We present here an original process combining top-down and bottom-up
approaches by annealing a thin gold film evaporated onto a hole template made
by etching a PS-PMMA copolymer film. Such process allows a better control of
the gold nanoparticle size distribution which provides a sharper localized
surface plasmon resonance. This makes such route appealing for sensing
applications since the figure of merit of the Au nanoparticles obtained after
thermal evaporation is more than doubled. Such process could besides allow
tuning the localized surface plasmon resonance by using copolymer with various
molecular weights and thus be attractive for surface enhanced raman
spectroscopy