Electrical properties of oxide-nitride dielectric films incorporating passivation oxide on polycrystalline silicon for advanced dynamic random access memory stacked capacitors

We demonstrate that electron trapping in oxide/nitride (ON) dielectric films with a passivation oxide on rugged polycrystalline silicon is lower than in those without passivation oxide. The leakage current at high field through the Si3N4 films incorporating a passivation oxide is smaller than through Si3N4 films without passivation oxide. The deposited passivation oxide allows the formation of thinner Si3N4 films and also reduces the leakage current through Si3N4 films at high field. Our results show that oxide-nitride layers on deposited passivation oxides have the low leakage current, tight dielectric breakdown distribution, and trapping characteristics suitable for advanced dynamic random access memory (DRAM) stacked capacitors.