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Title: Block copolymer nanolithography for the fabrication of patterned media.

Abstract

Abstract Bit patterned perpendicular media has the potential to increase the density of magnetic recording beyond what can be achieved by granular media. Self assembling diblock copolymers are of interest as templates for patterned media, as they potentially provide a low cost fabrication route. A method to fabricate the desired pattern using cylinder forming diblock copolymers of (PS-b-PMMA) as template is reported. Upon phase separation hexagonally packed cylinders of the minority phase (PMMA) surrounded by the continuous majority phase (PS) are obtained. The processing sequence began with spin coating the block copolymer on a suitable substrate, followed by annealing the block copolymer thin film in vacuum to orient it perpendicular to the substrate. Block copolymer templates were obtained by glacial acetic acid treatment which opened the pores in the block copolymer thin film. Ni was electrodeposited in the block copolymer templates and this pattern was then transferred onto the underlying substrate by ion milling

Authors:
 [1];  [1];  [1];  [1];  [1];  [2];  [2]
  1. ORNL
  2. Argonne National Laboratory (ANL)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Center for Nanophase Materials Sciences
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
962605
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Society Symposium Proceedings; Journal Volume: 1032
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COPOLYMERS; FABRICATION; MAGNETIC STORAGE DEVICES; PMMA; POLYSTYRENE; NICKEL; ELECTRODEPOSITION; THIN FILMS; SUBSTRATES

Citation Formats

Warke, Vishal V, Bakker, Martin G, Hong, Kunlun, Mays, Jimmy, Britt, Phillip F, Li, Xuefa, and Wang, Jin. Block copolymer nanolithography for the fabrication of patterned media.. United States: N. p., 2008. Web.
Warke, Vishal V, Bakker, Martin G, Hong, Kunlun, Mays, Jimmy, Britt, Phillip F, Li, Xuefa, & Wang, Jin. Block copolymer nanolithography for the fabrication of patterned media.. United States.
Warke, Vishal V, Bakker, Martin G, Hong, Kunlun, Mays, Jimmy, Britt, Phillip F, Li, Xuefa, and Wang, Jin. 2008. "Block copolymer nanolithography for the fabrication of patterned media.". United States. doi:.
@article{osti_962605,
title = {Block copolymer nanolithography for the fabrication of patterned media.},
author = {Warke, Vishal V and Bakker, Martin G and Hong, Kunlun and Mays, Jimmy and Britt, Phillip F and Li, Xuefa and Wang, Jin},
abstractNote = {Abstract Bit patterned perpendicular media has the potential to increase the density of magnetic recording beyond what can be achieved by granular media. Self assembling diblock copolymers are of interest as templates for patterned media, as they potentially provide a low cost fabrication route. A method to fabricate the desired pattern using cylinder forming diblock copolymers of (PS-b-PMMA) as template is reported. Upon phase separation hexagonally packed cylinders of the minority phase (PMMA) surrounded by the continuous majority phase (PS) are obtained. The processing sequence began with spin coating the block copolymer on a suitable substrate, followed by annealing the block copolymer thin film in vacuum to orient it perpendicular to the substrate. Block copolymer templates were obtained by glacial acetic acid treatment which opened the pores in the block copolymer thin film. Ni was electrodeposited in the block copolymer templates and this pattern was then transferred onto the underlying substrate by ion milling},
doi = {},
journal = {Materials Research Society Symposium Proceedings},
number = ,
volume = 1032,
place = {United States},
year = 2008,
month = 1
}
  • The self-assembly of block copolymers thin films laterally confined within square geometries that are incompatible with the bulk packing symmetry of the block copolymer microdomains is investigated. The lateral confinement is provided by chemical patterns made by oxidation nanolithography of octadecyltrichlorosilane-coated silicon surfaces. We find that the size and shape of the confinement affect the order of the block copolymer microdomains and their packing symmetries. Specifically, if the size of the square pattern is smaller than the characteristic grain size the hexagonally packed microdomains form a single-crystal oriented along the edges of the pattern and with 'edge-boundaries' located preferentially atmore » the perimeter of the pattern. If the size of the pattern is comparable with the natural bulk period of the copolymer, the packing symmetry changes from hexagonal to square. In this case the ordering induced by the pattern edges becomes dominant allowing the square lattice to be more stable than the hexagonal one.« less
  • A simple and viable method was developed to produce biaxial strain in monolayer graphene on an array of SiO{sub 2} nanopillars. The array of SiO{sub 2} nanopillars (1 cm{sup 2} in area, 80 nm in height, and 40 nm in pitch) was fabricated by employing self-assembled block copolymer through simple dry etching and deposition processes. According to high resolution micro-Raman spectroscopy and atomic force microscopy analyses, 0.9% of maximum biaxial tensile strain and 0.17% of averaged biaxial tensile strain in graphene were created. This technique provides a simple and viable method to form biaxial tensile strain in graphene and offers a practical platformmore » for future studies in graphene strain engineering.« less
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  • No abstract prepared.
  • Brownian Dynamics simulations are carried out to understand the effect of temperature and dielectric constant of the medium on microphase separation of charged-neutral diblock copolymer systems. For different dielectric media, we focus on the effect of temperature on the morphology and dynamics of model charged diblock copolymers. In this study we examine in detail a system with a partially charged block copolymer consisting of 75% neutral blocks and 25% of charged blocks with 50% degree of ionization. Our investigations show that due to the presence of strong electrostatic interactions between the charged block and counterions, the block copolymermorphologies are rathermore » different than those of their neutral counterpart at low dielectric constant, however at high dielectric constant the neutral diblock behaviors are observed. This article highlights the effect of dielectric constant of two different media on different thermodynamic and dynamic quantities. At low dielectric constant, the morphologies are a direct outcome of the ion-counterion multiplet formation. At high dielectric constant, these charged diblocks behavior resembles that of neutral and weakly charged polymers with sustainable long-range order. Similar behavior has been observed in chain swelling, albeit with small changes in swelling ratio for large changes in polarity of the medium. The results of our simulations agree with recent experimental results and are consistent with recent theoretical predictions of counterion adsorption on flexible polyelectrolytes.« less