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Title: Three-Tone Chemical Patterns for Block Copolymer Directed Self-Assembly

Journal Article · · ACS Applied Materials and Interfaces

Chemical patterns for directed self-assembly (DSA) of lamellaeforming block copolymers (BCP) with density multiplication can be fabricated by patterning resist on a cross-linked polystyrene layer, etching to create guide stripes, and depositing end-grafted brushes in between the stripes as background. To date, two-tone chemical patterns have been targeted with the guide stripes preferentially wet by one block of the copolymer and the background chemistry weakly preferentially wet by the other block. In the course of fabricating chemical patterns in an all-track process using 300 mm wafers, it was discovered that the etching process followed by brush grafting could produce a three-tone pattern. We characterized the three regions of the chemical patterns with a combination of SEM, grazing-incidence small-angle X-ray scattering (GISAXS), and assessment of BCP-wetting behavior, and evaluated the DSA behavior on patterns over a range of guide stripe widths. In its best form, the three-tone pattern consists of guide stripes preferentially wet by one block of the copolymer, each flanked by two additional stripes that wet the other block of the copolymer, with a third chemistry as the background. Three-tone patterns guide three times as many BCP domains as two-tone patterns and thus have the potential to provide a larger driving force for the system to assemble into the desired architecture with fewer defects in shorter time and over a larger process window.

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Science - Office of Basic Energy Sciences - Scientific User Facilities Division; USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division; National Science Foundation (NSF)
DOE Contract Number:
AC02-06CH11357
OSTI ID:
1352878
Journal Information:
ACS Applied Materials and Interfaces, Vol. 8, Issue 4; ISSN 1944-8244
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English