Interactions between plasma and block copolymers used in directed self-assembly patterning

Stephen Sirard, Laurent Azarnouche, Emir Gurer, William Durand, Michael Maher, Kazunori Mori, Gregory Blachut, Dustin Janes, Yusuke Asano, Yasunobu Someya, Diane Hymes, David Graves, Christopher J. Ellison, C. Grant Willson

Research output: Chapter in Book/Report/Conference proceedingConference contribution

10 Scopus citations


The directed self-assembly (DSA) of block copolymers offers a promising route for scaling feature sizes below 20 nm. At these small dimensions, plasmas are often used to define the initial patterns. It is imperative to understand how plasmas interact with each block in order to design processes with sufficient etch contrast and pattern fidelity. Symmetric lamella forming block copolymers including, polystyrene-b-poly(methyl methacrylate) and several high-χ silicon-containing and tin-containing block copolymers were synthesized, along with homopolymers of each block, and exposed to various oxidizing, reducing, and fluorine-based plasma processes. Etch rate kinetics were measured, and plasma modifications of the materials were characterized using XPS, AES, and FTIR. Mechanisms for achieving etch contrast were elucidated and were highly dependent on the block copolymer architecture. For several of the polymers, plasma photoemissions were observed to play an important role in modifying the materials and forming etch-resistant protective layers. Furthermore, it was observed for the silicon- and tin-containing polymers that an initial transient state exists, where the polymers exhibit an enhanced etch rate, prior to the formation of the etch-resistant protective layer. Plasma developed patterns were demonstrated for the differing block copolymer materials with feature sizes ranging from 20 nm down to approximately 5 nm.

Original languageEnglish (US)
Title of host publicationAdvanced Etch Technology for Nanopatterning V
EditorsQinghuang Lin, Sebastian U. Engelmann
ISBN (Electronic)9781510600171
StatePublished - 2016
Externally publishedYes
EventSPIE Conference on Advanced Etch Technology for Nano-patterning V - San Jose, United States
Duration: Feb 22 2016Feb 23 2016

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceSPIE Conference on Advanced Etch Technology for Nano-patterning V
Country/TerritoryUnited States
CitySan Jose

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


  • block copolymers
  • Directed self-assembly
  • High X
  • Plasma etching
  • PS-b-PMMA
  • Silicon-containing


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