Fin Width and Bias Dependence of the Response of Triple-Gate MOSFETs to Total Dose Irradiation

The total ionizing dose response of triple-gate MOSFETs is investigated for various fin widths and bias conditions. Experiments and simulations are used to analyze the buildup of trapped charge in the buried oxide and its impact on the threshold-voltage shift and subthreshold-slope degradation. The higher total-dose tolerance of multiple-gate FinFETs with narrow fins is attributed to lateral gate control over the electrostatic potential in the body and especially at the Si fin/BOX interface. It is demonstrated that ON-state irradiation is the worst-case bias configuration for triple-gate MOSFETs through extensive experimental analysis.