Etching properties of lead–zirconate–titanate thin films in Cl2/Ar and BCl3/Ar gas chemistries

Abstract

Etching characteristics of lead–zirconate–titanate (PZT) thin films fabricated by the sol–gel process were investigated using Cl2/Ar and BCl3/Ar inductively coupled plasma, respectively. The maximum etch rate of PZT thin films was obtained: Cl2 (70%)/Ar (30%) and BCl3 (70%)/Ar (30%) gas mixing ratio. The maximum etch rate was 160 nm/min at Cl2 (70%)/Ar (30%) and 179 nm/min at BCl3 (70%)/Ar (30%). Also, the etch rate was measured by varying the etching parameters such as rf power, dc-bias voltage, and chamber pressure. As rf power was raised, the etch rate of the PZT thin films increased in both Cl2/Ar and BCl3/Ar gas conditions. The increase of dc-bias voltage increases the PZT etch rate, and as the chamber pressure increases, the etch rate of PZT films decreases. Plasma diagnostics were performed using a Langmuir probe.