Comparison of chlorine- and fluorine-based inductively coupled plasmas for the dry etching of PZT films

Abstract

A comparative study on the etch rate and surface morphology of PZT films and etch selectivity for PZT over Pt has been conducted in chlorine- (Cl 2 and BCl3) and fluorine (CF4 and SF 6)-based inductively coupled plasmas. The PZT etch rate, surface morphology and etch selectivity for PZT over Pt films are a strong function of plasma composition, ion flux and ion energy in both chemistries. Chlorine-based inductively coupled plasmas produced higher etch rates for PZT (max. ̃3500 Å/minute) while fluorine-based plasmas showed higher etch rates (max. ̃1800 Å/minute) for the Pt film. The maximum etch selectivity ̃4.5 for PZT over Pt was obtained at a relatively high source power (900 W) and moderate RF chuck power (250 W) condition.