Investigation of Buried-Well Potential Perturba-tion Effects on SEU in SOI DICE-based Flip-Flop Under Proton Irradiation

The effects of buried-well potential pertur-bation under the BOX layer are studied in both a heavy ion SEU test and a high-energy proton-SEU test of an SOI DICE-based flip-flop. Their dependence on incident angle and back bias is discussed. We fabricated both DICE-based flip-flop and conventional flip-flop, which are designed as 80,000-stage shift-register chains. In a heavy ion test, considerable numbers of SEUs were ob-served at back bias exceeding 2.4 V, and a 10-times larger SEU-cross-section was finally recorded at back bias of 3.0 V compared with the total active area of a DICE-based flip-flop cell. This marks the first case where DICE topology was found to be broken by buried-well potential perturbation on an SOI DICE-based flip-flop. In a pro-ton test, one error was observed at back bias of 2.0 V. The SEU rate in the Van-Allen belt at an altitude of 2,300 km and an inclination of 90 degrees was estimated as be-ing once every five years.