Silicon crystallization in nanodot arrays organized by block copolymer lithography

Abstract

Asymmetric polystyrene-b-polymethylmethacrylate (PS-b-PMMA) block copolymers are used to fabricate nanoporous PS templates with different pore diameter depending on the specific substrate neutralization protocol. The resulting polymeric templates are used as masks for the subsequent deposition of a thin (h = 5 nm) amorphous Si layer by electron beam evaporation. After removal of the polymeric film and of the silicon excess, well-defined hexagonally packed amorphous Si nanodots are formed on the substrate. Their average diameter (d \ 20 nm), density (1.2 9 10 11 cm -2 ), and lateral distribution closely mimic the original nanoporous template. Upon capping with SiO 2 and high temperature annealing (1050°C, N 2 ), each amorphous Si nanodot rearranges in agglomerates of Si nanocrystals (d \ 4 nm). The average diameter and shape of these Si nanocrystals strongly depend on the size of the initial Si nanodot.

Template‐Assisted Fabrication of Nanostructured Arrays for Sensing Applications

“…Additionally, etching through the trenches of BCP can produce nanohole arrays. Inspired by these BCP‐based mechanisms, a Si nanodot and a nanohole array with high density can be prepared on a wafer scale –…”

Evolution of shape, size, and areal density of a single plane of Si nanocrystals embedded in SiO2 matrix studied by atom probe tomography

“…Practically, only 2D maps of the projection of isolated Si NCs or nanoaggregates containing Si NCs are obtained from this method. 18,22,23 Plasmon tomography is necessary to obtain a 3D description, but probably due to unstability under irradiation damage very few attempts are reported in the literature. 24,25 Moreover, even if a 3D morphology reconstruction can be achieved, it cannot provide a fully quantitative concentration analysis.…”