ELECTRICAL CHARACTERIZATION OF HIGHLY RELIABLE 8 NM OXIDE

Device scaling down requires the decreasing of any thermal treatment i n order to reduce dopant diffusion. The possibility of using steam oxi des grown at low temperatures to substitute dry thermal oxides for tun nel application in flash memory is investigated here comparing differe nt technologies: standard dry/steam and N2O nitrided dry/steam oxides. A direct comparison in terms of oxide defect level and breakdown char acteristics is presented, also considering the charge trapping behavio r of area and periphery capacitors. A correlation between residual cha rge trapping and intrinsic reliability of these oxides is also present ed, showing that the overall best performances are obtained by the nit rided oxides. The nitridation of steam oxide at high temperature resul ts in good charge trapping characteristics, comparable with those of a nitrided dry oxide; at the same time charge-to-breakdown improves, wh ile the defect level decreases. In the investigated thickness range ev en the nitridation of a steam oxide at low temperature resulted in a s uitable dielectric for tunnel application in flash memories.