Method of forming pattern
| Title: | Method of forming pattern |
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| Patent Number: | 8,808,973 |
| Publication Date: | August 19, 2014 |
| Appl. No: | 13/402400 |
| Application Filed: | February 22, 2012 |
| Abstract: | According to one embodiment, there is provided a method of forming a pattern including forming a polymer layer on a substrate, the polymer layer including a first and second regions, selectively irradiating either of the first and second regions with energy rays or irradiating the first and second regions with energy rays under different conditions to cause a difference in surface free energy between the first and second regions, thereafter, forming a block copolymer layer on the polymer layer, and causing microphase separation in the block copolymer layer to simultaneously form first and second microphase-separated structures on the first and second regions, respectively. |
| Inventors: | Mikoshiba, Satoshi (Yamato, JP); Asakawa, Koji (Kawasaki, JP); Nakamura, Hiroko (Yokohama, JP); Hattori, Shigeki (Yokohama, JP); Hieno, Atsushi (Kawasaki, JP); Azuma, Tsukasa (Kawasaki, JP); Seino, Yuriko (Yokohama, JP); Kanno, Masahiro (Yokohama, JP) |
| Assignees: | Kabushiki Kaisha Toshiba (Tokyo, JP) |
| Claim: | 1. A method of forming a pattern, comprising: forming a polymer layer on a substrate, the polymer layer including first and second regions, wherein the first region is to be patterned in a later step and the second region is not to be patterned in a later step; selectively irradiating either of the first and second regions with energy rays or irradiating the first and second regions with energy rays under different conditions to cause a difference in surface free energy between the first and second regions; forming a block copolymer layer on the polymer layer, the block copolymer layer including a block copolymer containing first and second block chains different from each other; and causing microphase separation in the block copolymer layer to simultaneously form first and second microphase-separated structures on the first and second regions, respectively, the first microphase-separated structure on the first region comprising a lamellar phase in which a first block chain layer and a second block chain layer are formed perpendicularly to the substrate and alternately arranged, and the second microphase-separated structure on the second region comprising a lamellar phase in which a first block chain layer and a second block chain layer are formed parallel to the substrate and alternately stacked. |
| Claim: | 2. The method according to Claim 1 , wherein the first block chain comprises polystyrene, the second block chain comprises polymethyl methacrylate, and the energy ray-irradiation is performed such that a contact angle of water on the first region is more than 80° and less than 90° and a contact angle of water on the second region is 75 to 80° or 90° or more. |
| Claim: | 3. The method according to claim 1 , further comprising: selectively removing either of the first and second block chain layers in the lamellar phase from at least the first phase-separated structure on the first region to form a mask patternformed perpendicularly to the substract; and etching the surface of the substrate using the mask pattern as an etching mask. |
| Claim: | 4. The method according to claim 1 , wherein the polymer layer comprises a silicon-based material. |
| Claim: | 5. The method according to claim 4 , wherein the silicon-based material is polysilane. |
| Claim: | 6. The method according to claim 1 , wherein, when viewed on a surface of the first microphase-separated structure on the first region, the first and second block chain layers in the lamellar phase are arranged in a direction perpendicularly to an interface between the second microphase-separated structure on the second region and the first microphase-separated structure on the first region. |
| Current U.S. Class: | 430/322 |
| Patent References Cited: | 6746825 June 2004 Nealey et al. 2003/0091752 May 2003 Nealey et al. 2008/0311347 December 2008 Millward et al. 2009/0242925 October 2009 Kitagawa et al. 2011/0059299 March 2011 Kim et al. 101077768 November 2007 2008-96596 April 2008 2009-298911 December 2009 10-2009-0063612 June 2009 200702910 January 2007 200949452 December 2009 |
| Other References: | Sang Ouk Kim, et al., “Epitaxial self-assembly of block copolymers on lithographically defined nanopatterned substrates”, letters to nature, vol. 424, Jul. 24, 2003, pp. 411-414. cited by applicant Ricardo Ruiz, et al., “Density Multiplication and Improved Lithography by Directed Block Copolymer Assembly”, Science, vol. 321, Aug. 15, 2008, 1 cover page and pp. 936-939. cited by applicant Korean Office Action issued Mar. 22, 2013, in Korea Patent Application No. 10-2012-15224 (with English translation). cited by applicant Office Action mailed Feb. 17, 2014, in Taiwanese Patent Application No. 101105510 (with English-language translation). cited by applicant |
| Primary Examiner: | Raymond, Brittany |
| Attorney, Agent or Firm: | Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P. |
| Accession Number: | edspgr.08808973 |
| Database: | USPTO Patent Grants |
| Language: | English |
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