| 초록 |
Tantalum carbo-nitride (TaCxNy) films were deposited with chemical vapor deposition (CVD) using tert-butylimido tris-diethylamido tantalum (TBTDET, tBu-N=Ta-(NEt2)3, Et=C2H5, tBu=C(CH3)3) between 350°C and 600°C with argon as a carrier gas. Fourier transform infrared (FT-IR) spectroscopy was used to study the thermal decomposition behavior of TBTDET in the gas phase. When the temperature was increased, C-H and C-N bonding of TBTDET disappeared and the peaks of ethylene appeared above 450°C in the gas phase. The growth rate and film density of TaCxNy film were in the range of 0.1nm/min to 1.30nm/min and of 8.92g/cm3 to 10.6g/cm3 depending on the deposition temperature. TaCxNy films deposited below 400°C were amorphous and became polycrystalline above 500°C. It was confirmed that the TaCxNy film was a mixture of TaC, graphite, Ta3N5, TaN, and Ta2O5 phases and the oxide phase was formed from the post deposition oxygen uptake. With the increase of the deposition temperature, the TaN phase was increased over TaC and Ta3N5 and crystallinity, work function, conductivity and density of the film were increased. Also the oxygen uptake was decreased due to the increase of the film density. With the increase of the TaC phase in TaCxNy film, the work function was decreased to 4.25eV and with the increase of the TaN phase in TaCxNy film, it was increased to 4.48eV. |
