IMPROVEMENTS OF DEPOSITED INTERPOLYSILICON DIELECTRIC CHARACTERISTICSWITH RTP N2O-ANNEAL

Nitridation of deposited instead of thermally grown oxides was studied to form high quality inter-poly silicon dielectric layers for nonvola tile memories. It was found that by optimizing the texture and morphol ogy of the polysilicon layers, and by optimizing the post-dielectric d eposition-anneal, very high-quality dielectric layers can be obtained. In this paper, it is shown that not only for deposited gate oxides, b ut also for deposited inter-polysilicon oxides, rapid thermal annealin g leads to previously unpublished improved electrical characteristics, like high charge to breakdown (Q(bd)approximate to 20 C/cm(2)) and lo wer leakage currents. Moreover, the annealed dielectrics had less elec tron trapping when stressed.