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.

Keywords:

• TiO₂
• plasma enhanced atomic layer deposition
• PEALD
• dielectric constant
• leakage current

ACKNOWLEDGEMENTS

This work was supported by Electronic Ceramics Center (ECC) of Dongeui University, which is supported by Busan Metropolitan City and Korea Science and Engineering Foundation (KOSEF) under Ministry of Science and Technology (MOST).