Impact of film properties of atomic layer deposited HfO ₂ resulting from annealing with a TiN capping layer

Atomic layer deposited HfO ₂ films void and exhibit poor electrical characteristics when annealed at high temperature unless a TiN capping layer is used. The TiN is removed prior to characterization of the dielectric. The authors find that capped HfO ₂ films annealed at 1000°C by rapid thermal process are smooth and void-free. The microstructure of HfO ₂ is modified from fully monoclinic to a mixed monoclinic and tetragonal phase when the capping layer is used. Conducting atomic force microscopy performed on these films shows fewer areas with high leakage current. Mo/HfO ₂ capacitors show improved CV characteristics and lower leakage current density.