Anisotropic etching of CoFeB magnetic thin films in C 2 H 5 OH/Ar plasma

The effect of SF6addition in a Cl2/Ar inductively coupled plasma for deep titanium etching

“…The study of titanium etching by a Cl 2 /Ar plasma was carried out with the parameters presented in table 1. It is known that nickel etch rate decreases quickly when Cl 2 is added to an Ar plasma [26]. Since Ni etching is predominantly led by physical mechanisms, the Ar + ion bombardment has more impact than the chemical reaction of chlorine radicals.…”

“…Consequently, by increasing the chlorine content in the plasma mixture, titanium etch rate is higher and nickel erosion is reduced, inducing a higher selectivity. The nickel etch rate is almost constant with pressure in an ICP reactor [26].…”

“…Ti:Ni selectivity increases by decreasing the self-bias from 0 to −25 V. Beyond −25 V for lower self-bias voltages until −300 V (225 W), the Ti:Ni selectivity decreases. According to [26], nickel etch rate raises proportionally with the self-bias voltage and induces a decrease of Ti:Ni selectivity. Figure 4 shows tilted SEM views of the etched surface for two different self-bias voltages (−150 and −300 V) after 10 min of etching with a Cl 2 /Ar plasma.…”

“…Titanium etching is due to both ion bombardment and reactions with chlorine-based species while nickel etching is mainly driven by a physical etching mechanism (ion sputtering) [26]. Ti:Ni selectivity decreases versus ICP power.…”