Formation of Nano-Crystalline Ru-Based Ternary Thin Films by Plasma-Enhanced Atomic Layer Deposition

Abstract

Ruthenium (Ru)-based ternary thin films, RuSiN, were prepared by plasma-enhanced atomic layer deposition (PEALD) with repetitions of supercycles consisting of Ru and SiNx PEALD subcycles at 270 degrees C. Resonance Rutherford backscattering spectrometry confirmed the successful incorporation of Si and N into Ru. Cross-sectional view transmission electron microscopy (TEM) and plan-view high resolution TEM analysis showed that the RuSiN film formed a nano-crystalline microstructure, consisting of Ru nanocrystals embedded in a SiNx amorphous matrix, whereas the Ru films were polycrystalline with columnar grains. Cu was electroplated on an similar to 8 nm thick RuSiN film, indicating that it is a viable candidate as a Cu direct-plateable diffusion barrier. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3506398] All rights reserved.