FABRICATION OF PHOTONIC BAND-GAP CRYSTALS

We describe the fabrication of three-dimensional photonic crystals usi ng a reproducible and reliable procedure consisting of electron beam l ithography followed by a sequence of dry etching steps. Careful fabric ation has enabled us to define photonic crystals with 280 nm holes def ined with 359 nm center to center spacings in GaAsP and GaAs epilayers . We construct these photonic crystals by transferring a submicron pat tern of holes from 70-nm-thick polymethylmethacrylate resist layers in to 300-nm-thick silicon dioxide ion etch masks, and then anisotropical ly angle etching the III-V semiconductor material using this mask. Her e, we show the procedure used to generate photonic crystals with up to four lattice periods depth. (C) 1995 American Vacuum Society.