Random telegraph noise in nanometer-scale CMOS transistors exposed to ionizing radiation

Abstract

Nanometer-scale transistors often exhibit random telegraph noise (RTN) with high device-to-device variability. Recent experiments up to Grad total ionizing dose (TID) demonstrate stable RTN in planar bulk-Si metal-oxide-semiconductor (MOS) transistors and in Si fin field-effect transistors (FinFETs). In these cases, pre-existing defects in the ultrathin gate dielectrics dominate the device low-frequency 1/f noise (LFN). In contrast, III–V MOS devices with lower quality oxide/semiconductor interfaces show significant increases in LFN at much lower doses, due to the TID-induced activation of high densities of border traps. Aggressively scaled devices fabricated in Si gate-all-around nano-wire FET technology exhibit prominent defects leading to LFN and RTN. Increases or decreases of LFN in these devices during irradiation and annealing results primarily from the activation or passivation of border traps and interface traps.