Correlation Length Measurement of Sidewall Roughness of Dry Etched Facet and Its Effect on Reflectivity

Abstract

Dry etching is an important tool to fabricate various semiconductor photonic devices. The roughness of etched sidewalls should be avoided as it reduces the scattering loss. We present a spatial frequency analysis of the sidewall roughness of dry etched facets processed by reactive ion etching. A characteristic parameter corresponding to a correlation length is estimated to be ~0.5 μm. In addition, its effect on reflectivities of etched reflectors is discussed.