TRAPPING, CONDUCTION, AND DIELECTRIC-BREAKDOWN IN SI3N4 FILMS ON AS-DEPOSITED RUGGED POLYSILICON

Rugged polysilicon stacked capacitors recently emerged as the storage structures of choice for the manufacture of advanced DRAM's. In this paper we 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. Our measurements show that rugged polysilicon capacitors present the low leakage current, the sharp breakdown distributions, and the trapping characteristics needed for advanced DRAM applications.