Proton irradiation effects on standard and oxygenated silicon diodes

Silicon diodes fabricated on oxygenated and standard (not oxygenated) silicon substrates, processed by different manufactories, have been irradiated for the first time by 34 MeV protons and for comparison by 24 GeV protons. The substrate oxygenation improves the radiation hardness of the devices by decreasing the acceptor introduction rate (beta) for both low and high energy proton irradiations. Anyway standard diodes from one manufactory present a beta value close to the oxygenated devices not only at 34 MeV but even at 24 GeV where the oxygenation effect is large. This suggests that also the processing plays an important role in the substrate radiation hardening.