Total Ionizing Dose Effects on Strained Ge pMOS FinFETs on Bulk Si

Abstract

We have characterized the total ionizing dose response of strained Ge $p$ MOS FinFETs built on bulk Si using a fin replacement process. Devices irradiated to 1.0 Mrad(SiO₂) show minimal transconductance degradation (less than 5%), very small $\text {V}_{th}$ shifts (less than 40 mV in magnitude) and very little ON/OFF current ratio degradation (<5%), and only modest variation in radiation response with transistor geometry (typically less than normal part-to-part variation). Both before and after irradiation, the performance of these strained Ge $p$ MOS FinFETs is far superior to that of past generations of planar Ge $p$ MOS devices. These improved properties result from significant improvements in processing technology, as well as the enhanced gate control provided by the strained Ge FinFET technology.