Effects of various surface pretreatments of polysilicon electrode prior to Si3N4 deposition on leakage current, time-dependent dielectric breakdown (TDDB) and charge trapping characteristics of thin Si3N4 films deposited on rugged and smooth poly-Si are investigated, Surface pretreatments consist of different combinations of HP clean, rapid thermal H-2-Ar clean, and rapid thermal NH3-nitridation (RTN) and are intended to modify the surface of bottom poly-Si electrode. Results show that RTN treatments lead to lower leakage current, reduced charge trapping, and superior TDDB characteristics as compared to rapid thermal H-2-Ar clean.