Dry etching of $NiFe∕Co$ and $NiFe∕Al–O∕Co$ multilayers in an inductively coupled plasma of $Cl2∕Ar$ mixture

Dry etching of $NiFe∕Co$ and $NiFe∕Al–O∕Co$ multilayers was carried out in inductively coupled $Cl2∕Ar$ plasmas. An ion-enhanced etch mechanism took a critical role for desorption of chlorine etch products. $NiFe∕Al–O∕Co$ showed a faster etch rate than $NiFe∕Co$ at various etch conditions. Anisotropic and smooth features were obtained using a photoresist mask. Sidewall contamination with etch products was observed at a higher $Cl2$ concentration $(>50%)$⁠. Postetch cleaning of the etched samples in deionized water reduced the chlorine residues substantially.