Abstract
Directed self-assembly (DSA) of high-χ block copolymer thin films is a promising approach for nanofabrication of features with length scale below 10 nm. Recent work has highlighted that kinetics are of crucial importance in determining whether a block copolymer film can self-assemble into a defect-free ordered state. In this work, different strategies for improving the rate of defect annihilation in the DSA of a silicon-containing, high-χ block copolymer film were explored. Chemo-epitaxial DSA of poly(4-methoxystyrene-block-4-trimethylsilylstyrene) with 5× density multiplication was implemented on 300 mm wafers by using production level nanofabrication tools, and the influence of different processes and material parameters on dislocation defect density was studied. It was observed that only at sufficiently low χN can the block copolymer assemble into well-aligned patterns within a practical time frame. In addition, there is a clear correlation between the rate of the lamellar grain coarsening in unguided self-assembly and the rate of dislocation annihilation in DSA. For a fixed chemical pattern, the density of kinetically trapped dislocation defects can be predicted by measuring the correlation length of the unguided self-assembly under the same process conditions. This learning enables more efficient screening of block copolymers and annealing conditions by rapid analysis of block copolymer films that were allowed to self-assemble into unguided (commonly termed fingerprint) patterns.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 48419-48427 |
| Number of pages | 9 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 11 |
| Issue number | 51 |
| DOIs | |
| State | Published - Dec 26 2019 |
Bibliographical note
Funding Information:This work is based on knowledge of unpublished material screening data and process evaluations performed by Dustin Janes. The authors are grateful for financial support and for materials support in formulating and demetallizing samples provided by Nissan Chemical Corporation. Nadia Vandenbroeck and Geert Mannaert are thanked for experimental assistance. Hitachi High-Technologies is acknowledged for providing DSA-APPS software. The authors also gratefully acknowledge etch support from Lam Research and partial financial support from the University of Minnesota Department of Chemical Engineering and Materials Science and College of Science and Engineering, the Kwanjeong Educational Foundation, The Rashid Engineering Regents Chair, The Welch Foundation (Grant F-1830), IDEMA/ASRC, and The NSF-NASCENT Engineering Research Center EEC-1160494.
Funding Information:
This work is based on knowledge of unpublished material screening data and process evaluations performed by Dustin Janes. The authors are grateful for financial support and for materials support in formulating and demetallizing samples provided by Nissan Chemical Corporation. Nadia Vandenbroeck and Geert Mannaert are thanked for experimental assistance. Hitachi High-Technologies is acknowledged for providing DSA-APPS software. The authors also gratefully acknowledge etch support from Lam Research and partial financial support from the University of Minnesota Department of Chemical Engineering and Materials Science and College of Science and Engineering, the Kwanjeong Educational Foundation, The Rashid Engineering Regents Chair, The Welch Foundation (Grant F-1830), IDEMA/ASRC, and The NSF-NASCENT Engineering Research Center EEC-1160494.
Publisher Copyright:
Copyright © 2019 American Chemical Society.
Keywords
- block copolymers
- correlation length
- directed self-assembly
- high χ
- kinetics