Loss Reduction of Si Wire Waveguide Fabricated by Edge-Enhancement Writing for Electron Beam Lithography and Reactive Ion Etching Using Double Layered Resist Mask with C60

Loss reduction methods for single-mode photonic wire in silicon-on-insulator were investigated, with a Si core size of 200 × 440 nm 2 , fabricated with electron beam lithography and dry etching, using a double layer of electron beam (EB) resist mask. The transverse electric (TE) mode propagation loss measured at a wavelength of 1550 nm was 4.5 dB/cm, which is, to the best of our knowledge, the lowest value ever attained for a Si wire waveguide fabricated by the parallel plate reactive ion etching (RIE) method.