Etch damage evaluation on (Bi4−xLax)Ti3O12 thin films during the etch process using inductively coupled plasma sources

The etching mechanism of (Bi4−xLax)Ti3O12 (BLT) thin films in Ar/Cl2 inductively coupled plasma (ICP) and plasma-induced damages at the etched surfaces were investigated as a function of gas-mixing ratios. The maximum etch rate of BLT thin films was 50.8 nm/min of 80% Ar/20% Cl2. From various experimental data, amorphous phases on the etched surface existed on both chemically and physically etched films, but the amorphous phase was thicker after the 80% Ar/20% Cl2 process. Moreover, crystalline “breaking” appeared during the etching in Cl2-containing plasma. Also the remnant polarization and fatigue resistances decreased more for the 80% Ar/20% Cl2 etch than for pure Ar plasma etch.