Low frequency noise characterization of TaSiN/HfO2 MOSFETs below room temperature

摘要

Low frequency noise characteristics are presented for TaSiN/HfO2/SiO2 n-MOSFETs in the 78-300K range. The general validity of the carrier number /correlated mobility fluctuations as the underlying noise mechanism at low temperatures was confirmed. The temperature independence of normalized noise implied that phonon scattering has no affect on high-k device noise. The dielectric trap density extracted using Unified Flicker Noise Model varied by an order of magnitude in the considered temperature range that is self-contradictory. Modifications are hereby proposed to the unified model that account for the non-uniform trap profile among other physical properties of dielectric materials in the gate stack. The new multi-stack unified noise (MSUN) model is shown to be in good agreement with the experimental data.