Estimation of enhanced low dose rate sensitivity mechanisms using temperature switching irradiation on gate-controlled lateral PNP transistor

The mechanisms occurring when the switched temperature technique is applied, as an accelerated enhanced low dose rate sensitivity （ELDRS） test technique, are investigated in terms of a specially designed gate-controlled lateral PNP transistor （GLPNP） that used to extract the interface traps （Nit） and oxide trapped charges （Not）. Electrical characteristics in GLPNP transistors induced by 60Co gamma irradiation are measured in situ as a function of total dose, showing that generation of Nit in the oxide is the primary cause of base current variations for the GLPNP. Based on the analysis of the variations of Nit and Not, with switching the temperature, the properties of accelerated protons release and suppressed protons loss play critical roles in determining the increased Nit formation leading to the base current degradation with dose accumulation. Simultaneously the hydrogen cracking mechanisms responsible for additional protons release are related to the neutralization of Not extending enhanced Nit buildup. In this study the switched temperature irradiation has been employed to conservatively estimate the ELDRS of GLPNP, which provides us with a new insight into the test technique for ELDRS.

Gate-controlled supercurrent effect in dry-etched Dayem bridges of non-centrosymmetric niobium rhenium

The application of a gate voltage to control the superconducting current flowing through a nanoscale superconducting constriction,named as gate-controlled supercurrent(GCS),has raised great interest for fundamental and technological reasons.To gain a deeper understanding of this effect and develop superconducting technologies based on it,the material and physical parameters crucial for the GCS effect must be identified.Top-down fabrication protocols should also be optimized to increase device scalability,although studies suggest that top-down fabricated devices are more resilient to show a GCS.Here,we investigate gated superconducting nanobridges made with a top-down fabrication process from thin films of the noncentrosymmetric superconductor niobium rhenium with varying ratios of the constituents(NbRe).Unlike other devices previously reported and made with a top-down approach,our NbRe devices systematically exhibit a GCS effect when they were fabricated from NbRe thin films with small grain size and etched in specific conditions.These observations pave the way for the realization of top-down-made GCS devices with high scalability.Our results also imply that physical parameters like structural disorder and surface physical properties of the nanobridges,which can be in turn modified by the fabrication process,are crucial for a GCS observation,providing therefore also important insights into the physics underlying the GCS effect.