Pulsed Laser-Induced Single-Event Transients in InGaAs FinFETs with sub-10-nm Fin Widths

The single-event transient (SET) response and charge collection mechanisms are investigated for InGaAs FinFETs on InP substrates with sub-10-nm fin widths through pulsed laser irradiation. The dependences on fin width, $V_{DS}$ and $V_{GS}$ are examined. Consistent with devices with fin widths larger than 10 nm, higher transient peak and greater charge collection are observed in wider fin devices as a result of larger active volumes. The amplitude of the SET and the collected charge also increase with $V_{DS}$ due to the enhancement of electric field along the channel, and decrease as the overdrive voltage increases due to the reduced excess electron density. Charge collection is influenced strongly by the shunt effect from source-to-drain when the laser spot covers the channel region, and the parasitic bipolar effect caused by accumulated holes underneath the channel.