Highly conductive and conformal hafnium nitride (HfNx) thin films were prepared by plasma-assisted atomic layer deposition using tetrakis(dimethylamido)hafnium and hydrogen plasma. The effects of deposition temperature, plasma pulse time, radio frequency power, and the N-2/H-2 ratio on the electrical characteristics of the films were investigated. The growth rate (thickness/cycle) was in the range of 0.85-1.45 nm/cycle, and the resistivity of the films varied from 4.0 to 1500 x 10(3) mu Omega cm, depending on the deposition conditions. Higher deposition temperature combined with higher power and longer exposure time of the hydrogen plasma was effective in decreasing the film resistivity. (c) 2006 The Electrochemical Society.