Substrate effects on the degradation of irradiated Si diodes

Irradiation damage in n⁺p and p⁺n Si diodes by 1-MeV fast neutrons and 1 to 2-MeV electrons is studied as a function of type of Si substrate and radiation source. The degradation of the electrical performance of diodes by irradiation increases with increasing fluence and is much larger for CZ-Si diodes than for FZ-Si diodes. The difference of radiation damage is thought to be due to the formation of lattice defects which are associated with the creation of oxygen related complexes. The degraded performance recovers by thermal annealing. The activation energy of reverse current recovery of n⁺ p Si diodes irradiated by neutrons with a fluence of 1×10 ¹³ n/cm² is calculated to be 0.35 and 0.19 eV