A semiconductor structure which includes a semiconductor on insulator (SOI) substrate. The SOI substrate includes a base semiconductor layer; a buried oxide (BOX) layer in contact with the base semiconductor layer; and an SOI layer in contact with the BOX layer. The semiconductor structure further includes a circuit formed with respect to the SOI layer, the circuit including an N type field effect transistor (NFET) having source and drain extensions in the SOI layer and a gate; and a P type field effect transistor (PFET) having source and drain extensions in the SOI layer and a gate. There may also be a well under each of the NFET and PFET. There is a nonzero electrical bias being applied to the SOI substrate. One of the NFET extensions and PFET extensions may be underlapped with respect to the NFET gate or PFET gate, respectively.