TCAD leakage current analysis of a 45 nm MOSFET structure with a high-k dielectric

Abstract

The models of electrophysical effects builtinto Sentaurus TCAD have been tested. The models providing an adequate modeling of deep submicron high-k MOSFETs have been selected. The gate and drain leakage currents for 45 nm MOSFETs with polysilicon gate and SiO₂, SiO₂/HfO₂ and HfO₂ gate dielectrics have been calculated using TCAD. It has been shown that the replacement of the traditional SiO₂ gate oxide by an equivalent HfO₂ dielectric reduces the gate leakage current by several orders of magnitude due to the elimination of the impact of the tunneling effect. Besides, the threshold voltage, saturation drain current, mobility, transconductance, etc., degrade within a range of 10–20%.