Total Ionizing Dose Effects on Triple-Gate FETs

This paper investigates the total ionizing dose response of advanced nonplanar triple-gate transistors with short gate length, as a function of device geometry. Experiments and three-dimensional (3-D) simulations using a radiation dedicated code are used to analyze the buildup of a trapped charge in the buried oxide and its impact on the device electrical characteristics. The behaviors of three prospective nonplanar devices are detailed and compared to the total ionizing dose degradation of a planar fully depleted single-gate architecture. The Omega-gate FET is shown to be the most tolerant to a 500 krad(SiO₂) total dose exposure thanks to the efficient control provided by the lateral gates over the electrostatic potential throughout the Si film and essentially at the Si fin/BOX interface