Comparison of Cl-2/He, Cl-2/Ar, and Cl-2/Xe plasma chemistries for dry etching of NiFe and NiFeCo

Cl-2/He, Cl-2/Ar, and Cl-2/Xe discharges operated under inductively coupled plasma conditions have been compared for patterning of Ni0.8Fe0.2 and Ni0. 8Fe0.13Co0.07 layers. There is a transition from net deposition to etching with increasing source power, as the relatively involatile chlorinated etch products are removed more efficiently by ion-assisted desorption. This tra nsition occurs at lower ion fluxes for Xe- and Ar-containing discharges tha n for He due to the more effective momentum transfer. The etch rates with a ll three mixtures also go through maxima, reflecting the need to balance et ch product formation and desorption. (C) 1999 The Electrochemical Society. S0013-4651(98)08-020-3. All rights reserved.