T. Tada et al., Fabrication of photonic crystals consisting of Si nanopillars by plasma etching using self-formed masks, JPN J A P 1, 38(12B), 1999, pp. 7253-7256
We fabricated two dimensional photonic crystals (a square and a triangular
lattice) with a photonic band gap (PBG) in the visible light range by perio
dically arranging Si nanopillars with a period of 270 nm. The pillar diamet
er and height are 50 nm and 1 mum, respectively. The fabrication process us
es iron clusters as nuclei for self-formation of etching masks during elect
ron cyclotron plasma etching with SF6 gas at -135 degreesC to Obtain high-a
spect-ratio Si nanopillars. The iron clusters are arranged by electron beam
lithography. The reflection spectra of the square lattice photonic crystal
have a peak around 570 nm for transverse magnetic polarization light while
that for transverse electric polarization have a peak around 550 nm. This
is consistent with our theoretical calculation that the photonic crystal ha
s a PEG at these wavelengths.