JP2010234669A - Method and device for forming fine uneven pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently prevent a fine uneven pattern transferred to a resist layer of a transfer substrate from getting damaged, when releasing a mold on the side for transferring the fine uneven pattern from the transfer substrate on the side for receiving the pattern to be transferred. <P>SOLUTION: This method for forming the fine uneven pattern includes a release process to peel the transfer substrate 14 from the mold 10, after transferring the fine uneven pattern of the mold 10 to the resist layer 12 of the transfer substrate 14 in which the resist layer 12 is formed on the substrate 16 and curing the fine uneven pattern. The release process comprises a curving process to curve the transfer substrate 14 to a specified curvature showing a projecting shape of the resist layer side, and a pressurizing process to pressurize the back side of the substrate in such a state that the circumferential edge of the transfer substrate 14 is immobilized, and keeps the specified curvature of the transfer substrate 14 from the start of release to the end of release, when the transfer substrate 14 and the mold 10 are released from each other by imparting a release force in a direction where they are mutually peeled apart. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method and apparatus for forming a fine concavo-convex pattern, and more particularly to a peeling technique for peeling a transferred resist layer from a mold without damaging the fine concavo-convex pattern.

  In recent years, in lithography processes in semiconductor manufacturing, those using ultraviolet rays (KrF, ArF, F2 laser) in the exposure process have been developed in order to realize high speed and high integration of integrated circuits. In the future, technological development using EUV light (extreme ultraviolet light) with a shorter wavelength is progressing, but there is a problem that the apparatus cost is high.

  In addition, the electron beam exposure technology that has been used for fine patterning until now requires a long time for exposure, so it is currently only used for small-scale trials for special applications, and it can be applied to semiconductor manufacturing that requires mass production. There is a problem that you can not.

  As a method to solve both of these problems (equipment cost and throughput), a nanoimprint technology is used to produce nano-sized fine concavo-convex patterns on a substrate using a polymer as a material to manufacture high-performance devices such as semiconductors, recording media, and optical elements. Has attracted attention.

  The nanoimprint method is a method in which a substrate coated with a resist (resin material) is pressed against a mold (mold) on which a fine concavo-convex pattern is formed by electron beam exposure or the like, and the fine concavo-convex pattern of the mold is transferred to a resist layer.

  As a feature of the nanoimprint technology, it has been confirmed that the device cost for miniaturization is lower than that of the EUV method and the like, and a fine concavo-convex pattern shape of several tens of nanometers can be transferred.

  However, in the nanoimprint technology, after transferring the fine concavo-convex pattern to the resist layer on the substrate, the fine concavo-convex pattern transferred to the resist layer is easily damaged when the resist layer and the mold are peeled off. is there. This is an unavoidable fundamental problem caused by taking a transfer process in which the mold and the resist layer are brought into contact with each other in order to form a fine uneven pattern in the nanoimprint technique.

  Several countermeasures for improving the problem of peeling failure have been proposed. For example, in Patent Document 1, a peeling start point is detected, and the peeling force is controlled based on the detected peeling start point. Patent Document 2 discloses a method of assisting peeling by providing a mold with a curved surface in advance. Patent Document 3 discloses a method for controlling a mold peeling method for a fine uneven pattern.

JP 2007-081048 A JP 2004-288845 A JP 2007-296683 A

  However, even if any of the peeling methods of Patent Documents 1 to 3 is adopted, the peeling failure problem cannot be essentially solved.

  The present invention has been made in view of such circumstances, and when the mold on the side to which the fine concavo-convex pattern is transferred and the transfer substrate on the side to be transferred are peeled off, the resist layer of the transfer substrate is used. Since the transferred fine concavo-convex pattern can be effectively prevented from being damaged, even if it is a nano-sized fine concavo-convex pattern, a fine concavo-convex pattern forming method and forming apparatus capable of forming a highly accurate fine concavo-convex pattern The purpose is to provide.

  In order to achieve the above object, according to a first aspect of the present invention, after transferring and curing a fine concavo-convex pattern of a mold onto a resist layer of a transfer substrate having a resist layer formed on the substrate, the transfer substrate and In the method for forming a fine concavo-convex pattern including a peeling step for peeling off the mold, the peeling step includes a bending step for bending the transfer substrate to a predetermined curvature with a convex convex side on the resist layer side, and the transfer substrate; When peeling by applying a peeling force in the direction of peeling the mold from each other, press the back side of the substrate with the peripheral edge of the transfer substrate fixed, and peel off the predetermined curvature of the transfer substrate. There is provided a method for forming a fine concavo-convex pattern, comprising a pressing step for maintaining from the start to the end of peeling.

  According to the first aspect of the present invention, when the transfer substrate is curved to a predetermined curvature, the transfer substrate and the mold are peeled from each other by applying a peeling force in a direction in which the transfer substrate and the mold are peeled from each other. The substrate back surface side of the transfer substrate was pressed with the portion fixed, and the predetermined curvature of the transfer substrate was maintained from the start of peeling to the end of peeling. By applying pressure on the back side of the substrate, peeling can be performed with the rigidity that prevents the transfer substrate from being deformed by the peeling force, and the predetermined curvature of the transfer substrate does not change from the start of peeling to the end of peeling. The peeling rate can be made substantially constant from the end of peeling to the end of peeling. Thereby, it can peel so that the fine uneven | corrugated pattern transcribe | transferred by the resist layer of the board | substrate for transfer may not be damaged. Therefore, even with a nano-sized fine uneven pattern, a highly accurate fine uneven pattern can be formed.

  In the forming method of the present invention, the predetermined curvature is preferably in the range of 1400 to 2800 mm in radius of curvature R.

  In the forming method of the present invention, the transfer substrate is curved by bringing a solid object having the contact surface having the predetermined curvature into contact with the back surface side of the substrate, and a plurality of suction holes formed on the contact surface. It is preferable to pressurize the back surface side of the substrate with the contact surface of the solid object by sucking the back surface of the substrate.

  As a preferable mode for performing the bending step and the pressurizing step, a solid object having a predetermined curvature and a contact surface having a suction hole is used.

  In the formation method of the present invention, it is preferable that the back side of the substrate is pressurized with a fluid to perform the bending of the transfer substrate and pressurization to the back side of the substrate together.

  This is a preferred embodiment in which the bending step and the pressurizing step are performed, and the back side of the substrate is pressurized with a fluid. If it is a fluid, unlike a solid substance, it can be appropriately adjusted to a desired predetermined curvature.

  In the forming method of the present invention, the pressurizing step is preferably performed at a timing before the peeling force is applied.

  As a result, it is possible to start peeling after ensuring the rigidity that the transfer substrate is not deformed by the peeling force, so that the peeling speed can be made more constant from the start of peeling to the end of peeling, and the fine unevenness is more difficult to damage. it can.

  In the forming method of the present invention, it is preferable that the fine concavo-convex pattern of the mold is transferred only to a curved region where the transfer substrate is curved to the predetermined curvature.

  When the peripheral edge of the transfer substrate is fixed, the peripheral edge of the transfer substrate is less likely to have a predetermined curvature, and the peeling speed of the region is less likely to be constant, but in the present invention, the transfer substrate is curved to bend to a predetermined curvature. Since the fine concavo-convex pattern of the mold is transferred only to the region, it is possible to further improve the debonding speed.

  According to a seventh aspect of the present invention, in order to achieve the above object, after transferring and curing a fine uneven pattern of a mold onto a resist layer of a transfer substrate having a resist layer formed on the substrate, the transfer substrate and In the apparatus for forming a fine concavo-convex pattern provided with a peeling device for peeling the mold, the peeling device includes a peripheral edge fixing means for fixing the peripheral edge of the transfer substrate, and a substrate back side of the transfer substrate. The abutting surface is formed to have a convex predetermined curvature, and a solid object having a large number of suction holes formed on the corresponding contact surface is brought into contact, and the back surface of the substrate is sucked by the suction holes to thereby remove the transfer substrate. A solid-type pressurizing unit that curves to a predetermined curvature and pressurizes the back surface of the substrate with the contact surface by a reaction force generated by the suction, and a peeling force in a direction to peel the transfer substrate and the mold from each other. Providing forming apparatus of the fine concavo-convex pattern comprising the a peel force applying means for applying.

  In order to achieve the above object, according to the present invention, after transferring a fine uneven pattern of a mold to a resist layer of a transfer substrate having a resist layer formed on the substrate and curing, the transfer In the fine unevenness pattern forming apparatus provided with a peeling device for peeling the substrate and the mold, the peeling device includes a peripheral edge fixing means for fixing a peripheral edge of the transfer substrate, and a substrate back side of the transfer substrate. In addition, the transfer substrate is sucked by sucking the back surface of the substrate with a plurality of suction holes formed in the contact surface in a state in which a solid object having a contact surface having a convex curvature is contacted. A solid-type pressurizing unit that curves to the predetermined curvature and pressurizes the back surface of the substrate with the contact surface by a reaction force generated by the suction, and a peeling force in a direction to peel the transfer substrate and the mold from each other. Providing forming apparatus of the fine concavo-convex pattern comprising the a peel force applying means for applying.

  Claims 7 and 8 of the present invention constitute the present invention as an apparatus, claim 7 comprises a fluid type as the pressurizing means, and claim 8 comprises a solid type.

  In the forming apparatus of the present invention, the predetermined curvature is preferably in the range of 1400 to 2800 mm in radius of curvature R.

  In the forming apparatus of the present invention, it is preferable that the peripheral edge fixing means is formed in a structure that sandwiches the peripheral edge of the transfer substrate.

  By using a structure in which the peripheral edge fixing unit sandwiches the peripheral edge of the transfer substrate, the peripheral edge of the transfer substrate can be reliably fixed against pressure from the back surface of the substrate.

  In the forming apparatus of the present invention, it is preferable that the peripheral edge fixing means is formed in a structure in which the neck is swung following the bending direction of the transfer substrate.

  This solves the problem that if the peripheral edge of the transfer substrate is fixed, the peripheral edge of the transfer substrate is less likely to have a predetermined curvature. That is, since the peripheral edge fixing means swings the head following the curve direction of the transfer substrate, the peripheral edge portion of the transfer substrate can be accurately formed with a predetermined curvature. Therefore, it is not necessary to limit the transfer area of the transfer substrate to which the fine uneven pattern of the mold is transferred.

  According to the fine concavo-convex pattern forming method and apparatus of the present invention, when the mold on the side to which the fine concavo-convex pattern is transferred and the transfer substrate on the side to be transferred are peeled off, the pattern is transferred to the resist layer of the transfer substrate. It is possible to effectively prevent the fine uneven pattern from being damaged. Therefore, even with a nano-sized fine uneven pattern, a highly accurate fine uneven pattern can be formed.

Process drawing showing the steps of forming fine uneven patterns Explanatory drawing explaining the union | merged thing which the mold and the board | substrate for transcription | transfer merged at the transfer process Explanatory drawing explaining the peeling apparatus provided with the fluid type pressurization means in the formation apparatus of the fine unevenness | corrugation pattern of this invention Explanatory drawing explaining the curved state of the peripheral part of the board | substrate for transfer fixed to the peripheral part fixing means Explanatory drawing explaining the pinching structure and the swing structure provided in the peripheral edge fixing means Explanatory drawing explaining the peeling mechanism in this invention Explanatory drawing explaining the peeling apparatus provided with the solid-type press means in the formation apparatus of the fine unevenness | corrugation pattern of this invention. Conceptual diagram explaining three peeling methods in Test A Table illustrating test results of test A Table illustrating the test results of test B

  Preferred embodiments of a method and apparatus for forming a fine concavo-convex pattern according to the present invention will be described in detail with reference to the accompanying drawings.

  While explaining each step of the fine uneven pattern forming method of the present invention, a peeling method and a peeling apparatus, which are features of the present invention, will be described.

<Mold production>
The metal material is subjected to three-dimensional solid processing using a semiconductor fine processing technique to form a mold 10 having a fine uneven pattern 10A as shown in FIG. In this case, the original may be molded with a metal material, the original may be transferred to a resin material to produce a resin stamper, and the resin stamper may be used as the mold 10. The material of the mold 10 can be appropriately selected according to the purpose, but metal, quartz, resin and the like can be suitably used. Ni, Si or SiO2 _, Cu, Cr, Pt, etc. can be used as the metal material, and polyethylene terephthalate, polyethylene naphthalate, polycarbonate, fluorine resin, etc. can be used as the resin material.

  And it is preferable to coat | cover a peeling layer on the surface of the fine uneven | corrugated pattern 10A of the produced mold 10. FIG. The release agent is preferably formed on the surface of the fine concavo-convex pattern 10 </ b> A so that it can be peeled off at the transfer interface between the mold 10 and the resist layer 12 without causing defects due to stress at the time of peeling after the transfer / curing step described later. As the release agent material, a material suitable for the purpose of being easily adhered and bonded to the mold side and hardly adsorbed to the resist layer side can be selected as appropriate. Among them, a fluorine resin having a low electronegativity is preferable in that it is difficult to adsorb on the resist layer side.

 As the thickness of the release layer, since the fine uneven pattern 10A changes when it is too thick, it is preferable to make it as thin as possible, specifically 5 nm or less, more preferably 3 nm or less.

  As a method for forming the release layer, application or vapor deposition of a release agent can be used. Further, after the release layer is formed, it is preferable to improve the adhesion to the mold 10 by means such as baking to improve the strength of the release layer itself.

  Using the mold 10 manufactured as described above, a fine uneven pattern 12A is formed on the resist layer 12 of the transfer substrate 14 by performing a coating process, a transfer process, and a peeling process.

[Coating process]
As shown in FIG. 1 (A), a resist solution in which a resin material for forming the resist layer 12 is dissolved in a solvent is applied to the substrate 16 to form a transfer substrate 14 on which the resist layer 12 is formed. To do. As a resin material for forming the resist layer 12, for example, a thermoplastic resin, a thermosetting resin, and a photocurable resin can be preferably used. Moreover, as a material of the board | substrate 16, a glass substrate, Si substrate, etc. can be used, for example.

  As a method for applying the resist solution onto the substrate 16, the following method can be suitably used.

  (1) The ink is dropped on an appropriate location on the substrate by a droplet device such as an ink jet, spreads by the fluidity of the resist solution itself, and uniformly applied onto the substrate 16.

  (2) By rotating the substrate 16 by spin coating, the resist solution dropped on the substrate 16 is spread and applied uniformly.

  (3) Apply uniformly on the substrate 16 using a bar coater or the like.

  The thickness of the resist layer 12 applied on the substrate 16 is determined by, for example, an optical measurement method using an ellipsometer or the like, or a contact measurement method such as a stylus type step gauge or an atomic force microscope (AFM). It can be measured.

[Transfer process]
Next, as shown in FIG. 1B, the fine uneven pattern 10 </ b> A of the mold 10 is transferred to the resist layer 12 of the transfer substrate 14. Generally, only the weight on which the mold 10 is placed on the resist layer 12 of the transfer substrate 14 is not transferred because the resist solution of the resist layer 12 is not filled in the concave portions of the fine concavo-convex pattern 10A formed on the mold 10. Therefore, in order to transfer the fine concavo-convex pattern 10A of the mold 10 to the resist layer 12 of the transfer substrate 14, it is necessary to forcibly fill by changing the surrounding pressure conditions. For example, the following filling method can be used suitably.

  (1) The mold 10 is pressed against the resist layer 12 with a press or the like. In this case, it becomes easier to fill the concave portion of the fine concavo-convex pattern 10 </ b> A with the resist solution by pressurizing or heating the resist layer 12.

  (2) After applying the resist solution on the substrate 16, the mold 10 is placed on the resist layer 12 and placed under heating and decompression conditions. As a result, air and air bubbles remaining in the concave portions of the fine concavo-convex pattern 10A are removed, so that the resist solution is filled in the concave portions.

[Curing process]
Next, the resist layer 12 to which the fine uneven pattern 10A of the mold 10 is transferred is cured. As a result, as shown in FIG. 2, a combined product 20 is formed in which the mold 10 and the transfer substrate 14 are combined. FIG. 2A is a longitudinal sectional view of the combined product 20, and FIG. 2B is a top view. In the present embodiment, the combined object 20 is described as having a circular shape, but is not limited to this, and may be, for example, a rectangular shape.

  As a method for curing the resist layer 12, the following method can be preferably used.

  (1) In the case of a photo-curing resin, the resist layer 12 is cured by irradiating the resist layer 12 with curing light in a wavelength band where the curing initiator reacts. FIG. 1B is an example in which the resist layer 12 is cured by irradiating curing light from the back surface of the transparent mold 10 that transmits light.

  (2) In the case of a resist material soluble in a solvent, it is dissolved in a solvent and cured by drying after transfer.

  (3) In the case of a thermoplastic natural polymer, it is cured by cooling the resist layer 12 after transfer.

[Peeling process]
Next, as shown in FIG. 1C, the transfer substrate 14 and the mold 10 are peeled off by applying a peeling force F in a direction in which they are peeled off from each other. FIG. 1C shows an example in which the mold 10 is peeled from the transfer substrate 14 by fixing the transfer substrate 14 and pulling the mold 10 upward in the vertical direction.

  In such a peeling process, conventionally, there has been a problem that the fine uneven pattern 12A transferred to the resist layer 12 is damaged by a peeling failure when the mold 10 is peeled off from the transfer substrate 14. In particular, the degree of damage was large when the fine uneven pattern to be transferred was a nano-sized extremely fine uneven form.

  Therefore, in the present invention, as the peeling step, a curving step for bending the transfer substrate 14 to a predetermined curvature with the resist layer 12 side convex, and a peeling force in the direction in which the transfer substrate 14 and the mold 10 are peeled from each other are applied. A pressing step of pressing the back side of the substrate with the peripheral edge of the transfer substrate 14 fixed and maintaining the predetermined curvature of the transfer substrate 14 from the start of peeling to the end of peeling. It was made to solve.

  FIG. 3 is an explanatory view of a peeling apparatus provided with a fluid pressurizing means in the present invention.

  As shown in FIG. 3, the peeling device mainly includes a peripheral edge fixing unit 24, a fluid pressure unit 26, and a peeling force applying unit 32.

  As shown in FIG. 3 (A), the peripheral edge fixing means 24 is configured so that the transfer substrate 14 is placed in a state where the combined product 20 in which the mold 10 and the transfer substrate 14 are combined is placed on the base 22 in the transfer process. The peripheral edge is fixed. The peripheral edge fixing means 24 mainly includes an annular member 24A supported on the peripheral edge on the base 22 and an annular pressing plate 24B formed wider than the upper surface of the annular member 24A.

  A plurality of bolts 24C are threaded through the annular pressing plate 24B at equal intervals, and female screws are vertically engraved from the upper surface toward the inside at the bolt corresponding positions of the annular member 24A. . The bolts 24C are preferably arranged at intervals of 120 degrees (three bolts) or 90 degrees (four bolts) of the annular pressing plate 24B, but the number of bolts is not limited as long as they are equidistant. Thereby, the front-end | tip part of the volt | bolt 24C which penetrated the press board 24B can be screwed by the internal thread formed in 24 A of annular members. Further, the height of the annular member 24A is lower than the thickness of the peripheral portion of the transfer substrate 14, and a nut member 24D that is screwed into the bolt 24C is provided on the upper surface of the pressing plate 24B.

  Therefore, as shown in FIG. 3B, in the state where the combined product 20 is placed on the base 22, the tip of the bolt 24C penetrating the annular pressing plate 24B is screwed into the female screw of the annular member 24A. The annular pressing plate 24B is coupled to the annular member 24A, and the nut member 24D is tightened to press the annular pressing plate 24B toward the annular member 24A. As a result, the peripheral edge of the transfer substrate 14 is sandwiched between the base 22 and the annular pressing plate 24B, so that the peripheral edge of the transfer substrate 14 can be reliably fixed by the peripheral edge fixing means 24.

  The material of the annular pressing plate 24B is preferably an elastic member (for example, made of rubber) so that when the transfer substrate 14 is bent, the peripheral portion of the transfer substrate 14 is also fixed and is easily bent.

  The fluid pressurizing means 26 includes a circular rubber sheet 28 laid in an annular member 24A on the base 22 and a pressurized fluid outlet 30A penetrating the base 22 to the base upper surface 22A. And a pressurized fluid supply device (not shown) connected to the pipe 30. And the peripheral part of the rubber-made sheet | seat 28 is adhere | attached on 22 A of base upper surfaces with an adhesive agent. As a result, a non-adhesive region that is not bonded with an adhesive is formed between the rubber sheet 28 and the base upper surface 22A. Therefore, the rubber sheet 28 can be inflated by supplying the pressurized fluid from the outlet 30A of the pipe 30 to the non-bonding region. As the pressurized fluid, gas or liquid can be used, and usually air or water is preferably used.

  Further, as shown in FIG. 3C, any peeling force applying means 32 may be any means for applying a vertical peeling force F to the mold 10 and peeling the mold 10 from the transfer substrate 14. Something like that.

  And in order to perform the peeling method of this invention using the peeling apparatus provided with said fluid type pressurization means, first, the unification thing 20 of FIG. 2 is put on the rubber-made sheet 28 like FIG.3 (B). At the same time, the peripheral portion of the transfer substrate 14 is fixed by the peripheral portion fixing means 24.

  Next, the pressurized fluid supply device supplies the pressurized fluid from the outlet 30 </ b> A to the non-bonding region between the base upper surface 22 </ b> A and the rubber sheet 28 via the pipe 30 to inflate the rubber sheet 28. Thus, the substrate rear surface of the transfer substrate 14 whose periphery is fixed by the periphery fixing means 24 is pressurized. Thereby, the resist layer side of the transfer substrate 14 is convexly curved. The curvature at which the transfer substrate 14 is curved is preferably in the range of 1400 to 2800 mm in radius of curvature R.

  Next, the peeling force applying means 32 is driven to peel the mold 10 from the transfer substrate 14. At that time, peeling is performed while the pressure is maintained so that the curvature of the transfer substrate 14 is maintained from the start to the end of peeling.

  Thereby, it can prevent effectively that the fine uneven | corrugated pattern 12A transferred to the resist layer 12 of the transfer substrate 14 at the time of peeling is damaged. Therefore, for example, even with the nano-sized fine uneven pattern 12A, a highly accurate fine uneven pattern can be formed.

  In such a peeling step, as shown in FIG. 4, the peripheral edge region W of the transfer substrate 14 fixed by the peripheral edge fixing means 24 is unlikely to have a predetermined curvature. Therefore, it is preferable that the fine concavo-convex pattern 10A of the mold 10 is transferred only to a curved region (inside the peripheral region W) where the transfer substrate 14 is curved to a predetermined curvature.

  In order to solve such a problem as a device, it is preferable that the peripheral edge fixing means 24 swings in the bending direction as shown in FIG. That is, the peripheral edge fixing means 24 is mainly pivotable via a plurality of support columns 24a erected on the peripheral edge portion of the base 22 at predetermined equal intervals, and the upper ends of the support columns 24a via pins 24b. The rotating member 24c is supported, the lower plate 24d is fixed to the rotating member 24c, the upper plate 24f is penetrated in a state where the bolt 24e is screwed, and the sealing member 24g is formed in a skirt shape. The The thickness of the rotating member 24 c in the vertical direction is formed to be thinner than the total thickness of the peripheral edge of the transfer substrate 14 and the peripheral edge of the rubber sheet 28. The struts 24a are preferably 120 degrees (three struts) or 90 degrees apart (four struts), but are not limited as long as they are equally spaced.

  The rotating member 24c is engraved with a female screw into which the front end of the bolt 24e is screwed, and a pressing nut member 24h is provided on the upper surface of the upper plate 24f.

  Then, with the peripheral portion of the transfer substrate 14 and the peripheral portion of the rubber sheet 28 positioned between the upper plate 24f and the lower plate 24d, the tip end portion of the bolt 24e penetrating the upper plate 24f is used as a rotating member. The upper plate 24f is screwed into the female screw 24c to connect the upper plate 24f to the rotating member 24c, and the nut member 24h is tightened to press the upper plate 24f toward the lower plate 24d. Thereby, the peripheral edge of the transfer substrate 14 and the peripheral edge of the rubber sheet 28 are sandwiched and fixed between the upper plate 24f and the lower plate 24d. Further, the sealing member 24g supported by the lower plate 24d is provided in a skirt shape, so that the fluid blown from the outlet 30A of the pipe 30 is sealed so as not to leak to the outside.

  As a result, the pressurized fluid is supplied from the pressurized fluid supply device through the piping 30 from the outlet 30A between the upper surface 22A of the base 22 and the rubber sheet 28 to inflate the rubber sheet 28. The back surface of the transfer substrate 14 whose peripheral edge portion is fixed by the portion fixing means 24 is pressurized. Therefore, the resist layer side of the transfer substrate 14 is convexly curved. In this case, the peripheral edge fixing means 24 rotates via the pin 24b and swings in the bending direction, so that the peripheral edge area W of the transfer substrate 14 fixed by the peripheral edge fixing means 24 has a predetermined curvature. Can solve the problem of difficulty.

  FIG. 6 is a schematic diagram for explaining a mechanism in which the fine concavo-convex pattern 12A is not easily damaged by performing the peeling step in the present invention. FIG. 6A shows the curvature of the transfer substrate 14 at the start of peeling and in the middle of peeling when the peeling step according to the present invention is performed.

  As can be seen from FIG. 6 (A), the peeling process in the present invention is performed in a state where the predetermined curvature of the transfer substrate 14 is maintained at the same curvature radius R suitable for peeling, both at the start of peeling and during the peeling. Therefore, it can peel at a substantially constant peeling speed from the start of peeling to the end of peeling.

  Here, the “peeling speed” refers to the amount of peeled area per unit peeling time at the transfer interface between the mold 10 and the resist layer 12 of the transfer substrate 14, and the constant peeling speed means from the start of peeling to the end of peeling. It means that the amount of peeled area per peeling time is constant.

  As described above, the reason why the curvature of the transfer substrate 14 can be made the same from the start of peeling to the end of peeling is to pressurize the back side of the transfer substrate 14 with the peripheral edge of the transfer substrate 14 fixed by the fixing frame 24A. It is considered that this is because the transfer substrate 14 is strongly strained, and the transfer substrate 14 is given rigidity enough to prevent deformation due to the peeling force F.

  In this way, by making the peeling rate from the start of peeling to the end of peeling substantially constant, as can be seen from the drawing in the middle of peeling in FIG. 6A, the fine unevenness close to the peripheral edge side of the transfer substrate 14 is obtained. By the time when the peeling is completed, peeling of fine irregularities in the vicinity of the central portion (peeling end interface portion) has progressed considerably. Thereby, the fine unevenness | corrugation of the center part which is the peeling termination | terminus interface peeled last is not peeled at a stretch at a big peeling speed. As a result, since the impact stress applied to the fine irregularities in the central portion that is finally peeled is reduced, the fine irregularities in the central portion can be effectively prevented from being damaged.

  On the other hand, FIG. 6B shows the transfer at the start of peeling and during the peeling in the case where the substrate back surface of the transfer substrate 14 is not pressurized even if the peripheral edge of the transfer substrate 14 is fixed to the fixing frame 24A. This shows the curvature of the substrate 14 for use.

  As shown in FIG. 6B, even if the peripheral portion of the transfer substrate 14 is fixed, if the transfer substrate 14 is not pressurized, the transfer substrate 14 forms a free surface whose curvature is changed by the peeling force F. Thereby, the transfer substrate 14 at the start of peeling forms the same radius of curvature R as in the peeling step of the present invention, but the transfer substrate 14 in the middle of peeling after the peeling has progressed has a radius of curvature R1, and the curvature at the start of peeling. It becomes smaller than the radius R. When the radius of curvature of the transfer substrate 14 becomes smaller as the peeling progresses, as shown in the drawing in the middle of peeling in FIG. 6B, peeling of fine irregularities near the peripheral edge side of the transfer substrate 14 is finished. Nevertheless, a state is formed in which the fine unevenness in the vicinity of the central portion (peeling end interface portion) is not peeled off at all. Thereby, the fine unevenness | corrugation of the center part which is a peeling termination | terminus interface peeled last is peeled at a stretch at a big peeling speed. As a result, the impact stress applied to the fine irregularities in the central portion that is finally peeled increases, so that the fine irregularities in the central portion are destroyed.

  FIG. 7 is a conceptual diagram of a peeling apparatus provided with a solid-state pressurizing unit different from the fluid-type pressurizing unit described in FIG.

  As shown in FIG. 7A, the peripheral edge fixing means 24 is provided with an annular member 24A formed in a cylindrical shape, and the upper end of the annular member 24A is bent inward to form a flange 24E. . The material of the annular member 24A is preferably made of rubber having elasticity so that the combined product 20 can be easily accommodated in the annular member 24A. Further, if a solid material 34 described later is configured to be slidable in the vertical direction with respect to the annular member 24A, the material of the annular member 24A can be formed of a metal or resin that does not expand or contract.

  Further, the solid-type pressurizing means 33 communicates with the solid hole 34 in which the contact surface 34A is formed with a predetermined convex curvature and a plurality of suction holes 34B are formed on the corresponding contact surface 34A, and the suction hole 34B. The suction pipe 36 sucks air from the internal space 34C of the solid object 34, and a suction device (not shown) connected to the suction pipe 36.

  As shown in FIG. 7C, the peeling force applying means 32 is any means as long as it applies a vertical peeling force to the mold 10 and peels the mold 10 from the transfer substrate 14. But you can.

  And in order to perform the peeling method of this invention using the peeling apparatus provided with said solid-type pressurization means 33, as shown in FIG.7 (B), the unification thing 20 of the mold 10 and the board | substrate 14 for transcription | transfer 14 first. Is placed on the contact surface 34A of the solid object 34, and the peripheral edge of the transfer substrate 14 is fixed by the peripheral edge fixing means 24. In this case, it is more preferable that the annular member 24A and the flange portion 24E are separated from each other, and the peripheral portion of the transfer substrate 14 is sandwiched as described with reference to FIG.

  Next, the suction device is driven to depressurize the internal space 34C of the solid material 34, whereby the back surface of the transfer substrate 14 is sucked through the suction holes 34B. As a result, the transfer substrate 14 is curved following the contact surface 34A of the solid object 34, so that the transfer substrate 14 is curved to a predetermined curvature. The curvature at which the transfer substrate 14 is curved is preferably in the range of 1400 to 2800 mm in radius of curvature R.

  In this case, the solid object 34 is slidably moved to the annular member 24A, and a cylinder device 35 is provided on the back surface of the solid object 34, and the solid object 34 is slid and pressed to the mold side, thereby transferring the substrate for transfer. 14 may be curved to a predetermined curvature.

  The cylinder device 35 includes a cylinder body (not shown), a cylinder rod 35A, a pressing rod 35B on the back surface of the solid object 34, and a pin 35C that connects the cylinder rod 35A and the pressing rod 35B.

  Further, a gap is formed between the solid object 34 and the annular member 24 </ b> A, and the gap is sealed by a ring-shaped elastic member (O-ring) 37. The elastic member 37 can tilt the solid object 34 within ± 5 mm with respect to the vertical direction of FIG. 7 by an external force.

  Therefore, when the solid substrate 34 is slid by the cylinder device 35 and the transfer substrate 14 is pressed by the cylinder device 35 to bend the transfer substrate 14, the solid material 34 is formed by the pins 35 </ b> C of the cylinder device 35 and the elastic member 37. Since it can be slightly tilted, it is possible to apply a pressing force evenly to the transfer substrate 14. Thereby, the transfer substrate 14 is curved following the contact surface 34A of the solid object 34 with high accuracy.

  In the peeling step according to the present invention, in addition to the above-described curvature of the transfer substrate 14, the substrate back surface of the transfer substrate 14 is pressed by the contact surface 34 </ b> A of the solid object 34 by a reaction force generated by suction.

  Next, when the peeling force applying means 32 is driven to peel the mold 10 from the transfer substrate 14, the back surface of the transfer substrate 14 is maintained so that the curvature of the transfer substrate 14 is maintained from the start of peeling to the end of peeling. Is peeled while being pressed by the contact surface 34 </ b> A of the solid object 34.

  Thereby, for the same reason as explained in the case of the peeling apparatus provided with the fluid type pressurizing means 26 described above, the fine uneven pattern 12A transferred to the resist layer 12 of the transfer substrate 14 is damaged at the time of peeling. It can be effectively prevented.

  Next, examples of the present invention will be described.

[Test A]
In the test A, the peelability was examined for the three peeling methods of Example 1, Comparative Example 1, and Comparative Example 2 of the present invention.

  Example 1 is a case where the peeling method according to the present invention was performed using the peeling apparatus described in FIG. 3 as shown in FIG. The peripheral edge portion of the transfer substrate 14 is fixed by the peripheral edge fixing means 24, and the fluid pressure means 26 pressurizes the back surface of the substrate with an assist pressure of 0.5 MPa so that the transfer substrate 14 has a curvature radius of 2100 mm. It was curved to become. Then, the mold 10 was peeled from the transfer substrate 14 by applying a vertical upward peeling force F to the mold 10 while maintaining the assist pressure of 0.5 MPa.

  In Comparative Example 1, as shown in FIG. 8B, the peeling apparatus described in FIG. 3 was used, but the back surface of the transfer substrate 14 was not pressurized with fluid (assist pressure 0). It is the same.

  In Comparative Example 2, as shown in FIG. 8C, a peeling force F is applied to one end side of the mold 10, and the mold 10 is peeled from one end side to the other end side of the transfer substrate 14. This is the case.

  The fabrication, coating process, transfer process, and curing process of the mold 10 are common to Example 1, Comparative Example 1, and Comparative Example 2.

<Mold production>
Using a nickel (Ni) material of vertical and horizontal 100 mm x 100 mm and thickness 1 mm, a fine uneven pattern (line and space) with a width of 0.5 μm, height of 2 μm, and pitch of 1 μm in a pattern formation area of vertical and horizontal 20 mm × 20 mm Shape) was formed by patterning with a stepper and dry etching to obtain a mold 10.

<Application process>
A resist solution containing a UV curable resin material (for example, PAK-01 manufactured by Toyo Gosei Co., Ltd.) is spin-coated on a disk-shaped glass substrate 16 (manufactured by Shin-Etsu Chemical) having a diameter of 147 mm (6 inches) and a thickness of 0.7 mm. It was applied with a device. Thus, a transfer substrate 14 in which the resist layer 12 was formed on the glass substrate 16 was produced.

<Transfer process>
The mold 10 on which the fine concavo-convex pattern 10 </ b> A is formed is aligned with the resist layer 12 of the transfer substrate 14. Then, by pressing the resist layer 12 from the mold side with an imprint apparatus, the air remaining in the concave portions of the fine concave / convex pattern 10A is removed by pressure change, and the fine concave / convex pattern 10A of the mold 10 is transferred to the resist layer 12 did.

<Curing process>
After the transfer process, the resist layer 12 was irradiated with light having a wavelength of 365 nm, which is the curing wavelength of the photocurable resin, to cure the resist layer 12.

[Test results]
The test results are shown in Table 1 of FIG.

  In Example 1, which was peeled off while applying an assist pressure of 0.5 MPa on the back surface of the transfer substrate 14, the curvature of the transfer substrate 14 can be uniformly maintained at a curvature radius of 2100 mm from the start of peeling to the end of peeling. The fine concavo-convex pattern 12A transferred to the resist layer 12 could be peeled from the mold 10 without damage.

  Further, in Comparative Example 1 where the backing surface of the transfer substrate 14 was peeled off without applying an assist pressure, the curvature of the transfer substrate 14 fluctuated and became non-uniform during peeling, and the transfer progressed as the peeling progressed. The radius of curvature of the substrate 14 is reduced. Thereby, in the case of the comparative example 1, damage was seen by the fine unevenness | corrugation of the center part of the board | substrate 14 for a transfer which is a peeling termination | terminus interface part (refer FIG. 8 (B)).

  In Comparative Example 2, when the transfer substrate 14 was peeled from the mold 10, damage was concentrated on the fine irregularities on the other end portion of the transfer substrate 14 which is the separation termination interface portion (FIG. 8C). reference).

  Further, as can be seen from Table 1 of FIG. 9, in Example 1, the peeling force F required for peeling is 4N (Newton), and peeling is performed with a force smaller than 10N of Comparative Example 1 and 8N of Comparative Example 2. I was able to.

  The peel force F is measured by attaching a load cell to the back surface of the mold 10 and pulling the mold 10 upward in the vertical direction via the load cell so that the mold 10 and the transfer substrate 14 are completely peeled off. The maximum value of F was measured.

[Test B]
In the test B, an appropriate assist pressure range and an appropriate radius of curvature for pressing the back surface of the transfer substrate 14 were examined. The mold preparation, coating process, and transfer process were the same as in Test A, and the assist pressure was changed in the range of 0 to 1.3 MPa in the peeling process. An assist pressure of 0 corresponds to Comparative Example 1 of Test A.

  The results of Test B are shown in Table 2 in FIG.

  As can be seen from Table 2 in FIG. 10, tests 2 to 4 formed in the range of the assist pressure in the range of 0.3 to 1.0 MPa and the radius of curvature in the range of 2800 to 1400 mm are the transfer substrates without causing the separation failure. Good fine unevenness patterns could be formed on the 14 resist layers 12.

  On the other hand, in the test 1 in which the assist pressure was 0 and the radius of curvature was ∞ (flat), damage was generated on the fine irregularities in the central portion of the transfer substrate 14 that is the peeling termination interface portion.

  In the test 5 in which the assist pressure was 1.3 MPa and the radius of curvature was 1000 mm, the glass substrate 16 of the transfer substrate 14 was broken due to excessive bending.

  DESCRIPTION OF SYMBOLS 10 ... Mold, 12 ... Resist layer, 14 ... Substrate for transfer, 16 ... Substrate, 20 ... Combined thing, 22 ... Base, 24 ... Peripheral part fixing means, 24A ... Ring member, 24B ... Pressing plate, 26 ... Fluid type Pressurizing means, 28 ... rubber sheet, 30 ... piping, 32 ... peeling force applying means, 33 ... solid pressurizing means, 34 ... solid matter, 36 ... suction piping

Claims (11)

A fine concavo-convex pattern comprising a peeling step for separating the transfer substrate and the mold after transferring and curing the fine concavo-convex pattern of the mold onto the resist layer of the transfer substrate having a resist layer formed on the substrate. In the forming method,
The peeling step includes
A curving step of curving the transfer substrate into a predetermined curvature convex on the resist layer side;
When the transfer substrate and the mold are peeled by applying a peeling force in the direction of peeling, the back surface side of the transfer substrate is pressed with the peripheral edge of the transfer substrate fixed. And a pressurizing step for maintaining the predetermined curvature from the start of peeling to the end of peeling.   The method of forming a fine concavo-convex pattern according to claim 1, wherein the predetermined curvature has a radius of curvature R in the range of 1400 to 2800 mm.   The transfer substrate is curved by bringing a solid object having a contact surface with the predetermined curvature into contact with the back surface side of the substrate, and the back surface of the substrate is sucked by a number of suction holes formed on the contact surface. 3. The method for forming a fine concavo-convex pattern according to claim 1 or 2, wherein the back surface side of the substrate is pressed by the contact surface of the solid object.   3. The method for forming a fine concavo-convex pattern according to claim 1 or 2, wherein the back side of the substrate is pressurized with a fluid, whereby the curve of the transfer substrate and the pressurization to the back side of the substrate are performed together.   The method for forming a fine unevenness pattern according to any one of claims 1 to 4, wherein the pressing step is performed at a timing before the peeling force is applied.   6. The method for forming a fine concavo-convex pattern according to claim 1, wherein the fine concavo-convex pattern of the mold is transferred only in a curved region where the transfer substrate is curved to the predetermined curvature. A fine concavo-convex pattern provided with a peeling device for separating the transfer substrate and the mold after transferring and curing the fine concavo-convex pattern of the mold onto the resist layer of the transfer substrate having a resist layer formed on the substrate. In the forming device,
The peeling device is
Peripheral edge fixing means for fixing the peripheral edge of the transfer substrate;
A fluid-type pressurizing means that is provided on the back side of the substrate of the transfer substrate, and inflates the back side of the substrate with a pressurized fluid so as to curve the transfer substrate to a predetermined curvature and pressurize the back side of the substrate;
An apparatus for forming a fine concavo-convex pattern, comprising: peeling force applying means for applying a peeling force in a direction in which the transfer substrate and the mold are peeled from each other. A fine concavo-convex pattern provided with a peeling device for separating the transfer substrate and the mold after transferring and curing the fine concavo-convex pattern of the mold onto the resist layer of the transfer substrate having a resist layer formed on the substrate. In the forming device,
The peeling device is
Peripheral edge fixing means for fixing the peripheral edge of the transfer substrate;
The back surface of the substrate is sucked by a large number of suction holes formed in the contact surface in a state in which a solid object having a convex contact surface is formed on the back surface side of the transfer substrate. Solid-state pressurizing means for curving the transfer substrate to the predetermined curvature and pressurizing the back surface of the substrate with the contact surface by a reaction force generated by the suction;
An apparatus for forming a fine concavo-convex pattern, comprising: peeling force applying means for applying a peeling force in a direction in which the transfer substrate and the mold are peeled from each other.   The apparatus for forming a fine unevenness pattern according to claim 7 or 8, wherein the predetermined curvature has a radius of curvature R in a range of 1400 to 2800 mm.   The apparatus for forming a fine unevenness pattern according to any one of claims 7 to 9, wherein the peripheral edge fixing means is formed so as to sandwich the peripheral edge of the transfer substrate.   The apparatus for forming a fine unevenness pattern according to any one of claims 7 to 10, wherein the peripheral edge fixing means is formed in a structure in which a neck is swung following the bending direction of the transfer substrate.

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