Study on the etching damage characteristics of PZT thin films after etching in Cl-based plasma

Abstract

In present work, we carried out the investigations of plasma-induced etching damage for the PZT thin films etched using the various Cl-based gas chemistries. The basic gas mixture was Cl 2/CF 4 (8/2) while Ar or O 2 were used as the additive gases (up to 20%). It was found that the etching in Cl 2/CF 4/Ar plasma provides higher a rate but degrades the remnant polarization more compared with Cl 2/CF 4/O 2 plasma. X-ray photoelectron spectroscopy showed the contamination of the etched surfaces by ZrCl x for both gas mixtures. The Auger electron spectroscopy and X-ray diffraction analyses show that Cl 2/CF 4/Ar plasma provides more significant etching damage, which cannot be recovered by the O 2 annealing. For the Cl 2/CF 4/O 2 plasma, annealing under the O 2 atmosphere helps to restore the ferroelectric properties resulting in good recovering of the remnant polarization.