Hafnium oxide (HfO2) thin films were synthesized from tetrakis(dimethylamino) hafnium (TDMAH) and ozone (O3) by atomic layer deposition (ALD) on 200 mm silicon wafers. Gradual saturation was observed for TDMAH exposure pulse. However O3 showed better saturation behavior for O3exposure. Yet, 100% step coverage was achieved for ~100nm trenches with aspect ratio of 35. Temperature dependence of the deposition rate was studied at susceptor temperature from 160°C to 420°C. The lowest deposition rate was observed at 320°C. Mercury probe measurements indicated the dielectric constant increased from 16 to 20 as susceptor temperature increased from 200°C to 320°C. Selected comparisons with tetrakis (ethylmethylamino) hafnium (TEMAH) were also made.
X. Liu, Dr. Sasangan Ramanathan, and Seidel, T. E., “Atomic layer deposition of hafnium oxide thin films from tetrakis (dimethylamino) hafnium (TDMAH) and ozone”, MRS Proceedings. Cambridge Univ Press, pp. 97-102, 2003.