Damage induced in 100% internal carrier collection efficiency silicon photodiodes by 10-60 keV ion irradiation

We measure the change in the response of 100% internal carrier collection e fficiency silicon photodiodes having 60 Angstrom SiO2 passivation layers du e to the damage induced by bombardment with 10-60 keV ions of H, He, N, Ne, and Ar. We find an initially exponential decrease in responsivity with inc reasing ion fluence Phi and use this to define a damage constant beta. The correlation of beta with the nuclear stopping power of the incident ion ins tead of the with the total energy lost to nuclear stopping indicates that d amage in a channel lying within the n-type silicon near the Si-SiO2 interfa ce dominates the radiation-induced change in the photodiode response. We us e a fluid model of electron transport in the channel to derive a universal curve to describe the damage as a function of ion fluence and to show that the damage constant beta is proportional to the damage cross section. Over the energy range of this study, damage cross sections of N+, Ne+, and Ar+ a re 10-100 times that of He+, and similar to 1000 times that of H.