Optical and electrical characterization of hafnium oxide deposited by MOCVD

The paper reports on electrical and optical investigations performed on HfO2 high-k films deposited by Metal-organic chemical vapor deposition (MOCVD). Spectroellipsometry investigations show the presence of a transition layer between HfO2 and the silicon substrate, which can be optically modelled as a mixture of Si and SiO2; this information is further used in the assessment of the electrical measurements. Hysteresis effects have been observed in the Capacitance-Voltage (C-V) measurements for the as-deposited sample as well as the annealed samples. For the samples with large hysteresis, Poole-Frenkel (PF) conduction is the most likely dominant conduction mechanism. The energy of dominant trap level was found to be ∼0.7 eV.