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Experimental heavy-ion responses of 3-kV charge-balanced (CB) SiC power devices are compared with those of 3.3-kV planar SiC devices. The devices are similar, except the epitaxial region of the CB devices is heavily doped compared with the planar devices. The higher doping in the epitaxial region results in loweron-resistance, but typically leads to a lower threshold drain voltage at which single-event burnout (SEB) occurs. The experimental results demonstrate, however, that the CB devices have a similar SEB threshold to the planar devices due to the improved electric field distribution.

Commercial Schottky-gate AlGaN/GaN high-electron-mobility transistors (HEMTs) exhibit a large peak in low-frequency (LF) noise magnitude at $\sim $ 325 K. An activation energy of 0.56 ± 0.05 eV is determined for the responsible generation–recombination (G–R) center via Arrhenius analysis. Comparisons with first-principles calculations and complementary experimental studies show that this G–R center is due to substitutional iron impurities, FeGa. Independent determination of the activation energy for this prominent noise peak enables recalibration of the Dutta–Horn model of LF noise for GaN-based HEMTs and a downward revision by $\sim $ 20% of past LF-noise estimates of effective defect energies. The resulting LF-noise-derived defect-energy distributions are consistent with deep-level-transient spectroscopy (DLTS) measurements on GaN-based diodes before and after 1.8-MeV proton irradiation. The activation of FeGa-related centers via defect dehydrogenation during high-voltage stress is demonstrated via LF noise measurements on AlGaN/GaN-on-SiC HEMTs.

This article presents a circuit design for measuring and emulating radiation-induced photocurrent pulses in dense, highly scaled integrated circuits (ICs) and experimental results from an implementation in a 45-nm partially depleted silicon-on-insulator (PD-SOI) process. This photocurrent measurement circuit (PMC) expands upon other work by introducing new capabilities and measurement procedures, including a method for capturing arbitrarily long pulses and an arbitrary-waveform generator (AWG) that enables flexible built-in self-test (BIST) capabilities as well as emulation of transient radiation events. Experimental PMC measurements of currents generated by flash X-ray irradiation, pulsed-laser irradiation, and AWG emulation show excellent agreement and are corroborated by technology computer-aided design (TCAD) simulations; in particular, AWG recreations of experimental flash X-ray photocurrent responses match the original data with as little as 1.375% mean absolute percentage error (MAPE). Comparisons of different transistor structures also indicate a relatively insignificant photocurrent response in body-tied devices, suggesting that floating body effects are a dominant factor for this process. Holistically, these results demonstrate the efficacy of the PMC.

Single-event burnout (SEB) and single-event leakage current (SELC) behavior of 1200 and 3300 V silicon carbide (SiC) power devices are analyzed based on heavy-ion irradiation tests. Both SEB and SELC degradation thresholds are improved in the 3300 V devices by at least 300 V compared to the 1200 V devices. Additionally, it was demonstrated that the measured SEB threshold is a strong function of the device bias and irradiation history and that bias and irradiation steps at intermediate voltages between the charge collection region and SEB region can result in parametric failure from accumulated leakage current rather than catastrophic failure by burnout.

The properties of defects in n-p-n Si bipolar junction transistors (BJTs) caused by 17-MeV Si ions are investigated via current–voltage, low-frequency (LF) noise, and deep level transient spectroscopy (DLTS) measurements. Four prominent radiation-induced defects in the base–collector junction of these transistors are identified via DLTS. At least two defect levels are observed in temperature-dependent LF 1/f noise measurements, one that is similar to a prominent defect in DLTS and another that is not. Defect microstructures are discussed. Our results show that DLTS and 1/f noise measurements can provide complementary information about defects in linear bipolar devices.

A re-evaluation of experimental results within the context of first-principles calculations strongly suggests that interface traps can contribute significantly to low-frequency (1/ $f$ ) noise in irradiated MOS devices. Hydrogen-induced trap activation and passivation are likely origins of the observed fluctuations. Measured and calculated activation energies for hydrogen drift, diffusion, and dissociation are consistent with energetics of 1/ $f$ noise. The dominant noise source is determined by densities of relevant defect precursors, hydrogen concentrations, device processing, and history. When present, hydrogen-induced interface-trap activation and passivation adds to noise due to border traps. These results should help assess and assure the performance and reliability of analog integrated circuits in high radiation environments.

Total-ionizing-dose (TID) effects are evaluated in top-gated IGZO thin-film transistors (TFTs) irradiated with different gate biases. Negative-bias irradiation leads to worst case degradation of TID response, primarily due to enhanced charge trapping in the SiO2 insulator that underlies the IGZO channel and serves as an oxygen-penetration layer during device processing. TID response comparisons with back-gated devices indicate that hydrogen also plays an important role in the observed degradation of top-gated devices. The source of this hydrogen is most likely SiN oxygen blocking layers. Comparisons with other display and alternative-channel MOS technologies illustrate that further optimization should enable the use of IGZO in future space applications.

Device-level failure probabilities derived from historical, similar radiation datasets can be inputted into a system-level radiation reliability model to provide insight into that system’s failure probability. A linear voltage regulator reliability model that utilizes historical total ionizing dose (TID) [< 100 krad(SiO2)] and displacement damage dose (DDD) measurements ( $ &lt; 9\times 10^{11}$ equivalent 1-MeV neutrons/cm2) is used as a demonstration system. This methodology aims to reduce engineering uncertainty at early design stages before radiation test data are available or on quick turn-around projects without radiation test budgets.

Total-ionizing-dose (TID) effects are evaluated in back-gated indium–gallium–zinc oxide (IGZO) thin-film transistors irradiated under different gate biases. Negative-bias irradiation leads to worst-case degradation of TID response in these devices, primarily as a result of enhanced charge trapping in the SiO2 overlayer. The relatively small peak transconductance decrease after irradiation illustrates that IGZO transistors are much less sensitive to interface-trap buildup and other instabilities due to hydrogen release and transport than amorphous Si thin film transistors examined previously. The TID response of devices with different gate sizes is also investigated. No significant geometry dependence is observed, which is promising for future scaling down of the technology.

Total-ionizing-dose (TID) effects in AlGaN/GaN high-electron-mobility transistors (HEMTs) are evaluated by dc and low-frequency noise measurements. Devices with and without passivation layers are irradiated with 10-keV X-rays up to 100 Mrad(SiO2) under different bias conditions. Irradiated devices show significant electrical shifts in threshold voltage and transconductance. At doses < 10 Mrad(SiO2), the TID-induced effects are related to the passivation of preexisting acceptor-like defects via hole capture, which induces negative threshold voltage shifts and improvement of transconductance. At doses $>$ 10 Mrad(SiO2), dehydrogenation of defects and impurity complexes leads to the creation of acceptor-like defects, which degrade the transconductance, shift positively the threshold voltage, and increase the low-frequency noise. Effects are enhanced in unpassivated devices and when the gate is biased at high voltage.

Total-ionizing-dose (TID) responses are investigated for fully depleted silicon-on-insulator (FDSOI) ring oscillators (ROs) in 3-D architectures. Operational frequencies decrease after irradiation in these devices due primarily to threshold voltage shifts and transconductance degradation due to interface-trap buildup in the pull-up $p$ MOSFETs. 3-D sequentially integrated FDSOI ROs fabricated in the bottom layer of the 3-D structure show the most significant frequency degradation. The ac-bias irradiation leads to greater shifts than static-bias irradiation in these devices due to enhanced interface-trap buildup. Circuit simulations reinforce the relative importance of transconductance degradation in pull-up $p$ MOSFETs to the TID response of these ROs.

Total ionizing dose (TID) irradiation and low-frequency noise characterization are performed on carbon nanotube field-effect transistors (CNTFETs). Large hysteresis due to high border-trap densities is observed in as-processed and irradiated devices. TID irradiation also leads to significant radiation-induced charge trapping in the surrounding dielectrics resulting in parametric degradation. Percolation-path switching and border traps contribute to low-frequency noise, with a relatively more prominent role for border traps after irradiation than before irradiation. These results show that process improvements are required to optimize both the initial operating characteristics and the radiation response of CNTFETs.

Negative bias-temperature instabilities and low-frequency noise are investigated in strained Ge ${p}$ MOS FinFETs with SiO textsubscript 2/HfO textsubscript 2 gate dielectrics. The extracted activation energies for NBTI in Ge ${p}$ MOS FinFETs are smaller than for Si ${p}$ MOSFETs. Low-frequency noise magnitudes at lower temperatures are unaffected by negative-bias-temperature stress (NBTS), but increase significantly for temperatures above $\sim 230$ K. The increased noise due to NBTS is attributed primarily to the activation of oxygen vacancies and hydrogen-related defects in the SiO2 and HfO2 layers.

Effects of programming/erasing (P/E) and total-ionizing dose (TID) are investigated on 2- and 40-fin charge-trap transistors (CTTs) fabricated in a 14-nm bulk-Si CMOS technology. Significant random telegraph noise (RTN) is observed in as-processed CTTs, especially for 2-fin devices. Trapped charge in programed devices does not significantly affect 1/ ${f}$ noise magnitudes, but P/E leads to trap activation/deactivation, causing changes in border-trap energy and spatial distributions. TID irradiation activates a large number of stable radiation-induced traps.

The effects of geometry and cycling are evaluated for charge-trapping NAND memory devices with SiON tunneling layers. Processing splits include SiON tunneling layers with and without $\text{H}_{2}/\text{D}_{2}$ high-pressure annealing. Programed and erased devices were irradiated up to 500 krad(SiO2) with 10-keV X-rays. Excellent retention and endurance are demonstrated for these devices before and after irradiation. Scaling devices to smaller dimensions enhances program/erase efficiency and radiation tolerance.

The temperature dependence of low-frequency noise is investigated from 80 to 320 K for nMOS and pMOS bulk Si FinFETs with SiO2/HfO2 gate dielectrics. Both types of devices show excellent stability during bias-temperature stress and high total-ionizing dose (TID) irradiation. nMOSFET 1/ $f$ noise generally decreases as measuring temperature increases, with three prominent individual defect-related peaks. These peaks in noise magnitude are most likely due to hydrogen shuttling near the interface and/or O vacancies in the HfO2. In contrast, the 1/ $f$ noise in pMOSFETs generally increases with increasing temperature without prominent peaks in noise magnitude. The gate-voltage dependence of low-frequency noise also is evaluated at different temperatures for both device types. Results confirm that the nMOS devices have effective border-trap energy distributions that are nonuniform and generally increase toward midgap, and the pMOS devices have more uniform defect-energy distributions that increase monotonically toward the valence band.

Experimental heavy-ion responses of silicon carbide (SiC) junction barrier Schottky (JBS) diodes are presented. Measured data indicate that heavy ions having range less than the epitaxial thickness do not cause degradation or catastrophic failure, even with the device biased above the rated breakdown voltage. Measured data also indicate that when the heavy ions have range longer than the epitaxial layer thickness, the devices exhibit degradation as single-event leakage current (SELC), as well as catastrophic single-event burnout (SEB) at biases less than half of the rated breakdown voltage. Device failure was observed when irradiating with high-energy ions having long ranges, but not when irradiating with low-energy ions that stop in the epitaxial layer. Mechanisms of observed heavy-ion effects are examined with technology computer aided design (TCAD) device modeling.