Block Copolymer Lithography: Periodic Arrays of ~10 ¹¹ Holes in 1 Square Centimeter

TLDR

Spin‑coated diblock copolymer thin films with well‑ordered spherical or cylindrical microdomains served as templates, and their microdomain patterns were transferred directly to the silicon nitride layer by two complementary techniques that produced opposite‑tone patterns. Dense periodic arrays of 20‑nm holes 40‑nm apart, hexagonally ordered with ~10×10 grain size, were fabricated, opening a route for nanometer‑scale surface patterning by spontaneous self‑assembly on length scales difficult to achieve with standard semiconductor lithography.

Abstract

Dense periodic arrays of holes and dots have been fabricated in a silicon nitride–coated silicon wafer. The holes are 20 nanometers across, 40 nanometers apart, and hexagonally ordered with a polygrain structure that has an average grain size of 10 by 10. Spin-coated diblock copolymer thin films with well-ordered spherical or cylindrical microdomains were used as the templates. The microdomain patterns were transferred directly to the underlying silicon nitride layer by two complementary techniques that resulted in opposite tones of the patterns. This process opens a route for nanometer-scale surface patterning by means of spontaneous self-assembly in synthetic materials on length scales that are difficult to obtain by standard semiconductor lithography techniques.