Local Defect Density in Polycrystalline High-k Dielectrics: CAFM-Based Evaluation Methodology and Impact on MOSFET Variability

A methodology to determine with nanometer resolution the defect density in polycrystalline HfO2 layers has been developed. This methodology is based on experimental data measured with conductive atomic force microscopy and the obtained results have been validated using Kelvin prove force microscopy measurements. The local defect density (
_ρox
) and thickness (t
_ox
) of the gate dielectric have been included into a device simulator to evaluate their impact on the I
_D
V
_G
curves of MOSFETs.