High rate dry etching of Ni0.8Fe0.2 and NiFeCo

A Cl-2/Ar plasma chemistry operated under electron cyclotron resonance (ECR) conditions is found to produce etch rates for NiFe and NiFeCo of greater than or equal to 3000 Angstrom min(-1) at less than or equal to 80 degrees C. The etch rates are proportional to ion density and average ion energy over a fairly wide range of conditions. Under the same conditions, fluorine or methane/hydrogen plasma chemistries produce rates :tower than the Ar sputter rate. The high ion current under ECR conditions appears to balance NiClx, FeClx, and CoClx etch product formation with efficient ion-assisted desorption, and prevents formation of the usual chlorinated selvedge layer that requires elevated ion etching conditions. Post Cl-2-etch removal of surface residues is performed with an in situ H-2 plasma exposure. (C) 1997 American Institute of Physics.