Scattering loss in silicon-on-insulator rib waveguides fabricated by inductively coupled plasma reactive ion etching

Abstract

Inductively coupled plasma reactive ion etching (ICPRIE) was used to etch rib the waveguide and U groove to achieve the integration of self-alignment connection between single mode fiber and rib waveguide in silicon-on-insulator (SOI) wafer. Interface roughness is one of the consequences of an ICPRIE process. Endface roughness, surface roughness, and sidewall roughness result in increasing scattering losses for waveguides. A series of atomic force microscope measurements were carried out to demonstrate the root-mean-square (rms) roughness of SOI rib waveguide etched by ICPRIE method. According to scalar scattering theory and Tien’s theory, scattering loss induced by the rms roughness was studied systematically.