Process development of methane-hydrogen-argon-based deep dry etching of InP for high aspect-ratio structures with vertical facet-quality sidewalls

We examine methane-hydrogen-argon-based deep dry etching of InP for facet-q uality sidewalk by reactive ion etching. A process is developed for etch de pths as high as 5.8 mum. Masks studied include Ni, NiCr, Ti, SiO2, and Ti-S iO2. Sidewall roughness was estimated to be a few nn (based on high resolut ion scanning electron micrographs). This may be useful for fabrication of o ptical microelectromechanical systems, photonic wires, and photonic crystal s in the InP material system. (C) 2001 American Vacuum Society.