Radiation effects in gate-all-around structures

Gate-all-around (GAA) devices have been characterized by current vs. voltage techniques after being exposed to 10-keV X-rays under a variety of bias conditions. Parameters such as mobility, oxide trapped charge, interface state density, and leakage currents were monitored. The SIMOX (separation by implanted oxygen) GAA device, which has no buried-oxide back-gate, suffers no contribution from traditional back-gate interface effects. The interface state density, as determined from subthreshold slope stretch-out at a 1 Mrad(SiO₂) X-ray dose, indicates radiation induced D_it levels of low to mid 10¹¹ #/eV-cm² for the variety of bias conditions applied. The observed degradation in mobility and interface-state density is a function of the specific gate-oxide process used and not inherent to the GAA process