Heavy-ion data suggest that a common mechanism is responsible for single-event burnout (SEB) in 1200-V power MOSFETs and junction barrier Schottky (JBS) diodes. Similarly, heavy-ion data suggest a ...common mechanism is also responsible for leakage current degradation in both devices. This mechanism, based on ion-induced, highly localized energy pulses, is demonstrated in simulations and shown to be capable of causing degradation and SEB for both the MOSFETs and JBS diodes.
Ion-induced degradation and catastrophic failures in high-voltage SiC junction barrier Schottky power diodes are investigated. The experimental results agree with earlier data showing discrete jumps ...in leakage current for individual ions and show that the boundary between leakage current degradation and a single-event-burnout-like effect is a strong function of linear energy transfer and reverse bias. TCAD simulations show high localized electric fields under the Schottky junction, and high temperatures generated directly under the Schottky contact, consistent with the hypothesis that the ion energy causes eutectic-like intermixture at the metal-semiconductor interface or localized melting of the silicon carbide lattice.
Ion- and terrestrial neutron-induced single-event burnout (SEB) data indicate that a thicker, more lightly doped epitaxial (epi) region significantly increases the threshold at which ion-induced SEB ...occurs in silicon carbide (SiC) power MOSFETs and junction barrier Schottky (JBS) diodes. Simulations indicate that the reduction of power dissipation along the core of the ion track is responsible for the increased robustness of the devices that have higher breakdown voltage ratings. Implications for circuit design show that using a 3300-V power MOSFET provides a significant increase in SEB threshold margin compared to a 1200-V MOSFET, with minor impact on power dissipation during normal operation.
This article presents design for a 650-V super-junction (SJ) power metal-oxide-semiconductor field effect transistor (MOSFET) which improves tolerance to both single-event burnout (SEB) and ...single-event gate rupture (SEGR). Experimental measurements of SEGR in a generic commercial planar gate SJ device are used to validate the accuracy of the design. In an SJ device with a planar gate, reducing the neck width improves the tolerance to gate rupture but significantly changes the electrical device characteristics. The trench gate SJ device design is shown to overcome this problem. A buffer layer and larger P + -plug are added to the trench gate SJ power transistor to improve SEB tolerance. The proposed trench gate structure improves the SEGR survivability by a factor of 10.
This article compares and analyzes the single-event gate rupture (SEGR) response of silicon planar gate super-junction (SJ) power metal oxide semiconductor field effect transistors (MOSFETs) and ...vertical double diffused power MOSFETs (VDMOSs). When an incident heavy-ion strike is perpendicular to the gate oxide, the SEGR tolerances of SJ power MOSFETs (SJMOSs) and VDMOSs are similar. But, for heavy-ion strikes that are at different angles, SJMOS has better SEGR tolerance than VDMOS. This improved performance of SJMOS is due to the presence of an additional horizontal electric field component in SJMOS devices. This is validated using the experimental data and simulation results in this article.
Cross sections and failure in time rates for neutron-induced single-event burnout (SEB) are estimated for SiC power MOSFETs using a method based on combining results from heavy ion SEB experimental ...data, 3-D TCAD prediction of sensitive volumes, and Monte Carlo radiation transport simulations of secondary particle production. The results agree well with experimental data and are useful in understanding the mechanisms for neutron-induced SEB data.
Low-energy ion-induced breakdown and single-event burnout (SEB) are experimentally observed in beta-gallium oxide (<inline-formula> <tex-math notation="LaTeX">\beta ...</tex-math></inline-formula>-Ga2O3) Schottky diodes with voltages well below those of expected electrical breakdown. Fundamentally different responses were observed among alpha particle, Cf-252, and heavy-ion irradiation. Technology computer-aided design (TCAD) simulations suggest that ion-induced burnout can be triggered at high voltages as a result of a single ion strike, leading to impact ionization, voltage-induced charge separation accentuated by the low intrinsic hole mobility in <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-Ga2O3, and breakdown. At significantly lower voltages, the cumulative buildup of displacement-damage-induced defects in <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-Ga2O3 during high-fluence ion irradiation can lead to defect-driven breakdown due to the generation and motion of negatively charged Ga vacancies and O interstitials. First-principles calculations show that defect clusters can be formed, which are much less resistive than the surrounding material. These clusters can be driven deeply into the device by the reverse bias, ultimately forming conduction paths that can facilitate the destruction of the device at reduced voltages.
Through-wafer two-photon absorption laser experiments were performed on bulk FinFETs. Transients show distinct signatures for charge collection from drift and diffusion, demonstrating the ...contribution of charge generated in the substrate to the charge collection process. This result was validated through heavy ion testing on more advanced bulk FinFETs with fin widths as narrow as 5 nm. The drain region dominates the charge collection, with as much as 45 fC of charge collected in the drain region.
The effects of 70-keV and 1-MeV electron irradiations on gate-controlled lateral PNP (GLPNP) transistors are evaluated with and without molecular hydrogen (H 2 ) soaking. At a given ionization dose, ...1-MeV electron irradiation causes more degradation of current gain in GLPNP transistors that have not been soaked in H 2 than 70-keV electrons. This is because linear bipolar transistors are sensitive to both ionization and displacement damage effects, and because 1-MeV electrons induce significant displacement damage in Si-based bipolar junction transistors and 70-keV electrons do not. In H 2 -soaked transistors, the degradation is much larger than in unsoaked devices, and similar amounts of degradation are observed for 70-keV electron irradiation and 1-MeV electron irradiation. This occurs because ionization-induced release, transport, and reactions of hydrogen in the bipolar-base oxide greatly enhance interface-trap buildup and dominate device response in H 2 -soaked devices, and because charge yield ratios for 70-keV and 1-MeV electron irradiations differ by less than ~20%.
The fifty year history of radiation effects in bipolar transistors at NSREC is summarized, covering neutron-induced displacement damage, total ionizing dose response (including enhanced low dose rate ...sensitivity, ELDRS) and single event effects. These phenomena, particularly TID and ELDRS in bipolar transistors, have received significant attention at NSREC. Several other radiation effects such as thermal mechanical shock, electrical overstress, prompt dose rate photoresponse and the response to neutral particle beams are not addressed.
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