This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2015-034019, filed on Feb. 24, 2015; the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a template forming method, a template, and a template base material.
An imprint method for transferring a mold of an original plate to a substrate has been given attention as a technique for forming a fine pattern of a semiconductor device, and the like with high productivity. In the imprint method, a template (original plate) formed with a concave-convex pattern (template pattern) and a resist applied on the substrate are brought into contact. The concave-convex pattern of the template is thereby filled with resin. The template pattern is transferred to the resist on the substrate by curing the filled resist.
When the template is impressed on the resist, the resist runs out to the outer side of a template pattern region, and such run-out degrades the quality of the resist pattern.
Exemplary embodiments of a template forming method, a template, and a template base material according to an embodiment will be explained below in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments.
According to the embodiment, a template forming method is provided. In the template forming method, the template pattern is formed on a first surface of the substrate. A high liquid repellent property portion is formed in a region different from the template pattern on a side of the first surface of the substrate. The high liquid repellent property portion has a higher contacting angle with respect to the resist than a portion without the high liquid repellent property portion formed therein.
The templates 10A, 10B according to the first embodiment each includes a pedestal unit (mesa) at a central region on a front surface side (bottom surface side in
The template 10A illustrated in
The liquid repellent portion 11 is formed to surround the side surface of the pedestal unit. The liquid repellent portion 12 is formed to surround the side surface and the outer peripheral region of the pedestal unit. The contacting angle with respect to the resist in the liquid repellent portions 11, 12 is higher than a predetermined value (e.g., 60°). The resist is a mixture having a resin (polymer), a photosensitizing agent, an additive, and a solvent as main components. Other than a photo-polymerization initiator, the resist may include an acryl-based monomer, acrylate, and the like depending on the chemicals.
In the present embodiment, a member having a high liquid repellent property is arranged on at least the side surface of the pedestal unit of the front surface side of the templates 10A, 10B. According to such configuration, when the templates 10A, 10B are pressed against the resist, the resist can be prevented from leaking out to the outer side of the pedestal unit.
An imprint process using the templates 10A, 10B will now be described. The imprint processes using the templates 10A, 10B are similar processes, and thus the imprint process using the template 10A will be described herein.
The imprint device (not illustrated) includes an original plate stage (template holding member) 21. As illustrated in
Thereafter, the template 10A is pressed against the resist 25. As illustrated in
When the template 10A is irradiated with a UV light in this state, the resist 25 is irradiated with the UV light and the resist 25 is cured as a result. A transfer pattern corresponding to the template pattern is thereby patterned on the resist 25 on the wafer 22. Subsequently, as illustrated in
Therefore, in the present embodiment, the template 10A includes the liquid repellent portion 11. Thus, when the template 10A is impressed on the resist 25, the resist 25 is less likely to ride over the liquid repellent portion 11. The run-out of the resist 25 from the template pattern thus can be suppressed. Therefore, the template 10A can be prevented from riding on the cured resist 25 in the imprint process to an adjacent shot. As a result, the breakage of the template 10A can be prevented. Furthermore, the degradation in the quality of the resist pattern can be prevented since the run-out of the resist 25 can be suppressed.
The liquid repellent portions 11, 12 may be formed before forming the template pattern, or may be formed after forming the template pattern. If the liquid repellent portions 11, 12 are formed before forming the template pattern, the liquid repellent portions 11, 12 are formed with respect to the template base material.
The template base materials 11A, 11B according to the first embodiment include the pedestal unit at the central region on the front surface side (bottom surface side in
The template base material 11A illustrated in
In the present embodiment, a member having a high liquid repellent property is arranged on at least the side surface of the pedestal unit of the front surface side of the template base materials 11A, 11B. According to such configuration, the templates 10A, 10B can be produced by forming the template pattern in the template base materials 11A, 11B. As a result, the resist 25 can be prevented from leaking out to the outer side of the pedestal unit when the templates 10A, 10B are pressed against the resist 25.
Next, a method for producing the templates 10A, 10B and the template base materials 11A, 11B will be described. The production processes of the templates 10A, 10B, and the template base materials 11A, 11B are similar processes, and thus the production method of the template base material 11B will be described herein.
Thereafter, as illustrated in
When forming the protecting portion 31, the chemicals having a high liquid repellent property with respect to the substrate 30 is attached to the region (upper surface of pedestal unit) to form the protecting portion 31 in the substrate 30. The chemical is a chemical containing silane such as silane coupling agent, and the like.
The substrate 30 formed with the protecting portion 31 is exposed to an atmosphere of a chemical 16 having a high liquid repellent property with respect to the resist 25. The chemical 16 is, for example, a fluorinated solvent such as perfluoropolyether (PEPE), and the like. The chemical 16 is, for example, a 20% liquid solution of water repellent coating agent in which the undiluted solution of a water repellent coating agent is diluted with a solvent.
When forming the liquid repellent portion 12, the substrate 30 is arranged such that the chemical 16 and the upper surface of the pedestal unit face each other. The chemical 16 is then heated to evaporate the chemical 16. The evaporated chemical 16 thereby attaches to the side surface of the pedestal unit and the outer peripheral region on the outer side of the pedestal unit to form the liquid repellent portion 12, as illustrated in
The protecting portion 31 may be formed by attaching a protective film such as a resin film, and the like. The protecting portion 31 may be a metal film or a semiconductor film. In this case, the metal film or the semiconductor film is formed on the upper surface of the pedestal unit to form the protecting portion 31. The protecting portion 31 may be a shielding member. In this case, the protecting portion 31 serving as the shielding member is proximately arranged with respect to the pattern surface, and then the substrate 30 is exposed to the atmosphere of the chemicals 16. A hard mask thus protects the upper surface of the pedestal unit from the chemical 16, and the chemical 16 attaches to the side surface of the pedestal unit and the outer peripheral region on the outer side of the pedestal unit to become the liquid repellent portion 12. Furthermore, when forming the liquid repellent portion 12, the protecting portion 31 is arranged on the substrate 30, and then the substrate 30 may be immersed in the chemical 16.
Therefore, according to the first embodiment, the template pattern is formed on the template pattern surface on the front surface of the substrate 30. The liquid repellent portions 11, 12 are formed in regions different from the template pattern surface. The liquid repellent portions 11, 12 have a higher contacting angle than the front surface (for example, template pattern surface), the back surface, the side surface, or quartz of the substrate 30. Therefore, when the templates 10A, 10B are impressed on the resist 25, the resist 25 is repelled by the liquid repellent portions 11, 12. The run-out of the resist 25 when the templates 10A, 10B are impressed on the resist 25 thus can be suppressed. As a result, the desired resist pattern can be formed, and the breakage of the templates 10A, 10B can be prevented.
A second embodiment will now be described using
In the second embodiment, the spot facing processing and the formation of the pedestal unit are carried out with respect to the quartz glass substrate, similar to the first embodiment. The quartz glass substrate thus becomes the substrate 30 before the liquid repellent portion 12 is formed.
Thereafter, the protecting portion 31 is formed on the pedestal unit, as illustrated in
Thereafter, as illustrated in
The protecting portion 31 may be removed using a liquid (solvent) such as a thinner, and the like in place of the RIE. When forming the liquid repellent portion 12, the protecting portion 31 may be arranged on the substrate 30, and then the substrate 30 may be immersed in the chemical 16.
Therefore, according to the second embodiment, the protecting portion 31 is removed using the RIE or the liquid such as the thinner, and the like, whereby the protecting portion 31 can be easily and accurately removed when producing the template base material 11B.
A third embodiment will now be described using
In the third embodiment, the spot facing processing and the formation of the pedestal unit are carried out with respect to the quartz glass substrate, similar to the first embodiment. The quartz glass substrate thereby becomes the substrate 30 before the liquid repellent portion 12 is formed.
When forming the liquid repellent portion 12, the substrate 30 is arranged such that the chemical 16 and the upper surface of the pedestal unit face each other. In other words, the upper surface of the pedestal unit is brought into contact with the chemical 16. The chemical 16 is then heated to evaporate the chemical 16.
As illustrated in
As a result, the chemical 16 attached to the side surface of the pedestal unit and the outer peripheral region on the outer side of the pedestal unit becomes the liquid repellent portion 12, and the chemical 16 attached to the upper surface of the pedestal unit becomes a liquid repellent portion 32. The liquid repellent portion 32 is a film formed at a position similar to the protecting portion 31.
Thereafter, as illustrated in
Therefore, according to the third embodiment, the liquid repellent portion 32 is formed on the pedestal unit using the chemical 16, so that the liquid repellent portion 12 and the liquid repellent portion 32, which is a substitute of the protecting portion 31, can be simultaneously formed. The upper surface of the pedestal unit thus can be easily covered. Therefore, the template base material 11B can be easily produced.
A fourth embodiment will now be described using
In the fourth embodiment, the spot facing processing and the formation of the pedestal unit are carried out with respect to the quartz glass substrate, similar to the first embodiment. Thus, the quartz glass substrate becomes the substrate 30 before the liquid repellent portion 12 is formed.
In the present embodiment, the liquid chemical 17 having a component similar to the chemical 16 is used. As illustrated in
As a result, the chemical 17 attached to the side surface of the pedestal unit and the outer peripheral region on the outer side of the pedestal unit becomes the liquid repellent portion 12, and the chemical 17 attached to the upper surface of the pedestal unit becomes the liquid repellent portion 32. Thereafter, as illustrated in
The protecting portion 31 may be provided at a position to form the liquid repellent portion 32. In this case, the upper surface of the pedestal unit does not make contact with the chemical 17, and thus the liquid repellent portion 32 is not formed on the upper surface of the pedestal unit. Therefore, the protecting portion 31 is removed instead of removing the liquid repellent portion 32. Furthermore, the protecting portion 31 may be a protective film such as a resin film, or a metal film or a semiconductor film. The liquid repellent portions 12, 32 may be formed by vapor deposition described in the first embodiment.
According to the fourth embodiment, the liquid repellent portion 32 is formed on the pedestal unit using the chemical 17, so that the liquid repellent portion 12 and the liquid repellent portion 32, which is a substitute of the protecting portion 31, can be simultaneously formed. The upper surface of the pedestal unit thus can be easily covered. Therefore, the template base material 11B can be easily produced.
A fifth embodiment will now be described using
The template 10C is formed with a liquid repellent portion 13 on the side surface of the seat unit. The liquid repellent portion 13 has a higher liquid repellent property with respect to the resist 25 than the front surface (for example, template pattern surface), the back surface, the side surface, or quartz of the template 10C. The liquid repellent portion 13 is formed to surround the side surface of the seat unit. The liquid repellent portion 13 has a higher contacting angle with respect to the resist 25 than a predetermined value (e.g., 60°). The liquid repellent portion 13 has a concave-convex structure, so that the liquid repellent property with respect to the resist 25 is enhanced by the lotus effect. The concave-convex structure may have a shape in which a concave portion and a convex portion are repeatedly lined at a predetermined period in a two-dimensional direction, or may have a shape in which such portions are unevenly lined.
In the present embodiment, a member having a high liquid repellent property is arranged on at least the side surface of the pedestal unit of the front surface side of the template 10C. According to such configuration, when the template 10C is pressed against the resist 25, the resist 25 can be prevented from leaking out to the outer side of the pedestal unit.
Next, a method for producing the template 10C will be described.
Thereafter, the side surface of the pedestal unit is subjected to the wet etching with respect to the substrate 30, so that the concave-convex structure (liquid repellent portion 13) is formed on the side surface of the pedestal unit. An alkaline liquid 63, and the like, for example, is used for the wet etching. The protective film 70 is then removed from the substrate 30 and the template pattern is formed on the pedestal unit, whereby the substrate 30 becomes the template 10C.
When the substrate 30 applied with the DSA material 64 is subjected to annealing, the DSA material 64 self-organizes. A hydrophilic part and a lipophilic part contained in the DSA material 64 thereby gather together according to a predetermined rule. When the DSA material 64 is self-organized, the concave-convex structure (liquid repellent portion 13) forms on the side surface of the pedestal unit in the substrate 30. Thereafter, the protective film 70 is removed from the substrate 30, and the template pattern is formed on the pedestal unit, whereby the substrate 30 becomes the template 10C. The guide pattern may be formed on the side surface of the pedestal unit before the DSA material 64 is applied.
The template 10C may be such that either one of the hydrophilic part or the lipophilic part of after the DSA material 64 is self-organized is removed. The template 10C may be such that either one of the hydrophilic part or the lipophilic part is removed without self-organizing the DSA material 64. Furthermore, the template 10C may be such that the liquid repellent process is performed on the DSA material 64 after the DSA material 64 is self-organized.
The liquid repellent portion 13 may be arranged with respect to the substrate 30 of after the template pattern is formed. In other words, the template pattern may be formed before the liquid repellent portion 13. In this case as well, the substrate 30 is formed with the liquid repellent portion 13 through a method similar to the template 10C.
According to the fifth embodiment, the template 10C can be easily formed since the liquid repellent portion 13 is formed using the wet etching, the ion implantation, and the like.
A sixth embodiment will now be described using
When forming the template 10D, the outer peripheral region on the side of the front surface of the quartz glass substrate is scraped. The plate thickness of the outer peripheral region thus becomes thinner than the central region. Furthermore, the template pattern is formed in the central region on the side of the front surface of the quartz glass substrate. Moreover, the liquid repellent portion 14 is formed in the outer peripheral region on the side of the front surface of the quartz glass substrate. The liquid repellent portion 14 merely needs to be formed in the vicinity of the border of the central region and the outer peripheral region. The liquid repellent portion 14 is formed through the methods described in the first to fifth embodiments.
Either one of the formation of the template pattern and the formation of the liquid repellent portion 14 may be carried out first. Either one of the formation of the template pattern and the cutting of the outer peripheral region may be carried out first.
The templates 10A to 10D described in the first to sixth embodiments are used in the lithography step of when manufacturing a semiconductor device (semiconductor integrated circuit). The lithography is carried out for every layer of the wafer process, for example. Specifically, one of the templates 10A to 10D is produced in advance. The imprint process is carried out with one of the templates 10A to 10D on the wafer applied with the resist 25. In the imprint process, for example, the resist 25 is patterned through a step and repeat method (repetition of impressing and separation with respect to resist 25). Thereafter, the lower layer side of the resist pattern is etched. The actual pattern corresponding to the template pattern is thereby formed on the wafer. When manufacturing the semiconductor device, the production process of the templates 10A to 10D, the imprint process, the etching process, and the like are carried out for every layer.
According to the sixth embodiment, the run-out of the resist 25 when the template 10D is impressed on the resist 25 can be suppressed, similar to the first embodiment. As a result, the desired resist pattern can be formed and the breakage of the template 10D can be prevented.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
---|---|---|---|
2015-034019 | Feb 2015 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
20030047822 | Hori | Mar 2003 | A1 |
20100233432 | Okushima | Sep 2010 | A1 |
20100264113 | Yoneda | Oct 2010 | A1 |
20110059406 | Kawamura | Mar 2011 | A1 |
20110104439 | Choi | May 2011 | A1 |
20120013042 | Ota | Jan 2012 | A1 |
20140011013 | Jin | Jan 2014 | A1 |
20140072668 | Yoneda et al. | Mar 2014 | A1 |
20150037540 | Kobayashi | Feb 2015 | A1 |
20160338228 | Suzuki | Nov 2016 | A1 |
Number | Date | Country |
---|---|---|
2012-006219 | Jan 2012 | JP |
2012-164787 | Aug 2012 | JP |
2014-013902 | Jan 2014 | JP |
2014-051050 | Mar 2014 | JP |
2014-160754 | Sep 2014 | JP |
5618663 | Nov 2014 | JP |
Number | Date | Country | |
---|---|---|---|
20160247673 A1 | Aug 2016 | US |