Development of a radiation tolerant 1M SRAM on fully-depleted SOI

1M SRAMs were fabricated on fully-depleted SOI using 0.5 um design rules. The SRAMs were evaluated for speed/power, prompt dose upset, SEE, and total dose hardness. As compared to the identical design fabricated on bulk CMOS, improved results were seen for performance and prompt dose hardness. On the other hand, a low n-channel snapback voltage degraded the standby leakage, total dose hardness, and SEU hardness. The total dose hardness was expectedly low since no attempt was made to harden the buried oxide for this evaluation. This effort reflects the most complicated circuit reported on fully-depleted SOI.