Thin Film Self-Assembly of a Silicon-Containing Rod–Coil Liquid Crystalline Block Copolymer

Journal Article · 04 January 2019 · Macromolecules

DOI: https://doi.org/10.1021/acs.macromol.8b01938 · OSTI ID:1498278

Shi, Ling -Ying  ^[1]; Lee, Sangho  ^[2]; Cheng, Li -Chen  ^[2]; Huang, Hejin ^[2]; Liao, Fen ^[3]; Ran, Rong ^[3]; Yager, Kevin G.  ^[4]; Ross, Caroline A.  ^[2]

---

1. Sichuan Univ., Chengdu (China); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
3. Sichuan Univ., Chengdu (China)
4. Brookhaven National Lab. (BNL), Upton, NY (United States)

The long-range ordering and directed self-assembly of thin films of a high interaction parameter rod–coil liquid crystalline block copolymer (LC BCP), poly(dimethylsiloxane)-b-poly{2,5-bis[(4-methoxyphenyl)-oxycarbonyl]styrene} (PDMS-b-PMPCS, or DM), is described. The LC BCP was spin-coated on a polystyrene brush functionalized substrate and then thermally annealed at different temperatures with respect to the LC ordering temperature. The effects of the wetting behavior, commensurability between the film thickness and the periodicity, and the LC orientation on the ordering and orientation of the microdomains are described. A monolayer of in-plane cylinders with excellent long-range ordering was produced, and was transferred into SiO_x patterns with tunable sub-10 nm feature sizes. Well-ordered multilayer in-plane cylinders were produced in thicker films, and the correlation between microstructure evolution and the LC ordering process was studied by grazing-incidence small-angle X-ray scattering (GISAXS) and wide-angle X-ray scattering (GIWAXS). Finally, the cylindrical rod–coil BCP was directed into a novel ladder morphology within lithographically patterned substrate trenches, as well as into patterns of parallel or transverse cylinders. As a result, the ordering of cylinders, the ladder morphology, and the etch selectivity and thermal stability of this high-interaction parameter silicon-containing LC rod–coil BCP demonstrate its applicability to nanoscale lithography.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012704
• OSTI ID: 1498278
• Report Number(s): BNL-211342-2019-JAAM
• Journal Information: Macromolecules, Vol. 52, Issue 2; ISSN 0024-9297
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English