Geometric Control of Chemically Nano-patterned Substrates for Feature Multiplication Using Directed Self-Assembly of Block Copolymers

In this study, directed self-assembly of block copolymers (BCP) was investigated as a function of the dimensions of the alternating stripes on chemically nano-patterned substrates, at a constant pattern pitch. It was shown that alignment of the block copolymer with the chemical pattern depends on the width of the guiding stripe. Also, when the ratio of this parameter over the natural periodicity of the BCP (W/L-o) is around 0.6, a high degree of perfection is achieved. Finally, the formulation of the BCP was found to impact the process window, as three batches with the same L-o, presented good alignment at different conditions.