RADIATION PROPERTIES OF SILICON METAL-OXIDE-SEMICONDUCTOR STRUCTURES WITH ZINC-DOPED OXIDES

In this paper Rie present the results of investigation of radiation-in duced effects in metal-oxide-semiconductor (MOS) structures with oxide s doped with moderate amounts of zinc during the oxide growth. It is s hown through secondary ion mass spectroscopy (SIMS) analysis that zinc , when present in the oxidation ambient, is effectively incorporated i nto the oxide matrix. Electrophysical parameters of the modified MOS s tructures are similar to those of the reference ones. On the other han d, radiation sensitivity of zinc-doped structures is significantly aff ected. While observing an enhanced radiation-induced positive charge b uildup, we have found that the Si-SiO2 interface and the near-surface silicon region were significantly hardened in these structures. The ob served effects strongly depend on the amount of zinc incorporated in t he oxide. It is also shown that postirradiation low-temperature anneal ing can result in the improvement of the oxide and the Si-SiO2 interfa ce characteristics. The main parameters characterizing the system, nam ely, the oxide charge, the density of interface states, and the minori ty carrier generation lifetime, are improved after the irradiation-the n-annealing treatment compared to those of simply postmetallization-an nealed MOS structures. A simple model to explain the observed radiatio n-induced ordering effect is also presented.