Characterization of single-event transients induced by high LET heavy ions in 16 nm bulk FinFET inverter chains

Single-event transient (SET) distributions and cross-sections are characterized for 16 nm bulk FinFET inverters with different threshold voltages and driving strengths using the heavy ion 181Ta with the energy of 1.07GeV and the Linear Energy Transfer (LET) of 85 MeV center dot cm2/mg. Lower threshold voltage makes shorter SET pulses and smaller cross-section, and reduces the upper limit of the SET pulse width, which is advantageous to harden the FinFET gates against the high LET heavy ion irradiation. Enhancing the driving strength changes the layout topology, leading to complicated impact on the radiation sensitivity for FinFET inverters. The source region is laid at one side of the drain region in P or N type transistor of the inverter with driving strength X1 (INV1), while there are two source regions at both sides of the drain region in P or N type transistor in the inverter with driving strength X2 (INV2), which makes INV2 is more SET tolerant than INV1. There are interdigitated two drain regions and three source regions in P or N type transistor of the inverter with driving strength X4 (INV4), which expands the sensitive area and cross-section. The test results indicate that the max SET pulse width is approximately proportional to the ratio of sensitive area to driving strength for the FinFET inverters, that is the max SET pulse width of INV4 is between INV1 and INV2.