Interhalogen plasma chemistries for dry etch patterning of Ni, Fe, NiFe and NiFeCo thin films

ICl/Ar and IBr/Ar plasmas operated in an inductively coupled plasma (ICP) s ource have been examined for dry etching of Ni, Fe, NiFe and NiFeCo. The re moval of the Fe etch products limits the etch rates under most conditions, but rates of similar to 500 Angstrom min(-1) are obtained for both NiFe and NiFeCo in both chemistries. The etched surfaces are smooth (atomic force m icroscopy root-mean-square roughness <1 nm) over a broad range of plasma co nditions, with small residual halogen concentrations(less than or equal to 2 at.%). (C) 1999 Elsevier Science B.V. All rights reserved.