Hf O₂ high-k dielectrics grown on (100)Ge with ultrathin passivation layers: Structure and interfacial stability

Abstract

We have investigated the growth of Hf O2 thin films on (100)Ge by molecular beam epitaxy. By means of transmission electron microscopy, the structural characteristics of the films grown on clean Ge surfaces are compared with those grown on passivation layers of Ge Ox and Ge Ox Ny. The interface was found to be very flat and thin, with an interfacial layer one or two monolayer thick. However, traces of Ge in the oxide have been detected when deposited on either one of the interfacial layers, which can be explained by the instability of the interfacial layers grown with an atomic oxygen/nitrogen beam, prior to the Hf O2 deposition. © 2005 American Institute of Physics.