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Proton irradiation is used to probe the physics of 4H-silicon carbide (SIC) Schottky barrier diodes (SBDs) and negative channel metal oxide semiconductor (nMOS) capacitors for the first time. Both 4H-SiC SBD diodes and SiC MOS structures show excellent radiation tolerance under high-energy, high-dose proton exposure. Unlike for SiC JBS diodes, which show a strong increase in series resistance after proton irradiation, these SiC SBDs show very little forward bias I-V degradation after exposure to 63.3 MeV protons up to a fluence of 5 x [10.sup.13] p/[cm.sup.2]. An improvement in reverse leakage current after irradiation is also observed, which could be due to a proton annealing effect. The small but observable increase in blocking voltage for these SiC SBDs is attributed to a negative surface charge increase, consistent with earlier gamma results. The resultant [Q.sub.eff] change of 4H-SiC nMOS capacitors under proton irradiation was used to quantify the radiation induced changes to the blocking voltage in the SBD diodes in MEDICI simulations, and showed a good agreement with the experimental data. Characterization of these capacitors also suggests that 4H-SiC MOS structures are radiation hard. Index Terms--Negative channel metal oxide semiconductor (nMOS) capacitors, Schottky barrier diodes (SBDs).

The effects of proton irradiation on the static (dc) and dynamic (switching) performance of high-voltage 4H-SiC Junction Barrier Schottky (JBS) diodes are investigated for the first time. In contrast to that observed on a high-voltage Si p--i--n diode control device, these SiC JBS devices show an increase (degradation) in series resistance ([R.sub.s]), a decrease (improvement) of reverse leakage current, and increase (improvement) in blocking voltage after high-fluence proton exposure. Measured breakdown voltages of post-irradiated SiC diodes increase on average by about 200 V after irradiation. Dynamic reverse recovery transient measurements show good agreement between the various dc observations regarding differences between high-power SiC and Si diodes, and show that SiC JBS diodes are very effective in minimizing switching losses for high-power applications, even under high levels of radiation exposure. Index Terms--Diode, junction barrier Schottky (JBS), proton radiation, Schottky barrier diodes (SBD), silicon carbide (SIC).

The effects of radiation on high-voltage 4H-SiC Schottky diodes for use in extreme environment power supplies are investigated for the first time. Diodes were fabricated with a wide range of barrier heights (1.06-1.60 eV) and were evaluated after being exposed to a [sup.60]Co gamma radiation source. DC current-voltage characteristics were measured after several radiation doses, with no observable degradation in the diode forward or reverse characteristics up to a total dose of 4 Mrad(Si). Measured breakdown voltages of postirradiated diodes increase approximately 200 V compared to the virgin devices and are attributed to increased negative interface charge, as determined by MOS capacitor measurements and correlated with numerical breakdown simulations. Index Terms--Diodes, gamma radiation, Schottky barrier, silicon carbide (SIC).

Proton irradiation is used to probe the physics of 4H-silicon carbide (SiC) Schottky barrier diodes (SBDs) and negative channel metal oxide semiconductor (nMOS) capacitors for the first time. Both 4H-SiC SBD diodes and SIC MOS structures show excellent radiation tolerance under high-energy, high-dose proton exposure. Unlike for SiC JBS diodes, which show a strong increase in series resistance after proton irradiation, these SiC SBDs show very little forward bias I-V degradation after exposure to 63.3 MeV protons up to a fluence of 5 × 1013 p/cm2. An improvement in reverse leakage current after irradiation is also observed, which could be due to a proton annealing effect. The small but observable increase in blocking voltage for these SiC SBDs is attributed to a negative surface charge increase, consistent with earlier gamma results. The resultant Qeff change of 4H-SiC nMOS capacitors under proton irradiation was used to quantify the radiation induced changes to the blocking voltage in the SBD diodes in MEDIC! simulations, and showed a good agreement with the experimental data. Characterization of these capacitors also suggests that 4H-SiC MOS structures are radiation hard. [ABSTRACT FROM AUTHOR]

The effects of proton irradiation on the static (dc) and dynamic (switching) performance of high-voltage.. 4H-SiC Junction Barrier Schottky (JBS) diodes are investigated for the first time. In contrast to that Observed on a high-voltage Si p - i -n diode control device; these sic JBS devices show a increase (degradation) in series resistance (Rs), a decrease (improvement) of reverse leakage current, and increase (improvement) in blocking voltage after high-fluence proton exposure. Measured breakdown voltages of post-irradiated SiC diodes `increase on average by about 200 V after irradiation. Dynamic reverse recovery transient measurements show good agreement, between the, various dc observations regarding differences between high-power SiC and Si diodes, and show that SiC JBS diodes are very effective in minimizing switching losses for high-power applications, even under high levels of radiation exposure. [ABSTRACT FROM AUTHOR]