Dan Gealy

Frenkel-Poole trap energy extraction of atomic layer deposited Al2O3 and HfxAlyO thin films

Frenkel-Poole (FP) trap energies of atomic layer deposited Al2O3 and HfxAlyO thin films with various Hf∕Al compositions have been extracted. Using a method based on the field and temperature dependence of FP conduction, intrinsic trap energies under zero electric field can be extrapolated. Results indicate that FP trap energies increase from 0.56to1.48eV when adding more and more Al to HfO2. The trap energy seems to be inversely proportional to the square of the dielectric constant of the film, suggesting that traps may originate from the same type of defect, whose energy level is mediated by the dielectric constant.

Correlation Between the

The change of the energy profile of the initially present HfSiO defects in nMOSFETs after Vth adjustment by As and Ar implantations is investigated. A fundamental correlation between the density of energetically deep traps and the initial Vth is revealed, suggesting that the negative bulk charge in HfSiO controls the Vth.