Atomic Layer Deposition of Ru and RuO2 for MIMCAP Applications

Abstract

Ruthenium (Ru) and Ruthenium-oxide (RuO2) are interesting electrodes for Metal-Insulator-Metal capacitor (MIMCAP) applications when combined with the high-k dielectric strontium titanate (SrTiO3). In this work, Atomic Layer Deposition (ALD) of Ru and RuO2 on TiN and SrTiO3 on 300 mm Si substrates is studied using a commercial thermal ALD reactor, and (Methylcyclopentadienyl)(Pyrrolyl)Ruthenium as a precursor and O2 as a co-reactant. It is found that a linear growth can be achieved for both Ru and RuO2 on a selected TiN after a short incubation. The deposition behavior and layer properties such as uniformity, adhesion and roughness depend strongly on substrate state. For the ALD of Ru on SrTiO3, surface treatment is needed for a controllable deposition: H2/He plasma treatment can activate the SrTiO3 surface and results in a linear growth of a metallic Ru layer.