Etching characteristics of (Na0.5K0.5)NbO3 thin films in an inductively coupled Cl-2/Ar plasma

The investigation of etch characteristics for (Na0.5K0.5)NbO3 (NKN) thin films in Cl-2/Ar inductively coupled plasma was carried out. It was found that the NKN etch rate is a monotonic function of both in put power and negative dc bias as it generally expected from the corresponding variations of plasma parameters. At the same time, NKN etch rate shows a non-monotonic behavior as a function of Cl-2/Ar mixing ratio with a maximum of 750 angstrom/min at Cl-2 (80%)/Ar (20%). The analysis of these data togeter with the XPS results for both as-deposited and etched NKN films allowed one to assume ion assisted etch mechanism and defined a concurence of chemical and physical etch pathways as a most probable reason for etch rate maximum.