Very Thin TiO2 Films Prepared by Plasma Enhanced Atomic Layer Deposition (PEALD)

Abstract

TiO2 thin films were prepared by plasma-enhanced atomic layer deposition (PEALD) with an alternating supply of reactant sources, Ti(N(CH3)2)4; Tetrakis(dimethylamino)titanium and O2 plasma. The uniform and smooth TiO2 thin films were successfully deposited by PEALD and the film thickness per cycle was saturated at approximately 0.36 Å at 200°C. Excellent step coverage of TiO2 thin films was obtained by Ti(N(CH3)2)4 chemisorbed chemical reactions with O2 plasma on the surface. While dielectric constant of TiO2 films slightly decreased with increasing annealing temperature, the leakage current characteristics of TiO2 films were significantly improved with increasing annealing temperature. The leakage current density of a 36 nm-TiO2 film on Si substrate annealed at 600°C was approximately 1 × 10− 6 A/cm2 at 400 kV/cm.