if the variation in luminance of the image exceeds a predetermined range, the liquid of the resin R to be supplied onto the substrate It can be determined that the drop is missing, that is, the imprint process is abnormal.

  In S202, whether the imprint process is good or bad is determined, and if the imprint process is determined to be abnormal, the imprint process is stopped, for example, a defective product lacking a part of the pattern on the substrate. Can be prevented from producing. Further, in S202, when it is detected that the droplet of the resin R to be supplied onto the substrate is missing as an abnormality of the imprint process, the process of automatically removing dust attached to the dispenser 11 (discharge port) is automatically performed. It is also possible to continue the imprint process by performing the process.

  In S203, after the start of the stamping process (S102-1), the quality of the imprint process is determined based on the image captured by the observation unit 9 (image sensor 9b). In determining whether or not the imprint process is good in S203, it is determined whether or not particles are attached to the substrate W.

  The determination of pass / fail of the imprint process in S203 will be specifically described. Here, the substrate W is used by using a difference image representing a luminance difference for each pixel at the same position between the image captured by the image sensor 9b after the start of the stamping process (S102-1) and the reference image. It is determined whether or not particles are attached to the surface. As a reference for determining whether the imprint process is good or bad, an image when the stamp process is normally performed is used. The reference image is an image captured by the image sensor 9b after the start of the stamping process (S102-1) when the imprint process is normal.

  FIG. 7B is a difference image obtained when particles are not attached to the substrate W as shown in FIG. The difference image shown in FIG. 7B is a difference image that does not change greatly and includes only a low luminance value. This is because normal images are compared with each other. FIG. 7D is a difference image obtained when the particles G are attached to the substrate W as shown in FIG. In the difference image shown in FIG. 7 (d), a large difference is generated between the reference image and a portion G ′ where the particles G attached to the substrate W exist, so that the difference image includes a high luminance value. Yes. Therefore, when the difference image between the image captured by the image sensor 9b after the start of the stamping process and the reference image includes a luminance value exceeding a predetermined luminance value, the particles G adhere to the substrate W. That is, it can be determined that the imprint process is abnormal.

  If the stamping process is continued with the particles G attached to the substrate W, the mold M and the particles G may come into contact with each other, and the pattern P of the mold M may be damaged. Therefore, it is preferable to determine whether or not the particles G are attached to the substrate W (S203) at the timing when the mold M and the resin R on the substrate come into contact with each other. As a result, it is possible to determine at an early stage that the particles G are attached to the substrate W (imprint processing abnormality). When the particles G are attached to the substrate W, the stamping process is interrupted. Thus, damage to the mold M can be avoided. Further, not only the particles G attached on the substrate but also particles attached to the mold M can be determined. Thus, the presence or absence of particles present between the mold M and the substrate W can be determined (detected).

In order to detect the timing at which the mold M contacts the resin R on the substrate, the force sensor 16 may be used. FIG. 8 is a diagram for explaining the timing for determining whether the imprint process is good (S203). In FIG. 8, the output from the force sensor 16 disposed on the substrate chuck 1 (force detected by the force sensor 16) is used on the vertical axis, and the time from the start of the stamping process to the end of the stamping process is used on the horizontal axis. doing. FIG. 8 shows a change in force (imprinting force) generated by the contact between the mold M and the resin R on the substrate in the imprinting process. Referring to FIG. 8, at the start of the stamping process, the output of the force sensor 16 is zero because the mold M and the resin R on the substrate are separated. As the stamping process proceeds and the mold M and the resin R on the substrate start to contact, the output of the force sensor 16 gradually increases. Therefore, it may be determined whether or not the particles G are attached to the substrate W at the timing when the force sensor 16 detects the force generated by the contact between the mold M and the resin R on the substrate. Further, there may be a time margin from when the mold M contacts the resin R on the substrate to when the mold M contacts the particle G attached to the substrate W. In such a case, at the timing T ₁ to the output of the force sensor 16 exceeds the threshold value Th, determination may be performed whether the particles G in the substrate W is attached. Note that it is also possible to detect the timing at which the mold M and the resin R on the substrate are in contact with each other by using an image captured by the observation unit 9 (imaging device 9b) instead of the force sensor 16. For example, the presence / absence of particles existing between the mold M and the substrate W is determined at the timing when the size (diameter) of the interference fringe imaged by the image sensor 9b is larger than a predetermined size PS.

  In S204, the quality of the imprint process is determined based on the image captured by the observation unit 9 (image sensor 9b) after the start of the stamp process (S102-1) in parallel with S203. As a reference for determining the quality of the imprint process, an image of interference fringes captured by the image sensor 9b is used. In the determination of the quality of the imprint process in S204, the contact state between the mold M and the resin R on the substrate and the mutual attitude between the mold M and the resin R are determined based on the interference fringes as shown in FIG. To do. For example, information on at least one of the position and roundness of the imaged interference fringes as shown in FIG. 2B is obtained, and based on such information, the mold M contacts the resin R on the substrate in a tilted state. It is determined whether or not. Information on at least one of the position and roundness of the interference fringe is obtained when the interference fringe imaged by the imaging element 9b after the start of the stamping process and the mold M and the resin R on the substrate normally contact each other. It can be obtained by comparing with a reference interference fringe. Note that the quality determination of the imprint process in S204 is the same as the quality determination (S206) of the imprint process performed after the start of a release process (S104-1) described later, and therefore detailed description here. Description is omitted.

  With reference to FIG. 9 and FIG. 10A to FIG. 10C, the timing for determining whether the imprint process is acceptable (S204) will be described. FIG. 9 shows an alignment signal generated by the alignment scope 5. In FIG. 9, the vertical axis indicates the intensity of the alignment signal, and the horizontal axis indicates the time from the start of the stamping process to the end of the stamping process.

FIG. 10 (a) shows a state of the mold M and the substrate W at the timing _{T A} shown in FIG. The alignment scope 5 detects the mold side mark 7 and the substrate side mark 6 by detecting the reflected light RL. Therefore, when the mold side mark 7 and the substrate side mark 6 are separated as shown in FIG. 10A, the mold side mark 7 and the substrate side mark 6 are moved as shown in FIG. Since it cannot be detected, no alignment signal is generated.

FIG. 10 (b) shows a state of the mold M and the substrate W at a timing _{T B} shown in FIG. As shown in FIG. 10 (b), at the timing T _B, in contact with the resin R in the mold M and the substrate, the resin R are beginning to fill in the pattern P of the mold M. As the mold side mark 7 and the substrate side mark 6 approach each other, the mold side mark 7 and the substrate side mark 6 begin to be detected, but while the resin R filling the pattern P of the mold M is in progress, the resin R The reflected light RL fluctuates due to the movement of. Therefore, as shown in FIG. 9, the alignment signal generated by the alignment scope 5 varies.

FIG. 10 (c) shows a state of the mold M and the substrate W at a timing _{T C} shown in FIG. As shown in FIG. 10 (c), the timing T _C, the resin R on the substrate is sufficiently filled in the pattern P of the mold M, without the resin R moves, the reflected light RL is stabilized. Therefore, as shown in FIG. 9, the alignment signal generated by the alignment scope 5 is also stable.

Therefore, as shown in FIG. 9, at the timing T _D the alignment signal generated by the alignment scope 5 is stabilized at a pre-set period in PP, in contact with the resin R on the substrate in a state where the mold M inclined It may be determined whether or not there is. As described above, by using the alignment scope 5, it is possible to specify the timing for determining whether the imprint process is good or bad (S204). However, the present invention is not limited to this. Instead of using the alignment scope 5, as described above, the force sensor 16 may be used to specify the timing for determining whether the imprint process is good (S204). In this case, at the timing when the output of the force sensor 16 exceeds the threshold or when the force sensor 16 detects the force generated by the contact between the mold M and the resin R on the substrate, the resin on the substrate with the mold M tilted. It is determined whether or not R is touching.

In the stamping step, the mold M and the substrate W are aligned based on the detection result of the alignment scope 5 within the period AP shown in FIG. To determine the quality of the imprint process at timing T _C, when it is determined that the imprinting is abnormal, by stopping the imprint process is performed in vain alignment between the mold M and the substrate W This can be prevented.

  In S205, in parallel with S203 and S204, the quality of the imprint process is determined based on the image captured by the observation unit 9 (imaging element 9b) after the start of the stamp process (S102-1). In determining whether the imprint process is good or not in S205, it is determined whether or not there is a drop of resin R droplets to be supplied from the dispenser 11 onto the substrate.

  In the imprint apparatus 100, in order to shorten the time required to supply the resin R to the substrate W, the dispenser 11 causes the droplets of the resin R to be dropped as shown in FIGS. 14 (a) and 14 (c). A plurality of discharge ports 61 for discharging are arranged in a line. In the supply process (S101), as shown in FIGS. 14B and 14D, while the substrate stage 2 is moved in the scanning direction 62, droplets of the resin R are discharged from the plurality of discharge ports 61 of the dispenser 11. The resin R is supplied to the substrate W by discharging.

  FIG. 14B shows an image captured by the image sensor 9b during the stamping process when the supply of the resin R to the substrate W is normally performed. A state in which the pattern P is filled is shown. FIG. 14B shows an interference fringe observed in the stamping process (FIG. 2) at a timing after the circle at the center of the interference fringe spreads over the entire surface of the mold M (pattern P) as the stamping process proceeds. Interference fringes are shown. Referring to FIG. 14B, it can be confirmed that there is no variation in the luminance of the pixels in the region corresponding to the mold M (pattern P), and there is no omission of droplets of resin R to be supplied onto the substrate.

  On the other hand, FIG. 14D is an image captured by the image sensor 9b during the stamping process when the resin R is not normally supplied to the substrate W. Note that the case where the supply of the resin R to the substrate W is not normally performed means that, for example, dust adheres to some of the discharge ports 63 of the plurality of discharge ports 61 of the dispenser 11, and the resin R This is a case where the liquid droplets cannot be discharged. Referring to FIG. 14D, it can be confirmed that the luminance of the pixel is different in the region 64 on the substrate corresponding to the discharge port 63 of the dispenser 11 as compared with other regions.

  FIGS. 15A and 15B are diagrams for explaining the interference fringes observed in FIG. 14D. FIG. 15A shows the gap between the mold M and the substrate W during the stamping process and the filling of the resin R into the pattern P of the mold M. FIG. FIG. 15B shows a part of an image captured by the image sensor 9b. Referring to FIG. 15B, in the region 121 where the droplets of the resin R do not fall out, the mold M and the resin R having a close refractive index are in contact with each other. The reflectivity is very small. For this reason, the reflected light in the region 121 where the resin R droplet does not fall out becomes weak, and as a result, a dark image is obtained in the image sensor 9b.

  On the other hand, there is a gap between the mold M and the resin R in the region 122 where the resin R droplets are missing. For this reason, the reflected light from the mold M interferes with the reflected light from the resin R, and as a result, a bright image is obtained in the image sensor 9b. In other words, a region where a gap exists between the mold M and the resin R is a bright image. Accordingly, since the dropout of the resin R can be detected in an area larger than the size of one droplet of the actual resin R, the resolution required for detecting one droplet of the resin R is exceeded. The observation unit 9 (image sensor 9b) having a low resolution can detect the dropout of the resin R droplet.

  Thus, it can be determined from FIG. 14D obtained by the image sensor 9b whether or not there is a drop of resin R droplets to be supplied from the dispenser 11 onto the substrate. In addition, as shown in FIG. 14D, the interference fringes have a single line (one line) due to a drop in one place, and a drop in a plurality of places. This includes the case where a plurality of shaded stripes (multiple lines) are repeated.

  As described above, in the determination of the quality of the imprint process in S205, it is determined whether or not the resin R droplets to be supplied from the dispenser 11 onto the substrate are missing. At this time, an image (interference fringe) captured by the image sensor 9b in the stamping process is compared with a reference image (reference interference fringe) obtained when the dispenser 11 normally ejects the droplets of the resin R. The determination of the quality of the imprint process in S205 will be specifically described by taking as an example the case of using the presence or absence of vertical stripes (bright and dark lines) in the scan direction (movement direction) in the image captured by the image sensor 9b.

  FIG. 16 shows a difference image between the image shown in FIG. 14B and the image shown in FIG. Referring to FIG. 16, in the difference image, pixels with a difference become white, and pixels without a difference become dark. In the difference image, the boundary line 131 where the brightness of the pixel changes is extracted, and the boundary line 131 is parallel to the scanning direction 62, that is, whether the boundary line 131 approximates a straight line indicating the scanning direction 62. Based on this, the presence or absence of vertical stripes in the scan direction is determined.

  In this embodiment, whether or not there is a drop in the resin R droplet is also determined in S202. In S202, since the droplets of the resin R on the substrate are directly observed, as shown in FIG. 6B, in the image obtained by the image sensor 9b, the luminance for each pixel differs depending on the presence or absence of the droplets. ing. On the other hand, in S205, since the stamping process is started and the interference fringes when the pattern P of the mold M is filled with the resin R are observed, as shown in FIGS. 14B and 14D, There is little change in luminance for each pixel. Therefore, compared to S202, in S205, it is possible to allow the image pickup device 9b to have a low resolution, and to detect the drop of the droplet of the resin R as a clearer vertical stripe.

Note that the timing of the determination of the quality of the imprint process (S205), as the timing T _D shown in FIG. 9, the resin R may be filled timing pattern P of the mold M. Further, the region 64 (vertical streak) detected when the resin R droplet is missing can be detected even during the filling of the resin R such that the interference fringes shown in FIG. 2 are obtained. Therefore, the timing for performing quality determination of imprint processing (S205) is not limited to the timing T _D shown in FIG. 9, the area 64 shown in FIG. 14 (d) may be any timing detectable.

In S205, whether or not the imprint process is good is determined. If it is determined that the imprint process is abnormal, the imprint process is stopped, for example, a defective product lacking a part of the pattern on the substrate. Can be prevented from producing.
Further, in S205, when it is detected that the droplet of the resin R to be supplied onto the substrate is missing as an abnormality of the imprint process, the process of automatically removing dust attached to the dispenser 11 (discharge port) is automatically performed. It is also possible to continue the imprint process by performing the process.

  In S206, after the start of the release process (S104-1), the quality of the imprint process is determined based on the image captured by the observation unit 9 (image sensor 9b). In the mold release process, as shown in FIG. 11A, when the mold M is pulled away from the cured resin R on the substrate in a tilted state, the pattern of the resin R formed on the substrate falls down or is damaged. Or

  Therefore, in the determination of the quality of the imprint process in S206, based on the interference fringes as shown in FIGS. 2B and 11B, the mold M is pulled away from the cured resin R on the substrate in a tilted state. It is determined whether or not. As a reference for determining the quality of the imprint process, an image of interference fringes captured by the image sensor 9b is used. Specifically, as shown in FIG. 11B, first, the position of interference fringes (Pos X, Pos Y) and roundness (ratio between Width and Height) are obtained. The position and roundness of the interference fringes are the reference interference fringes obtained when the interference fringes imaged by the image sensor 9b after the start of the mold release process and the mold M and the resin R on the substrate are normally separated. Can be obtained by comparing When the position and roundness of the interference fringes exceed the threshold value, it is determined that the mold M is separated from the cured resin R on the substrate in an inclined state, that is, the imprint processing is abnormal. . Thus, even when the state of the substrate W changes greatly in a short period, the quality of the imprint process can be determined with high accuracy by using the interference fringes imaged by the image sensor 9b.

  With reference to FIG. 12A to FIG. 12C, the timing for determining whether the imprint process is good (S206) will be described. FIGS. 12A to 12C show images (interference fringes) picked up by the image pickup device 9b as time elapses in the mold release process. In the release treatment, as described above, the mold M is deformed into a convex shape on the substrate side in order to reduce the release force, which is a force for pulling the mold M away from the cured resin R on the substrate. As a result, the cured resin R on the substrate is pulled away from the outer peripheral portion of the mold M, and peeling of the resin R from the substrate W can be prevented. Accordingly, in the mold release process, a gap is generated between the mold M and the substrate W as in the stamping process, and interference fringes as shown in FIGS. 12A to 12C are observed. 12A to 12C, as the contact area between the mold M and the cured resin R on the substrate decreases, the size of the interference fringes gradually decreases. Therefore, it is determined whether or not the mold M is pulled away from the cured resin R on the substrate at a timing when the size (diameter) of the interference fringes becomes smaller than a predetermined size PS.

  Generally, since the mold release process is performed in a short time, it is difficult to specify the timing for determining whether or not the mold M is separated from the cured resin R on the substrate in a tilted state. On the other hand, in the present embodiment, the timing for determining whether or not the mold M is separated in a tilted state from the cured resin R on the substrate by using the interference fringes (size) captured by the image sensor 9b. It is possible to specify.

  In S207, the quality of the imprint process is determined based on the image captured by the observation unit 9 (image sensor 9b) after the release process. As a reference for determining the quality of the imprint process, an image of interference fringes captured by the image sensor 9b is used. In the determination of whether the imprint process is good in S207, it is determined whether or not the pattern is normally formed on the substrate W, for example, whether or not the resin R is peeled off from the substrate W.

  By separating the mold M from the cured resin R on the substrate, a resin R having a pattern corresponding to the pattern P of the mold M is formed on the substrate W. FIG. 13A shows an image picked up by the image pickup device 9b when the mold release process is normally performed. If the pattern P of the mold M is a periodic line and space pattern, as shown in FIG. 13A, the luminance is low at the location of the resin R formed on the substrate W, and the luminance is at other locations. A high image can be obtained. FIG. 13C shows an image captured by the image sensor 9b when the release process is not performed normally, for example, when the resin R is peeled off from the substrate W and adhered to the mold M. In this case, as shown in FIG. 13C, an image having a high luminance at the portion 71 where the resin R is peeled off is obtained.

  Therefore, is the resin R peeled off from the substrate W using the difference image representing the difference in luminance for each pixel at the same position between the image captured by the image sensor 9b after the mold release process and the reference image? Determine whether or not. The reference image is an image captured by the image sensor 9b after the release processing when the imprint processing is normal.

  FIG. 13B is a difference image obtained when the resin R is not peeled from the substrate W as shown in FIG. In the difference image shown in FIG. 13B, there is no large change, and the difference image includes only a low luminance value. This is because normal images are compared with each other. FIG. 13D is a difference image obtained when the resin R is peeled from the substrate W as shown in FIG. The difference image shown in FIG. 13D is a difference image including a high luminance value because a large difference is generated between the reference image and the portion 72 where the resin R is peeled off. Therefore, if the difference image between the image captured by the image sensor 9b after the start of the mold release process and the reference image includes a luminance value that exceeds a predetermined luminance value, the resin R is peeled off from the substrate W. That is, it can be determined that the imprint process is abnormal.

  Such determination of the quality of the imprint process using the difference image is also effective when determining the quality of the imprint process for a substrate having a base on which a pattern has already been formed. In this case, it is necessary to prepare a reference image for each background.

  In the imprint apparatus 100 of the present embodiment, in each process of the imprint process, it is possible to correctly determine whether the imprint process is good or not by grasping the state of the substrate W with high accuracy. Thereby, in the imprint apparatus 100, it becomes possible to suppress the influence of the abnormality of an imprint process, and it can improve productivity.

  Further, in the imprint apparatus 100 of the present embodiment, the timing for determining whether the imprint process is good or bad is specified using information from the alignment scope 5, the force sensor 16, and the observation unit 9. Accordingly, it is possible to specify a timing suitable for determining whether the imprint process is good, not the timing of switching each process of the imprint process. In the stamping process or the like, it is possible to determine whether the imprint process is good or bad at different timings according to the state of the substrate W.

  In the present embodiment, the quality of the imprint process is determined in the supply process, the stamp process, and the release process, but the present invention is not limited to this. For example, the quality of the imprint process may be determined in at least two of the supply process, the stamp process, and the release process, and the quality of the imprint process may be determined in at least one of the supply process and the stamp process. You may go. Further, whether the imprint process is good or bad may be determined between the stamping process and the curing process or between the curing process and the release process.

  If it is determined that the imprint process is abnormal, an error process corresponding to the abnormality is performed. For example, when it is determined in S203 that the particle G is attached to the substrate W, a process for removing the particle G is performed, or a process for storing the position on the substrate to which the particle G is attached is performed. be able to. If the particle G cannot be removed, the imprint process may be stopped, or the mold M may not be brought into contact with the particle G (a pattern is not formed).

  Moreover, in this embodiment, the photocuring method which hardens resin by irradiating an ultraviolet-ray (light) was demonstrated as an example as a resin curing method. However, the resin curing method is not limited to the photocuring method, and may be a thermal cycle method. In the thermal cycle method, a thermoplastic resin is heated to a temperature equal to or higher than the glass transition temperature to bring fluidity into contact with the mold and the resin, and the resin is cured by cooling the resin. Then, a pattern is formed on the substrate by pulling the mold away from the cured resin on the substrate.

  A method for manufacturing a device (semiconductor device, magnetic storage medium, liquid crystal display element, etc.) as an article will be described. Such a manufacturing method includes a step of forming a pattern on a substrate (wafer, glass plate, film-like substrate, etc.) using the imprint apparatus 100. The manufacturing method further includes a step of processing the substrate on which the pattern is formed. The processing step may include a step of removing the remaining film of the pattern. Further, it may include other known steps such as a step of etching the substrate using the pattern as a mask. The method for manufacturing an article in the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

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

DESCRIPTION OF SYMBOLS 100: Imprint apparatus 9: Observation part 9b: Image pick-up element 12: Control part M: Mold W: Board | substrate

Claims (19)

An imprint apparatus that performs an imprint process for forming a pattern using a mold on an imprint material on a substrate,
An imaging unit that captures an image of at least one of the mold and the substrate;
A determination unit for determining whether the imprint process is good or bad,
The imprint process includes a first step of supplying an imprint material on the substrate, and a second step of bringing the mold into contact with the imprint material on the substrate,
The determination unit changes a criterion for determining the quality of the imprint process in each step of the imprint process, and determines the quality of the imprint process based on an image captured by the imaging unit. An imprint apparatus characterized by the above. The imprint process includes a third step of separating the mold from the cured imprint material on the substrate;
The imprint apparatus according to claim 1, wherein the determination unit determines whether the imprint process is good or not based on an image captured by the imaging unit in the third step. A dispenser for discharging droplets of the imprint material on the substrate;
The imaging unit images the droplet on the substrate to which the imprint material is supplied by the dispenser,
3. The imprint apparatus according to claim 1, wherein the determination unit determines whether or not the imprint process is good based on the droplet imaged by the imaging unit in the first step. 4. .   The determination unit compares the array of droplets imaged by the imaging unit with the reference array of the droplets obtained when the dispenser normally ejects the imprint material. The imprint apparatus according to claim 3, wherein it is determined whether or not the droplet to be supplied is missing. The imaging unit images interference fringes between light reflected by the mold and light reflected by the substrate;
5. The imprint apparatus according to claim 1, wherein the determination unit determines whether the imprint process is good or not based on the interference fringes in the second step. 6.   The imprint apparatus according to claim 5, wherein the determination unit determines whether or not there is a foreign object existing between the mold and the substrate based on the interference fringes in the second step.   Whether the determination unit is in contact with the imprint material on the substrate in a state where the mold is tilted based on information on at least one of the position and roundness of the interference fringes imaged by the imaging unit The imprint apparatus according to claim 5, further comprising: A dispenser for discharging droplets of the imprint material on the substrate;
6. The determination unit according to claim 5, wherein the determination unit determines whether or not the liquid droplets to be supplied from the dispenser onto the substrate are missing based on the interference fringes imaged by the imaging unit. The imprint apparatus described.   The determination unit compares the interference fringe imaged by the imaging unit with a reference interference fringe obtained when the droplets to be supplied from the dispenser onto the substrate are not dropped, and the dispenser By detecting the presence or absence of bright and dark lines generated in the direction of movement of the substrate while discharging droplets, it is determined whether or not the droplets to be supplied onto the substrate are missing. The imprint apparatus according to claim 8.   The determination unit detects the presence / absence of the bright and dark lines in the interference fringes based on whether or not the interference fringes captured by the imaging unit approximate a straight line parallel to the moving direction. The imprint apparatus according to claim 9, wherein: A force sensor for detecting a force generated by contact between the mold and the imprint material on the substrate;
The imprint unit according to any one of claims 5 to 7, wherein the determination unit determines whether the imprint process is good or not at a timing when a force detected by the force sensor exceeds a threshold value. Printing device. A force sensor for detecting a force generated by contact between the mold and the imprint material on the substrate;
The imprint apparatus according to claim 5, wherein the determination unit determines whether the imprint process is good or not at a timing when the force sensor detects the force. An alignment detection unit that generates an alignment signal by detecting a mark formed on the mold and a mark formed on the substrate;
8. The method according to claim 5, wherein the determination unit determines whether the imprint process is good or bad at a timing when the alignment signal generated by the alignment detection unit is stable within a preset period. The imprint apparatus according to claim 1.   8. The determination unit according to claim 5, wherein the determination unit determines whether or not the imprint process is good at a timing when a size of an interference fringe imaged by the imaging unit is larger than a predetermined size. The imprint apparatus of any one of them. The imaging unit images interference fringes between light reflected by the mold and light reflected by the substrate;
The imprint apparatus according to claim 2, wherein in the third step, the determination unit determines whether the imprint process is good or not based on an interference fringe imaged by the imaging unit.   16. The determination unit according to claim 15, wherein the determination unit determines whether the imprint process is good or not at a timing when a size of an interference fringe imaged by the imaging unit becomes smaller than a predetermined size. Imprint device. An imprint apparatus that performs an imprint process for forming a pattern using a mold on an imprint material on a substrate,
An imaging unit that captures an image of at least one of the mold and the substrate;
A determination unit for determining whether the imprint process is good or bad,
The imprint process includes a first step of supplying an imprint material onto the substrate, a second step of bringing the mold into contact with the imprint material on the substrate, and a cured imprint material on the substrate. A third step of separating the mold,
The determination unit determines whether the imprint process is good or not in a plurality of steps among the first step, the second step, and the third step. An imprint method for performing an imprint process for forming a pattern using a mold on an imprint material on a substrate,
The imprint process includes a first step of supplying an imprint material on the substrate, and a second step of bringing the mold into contact with the imprint material on the substrate,
In the imprint method, in each step of the imprint process, the standard for determining the quality of the imprint process is changed, and based on an image acquired by imaging at least one of the mold and the substrate, An imprint method comprising a step of determining whether the imprint process is good or bad. Forming a pattern on a substrate using the imprint apparatus according to any one of claims 1 to 17, and
Processing the substrate on which the pattern has been formed in the step;
A method for producing an article comprising: