Thin oxide degradation after high-energy ion irradiation

We have investigated the degradation induced by I- and Si-ions on 10- and 3 -nm-thick oxide MOS capacitors. Ten-manometer oxides were biased at low ele ctric field (less than or equal to 3.3 MV/cm) during irradiation up to 100 Mrad(Si). DC radiation induced leakage current (RILL) has been observed aft er irradiation, and the differences of RILC characteristics between 10-nn a nd thinner oxides are discussed. In 10-nm oxides, RILL is attributed to mul titrap assisted tunneling, which is reduced by subsequent Fowler-Nordheim e lectron injection. The density of the radiation-induced positive charged de fect, the positive charge recombination by Fowler-Nordheim electron injecti on, and the negative charge trapping in radiation-induced neutral electron traps have been also addressed. On the other side, radiation-induced soft b reakdown (RSB) is triggered by I-ions in 3-nm oxides at low doses (< 1 krad (Si)) for moderate applied electric fields (4.4 MV/cm). Silicon ion irradia tion is unable to produce RSB and RILL in 10-nm oxides, but it can generate a peculiar RILC in 3-nm oxides.