Laser Treatment at Room Temperature for Improvement of Dielectric Properties in Plasma-Enhanced Atomic Layer Deposited TiO₂ Thin Films

Abstract

TiO₂ dielectric films with 38 nm thickness were grown on Si (100) substrates at 200°C using plasma-enhanced atomic layer deposition (PEALD) technique. Laser-irradiated TiO₂ films kept an amorphous phase similar to as-grown films and showed an increase in permittivity with increasing laser powers and the number of laser shots at constant laser power. Laser-irradiation of TiO₂ films at room temperature produces an oxygen vacancy at the film surface. The high frequency dependence of capacitance at low frequency in laser-irradiated films was due to an increase of space charges such as oxygen vacancy, resulting in an increase of permittivity in laser-irradiated TiO₂ films because of an additional space charge polarization.

Keywords:

• TiO₂ thin films
• PEALD
• laser-irradiation
• permittivity
• low temperature deposition

ACKNOWLEDGMENT

This work was supported by Korea Research Foundation Grant (KRF-2002-042-D00066), the Brain Korea 21 project in 2003, and was partially supported by the Korea Science and Engineering Foundation through the Research Center for Advanced Magnetic Materials at Chungnam National University.