Fabrication of high-aspect-ratio poly(2-hydroxyethyl methacrylate) brushes patterned on silica surfaces by very-large-scale integration process

We used a novel fabricated process including electron beam and isotropic oxygen plasma to generate signal line patterns of polymerized 2-hydroxyethyl methacrylate (HEMA) on patterned Si(1 0 0) surfaces. Isotropic oxygen plasma was introduced to enhance the resolutions of the line and dots patterns of the PHEMA brush are approached to 350 nm and 2 mu m, respectively. We established the surface grafting polymerization kinetics of the PHEMA chains on silicon surface by to fit the thickness and number-average molecular weight (M-n). The propagation rate (k(p)) and active grafting specie deactivation rate (k(d)) lies in the range of similar to 3.6 x 10(-2) s(-1) M-1 and 4.8 x 10(-5) s(-1), respectively. The measured thicknesses by ellipsometer and analyzed M-n of "free" PHEMA by gel permeation chromatography (GPC) are fitted well by the polymerization kinetic model. In addition, aspect-ratios (height/width) are used to define the shape of patterned PHEMA brushes. The high-aspect-ratio of the PHEMA brush line with width of 350 nm is 0.27. We use a graft polymerization/solvent immersion method for generating various patterns of polymer brushes to investigate the deformation of the PHEMA brush through aspect-ratios. (C) 2010 Elsevier Inc. All rights reserved.