Fluorine passivation in poly-Si∕TaN∕HfO2 through ion implantation

Fluorine (F) passivation in poly-Si∕TaN∕HfO2∕p-Si gate stacks through gate ion implantation has been studied. It has been found that when the TaN thickness was less than 15nm, the mobility and subthreshold swing improved significantly in HfO2 n-channel metal-oxide-semiconductor field effect transistors. Cross-section electron energy loss spectroscopy mapping shows that F atoms were distributed in both TaN and HfO2 layers, indicating that it is necessary to have a thin TaN layer.