Silica microchannel fabrication using fluorine based rie with alas a mask

Abstract

The silica microchannel fabrication process has been executed with Al thin films as the sacrificial layer during Reactive Ion Etching Process (RIE). CF4/Ar and SF6/Ar plasmas has been used to investigate etch rate of Al thin films and silica wafer. Energy Dispersive X-ray (EDX) analysis has been used to investigate the chemical residues on the surface of silica wafer after RIE process. The transparency of the silica waveguide has also been inspected based on fringe visibility with the aid of the Twyman-Green Interferometer (TGI) for interferometry measurements. The results demonstrate that CF4/Ar plasma etches silica faster than SF6/Ar plasma while keeping the etching rate of Al minimal. Residues are also less visible on the surface of the microchannel when applying CF4/Ar plasma.