Experimental Investigation of the Joint Influence of Reduced Supply Voltage and Charge Sharing on Single-Event Transient Waveforms in 65-nm Triple-Well CMOS

Full waveforms of single-event transients (SETs) in inverter chains were measured under focused heavy-ion microbeam irradiation. Inverter chains of varying spacings were irradiated with
⁴⁸
Ca and
¹⁹⁷
Au ions. The influence of changing the supply voltage from subthreshold to nominal level on SET forming and propagation was investigated, and the role of charge sharing is discussed. Key factors that influence SET widths and cross sections are identified across the applied range of supply voltages. A simple method is presented for estimating average SET widths at decreased supply voltages, and is based on the SET width measurements at nominal supply voltage, transistor-level simulations, and extracted circuit parameters. The proposed method matches well with the measured data.