LEAKAGE CURRENT AND RELIABILITY OF THIN NITRIDE FILMS ON AS-DEPOSITED RUGGED POLYCRYSTALLINE SILICON

The leakage current and reliability characteristics of thin oxide/nitride (ON) storage dielectrics on as-deposited rugged polycrystalline silicon layers are discussed. Rugged capacitors showing capacitance improvements as high as 53% exhibit only a slight increase in leakage current when compared to smooth structures. Even though these capacitors have a shorter lifetime at high electric fields, time-dependent dielectric breakdown data at various fields show that their field acceleration coefficient is larger. However, lifetime extrapolations to low operating fields might be inaccurate if the field enhancement at the electrode asperities is not taken into account for the rugged capacitors.