Block copolymer lithography: periodic arrays of about 10 to the 11th power holes in 1 square centimeter

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.
In general, feature sizes greater than 300 nm are routinely produced by photolithography techniques. For feature sizes between 300 and 30 nm, electron beam lithography is commonly used. However, feature [...]