Dry etching of CoFe films using a CH4∕Ar inductively coupled plasma for magnetic random access memory application

In this study, the CoFe thin film was studied using an inductively coupled plasma system in $\mathrm{C}{\mathrm{H}}_4$ -based gas chemistries. The etch rate of the CoFe thin film was systemically studied by the process parameters including the gas mixing ratio, the rf power, the dc-bias power, and the process pressure. The best gas composition for etching was in $\mathrm{C}{\mathrm{H}}_4$ (20%)/Ar (80%) ratio. As the rf power and the dc-bias voltage were increased, the etch rate of the CoFe thin film increased in a $\mathrm{C}{\mathrm{H}}_4∕\mathrm{Ar}$ inductively coupled plasma system. The best process pressure condition for etching was $10\mathrm{mTorr}$ in the $\mathrm{C}{\mathrm{H}}_4∕\mathrm{Ar}$ inductively coupled plasma system. The changes in the components on the surface of the CoFe thin film were investigated with energy dispersive x ray.