Total ionizing dose (TID) radiation response of the custom bandgap voltage reference (BGR) fabricated with 65 nm, 40 nm and 28 nm commercial bulk CMOS technologies is investigated. TID response is assessed employing Co-60 gamma ray source. The measurements indicate that the voltage reference is reduced by 5.67% in 28 nm, 0.56% in 40 nm and increased by 1.28% in 65 nm devices under irradiation up to 1.2 Mrad(Si) TID. After 48 hours of annealing, the voltage reference changes are just -1.84% in 28 nm, 0.14% in 40 nm and 1.14% in 65 nm. The obtained results demonstrate that the custom BGR has naturally superior TID response due to the circuit design margins.

Based on three-dimensional (3D) technology computer aided design (TCAD) simulations, the supply voltage and temperature dependence of single-event transient (SET) pulse width in 28-nm fully-depleted silicon-on-insulator (FDSOI) metal-oxide-semiconductor field-effect transistors (MOSFETs) is investigated. FDSOI MOSFETs are symmetry devices with a superior control of the short channel effects (SCEs) and single-event effects (SEEs). Previous studies have suggested that the SET width is invariant when the temperature changes in FDSOI devices. Simulation results show that the SET pulse width increases as the supply voltage decreases. When the supply voltage is below 0.6 V, the SET pulse width increases sharply with the decrease of the supply voltage. The SET pulse width is not sensitive to temperature when the supply voltage is 1 V. However, when the supply voltage is 0.6 V or less, the SET pulse width exhibits an anti-temperature effect, and the anti-temperature effect is significantly enhanced as the supply voltage drops. Besides, the mechanism is analyzed from the aspects of saturation current and charge collection.

A fault-tolerant hardening-by-design frequency divider has been proposed for clock and data recovery in a 28-nm CMOS process. By means of the mandatory updating mechanism, the proposed divider can update the state of the D flip-flops from an error state to a correct state so as to avoid single-event transient (SET) accumulation in different finite-state machines (FSMs). Our proposed divider also does not destroy the original structure and can, thus, greatly reduce performance degradation. Laser tests show that the threshold of the proposed divider can be significantly improved. The heavy-ion experiment shows good SET/single-event upset (SEU) tolerance during the ion strike under 83.7 MeV·cm ² /mg.

In analog circuit design, the bulks of MOSFETs can be tied to their respective sources to remove body effect. This paper models and analyzes the sensitivity of single-event transients (SETs) in common source (CS) amplifier with bulk tied to source (BTS) in 40 nm twin-well bulk CMOS technology. The simulation results present that the proposed BTS radiation-hardened-by-design (RHBD) technique can reduce charge collection and suppress the SET induced perturbation effectively in various input conditions of the circuit. The detailed analysis shows that the mitigation of SET is primarily due to the forward-bias of bulk potential. This technique is universally applicable in radiation-hardening design for analog circuits with negligible penalty.