Fabrication of patterned high-density polymer graft surfaces. II. Amplification of EB-patterned initiator monolayer by surface-initiated atom transfer radical polymerization

Patterned films of a low-polydispersity polymer densely end-grafted on a silicon substrate were fabricated for the first time by the combined use of electron beam (EB) lithography and living radical polymerization; a focused EB was scanned on an initiator-immobilized substrate to selectively bombard and decompose the initiator, and then the EB-induced pattern was amplified by the atom transfer radical polymerization (ATRP) technique using Cu/ligand complexes. Ellipsometric and atomic force microscopic studies indicated that doses sufficiently larger than 2000 μC/cm2 would completely decompose the monolayer of the initiator, 2-(4-chlorosulfonylphenyl)ethyltrichlorosilane, and that the surface-initiated ATRP could amplify the EB-produced fine pattern of the initiator monolayer.