JP2013058767A - Method for forming pattern and method for manufacturing template - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming an imprint pattern having a high-precision fine pattern, and a method for manufacturing a template.SOLUTION: A method for forming a pattern includes the steps of: forming a polymerizable resin layer 33 on a chrome thin film 41 laminated on a substrate 31; superimposing a prepared transparent imprint template 10 on the polymerizable resin layer 33 on the quartz substrate 31 to shape the polymerizable resin layer 33 by using a first pattern 13 as a pattern of the imprint template 10; forming a second pattern 43 constituted by unevenness having an inverse shape of the first pattern on the polymerizable resin layer 33; forming a third pattern 45 on the quartz substrate 31 by using the second pattern 43 as a mask; and forming a forth pattern 47 constituted by unevenness on a surface of the substrate 31 by using the third pattern 45 as a mask.

Description

  The present invention relates to a pattern forming method and a template manufacturing method for forming a highly accurate fine pattern.

  In the field of manufacturing semiconductors and the like, it is desired to efficiently form a fine resist pattern for use in photolithography. However, in conventional photolithography, it is necessary to use an expensive optical device and go through a process with many steps and many kinds of materials used.

Therefore, the following nanoimprint lithography (hereinafter referred to as NIL) in which a resist pattern is formed using an imprint template (also referred to as a mold or a mold) has been proposed.
For example, “applying a moldable layer to the surface of a substrate, providing a mold with a molding surface having a plurality of protruding features, pressing the molding surface and the moldable layer together by direct fluid pressure, and protruding features A method for treating the surface of a substrate comprising the steps of reducing the thickness of the lower moldable layer to produce a thinned region and removing the mold from the moldable layer "or in addition to this method “A method of further removing the material of the moldable layer from the thinned area and selectively further processing the exposed area of the substrate in order to selectively expose the area of the substrate” It has been proposed (see, for example, [Patent Document 1]).

  Or, “a step of forming a photocurable material layer made of a liquid photocurable material on a base substrate and a light transmissive material, and a groove having a predetermined pattern is formed on one surface side. A step of pressure-bonding the mold to the base substrate such that the one surface side faces the surface side of the base substrate on which the photocurable material layer is formed, and light from the other surface side of the mold. Irradiating to cure the photocurable material layer, forming a resist pattern comprising the photocurable material and having a pattern that fits into the predetermined pattern, and removing the mold from the base substrate There has also been proposed a “manufacturing method of a semiconductor device” including a step and a step of etching the base substrate using the resist pattern as a mask (see, for example, [Patent Document 2]). .).

JP-T-2004-504718 Special Table 2000-194142

  In the NIL as described in Patent Document 1 and Patent Document 2 described above, since the success or failure of the resist pattern is determined by the uneven pattern formed on the surface of the template, it is very important to manufacture the template with high accuracy. . Therefore, it has been attempted to manufacture a mold for NIL through a process similar to that for manufacturing a Levenson type phase shift mask using, for example, quartz as a substrate, as in photolithography.

  That is, a photomask blank in which a chromium (Cr) thin film is laminated on a quartz substrate is prepared, the chromium thin film is patterned by photolithography, and then the quartz substrate is etched using the patterned chromium thin film as a mask. Thereafter, a chromium thin film is removed to obtain a mold for NIL using quartz as a substrate. Since the quartz substrate has good ultraviolet transmittance, when NIL is applied to a target substrate that is not necessarily transparent, if the intervening resin is ultraviolet curable, ultraviolet irradiation is performed from the side of the NIL mold. Has the advantage of being able to do it.

  However, in the case of the above method, the etching of the chromium thin film is difficult to control the shape as compared with the etching of the silicon-based material, and it is difficult to form a fine pattern with high accuracy. In addition, the NIL mold requires a relatively deep etching of the quartz substrate, but it is difficult to make the etching depth constant because the etching depth is affected by the area of the opening. In addition, in order to perform deep etching with a resin resist, it is necessary to increase the thickness of the resist to a level comparable to the etching depth, but there is a limit when performing resist application, exposure, and development. There was a problem that there was.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a pattern forming method and a template manufacturing method for forming a highly accurate fine pattern.

  In order to achieve the above-mentioned object, a first invention is a method for forming a concavo-convex pattern by nanoimprinting, comprising a step of preparing a transparent imprint template, and a polymerizable resin on a quartz substrate on which a chromium thin film is laminated A step of forming a layer, the imprint template and the polymerizable resin layer on the quartz substrate are overlapped, and the polymerizable resin layer is applied by a first pattern which is a pattern of the imprint template. A step of forming, a step of curing the polymerizable resin, and forming a second pattern composed of concavities and convexities that are reverse shapes of the first pattern on the polymerizable resin layer, and the second pattern Forming a third pattern on the quartz substrate using a mask as a mask, and forming irregularities on the surface of the quartz substrate using the third pattern as a mask. A pattern forming method using the imprint template, characterized by comprising a step of forming a fourth pattern.

  The first pattern is formed by lithography. In the lithography process, pattern data obtained by correcting in advance dimensions that change due to transparency is used.

  The second invention is a method for producing a template used for nanoimprinting by nanoimprinting, comprising the steps of preparing a transparent imprinting template and forming a polymerizable resin layer on a quartz substrate on which a chromium thin film is laminated. A step of superimposing the imprint template and the polymerizable resin layer on the quartz substrate, and shaping the polymerizable resin layer by a first pattern which is a pattern of the imprint template; , Curing the polymerizable resin, forming a second pattern composed of concavities and convexities that are reverse shapes of the first pattern on the polymerizable resin layer, and using the second pattern as a mask, Forming a third pattern on the quartz substrate, and using the third pattern as a mask, the surface of the quartz substrate is configured to be uneven. And a method for manufacturing a template using a template for imprint, characterized by comprising a step of forming a fourth pattern.

  By the method of the present invention, a highly accurate fine pattern and an imprint template having the pattern can be manufactured.

Flowchart showing a method for manufacturing imprint template 10 The figure which shows each process in manufacture of the template 10 for imprints. The figure which shows each process at the time of forming an uneven | corrugated pattern using the template 10 for imprints. The figure which shows each process at the time of forming an uneven | corrugated pattern on the board | substrate with which the chromium film-forming was formed using the template 10 for imprints.

  A method for manufacturing an imprint template 10 according to an embodiment of the present invention and a method for forming irregularities using the imprint template 10 will be described below in detail with reference to the accompanying drawings.

  First, a method for manufacturing the imprint template 10 will be described with reference to FIGS.

  FIG. 1 is a flowchart illustrating a method for manufacturing the imprint template 10, and FIG. 2 is a diagram illustrating each process in manufacturing the imprint template 10.

  As shown in FIG. 2A, a thin film 15 is formed on the transparent substrate 11 (step 101). The thin film 15 is made of silicon or a silicon compound. Next, as shown in FIG. 2B, an electron beam resist is applied to the surface of the thin film 15 to form a photosensitive resin layer 17 (step 102). Next, drawing is performed on the surface of the photosensitive resin layer 17 using an electron beam drawing apparatus (not shown) (step 103). When performing electron beam drawing on the surface of the photosensitive resin layer 17, pattern data in which dimensional variations caused by oxidation are corrected in advance is used. Next, as shown in FIG. 2C, development is performed to form an uneven resist pattern 21 on the transparent substrate 11. Next, as shown in FIG. 2D, the thin film 15 is etched using the resist pattern 21 as a mask to form a silicon pattern 23 on the transparent substrate 11 (step 105). Next, as shown in FIG. 2E, the silicon pattern 23 is oxidized to form the silicon oxide pattern 13 on the surface of the transparent substrate 11 (step 106). In this way, the imprint template 10 having the silicon oxide pattern 13 formed on the surface of the transparent substrate 11 is obtained. As described above, an accurate silicon oxide pattern 13 can be obtained by using the corrected pattern data at the time of electron beam drawing.

  Examples of the method for oxidizing the silicon pattern 23 include a method using thermal oxidation, a method using oxygen ion implantation, and a method of supplying ozone gas while heating. In thermal oxidation, since it is necessary to heat the substrate to a high temperature close to 1000 ° C., there is a concern that the substrate may be distorted depending on the material constituting the substrate. In the method of supplying ozone gas, the silicon oxide pattern 13 can be formed even at a relatively low temperature.

  In the imprint template 10 obtained through the above process, a transparent silicon oxide pattern 13 is formed on the transparent substrate 11.

Thus, the transparent imprint template 10 similar to that produced from a single transparent material such as quartz can be obtained by the manufacturing method in the present embodiment.
A fine pattern can be accurately formed on the silicon-based thin film 15. This is because the imprint template 10 can form a fine silicon pattern 23 by photolithography. Since the silicon oxide pattern 13 is formed by oxidizing the silicon pattern 23, the silicon oxide pattern 13 is as fine as the silicon pattern 23. Therefore, in the imprint template 10, a transparent and highly accurate fine pattern can be obtained without directly etching the transparent substrate 11.

Next, a method for forming an uneven pattern using the imprint template 10 will be described with reference to FIG.
FIG. 3 is a diagram showing each step when forming a concavo-convex pattern on another substrate using the imprint template 10.

As shown to Fig.3 (a), the quartz substrate 31 of the object which forms an unevenness | corrugation is prepared. An imprint resist 33 made of a polymerizable resin or the like is applied to the surface of the quartz substrate 31. Next, as shown in FIG. 3B, the imprint template 10 and the quartz substrate 31 are overlapped. Next, as shown in FIG. 3C, the imprint template 10 is brought into close contact with the imprint resist 33. The imprint resist 33 is shaped by the unevenness of the silicon oxide pattern 13 of the imprint template 10. Next, the imprint resist 33 is cured while the imprint template 10 and the quartz substrate 31 are in close contact with each other. Next, as shown in FIG. 3D, the imprint template 10 is removed and a pattern 35 is formed on the imprint resist 33. Next, as shown in FIG. 3E, the quartz substrate 31 is etched using the pattern 35 as a mask to form a pattern 37 on the quartz substrate 31.
Through the above process, an uneven pattern is formed on the quartz substrate 31 using the imprint template 10.

FIG. 4 is a diagram showing another embodiment of the method for forming an uneven pattern. As shown in FIG. 4, instead of the quartz substrate 31 of FIG. 3A, a quartz substrate 31 having a chromium thin film 41 formed thereon is used.
First, as shown in FIG. 4A, a chromium thin film 41 is laminated on a quartz substrate 31, and an imprint resist 33 is applied on the chromium thin film 41. Next, as shown in FIG. 4B, the imprint template 10 and the quartz substrate 31 on which the chromium thin film 41 is laminated are overlaid. Next, as shown in FIG. 4C, the imprint template 10 is brought into close contact with the imprint resist 33. The imprint resist 33 is shaped by the unevenness of the silicon oxide pattern 13 of the imprint template 10. Next, the imprint resist 33 is cured while the imprint template 10 and the quartz substrate 31 are in close contact with each other. Next, as shown in FIG. 4D, the imprint template 10 is removed and a pattern 43 is formed on the imprint resist 33. Next, as shown in FIG. 4E, the chromium thin film 41 is etched using the pattern 43 as a mask to form a pattern 45 on the quartz substrate 31. Next, as shown in FIG. 4F, etching is performed on the quartz substrate 31 using the pattern 45 as a mask to form an uneven pattern 47 on the quartz substrate 31.

  Thus, by using the imprint template 10, a highly accurate uneven pattern can be formed on the quartz substrate 31.

  The preferred embodiments of the imprint template manufacturing method and the like according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

  For example, since the imprint template 10 has high transparency and transmits ultraviolet light, it is also applied to photocuring imprint. When the imprint template 10 is applied to photocuring imprinting, a photocurable resin is used as the imprint resist 33 in FIG.

10 ......... Imprint template 11 ......... Transparent substrate 13 ......... Silicon oxide pattern 15 ......... Thin film 17 ...... Photosensitive resin layer 19 ......... Mask 21 ......... Resist pattern 23 ......... Silicone pattern

Claims (2)

A method for forming a concavo-convex pattern by nanoimprinting,
Preparing a transparent imprint template;
Forming a polymerizable resin layer on a quartz substrate on which a chromium thin film is laminated;
Overlaying the imprint template and the polymerizable resin layer on the quartz substrate, and shaping the polymerizable resin layer by a first pattern that is a pattern of the imprint template;
Curing the polymerizable resin, and forming a second pattern composed of concavities and convexities that are reverse shapes of the first pattern on the polymerizable resin layer;
Forming a third pattern on the quartz substrate using the second pattern as a mask;
Forming a fourth pattern composed of irregularities on the surface of the quartz substrate using the third pattern as a mask;
A pattern forming method using an imprint template, comprising: A method for producing a template used for nanoimprinting by nanoimprinting,
Preparing a transparent imprint template;
Forming a polymerizable resin layer on a quartz substrate on which a chromium thin film is laminated;
Overlaying the imprint template and the polymerizable resin layer on the quartz substrate, and shaping the polymerizable resin layer with a first pattern that is a pattern of the imprint template;
Curing the polymerizable resin, and forming a second pattern composed of concavities and convexities that are reverse shapes of the first pattern on the polymerizable resin layer;
Forming a third pattern on the quartz substrate using the second pattern as a mask;
Forming a fourth pattern composed of irregularities on the surface of the quartz substrate using the third pattern as a mask;
A method of manufacturing a template using an imprint template, comprising:

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