Figure 1: PS-b-PMMA self-assembly on e-beam-irradiated SiO2/Si substrate.
From: Directed block copolymer self-assembly implemented via surface-embedded electrets
(a) Schematic description for fabricating PS-b-PMMA films with perpendicular orientation on e-beam-irradiated SiO2/Si substrates. SEM images of PS-b-PMMA films self-assembled on the SiO2/Si wafers whose central regions were irradiated by e-beam: (b) Cylinder-forming PS-b-PMMA (46k-b-21k) with thickness of 37 nm and (c) lamella-forming PS-b-PMMA (53k-b-54k) with thickness of 56 nm (scale bars, 200 nm). The insets in b and c are the corresponding low-magnification images (scale bars, 1 μm), in which the bright contrast indicates a uniform formation of the perpendicular orientation. The samples were treated by Ar plasma to selectively remove PMMA to improve the SEM image contrast.
