Interfacial Properties of Hf-silicate∕Si and Hf-silicate∕Al[sub 2]O[sub 3]∕Si Deposited by Atomic Layer Chemical Vapor Deposition

Abstract

Ultrathin HfxSiyOz and Hf xSiyOz/Al2O3, grown on Si surfaces by atomic layer chemical vapor deposition, were characterized in terms of their interface properties using X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy. The formation of Hf-silicide at HfxSiyOz/Si interfaces was induced by the reaction of metallic Hf atoms with Si substrate atoms; this formation was suppressed by the presence of Al2O3 interlayers between HfxSiyOz and Si. As the Al2O 3 interlayer thickness increased, the Hf 4f XPS peak intensity from Hf-silicide decreased and completely disappeared for Al2O3 thickness greater than 10 nm. Effects of Al2O3 interlayers on the atomic structure of the films were also discussed. © 2005 The Electrochemical Society. All rights reserved.