New hot-carrier degradation phenomenon in nano-scale floating body MOSFETS

New hot-carrier degradation phenomenon that depends on gate bias in nano-scale floating body MOSFETs is identified using 2-D device simulation and hot-carrier injection measurements. In the case of sufficiently high gate voltage, the potential of the floating body is elevated due to the ohmic voltage drop at the source extension resulting in impact ionization at the source as well as drain junctions. Hot carrier stress with accelerated gate voltage may lead to an incorrect estimation of lifetime in nano-scale floating body MOSFETs.