Etching characteristics and mechanism of indium tin oxide filmsin an inductively coupled H Br ∕ Ar plasma

The investigations of etch characteristics and mechanisms for indium tin oxide ( In 2 O 3 ) 0.9 : ( Sn O 2 ) 0.1 (ITO) thin films using H Br ∕ Ar inductively coupled plasma were carried out. The ITO etch rate was measured in the range of 0%-100% Ar in the H Br ∕ Ar mixture at fixed gas pressure ( 6 mTorr ) , input power ( 700 W ) , and bias power ( 200 W ) . Plasma parameters and composition were examined with a combination of plasma diagnostics by double Langmuir probe and global (zero-dimensional) plasma model. It was found that the ITO etch rate follows the behavior of Br atom flux but contradicts with that for H atoms and positive ions. This suggests that the ITO etch process is not limited by the ion-surface interaction kinetics and appears in the reaction-rate-limited etch regime with the Br atoms as the main chemically active species.