Versatile Reactive Gradient Block Copolymer System for Highly Robust Nanopatterns With Spontaneous Vertical Orientation

Vertically oriented patterns with desired physicochemical properties fabricated via directed self-assembly of high-χ block copolymers (BCPs) are critical for enhancing device performance, particularly in semiconductors. However, the lack of chemical structural tunability and challenges in vertically orienting the conventional high-χ BCPs have impeded practical applications. This study introduces poly(methyl methacrylate-block-(pentafluorophenyl acrylate-gradient-styrene)), a novel reactive polymer gradient-random block containing BCP (GRC-BCP) system. This unique system provides structural expandability through post-polymerization modifications. Moreover, using the tailored gradient block structure, vertically oriented patterns can be realized on diverse substrates without surface neutralization. Vertically oriented patterns with precisely controlled linewidths ranging from 7 to 13 nm are successfully achieved in organosilicon and organotin GRC-BCPs, synthesized via this system. Furthermore, this work demonstrates that the organosilicon GRC-BCP can be applied as a highly robust photoresist height enhancer for extreme ultraviolet lithography. After Si deep etching, this work obtains Si patterns with an aspect ratio of 5.78 at 13 nm half-pitch, line edge roughness of 1.05 nm, and line width roughness of 1.66 nm. Offering efficient synthesis and broad utility, the reactive polymer GRC-BCP system is expected to be expanded to various applications as a platform material where vertically oriented patterns with applicable functionalities are essential.