Reactive ion etching of Ge-Sb-Se ternary chalcogenide glass films in fluorine plasma

Abstract

Ternary Ge-Sb-Se chalcogenide glass (ChG) is emerging as an attractive material for fabricating micro optical devices due to the excellent optical properties. This paper reports the reactive ion etching (RIE) of ternary ChG films using CHF3 plasma for patterning microstructures. The influences of the etching parameters, including the ICP power, the chamber pressure, and the gas flow rate, on the etching rate and the anisotropy are investigated and optimized. Grass-like residues are found in high chamber pressure, and the formation mechanism is discussed. The results show that high RF power, low gas flow rate, and low chamber pressure are beneficial to achieving high etching rates and improving good anisotropy. The optimized etching parameters can be used as a baseline for patterning Ge-Sb-Se optical microstructures using reactive ion etching.