HfO2 gate dielectrics deposited via tetrakis diethylamido hafnium

HfO2 films deposited via tetrakis diethylamido hafnium (TDEAH) precursor using MOCVD (metal organic chemical vapor deposition) are presented. TDEAH is a promising precursor candidate for the deposition of high permittivity gate dielectrics. We report the impact of process and annealing conditions on the physical and electrical properties of the film. Deposition and annealing temperatures influence the microstructure, density, and impurity levels of TDEAH HfO2 films. Spectroscopic ellipsometry shows that film microstructure manifests itself in the optical properties of the film, particularly in the presence of a band edge related feature at 5.8 eV. An impurity analysis using Auger electron spectroscopy, secondary ion mass spectroscopy, and Raman spectroscopy, indicates that carbon impurities from the precursor exist as clusters within the HfO2 dielectric. The impact of deposition temperature and annealing temperature on the capacitance vs. voltage and current density vs. voltage characteristics of platinum gated capacitors is studied. Correlation of physical film properties with the capacitance and leakage behavior of the TDEAH HfO2 films indicates that impurities, in the form of carbon clusters, and low HfO2 film density are detrimental to the electrical performance of the gate dielectric. (C) 2003 The Electrochemical Society.