JP2019117844A - Mold, replica mold, imprint apparatus, and article manufacturing method - Google Patents

Abstract

To provide an advantageous technique for highly accurate replication of a mold for imprinting.SOLUTION: The mold for producing a replica mold by imprinting includes: a first surface; a mesa, having a pattern portion on which a pattern to be transferred to a replica mold is formed, projecting from the first surface; and a projection, surrounding the mesa and further projecting than the mesa in the first surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mold for imprinting, a replica mold, an imprinting apparatus, and an article manufacturing method.

  The imprint apparatus cures the imprint material in a state in which the imprint material supplied on the substrate as the object to be processed and the mold are in contact with each other, and the mold is separated from the cured imprint material. Form a pattern of imprint material.

  When, for example, a semiconductor device is manufactured using an imprint apparatus, the object to be processed is a semiconductor wafer. On the other hand, imprint technology can also be used for the technology which manufactures a replica mold using a master mold, as shown, for example in patent documents 1.

JP, 2013-175671, A

  By the way, in order to transfer the pattern to the object to be treated satisfactorily, it is necessary to make the thickness (remaining film thickness) of the imprint material remaining between the pattern portion of the mold and the object to be treated uniform. The residual film thickness is required to be a few tens of nm from the viewpoint of CD accuracy. Therefore, the uniformity of the residual film thickness is deteriorated due to the volume change due to the evaporation of the imprint material after the imprint material is supplied to the object to be treated and before the completion of the curing process.

  Furthermore, the pattern portion of the master mold and the pattern transfer area of the replica mold have a step structure (mesa structure) higher than the outer periphery thereof. As a result, when the two molds come in contact with each other through the imprint material, the gap on the outer side of the mesa portion is increased by the amount of the step structure, and the imprint material is likely to be volatilized. Therefore, volatilization of the imprint material proceeds more remarkably near the outer peripheral portion of the object to be processed in the production of the replica mold, and the residual film thickness becomes thinner.

  An object of the present invention is, for example, to provide an advantageous technique for highly accurate replication of a mold for imprinting.

  According to one aspect of the present invention, there is provided a mold for producing a replica mold by imprint, the mold having a first surface and a pattern portion on which a pattern to be transferred to the replica mold is formed, A mold is provided, comprising: a mesa portion projecting from a surface; and a projection portion surrounding the mesa portion on the first surface and further projecting beyond the mesa portion.

  According to the present invention, it is possible to provide an advantageous technique for highly accurate replication of a mold for imprinting.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows schematic structure of the imprint apparatus in embodiment. The figure explaining the structural example of the master mold in 1st Embodiment. The figure explaining the structural example of the master mold in 1st Embodiment. The figure which shows an example of the method of substituting the air | atmosphere between an imprint material and a master mold with gas. The figure which shows the structural example of the replica mold in 2nd Embodiment. The figure explaining the articles | goods manufacturing method in embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the following embodiment shows only the specific example of implementation of this invention, and this invention is not limited to the following embodiment. In addition, not all combinations of features described in the following embodiments are essential for solving the problems of the present invention.

  First, an outline of the imprint apparatus according to the embodiment will be described. The imprint apparatus brings the imprint material supplied on the substrate into contact with a mold and applies energy for curing to the imprint material, thereby forming a pattern of a cured product on which the concavo-convex pattern of the mold is transferred. Device.

  As the imprint material, a curable composition (sometimes referred to as an uncured resin) which is cured by receiving energy for curing is used. As energy for curing, electromagnetic waves, heat, etc. may be used. The electromagnetic wave may be, for example, light whose wavelength is selected from the range of 10 nm or more and 1 mm or less, such as infrared light, visible light, and ultraviolet light. The curable composition may be a composition which is cured by irradiation of light or by heating. Among these, the photocurable composition which is cured by irradiation with light contains at least a polymerizable compound and a photopolymerization initiator, and may further contain a nonpolymerizable compound or a solvent as required. The non-polymerizable compound is at least one selected from the group consisting of a sensitizer, a hydrogen donor, an internal release agent, a surfactant, an antioxidant, a polymer component and the like. The imprint material can be disposed on the substrate in the form of droplets or in the form of islands or films formed by connecting a plurality of droplets by the imprint material supply unit. The viscosity (the viscosity at 25 ° C.) of the imprint material may be, for example, 1 mPa · s or more and 100 mPa · s or less. As a material of the substrate, for example, glass, ceramics, metals, semiconductors, resins and the like can be used. If necessary, a member made of a material different from that of the substrate may be provided on the surface of the substrate. The substrate is, for example, a silicon wafer, a compound semiconductor wafer, or quartz glass.

  FIG. 1 shows a schematic configuration of an imprint apparatus in the present embodiment. As described above, in imprint technology, it is necessary to bring the imprint material supplied on a substrate (for example, a semiconductor wafer for device fabrication) into direct contact with a mold (template). Such contact limits the life of the mold. Therefore, typically, a master mold is produced by first forming a pattern on a template substrate such as glass or quartz by, for example, electron beam technology. Typically, this master mold is not used to form a pattern on a semiconductor wafer for device fabrication, but instead, one or more replica molds are made by mold replication processing, and semiconductors using that replica mold Form a pattern on the wafer.

  Such mold replication processing can be performed by incorporating the imprint technique as described above. Therefore, the imprint apparatus 1 shown in FIG. 1 can be diverted to the production of a replica mold by transferring a pattern formed on a master mold onto a replica substrate, in addition to imprinting on a substrate for manufacturing a device. It is. Hereinafter, the production of a replica mold by the imprint apparatus 1 will be described. In the present embodiment, the imprint apparatus 1 adopts a photo-curing method in which the imprint material is cured by irradiation of light (ultraviolet light). In the present embodiment, as shown in FIG. 1, an axis parallel to the direction in which the master mold 11 is irradiated with ultraviolet light is taken as the Z axis, and the X and Y axes are determined in the direction orthogonal to the Z axis. .

  The replica mold 8 is a mold of a blank which is to be a replica of the master mold 11 by imprint processing, and for example, a material which transmits ultraviolet light such as quartz is used. The imprint material 21 is supplied to the processing surface of the replica mold 8.

  The master mold 11 is a mold in which a pattern of asperities to be transferred to the imprint material 21 supplied on the replica mold 8 is formed on the surface facing the replica mold 8. Here, as a material of the master mold 11, a material which transmits ultraviolet light such as quartz is used.

  The curing unit 5 cures the imprint material 21 by irradiating the imprint material 21 with ultraviolet light through the master mold 11. The curing unit 5 may include a light source 16 for generating ultraviolet light, and an optical system 17 for adjusting the ultraviolet light from the light source 16 to light suitable for imprinting.

  The imprint head 3 is configured to be movable while holding the master mold 11. The imprint head 3 can include a master mold holding unit 12 and a master mold driving unit 19. The master mold holding unit 12 holds the master mold 11 with a vacuum suction pad or the like. The master mold holding unit 12 is held by a master mold driving unit 19. Master mold drive unit 19 includes a drive system (moving mechanism) for adjusting the distance between replica mold 8 and master mold 11 when transferring the pattern of master mold 11 to replica mold 8 and is driven in the Z-axis direction It can. In addition, since the master mold drive unit 19 is required to perform highly accurate positioning at the time of pattern transfer, the master mold drive unit 19 may include a plurality of drive systems such as a coarse movement drive system and a fine movement drive system. Furthermore, the master mold driving unit 19 corrects the tilt of the master mold 11 not only in the Z axis direction but also in the X axis direction, the Y axis direction, or the θ (rotation around the Z axis) direction. It may have a tilt function.

  The stage device 2 can hold the replica mold 8 and correct (align) the translational shift of the replica mold 8 and the master mold 11 at the time of imprinting. The stage device 2 can include a replica mold holding unit 9 and a replica mold stage 10. The replica mold holding unit 9 holds the replica mold 8 with a vacuum suction pad or the like. Further, the replica mold holding unit 9 is supported by the replica mold stage 10. The replica mold stage 10 is a drive system driven in the X-axis direction and the Y-axis direction for correcting (alignment) the translational shift of the replica mold 8 and the master mold 11. Further, the drive system in the X-axis direction and the Y-axis direction may be configured by a plurality of drive systems such as a coarse movement drive system and a fine movement drive system. Furthermore, even if it has a drive system for position adjustment in the Z-axis direction, a position adjustment function for the replica mold 8 in the θ (rotation around the Z axis) direction, and a tilt function for correcting the tilt of the replica mold 8 Good.

  The imprint material supply unit 7 supplies the imprint material 21 to the replica mold 8. The imprint material supply unit 7 discharges the imprint material 21 onto the replica mold 8 from, for example, a discharge nozzle held by the master mold holding unit 12. Here, as the imprint material 21, an ultraviolet curable resin having a property of being hardened by irradiation of ultraviolet light is used. Further, the amount of the imprint material 21 to be discharged is appropriately determined by the thickness of the imprint material 21 to be required, the pattern density to be transferred, and the like.

  When air bubbles (atmosphere) exist between the master mold 11 and the imprint material 21 when the master mold 11 contacts the imprint material 21 supplied onto the replica mold 8, the imprint material 21 is formed after curing. Unfilled defects may occur in the formed pattern. In order to prevent the occurrence of such unfilled defects, the gas between the master mold 11 and the imprint material 21 is at least one of high solubility and / or high diffusivity with respect to the imprint material 21. It is preferable to replace with a gas having Examples of the gas having such properties include helium. Thus, in the present embodiment, the gas supply unit 40 supplies such a gas between the imprint material 21 on the replica mold 8 and the master mold 11 from, for example, a gas supply nozzle held by the master mold holding unit 12. Do.

  The imprint apparatus 1 may be housed in a clean chamber (not shown) in order to maintain the atmosphere in a clean environment. In addition, the imprint apparatus 1 includes a surface plate 20 for supporting the stage device 2, a support 14 for supporting the master mold holding unit 3, and a support 15 for supporting the support 14.

  The control unit 6 controls the operation, adjustment, and the like of each component of the imprint apparatus 1. The control unit 6 may be housed in the clean chamber as described above, or may be provided outside the clean chamber. The control unit 6 performs an imprint process of transferring the pattern of the master mold 11 to the replica mold 8 as follows, for example. First, the imprint material 21 is supplied onto the replica mold 8 by the imprint material supply unit 7. Thereafter, the master mold 11 is lowered by the imprint head 3 to be in contact with the imprint material 21 on the replica mold 8. Thus, the imprint material 21 flows into the groove of the pattern formed on the master mold 11. In this state, the imprint material 21 is cured by irradiating the imprint material 21 with ultraviolet light by the curing unit 5. By curing the imprint material 21, a pattern (circuit pattern) of the master mold 11 by the imprint material 21 is formed. After the imprint material 21 is cured, the master mold 11 is lifted from the cured imprint material 21 by raising the master mold 11 by the imprint head 3. In the imprint apparatus 1 of the present embodiment, the imprint head 3 is driven to be in contact with the imprint material 21 on the fixed replica mold 8, but there is also an opposite configuration. sell. That is, the stage device 2 may be driven with respect to the fixed master mold 11 so as to bring the imprint material 21 on the replica mold 8 into contact. Alternatively, the configuration may be such that the imprint head 3 and the stage device 2 are driven up and down, respectively. That is, it is sufficient to have a drive unit that changes the relative position of the master mold 11 and the replica mold 8. The imprinting process for producing the replica mold 8 in the present embodiment is as described above.

First Embodiment
With reference to FIG. 2, the structural example of the master mold 11 in 1st Embodiment is demonstrated. FIG. 2A shows a state in which the imprint material 21 is supplied to the replica mold 8 and in contact with the master mold 11. The master mold 11 has a mold main body 11 a and a pattern portion 11 c. The master mold 11 has a mesa portion which protrudes from a first surface 11 d which is a surface facing the replica mold 8 (which is convex with respect to the replica mold 8 more than the main body portion 11 a), and the pattern portion 11 c It is formed in the part.

  The pattern portion of the replica mold 8 also has a mesa structure which is convex with respect to the master mold 11. Therefore, when the pattern portion of the master mold 11 and the pattern portion of the replica mold 8 come in contact with each other through the imprint material 21, a space 31 is formed outside the contact area. Volatile components of the imprint material can flow into this space 31. As the space 31 is larger, more volatilized components of the imprinting material are more likely to flow into, so volatilization of the imprinting material significantly progresses near the outer peripheral portions of both molds, and the residual film pressure becomes thin.

  In order to address this issue, the master mold 11 in the present embodiment has a protrusion 11 b surrounding the mesa portion on the first surface 11 d and protruding further than the mesa portion with respect to the replica mold 8. The protrusion 11 b fills a space around the pattern portion 11 c and the pattern transfer region of the replica mold 8 when, for example, the pattern portion 11 c is brought into contact with the imprint material 21 on the pattern transfer region of the replica mold 8. It is formed as. Since the gap between the replica mold 8 and the protrusion 11b is narrowed by the presence of the protrusion 11b, the diffusion of the volatile component of the imprint material 21 to the outside of the protrusion 11b is suppressed. Then, the pressure of the volatile component of the imprint material 21 volatilized in the space 31 is increased, the further volatilization of the imprint material 21 is suppressed, and the volume change of the imprint material 21 due to the volatilization can be suppressed. The height of the protrusion 11b (the thickness in the Z direction in FIG. 2A) is determined from the viewpoint of the diffusion suppression effect by the narrow gap and the avoidance of interference of the protrusion 11b with the replica mold 8. Such a height of the protrusion 11 b may be, for example, a value within the range of 50 to 55 μm.

  FIG. 2 (b) is a view of the master mold 11 as viewed on the XY plane. The protrusion 11 b is disposed so as to surround the mesa portion, that is, to surround the outer periphery of the pattern portion 11 c. By this, the effect of volatilization suppression can be obtained in all directions of the outer periphery of the imprint material 21.

  In the example of FIGS. 2A and 2B, the protrusion 11b is formed only on a part of the outer periphery of the pattern portion of the master mold 11, but as shown in FIGS. 3A and 3B. The protrusion 11 b may be formed to extend to the end of the master mold 11.

  FIG. 4 shows an example of a method of replacing the air between the imprint material 21 supplied onto the replica mold 8 and the master mold 11 with a gas. The control unit 6 controls the imprint material supply unit 7 to supply the imprint material 21 to the replica mold 8 (FIG. 4A). Thereafter, the control unit 6 controls the replica mold stage 10 to make the replica mold 8 pass below the gas supply unit 40 (FIG. 4 (b)) and move it to a position below the master mold 11 (see FIG. 4 (c). The control unit 6 supplies the gas from the gas supply unit 40 in accordance with the movement of the replica mold 8. Thus, gas can be effectively drawn between the imprint material 21 supplied onto the replica mold 8 and the master mold 11. In FIG. 4, the protrusion 11 b has a smaller degree of protrusion (that is, a smaller thickness (height in the Z direction)) as it goes away from the mesa portion so as not to impede the flow of the gas. It has a shape.

  In the above example, as shown in FIGS. 4B and 4C, while the gas is being supplied by the gas supply unit 40, the replica mold 8 forms a pattern via the lower side of the gas supply unit 40. Move to the position where At this time, the control unit 6 controls the master mold driving unit 19 (moving mechanism) so that the protrusion 11b does not interfere with the imprint material 21 or the replica mold 8 during the movement thereof, and thereby the master mold 11 and the replica mold Let 8 be separated.

  The above-mentioned protrusion 11b may be integrally molded with the main body 11a of the master mold 11, or may be formed separately from the main body 11a. When the protrusion 11b is configured separately from the main body 11a, the protrusion 11b may be added by forming a thin film on the main body 11a by vapor deposition or coating.

  Then, the manufacturing method of the replica mold using the master mold of 1st Embodiment is demonstrated using FIG. The master mold 11 is introduced into the imprint apparatus 1 and transported to the imprint head 3 by a master mold transport unit (not shown). The master mold holding unit 12 holds the master mold 11. On the other hand, a blank replica mold 8 is transported to the stage device 2 by a replica mold transport unit (not shown) and held by the replica mold stage 10 via the replica mold holding unit 9. The control unit 6 controls the replica mold stage 10 holding the replica mold 8 to drive the replica mold 8 below the imprint material supply unit 7. Thereafter, the control unit 6 controls the imprint material supply unit 7 to supply the imprint material 21 to the replica mold 8. Next, the control unit 6 controls the replica mold stage 10 to move under the gas supply unit 40 and move under the master mold 11. At this time, by supplying the gas from the gas supply unit 40, the gas is drawn between the imprint material 21 supplied on the replica mold 8 and the master mold 11, and the atmosphere and the gas are replaced.

  After the pattern transfer region of the replica mold 8 is arranged to face the pattern portion of the master mold 11, the control unit 6 causes the imprint material 21 and the pattern portion of the master mold 11 to be lowered by the descent driving of the master mold driving unit 19. And contact. Thus, the imprint material 21 flows into the groove of the pattern formed on the master mold 11. While the imprint material 21 is filled up to every corner of the unevenness of the pattern portion, a part of the imprint material 21 volatilizes and diffuses to the adjacent space, but in the present embodiment, the protrusion of the master mold 11 The volatilization of the imprint material 21 is suppressed by the presence of the portion 11 b. When the filling of the fine pattern portion of the imprint material 21 is completed, the control unit 6 causes the imprint material 21 to be irradiated with ultraviolet light by the effect unit 5 to cure the imprint material 21. Thereafter, the imprint material 21 and the pattern portion of the master mold 11 are pulled apart by the upward driving of the master mold driving unit 19.

  The pattern of the master mold 11 is transferred to the imprint material 21 supplied to the replica mold 8 by the above imprint operation. In this imprint operation, volatilization of the imprint material 21 is suppressed, and a decrease in volume of the imprint material 21 can be prevented, so that the transferred pattern can obtain a residual film of uniform thickness. The replica mold 8 is etched using the imprint material 21 as a mask by an etching processing unit or etching apparatus (not shown), and a pattern is generated in the pattern transfer region of the replica mold 8.

Second Embodiment
Next, a second embodiment will be described. FIG. 5A shows a state in which the imprint material 21 is supplied to the blank replica mold 25 and the replica mold 25 and the master mold 11 are aligned so as to face each other. The replica mold 25 has a main body portion 25a and a pattern portion 25c which is a pattern transfer region. The replica mold 25 has a mesa portion which protrudes from the first surface 25d which is a surface facing the master mold 11 (which is convex with respect to the master mold 11 relative to the main portion 25a), and the pattern portion 25c is formed on the mesa portion. Is formed.

  In the first embodiment, the protrusion 11 b is provided on the master mold 11 side. On the other hand, in the present embodiment, on the contrary, the replica mold 25 has a protrusion 25 b surrounding the mesa portion on the first surface 25 d and protruding further than the mesa portion with respect to the master mold 11. The protruding portion 25 b fills the space around the pattern portion 25 c and the pattern portion of the master mold 11, for example, when the imprint material 21 on the pattern portion 25 c is brought into contact with the pattern portion of the master mold 11. Is formed.

  FIG. 5B shows the master mold 11 in contact with the imprint material 21 after the imprint material 21 is supplied to the replica mold 25. Similar to the first embodiment, the presence of the protrusion 25 b can suppress the volume change of the imprint material 21 due to the volatilization.

  After the pattern is formed on the replica mold 25 by the etching process, the replica mold 25 having the projecting portion 25 b can be used as a master mold to produce other replica molds of the second and subsequent generations. Further, the protrusion 25b may be added by forming a thin film on the main body 25a by vapor deposition or coating, whereby the protrusion 25b may be configured to be removable or removable from the main body 25a. In this case, the process of removing the protrusion 25 b from the replica mold 25 is performed, and the replica mold 25 from which the protrusion 25 is removed is used as a mold in a semiconductor device imprint apparatus using a semiconductor wafer as a work. You can also.

<Embodiment of a method of manufacturing an article>
The pattern of the cured product formed using the imprint apparatus is used permanently on at least a part of various articles or temporarily for manufacturing various articles. The article is an electric circuit element, an optical element, a MEMS, a recording element, a sensor, or a mold. Examples of the electric circuit element include volatile or nonvolatile semiconductor memories such as DRAM, SRAM, flash memory and MRAM, and semiconductor elements such as LSI, CCD, image sensor, and FPGA. The mold may, for example, be a mold for imprinting.

  The pattern of the cured product is used as it is as a component member of at least a part of the article or temporarily used as a resist mask. After etching, ion implantation, or the like is performed in the substrate processing step, the resist mask is removed.

  Next, an article manufacturing method will be described with reference to FIG. In step SA, a substrate 1z such as a silicon substrate having a workpiece 2z such as an insulator formed on the surface is prepared, and then an imprint material 3z is applied to the surface of the workpiece 2z by an inkjet method or the like. . Here, a state in which a plurality of droplet-shaped imprint materials 3z are applied onto a substrate is shown.

  In step SB, the mold 4z for imprint is faced with the side on which the concavo-convex pattern is formed facing the imprint material 3z on the substrate. Here, as described above, the replica mold 25 from which the protrusion 25 is removed may be used as the mold 4z.

  In step SC, the substrate 1z to which the imprint material 3z is applied is brought into contact with the mold 4z, and pressure is applied. The imprint material 3z is filled in the gap between the mold 4z and the workpiece 2z. In this state, when light is irradiated through the mold 4z as energy for curing, the imprint material 3z is cured.

  In step SD, after the imprint material 3z is cured, when the mold 4z and the substrate 1z are separated, a pattern of a cured product of the imprint material 3z is formed on the substrate 1z. In the pattern of the cured product, the concave portions of the mold correspond to the convex portions of the cured product and the convex portions of the mold correspond to the concave portions of the cured product, that is, the uneven pattern of the mold 4z is transferred to the imprint material 3z It will be done.

  In step SE, when etching is performed with the pattern of the cured product as the etching resistant, the portion of the surface of the workpiece 2z where the cured product is absent or thin remains is removed to form a groove 5z.

  In step SF, when the pattern of the cured product is removed, an article having grooves 5z formed on the surface of the workpiece 2z can be obtained. Although the pattern of the cured product is removed here, it may be used, for example, as a film for interlayer insulation included in a semiconductor element or the like, that is, as a component of an article without removing it even after processing.

1: Imprint apparatus 2: 2: Stage apparatus 3: 3: Imprint head 6: 6: Control unit 7: 7: Imprint material supply unit 8: Replica mold 11: Master mold 21: Imprint material 40: Gas supply Department

Claims (9)

A mold for producing a replica mold by imprinting,
First side,
A mesa portion projecting from the first surface, having a pattern portion on which a pattern to be transferred to the replica mold is formed;
A protrusion surrounding the mesa portion on the first surface and further projecting beyond the mesa portion;
A mold characterized by having:   The protruding portion is formed to fill a space around the pattern portion and the pattern transfer region when the pattern portion and the imprint material on the pattern transfer region of the replica mold are brought into contact with each other. The mold according to claim 1, characterized in that:   The mold according to claim 2, wherein the protrusion is formed to extend to an end of the mold.   The mold according to any one of claims 1 to 3, wherein the protrusion has a shape in which the degree of protrusion decreases with distance from the mesa portion. It is a replica mold to which a pattern of a master mold is transferred by imprinting, and
First side,
A mesa portion projecting from the first surface, having a pattern transfer region to which the pattern of the master mold is transferred;
A protrusion surrounding the mesa portion on the first surface and further projecting beyond the mesa portion;
A replica mold characterized by having:   The protruding portion fills a space around the pattern transfer region and the pattern portion of the master mold when the imprint material on the pattern transfer region is brought into contact with the pattern portion of the master mold. The replica mold according to claim 5, wherein the replica mold is formed in   The replica mold according to claim 5, wherein the protrusion is configured to be removable from the first surface. An imprint apparatus which forms a pattern on an imprint material on a replica mold using the mold according to any one of claims 1 to 4 as a master mold,
A moving mechanism that holds and moves the master mold;
A gas supply unit which is provided outside the master mold and supplies a gas between the master mold and the imprint material;
When the replica mold is moved to a position where the formation of the pattern is performed via the lower side of the gas supply unit while the gas is supplied by the gas supply unit, the protrusion is the imprint material and A control unit that controls the moving mechanism so as not to interfere with each other;
An imprint apparatus comprising: Forming a pattern on a substrate using the replica mold from which the protrusion according to claim 7 is removed from the first surface;
Processing the substrate on which the pattern is formed;
And manufacturing an article from the processed substrate.

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