Quadruple-hole multiplication by directed self-assembly of block copolymer

Directed Self-Assembly (DSA) of cylindrical block copolymer with graphoepitaxy strategy offering significant potential for contact hole multiplication in semiconductor manufacturing at technology nodes below 7 nm (sub-7 nm). This technique allows precise control over the number of DSA-generated holes and their critical dimensions (CD) by manipulating the guiding template geometry and size. The results indicate that DSA quadruple-hole multiplication patterns aligned top-bottom and left-right, with a long-axis spacing of 55-65 nm and a short-axis spacing of 30-40 nm could be achieved through precisely designing template holes with long-axis dimension and short-axis dimension. The formed DSA pattern was successfully transferred to the underlying hard mask layer, creating a large-area quadruple-hole array with a CD of approximately 17 nm. A comprehensive investigation of guiding template size and morphology on multiplication hole patterning enhances the understanding of the self-assembly behavior in confined elliptical spaces. In conclusion, this work highlights the importance of optimizing guiding template size for contact hole multiplication in integrated circuit fabrication.