Radiation induced depassivation of latent plasma damage

The radiation impact on antenna devices can give new insights on basic mechanisms underlying the latent plasma damage nature and radiation hardness of commercial CMOS technologies for space applications. When MOS structures are exposed to ionizing radiation, electron-hole (e/sup -/-h/sup +/) pairs are created along the track of the incident particle. Some fraction of these e/sup -/-h/sup +/ pairs will recombine, and that fraction is a function of the oxide material, the kind of radiation, and the applied oxide electric field. In general, thinner oxides are less prone to radiation effects than thicker ones; applied bias permits to investigate (modulate) the trap creation in the bulk oxide and at the interface. In this study X-rays and e-beam sources have been considered. Although an e-beam LINAC with 8 MeV electrons is a standard source for radiation hardness characterization, its use is difficult for irradiating wafer with a large diameter. On the other side, fully automated protestations with X-ray tubes are commercially available. As a fair comparison, for a given dose and SiO/sub 2/ oxide technology, X-rays usually have a larger detrimental impact on MOSFET I-V characteristics with respect to the e-beam. Electrical stresses reactivate the latent plasma damage as well as ionizing radiation, but fewer studies have addressed the latter aspect and most of them date back to the older MOS technologies of the 70's and 80's. More recently, plasma damage reactivation in a 17.5- nm oxide due to ionizing, radiation has been addressed. The rapid evolution of plasma equipments and MOS technologies, such as the reduction of the gate oxide thickness well below 10 nm and the increase of the metal levels, suggests extending this investigation to more recent CMOS generations. This has been the purpose of this work, which is concentrated on the latent damage reactivation induced by ionizing radiation on a commercial 0.35 /spl mu/m (t/sub ox/=7 nm) CMOS technology.