Low Temperature Deposition of TaCN Films Using Pentakis(diethylamido)tantalum

Ta(CN) films were thermally deposited at low temperature (≤400°C) using single source pentakis(diethylamido)tantalum (PDEAT) as a precursor. The activation energy of the surface reaction is about 0.79 eV and the maximum deposition rate obtained is about 100 Å/min at 350°C. The resistivity of the as-deposited film decreases as the deposition temperature increases and the minimum value of resistivity obtained is 6000 µ Ω-cm for the sample deposited at 400°C. There is no aging effect of the film resistivity after air exposure. Major chemical elements in the films are identified as Ta, C, and N with some amounts of O by Auger electron spectroscopy (AES). Most of the carbon elements in the film is identified as bonded to Ta by X-ray photoelectron spectroscopy (XPS). The microstructural investigation using high resolution transmission electron microscopy (HRTEM) reveals a nanocrystalline phase with an average grain size of about 30 Å.