CO2/SF6-based Deep Reactive Ion Etching of Si

We demonstrated the vertical etching of Si by CO 2 /SF 6 -based deep reactive ion etching (deep-RIE) and investigated the dependence of the etching profile on the passivation process time, CO 2 flow rate, inductively coupled plasma (ICP) power, and process pressure.In addition, we demonstrated the microloading effect and investigated the fluorine resistance of the passivation film by XeF 2 vapor-phase etching.Furthermore, to investigate the composition of the sidewall passivation film, we performed the optical emission spectroscopy of the plasma during the deep-RIE and energy-dispersive X-ray and X-ray photoelectron spectroscopy analyses of the chemical composition of the passivation film on the etched Si sidewall.We found that the main components of the sidewall passivation film in CO 2 /SF 6 -based deep-RIE are C and O derived from the CO 2 plasma and Si oxides.