Etching of Pt/RuO2 Bilayer Electrode for PZT in a High Density O2/Cl2 Plasma

초록

Bilayer of Pt and RuO2 have been studied as bottom electrodes of ferroelectric or high dielectric storage capacitors in future semiconductor memory devices because of copensating advantages of each materials. Pt electrodes have been known to provide lesser leakage current and better dielectric properties for ferroelectric capacitors than RuO2, while RuO2 is easier for patterning by dry etching than Pt. Pt films are hard to form volatile compounds with any reaction gas in dry etching at room temperature, and often forms hillocks. RuO2 electrodes have poor leakage but good fatigue characteristics, and easier to be etched by O2 containng plasma.