Nanopattern fabrication via AP-UVO exposure of a self-organized block copolymer

Block copolymers were used to achieve nanoscale patterning. Block copolymers, particularly polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA), produce patterns from which one block polymer may be selectively etched. However, the selective wet etching of PMMA with acetic acid can induce the remaining PS structures to collapse due to capillary forces between adjacent PS domains during drying. This study presents an alternative approach to the formation of nanoscale patterns by using an atmospheric UV-ozone (AP-UVO, λ = 365 nm) exposure system. Compared with the general etching system, AP-UVO exposure is relatively low cost, can potentially be scaled up, and proceeds via a simple process. In addition, we demonstrate that the line and space (L/S) sizes of the block copolymer pattern can be controlled by using the AP-UVO etch time. Also, we were able to obtain well-ordered patterns from the combining the AP-UVO exposure process with a control process of block copolymers conditions. These results suggest that the AP-UVO exposure method with block copolymers may be used to form etch masks, particularly for the fabrication of graphene nanoribbons, quantum dots, nano grid wires, and nanopores.