SrTa₂O₆ Thin Films Deposited by Plasma-Enhanced Atomic Layer Deposition

Abstract

SrTa 2 O 6 (STO) thin films were prepared by plasma-enhanced atomic layer deposition (PEALD) with an alternating supply of reactant sources, Sr[Ta(C 2 H 5 O) 5 (C 4 H 10 NO)] 2 {strontium bis-[tantalum penta-ethoxide dimethyllaminoethoxide]; Sr(Ta(OEt) 5 ·dmae) 2 } and O 2 plasma. It was observed that the uniform and conformal STO thin films were successfully deposited using PEALD and the film thickness per cycle was saturated at approximately 0.8 Å at 300°C. Electrical properties of STO thin films prepared on Pt/SiO 2 /Si substrates at various annealing temperatures were investigated. While the grain size and dielectric constant of STO films increased with increasing annealing temperature, the leakage current characteristics of STO films slightly deteriorated. The leakage current density of a 40 nm STO film annealed at 600°C was approximately 5×10 -8 A/cm 2 at 3 V.