The Effects of $\gamma$ Radiation-Induced Trapped Charges on Single Event Transient in DSOI Technology

Abstract

The effects of $\gamma$ radiation-induced positive trapped charges in the top buried oxide layer $\boldsymbol{(\mathrm{Q}_{\text{BOX}1})}$ on the single event transient (SET) response of Double Silicon-On-Insulator (DSOI) transistors are examined for the first time through $\gamma$ radiation and pulsed laser experiments. After $\gamma$ radiation, a significant negative shift of threshold voltage for back-channel is observed for both DSOI NMOS and PMOS due to the $\mathrm{Q}_{\text{BO}\mathrm{X}1}$. The SET current was measured at the device level, and the SET current peak and full width at half maximum (FWHM) were calculated. The impact of $\boldsymbol{\mathrm{Q}_{\text{BOX}1}}$ and back-gate bias on the SET current of the DSOI devices are analyzed in detail. The experiments demonstrate that the SET current of NMOS is enhanced due to the parasitic bipolar transistor (PBT) effect activated by $\boldsymbol{\mathrm{Q}_{\text{BOX}1}}$, which can be mitigated by applying a dynamic back-gate bias. However, the $\boldsymbol{\mathrm{Q}_{\text{BOX}1}}$ inhibits the SET current and PBT for DSOI PMOS. TCAD simulations further validate this physical mechanism, and then the back-gate bias strategy is proposed for DSOI devices and circuits.