Fabrication of sloped sidewalls by inductively coupled plasma etching for silicon micro-optic structures

摘要

Current work on deep-reactive ion etching has primar-nily focused on creating vertical sidewalls for microelectromechani-ncal system and electronics applications. For micro-optical and micro-noptoelectromechanical system structures control of the sidewall anglesnother than vertical is as important as the ultimate depth. In this work,nwe investigate the control of sidewall profiles using an inductively cou-npled plasma technique. The material systems being investigated on blan-nket samples are silicon and silicon dioxide with CF4, CHF3, and SF6nchemistries. Micro-optic structures are created by photolithography andnCHF3 gas has been explored to achieve a wide range of etch rates, smoothnetch profiles, and sidewall angles. The etch profiles are characterized bynscanning electron microscopy