RADIATION-TOLERANT, SIDEWALL-HARDENED SOI/MOS TRANSISTORS.

Total dose radiation effects were measured for sidewall-hardened n-channel silicon-on-insulator (SOI)/MOS transistors, fabricated in zone-melt-recrystallized (ZMR) and oxygen-implanted (SIMOX) SOI materials. The radiation responses of transistors are compared with three types of sidewall or edge configurations: island transistors with passivated edges, island transistors without passivated edges, and edgeless (enclosed-gate) transistors. Data from these three test devices allow clear separation of front-, back-, and edge-channel conduction. Passivated edge channels were hard to **6**0Co doses in excess of 24 Mrad(Si). The overall hardness of the passivated-edge transistors is limited only by the radiation-induced threshold voltage shifts (about minus 1 V at 1. 0 Mrad) of the top channel. No significant differences in total-dose response of ZMR and SIMOX devices were observed under the radiation conditions used.