Deposition of hard metal nitride-like coatings in an electron cyclotron resonance discharge

Hard titanium, zirconium and chromium nitride-like coatings were grown in a high-density microwave electron cyclotron resonance discharge. The organometallic deposition precursors were titanium (IV) isopropoxide and tetrakis(dimethylamino)titanium, zirconium 2-methyl-2-butoxide and zirconium t-butoxide, and bis(ethylbenzene)chromium, with ammonia as the reactive gas. The deposited metal nitride-like coatings have nano-indentation hardness values of 20–28 GPa for TiN-like coatings, 17–21 GPa for ZrN-like coatings and 25–31 GPa for CrN-like coatings. Growth rates were 10–20 nm/min. X-Ray photoelectron spectroscopic analyses showed the compositions of titanium-, zirconium- and chromium-containing coatings to be TiCxOyNz, ZrCxOyNz and CrCxOyNz with significant carbon and oxygen atomic concentrations. The titanium nitride-like and zirconium nitride-like coatings had characteristic gold coloring and lasted more than 1000 h in an ASTM B117 salt-fog corrosion test without color change or visible corrosion.