The effects of α-particle-induced parasitic bipolar current on soft errors in submicron 6-transistor SOI SRAMs were numericaly studied. It was shown that the bipolar current induces soft errors and that there exists a critical quantity which determines the soft error occurrence in the SOI SRAMs. Simulated soft error rates were in the same order as those for bulk SRAMs.

We propose and fabricate n+-p+ double-gate SOI MOSFETs for which threshold voltage is controlled by interaction between the two gates. Devices have excellent short channel immunity, dispite a low channel doping concentration of 1015 cm-3, and enable us to design a threshold voltage below 0.3 V while maintaining an almost ideal subthreshold swing. We demonstrated 27 ps CMOS inverter delay with a gate length of 0.19 µm, which is, to our knowledge, the lowest delay for this gate length despite rather a thick 9 nm gate oxide. This high performance is a result of the low threshold voltage and negligible drain capacitance. We also showed theoretically that we can design a 0.1 µm gate length device with an ideal subthreshold swing, and that we can expect less than 10 ps inverter delay at a supply voltage of 1 V.