Characterization of Ru and RuO₂ thin films prepared by pulsed metal organic chemical vapor deposition

Abstract

Ultra-thin ruthenium (Ru) layers were fabricated by pulsed metal organic chemical vapor deposition in an Aixtron Tricent reactor using a metal-organic Ru precursor. Layer deposition was performed on different metal barrier combinations and on Al2O3 dielectric layers used in the fabrication of advanced Metal-Insulator-Metal (MIM) capacitor structures and on thermal SiO2 as reference structure. Ru layers with a thickness of 10 nm were characterized by Spectroscopic Ellipsometry (SE) and additional reference methods such as Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), and X-Ray Reflectometry (XRR). As deposited and in situ annealed Ru layers were characterized by SE applying Drude-Lorentz- and Effective Medium Approximation (EMA) models. It was shown that the deposited layers consist of a Ru-RuO2 bilayer structure. By in situ annealing, the RuO2 layer thickness is reduced and highly pure Ru films are obtained. On the metal barriers the formation of a metal oxide interface, which is related to the deposition process, was determined

Dielectric Material Options for Integrated Capacitors

“…More details can be found elsewhere. [2][3][4] Film thicknesses were determined by spectroscopic ellipsometry and TEM. Generally the dielectric film thickness was adjusted to 50 ± 5 nm, the additional dielectric in the stacked film variants were minimized to a few nm.…”

Physical Characterization of PECVD and PEALD Ru(-C) Films and Comparison with PVD Ruthenium Film Properties

“…Within this model, n and k are described continuously through the use of a 3 rd order oscillation approximation, according to the Kramers-Kronig relation. 47 The complex dielectric function according to the 3 rd order Lorentz oscillation model is described as follows by eq. 1.…”