MOCVD of Titanium Nitride from a New Precursor, Ti[N(CH3)C2H5]4

A new TiN precursor, tetrakis(ethylmethylamido)titanium (TEMAT), has been developed and characterized in terms of volatility and stability under CVD process conditions. In addition, titanium nitride thin films were prepared by means of metal organic chemical vapor deposition (MOCVD) technique, using TEMAT as a precursor. Depositions on SiO 2 patterned wafers were carried out at 250−350 °C and the pressure of 1 Torr, yielding growth rates from 50 to 1550 Å/min. Excellent bottom coverage of ∼90% over 0.35 μm contacts with an aspect ratio of 2.9 was achieved at 300 °C. This excellent bottom coverage could be explained by the fact that the TiN deposition was surface reaction controlled with an activation energy of ∼1.0 eV. AES analysis revealed the low carbon level (∼18 at. %) in TEMAT-sourced TiN films, which was ∼2× lower than that in TiN films prepared from tetrakis(diethylamido)titanium (TDEAT). We proposed the possible reaction mechanism responsible for the low carbon contents in the films, based on the byproduct gases detected by quadrupole mass spectrometer (QMS). TEMAT also produced better crystalline and less air-reactive films than tetrakis(dimethylamido)titanium (TDMAT). Consequently, the TEMAT compound can be a promisint precursor for MOCVD TiN.