Abstract
We developed a low-pressure chemical vapor deposition (LPCVD) TaNx system and deposited TaNx films as diffusion barriers, the films were grown at the temperature of 400~450℃ using tantalum pentabromine (TaBr5), ammonia (NH3) as co-reactants, and argon (Ar) as the carry gas of TaBr5. The TaNx films were observed by scanning electron microscopy (SEM) to find out the thickness.I-V curve were used to measure the resistivity. A we used glazing angle x-ray diffraction (XRD) to realize the crystalline structure. The depth profiles were analyzed using Auger electron spectrometry (AES) in order to understand the films composition .To studied the thermal stability, we constructed the MOS (Cu/TaN/PEoxide/Porous/Si) capacitors and the capacitors were annealed in nitrogen ambient at the temperature from 350-500℃ for 30 minutes for the thermal stability。 From XRD,Ta3N5(200),(220),(320),(311),and(002) crystalline structures, can be observed in the film deposited at 450℃ with 25 minutes. The amorphous structure formed at deposited temperature 400℃ with 20 minutes. The resistivity increases with the temperature. As the thickness reduces, the resistivity increases. It might be related to the grain size and composition of film. For thermal stability study, the TaN thin film are stable at 400~450℃ from C-V measurement.