Current transport mechanism for HfO2 gate dielectrics with fluorine incorporation

Abstract

In this article, the current transport mechanism of fluorinated HfO2 gate dielectrics is investigated. Based on the experimental results of the temperature dependence of gate leakage current and Fowler-Nordheim tunneling characteristics at 77 K, we have extracted the energy band diagrams and current transport mechanisms for TaN/HfOF/fluorinated-interfacial layer (IL)/Si structures. In particular, we have obtained the following quantities that will be useful for modeling and simulation: (i) fluorinated IL/Si barrier height (or conduction band offset): 3.2 eV; (ii) TaN/HfOF barrier height: 2.6 eV; and (iii) trap levels at 1.3 eV (under both gate and substrate injections) below the HfOF conduction band which contributes to Frenkel-Poole conduction. (C) 2007 The Electrochemical Society.