International Conference on Thin Film Deposition of Oxide Multilayers Hybrid Structures

J. Phys. IV France 11 (2001) Pr11-261-Pr11-265
DOI: 10.1051/jp4:20011142

Effects of active surface nitridation on the properties of high permittivity films deposited by UV-assisted CVD

B.J. O'Sullivan¹, E. O'Connor¹, R. Howley¹, P.K. Hurley¹, J.-Y. Zhang², N. Kaliwoh², Q. Fang², I. W. Boyd², C. Dubourdieu³, M.A. Audier³, J.P. Sénateur³, H.O. Davies⁴, T.J. Leedham⁴, A.C. Jones⁴ and B. Semmache<sup>5

1</sup>  National Microelectronics Research Centre, Lee Maltings, Prospect Row, Cork, Ireland
²  Department of E&EE, University College London, Torrington Place, London WC1E 7JE, U.K.
³  Institut National Polytechnique de Grenoble, LMGP, BP. 46, 38402 Saint-Martin-d'Hères, France
⁴  Inorgtech, 25 James Carter Road, Mildenhall, Suffolk IP28 7DE, U. K.
⁵  J.I.P. Elec, 11 chemin du Vieux Chêne, 38240 Meylan Zirst, France

Abstract
An in situ low temperature chemical vapour deposition (CVD) system, featuring surface nitridation, dielectric layer deposition and post deposition anneal is presented. Processing is performed under the influence of ultra-violet radiation. After a range of nitridation treatments, Ta₂O₅ films are deposited and the effects of the N₂O step on the dielectric films are analysed. From the electrical analysis performed, the nitridation step reduces the SiO₂ equivalent thickness and leakage currents flowing, while also increasing the effective breakdown field of the films. Transmission electron microscopy (TEM) analysis reveals a thinner interface layer between substrate and dielectric, with increasing nitridation time.

© EDP Sciences 2001