Dry Etch Patterning of LaCaMnO₃ and SmCo Thin Films

A number of different plasma chemistries have been employed for patterning of and SmCo thin films for application in magnetic‐field‐biased structures based on the colossal magnetoresistive effect. For there was no chemical enhancement in etch rate over simple Ar sputtering for , and plasmas under high ion density conditions. This is expected based on the vapor pressures of the prospective etch products. For SmCo, however, etch rates up to 7000 Å min⁻¹ were obtained in /Ar plasmas, which is an order of magnitude faster than Ar sputtering under the same experimental conditions. Smooth etched surface morphologies and anistropic sidewalls were obtained for both materials over a wide range of plasma source and chuck powers.