Tantalum oxide films were deposited on Si substrates by chemical vapor deposition using the precursor Ta[N(CH3)2]5, and an oxidizing agent—O2, H2O, or NO. Temperatures ranged between 400 and 500 °C and total pressures between 10−3 and 9 Torr. NO did not lead to satisfactory film growth rates. Insignificant (<1 at. %) N and up to a few percent C are incorporated when O2 is the oxidant and the total pressure is in the Torr regime. In the milliTorr regime, the Ta2O5 films, grown using either O2 or H2O, contain readily detectable amounts of C and N. For the films grown with O2 in the Torr regime, leakage currents were significantly lowered when the flow rate of O2 increased from 100 to 900 sccm.

Investigation and modeling of the electrical properties of metal-oxide-metal structures formed from chemical vapor deposited Ta 2 O 5 films

We have studied the thermal growth chemistry and bonding structure of three promising ultrathin (5–20Å), nitrogen rich passivation layers on Si(100), namely-Si3N4, NO/Si(100) grown oxynitride and NO annealed SiO2. These films are intended to serve as substrates with excellent diffusion barrier/interface properties during deposition of high- K dielectrics such as Ta2O5, with tSiO2 equivalent <30Å for ULSI applications. In this paper we show that it is possible to form films with a tailored composition and nitrogen profile using techniques that can easily be integrated with existing silicon processing technology. Alternating growth and surface analysis by X-Ray Photoelectron Spectroscopy (XPS) is used to non destructively characterize the growth.