An extended study was made of induced lattice defects and of their effect upon In0.53Ga0.47As p-i-n photodiodes which were subjected to 1MeV fast neutron irradiation. Degradation of the electrical performance increased with increasing neutron fluence. The lattice defects in the epitaxial layers, before and after irradiation, were studied by means of deep-level transient spectroscopy. Before irradiation, native defects which were associated with Ga vacancies were observed. The irradiation introduced electron capture levels that were affected by displacement damage related local disordering and stoichiometry in the epitaxial layers. The difference in radiation damage between 1MeV fast neutrons and 1MeV electrons was considered while taking account of the number of knock-on atoms and of the non-ionizing energy loss. The radiation source-dependence of performance degradation was attributed to the differences in mass and the probability of nuclear collision with respect to the formation of lattice defects.

N.A.Sobolev, A.M.Emelyanov, J.A.Kudryavtsev, R.N.Kyutt, M.I.Makovijchuk, J.A.Nikolaev, E.O.Parshin, V.I.Sakharov, I.T.Serenkov, E.I.Shek, K.F.Shtelmakh: Solid State Phenomena, 1997, 57-58, 257-62