Latent Reliability Degradation of Ultrathin Amorphous HfO2 Dielectric After Heavy Ion Irradiation: The Impact of Nano-Crystallization

The reliability degradation of HfO
₂
-based devices under heavy ion irradiation is still an open question. In this letter, the ultrathin amorphous HfO
₂
gate stacks were irradiated by different types of swift heavy ions (SHIs). The fine structure of latent track in amorphous HfO
₂
is crystalline phase along the particle trajectory. The effects of latent track on the electrical properties were characterized by the high frequency capacitance-voltage (C-V) and the leakage current density-voltage (J-V) measurements. The quantitative relationship between microstructure changes and electrical properties provides a new method to estimate the threshold of the electronic energy loss ((dE/dx)
_e
) for crystallization and allows for prediction of device sensitivity to SHIs irradiation.