Hafnium oxide gate stack prepared by in situ rapid thermal chemical vapor deposition process for advanced gate dielectrics

A high-quality HfO2 gate stack with equivalent oxide thickness (EOT) of 7.8 Angstrom and a leakage current of J(g)=0.5 mA/cm(2) @ V-g=-1.0 V has been achieved by an in situ rapid thermal chemical vapor deposition process. It is found that both NH3-based interface layer and N-2 postdeposition annealing are very effective in reducing EOT and leakage, and at the same time, improving film qualities. These HfO2 gate stacks show negligible frequency dependence, small hysteresis in capacitance-voltage (C-V) and weak temperature dependence of the leakage current. They also show negligible charge trapping at high voltage stress. (C) 2002 American Institute of Physics.