Dry and Wet Etch Processes for NiMnSb Heusler Alloy Thin Films

A variety of plasma etching chemistries were examined for patterning NiMnSb Heusler alloy thin films and associated barrier layers. Chemistries based on , and were all found to provide faster etch rates than pure Ar sputtering. In all cases the etch rates were strongly dependent on both the ion flux and ion energy. Selectivities of ⩾20 for NiMnSb over were obtained in ‐based discharges, while selectivities ⩽5 were typical in , and plasma chemistries. Wet etch solutions of and were found to provide reaction‐limited etching of NiMnSb that was either nonselective or selective, respectively, to .