Inductively coupled plasma etching of CoFeB, CoZr, CoSm and FeMn thin films in interhalogen mixtures

Two new plasma chemistries (ICl and IBr) have been employed for patterning of CoFeB, CoZr, CoSm and FeMn thin films for application in magnetic memories. The interhalogen mixtures produced faster etch rates for FeMn, CoSm, and CoZr in both chemistries compared to Cl2 plasmas under the same conditions. The etch rates are a strong function of discharge composition, pressure, ion flux and ion energy. The data are consistent with an ion-assisted desorption mechanism for the metal chloride etch products. No effect on magnetic properties of etched CoSm was detectable under our conditions.