Refractive index control and etching of C–S–Au film by plasma processes

Carbon–sulfur–gold (C–S–Au) film and amorphous carbon film are considered to use for a photonic crystal as a high and low refractive index material. Practically two-dimensional photonic crystal is under fabrication for an optical wave-guide. These materials have advantages for the use because the materials were optically transparent in the visible wavelength range and the films have process compatibility for the O2 plasma etching. The C–S–Au film was formed by co-operative process of plasma CVD and sputtering with using gold plate discharge electrode and optical properties were characterized.