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 SiO2 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.

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TiN films were prepared using a new Ti precursor, tetrakis(ethylmethylamido)titanium (TEMAT) and ammonia. The premixing of NH3 and TEMAT provided the control over the gas phase reaction of the two reactants to generate the intermediates required for the deposition of high-quality TiN films. Film resistivities of 800–1200 µ Ω-cm and low levels of impurities were obtained in TiN films deposited under the condition of low NH3/TEMAT ratios, wafer temperature of 350°C and total reactor pressure of 1 Torr. In addition, the introduction of a small amount of ammonia improved the diffusion barrier property for Cu metallization up to 600°C. Slight degradation in the conformality of TiN films was observed at the low ratio of NH3/TEMAT. Furthermore, the addition of NH3 tended to improve the surface morphology of TiN films and did not cause any particle generation due to the low process pressure of 1 Torr. X-ray photoelectron spectroscopy (XPS) analysis revealed the role of ammonia in the homogeneous reaction.

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