Room Temperature Annealing of Gamma Radiation Damage in Zener Diodes

Gamma radiation is detrimental to semiconductor-based sensors or instrumentation. The ensuing damage can be very difficult to repair with conventional annealing approaches, particularly in as-deployed conditions. This study proposes application of the non-thermal electron wind force (EWF) to restore device performance and thus improve resilience to radiation exposure. The technique is demonstrated on Zener diodes exposed to Co-60 gamma radiation doses up to 2.65 Mrad (Si), which resulted in significant degradation of forward and reverse bias currents due to the formation of radiation-induced defects. EWF annealing, conducted at near-ambient temperatures for just one minute, not only completely restored the forward current affected by 2.65 Mrad (Si) of gamma radiation but also enhanced it beyond the pristine condition. In terms of reverse bias, the treatment achieved a recovery of 74.5%. Raman spectroscopy revealed increased full width at half maximum values of the characteristic peak of phonon mode of crystalline Si following the EWF annealing, indicating healing of lattice disorder and defects. Thermal annealing at 100 °C for 90 min showed no recovery or even more degradation, probably due to additional thermal stress. Because EWF annealing requires only electrical connections, it can be implemented “in-operando,” extending lifetime of semiconductor devices in radiation environments.