Trapping, conduction, and dielectric breakdown in Si/sub 3/N/sub 4/ films on as-deposition rugged polysilicon

Abstract

Rugged polysilicon stacked capacitors recently emerged as the storage structures of choice for the manufacture of advanced DRAMs. The authors present the charge-trapping characteristics of such capacitors showing a capacitance increase of more than 50%. It is observed that electron trapping is dominant on rugged structures, whereas hole trapping is observed on smooth structures. Conduction and breakdown properties are also reported. Measurements show that rugged polysilicon capacitors provide the low leakage current, the sharp breakdown distributions, and the trapping characteristics needed for advanced DRAM applications.