Radiation Effects in MOS Oxides

TLDR

Electronic devices in space environments contain various oxides and insulators that accumulate ionizing radiation–induced charge, leading to threshold voltage shifts, increased leakage currents, and device failure, with total‑dose effects dominated by oxide‑trapped and interface‑trap charges in parasitic field and SOI buried oxides. Researchers have examined hafnium oxides and reoxidized nitrided oxides as silicon‑oxide replacements, while heavy ions can also damage oxides via single‑event gate rupture, reduced device lifetime, and large voltage shifts in power MOSFETs. In advanced technologies employing alternate dielectrics, radiation‑induced voltage shifts are negligible, suggesting improved total‑dose tolerance.

Abstract

Electronic devices in space environments can contain numerous types of oxides and insulators. Ionizing radiation can induce significant charge buildup in these oxides and insulators leading to device degradation and failure. Electrons and protons in space can lead to radiation-induced total-dose effects. The two primary types of radiation-induced charge are oxide-trapped charge and interface-trap charge. These charges can cause large radiation-induced threshold voltage shifts and increases in leakage currents. Two alternate dielectrics that have been investigated for replacing silicon dioxide are hafnium oxides and reoxidized nitrided oxides (RNO). For advanced technologies, which may employ alternate dielectrics, radiation-induced voltage shifts in these insulators may be negligible. Radiation-induced charge buildup in parasitic field oxides and in SOI buried oxides can also lead to device degradation and failure. Indeed, for advanced commercial technologies, the total-dose hardness of ICs is normally dominated by radiation-induced charge buildup in either parasitic field oxides and/or SOI buried oxides. Heavy ions in space can also degrade the oxides in electronic devices through several different mechanisms including single-event gate rupture, reduction in device lifetime, and large voltage shifts in power MOSFETs.