Impact of Back-Gate Radiation on Single-Event Effects of Ultrathin Body and Buried Oxide Fully Depleted Silicon-on-Insulator MOSFETs.

A trajectory comparison method is proposed to study the impact of back-gate radiation on single-event effects (SEE) of ultrathin body and buried oxide (UTBB) fully depleted silicon-on-insulator (FDSOI) MOSFETs using Synopsys Sentaurus technology computer-aided design (TCAD) tools. Based on the series coupling capacitance model of the threshold voltage, the influence of device parameters such as buried oxide (BOX) thickness, ground plane doping and back biasing on the back-gate radiation effect is analyzed. The electrostatic potential difference between the BOX/substrate interface and substrate region decreases due to the reduced width of the substrate depletion region caused by back-gate radiation, leading to a positive shift in the threshold voltage and a decrease in the transient leakage current. The back-gate radiation effect is enhanced with reduced BOX layer thickness and ground-plane doping. UTBB FDSOI devices under reverse back biasing from 0 V to −0.5 V, which expands the depletion region, show a more dramatic decrease in the transient leakage current than those under forward back biasing. The findings contribute to a better understanding of the SEE mechanism of UTBB FDSOI devices and are helpful in radiation hardness optimization. [ABSTRACT FROM AUTHOR]