Solvent-Tunable Orientation and Confinement-Induced Feature Compression in High-χ Cylindrical Block Copolymer Thin...

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Polymer Chemistry

Background:

• Block copolymers (BCPs) are crucial for bottom-up nanofabrication in microelectronics.
• Controlling the orientation of high-chi BCPs is challenging due to strong incompatibility and complex interfacial interactions.
• Directed self-assembly (DSA) is a key technique for high-resolution patterning.

Purpose of the Study:

• To investigate the effects of solvent-block interactions on BCP orientation control.
• To achieve control over both horizontal and vertical orientations of cylindrical high-chi BCPs.
• To explore template compatibility and process windows for nanofabrication.

Main Methods:

• Investigated poly[2-(perfluorobutyl) ethyl methacrylate]-block-poly(2-vinylpyridine) (PFPV) high-chi BCPs.
• Modulated the chi parameter between the solvent and BCP blocks.
• Analyzed feature compression under side-wall confinement and template width effects.

Main Results:

• Achieved controlled horizontal and vertical orientations of PFPV cylindrical BCPs.
• Observed significant feature compression in nanostructures under confinement (smaller than L0 = 16 nm).
• Identified template dimensions (e.g., < 104 × 216 nm²) for well-ordered self-assembled morphologies and analyzed pattern formation beyond confinement limits.

Conclusions:

• Solvent-tunable orientation control is feasible for high-chi BCPs.
• High-chi BCPs show potential for fabricating dense line arrays for advanced technology nodes.
• Understanding template compatibility is crucial for successful BCP-based nanofabrication.