V. Ferletcavrois et al., TOTAL-DOSE EFFECTS ON A FULLY-DEPLETED SOI NMOSFET AND ITS LATERAL PARASITIC TRANSISTOR, I.E.E.E. transactions on electron devices, 44(6), 1997, pp. 965-971
The dose induced threshold voltage shift of fully-depleted NMOS transi
stors is strongly correlated with charge trapping in the buried oxide.
Thinner buried oxides, which are less dose sensitive than thicker one
s, not necessarily improve the radiation hardness of fully-depleted tr
ansistors because of the higher coupling effect, The lateral parasitic
transistor is more affected by the buried oxide charge trapping than
the main active transistor, The lateral and back surface conduction in
the thin part of the mesa edge, increases with ionizing dose and adds
to the front surface conduction, Body tie is the only lateral isolati
on immune to dose effects.