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Chang B, Loo WS, Yu B, Dhuey S, Wan L, Nealey PF, Ruiz R. Sequential Brush Grafting for Chemically and Dimensionally Tolerant Directed Self-Assembly of Block Copolymers. ACS APPLIED MATERIALS & INTERFACES 2023; 15:2020-2029. [PMID: 36534025 PMCID: PMC9837782 DOI: 10.1021/acsami.2c16508] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
We report a method for the directed self-assembly (DSA) of block copolymers (BCPs) in which a first BCP film deploys homopolymer brushes, or "inks", that sequentially graft onto the substrate's surface via the interpenetration of polymer molecules during the thermal annealing of the polymer film on top of existing polymer brushes. By selecting polymer "inks" with the desired chemistry and appropriate relative molecular weights, it is possible to use brush interpenetration as a powerful technique to generate self-registered chemical contrast patterns at the same frequency as that of the domains of the BCP. The result is a process with a higher tolerance to dimensional and chemical imperfections in the guiding patterns, which we showcase by implementing DSA using homopolymer brushes for the guiding features as opposed to more robust cross-linkable mats. We find that the use of "inks" does not compromise the line width roughness, and the quality of the DSA as a lithographic mask is verified by implementing a robust "dry lift-off" pattern transfer.
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Affiliation(s)
- Boyce
S. Chang
- Molecular
Foundry, Lawrence Berkeley National Lab, Berkeley, California 94720, United States
| | - Whitney S. Loo
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois 60637, United States
| | - Beihang Yu
- Molecular
Foundry, Lawrence Berkeley National Lab, Berkeley, California 94720, United States
| | - Scott Dhuey
- Molecular
Foundry, Lawrence Berkeley National Lab, Berkeley, California 94720, United States
| | - Lei Wan
- Western
Digital, San Jose, California 95119, United States
| | - Paul F. Nealey
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois 60637, United States
- Materials
Sciences Division, Argonne National Lab, Lemont, Illinois 60439, United States
| | - Ricardo Ruiz
- Molecular
Foundry, Lawrence Berkeley National Lab, Berkeley, California 94720, United States
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Jacobberger RM, Thapar V, Wu GP, Chang TH, Saraswat V, Way AJ, Jinkins KR, Ma Z, Nealey PF, Hur SM, Xiong S, Arnold MS. Boundary-directed epitaxy of block copolymers. Nat Commun 2020; 11:4151. [PMID: 32814775 PMCID: PMC7438520 DOI: 10.1038/s41467-020-17938-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 07/20/2020] [Indexed: 11/13/2022] Open
Abstract
Directed self-assembly of block copolymers (BCPs) enables nanofabrication at sub-10 nm dimensions, beyond the resolution of conventional lithography. However, directing the position, orientation, and long-range lateral order of BCP domains to produce technologically-useful patterns is a challenge. Here, we present a promising approach to direct assembly using spatial boundaries between planar, low-resolution regions on a surface with different composition. Pairs of boundaries are formed at the edges of isolated stripes on a background substrate. Vertical lamellae nucleate at and are pinned by chemical contrast at each stripe/substrate boundary, align parallel to boundaries, selectively propagate from boundaries into stripe interiors (whereas horizontal lamellae form on the background), and register to wide stripes to multiply the feature density. Ordered BCP line arrays with half-pitch of 6.4 nm are demonstrated on stripes >80 nm wide. Boundary-directed epitaxy provides an attractive path towards assembling, creating, and lithographically defining materials on sub-10 nm scales.
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Affiliation(s)
- Robert M Jacobberger
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Vikram Thapar
- School of Polymer Science and Engineering, Chonnam National University, Gwangju, 61186, South Korea
| | - Guang-Peng Wu
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA.
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, and Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Tzu-Hsuan Chang
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Vivek Saraswat
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Austin J Way
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Katherine R Jinkins
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Zhenqiang Ma
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Paul F Nealey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Su-Mi Hur
- School of Polymer Science and Engineering, Chonnam National University, Gwangju, 61186, South Korea.
| | - Shisheng Xiong
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA.
- School of Information Science and Technology, Fudan University, Shanghai, 200433, China.
| | - Michael S Arnold
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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