BESS - A SOURCE STRUCTURE THAT FULLY SUPPRESSES THE FLOATING BODY EFFECTS IN SOI CMOSFETS

The most serious problem preventing the widespread use of SOI CMOSFET' s-the floating body effects-are almost fully suppressed by a new sourc e structure. Ln an nMOSFET, this new structure can be represented by a n equivalent circuit of a bipolar embedded source structure (BESS) jus t beneath the n(+) source junction, Zn the source region, or p-type (o r n(-)-type) recombination centers are embedded in a low-impurity-diff usion region (the base) and acts as a collector of the excess body car riers. The low-impurity-source region lowers the diffusion potential b arrier for holes at the source junction. The solid-phase epitaxial reg rowth mechanism of the Si+ implanted amorphous SOI layer was studied a nd applied to fabricate a prototype of this device capable of symmetri c source-drain operations with the same source-drain breakdown voltage as that of a bulk device.