A simplified box (buried-oxide) isolation technology for megabit dynamic memories

A simplified version of BOX isolation technology is described. The new process has been greatly simplified over the original BOX by introducing an additional non-critical masking step. The body effect observed in narrow channel devices is reduced in the new structure. The capacitance measurement on diffused junctions in BOX structure shows smaller contributions from diode perimeter as compared to LOCOS structure. Hot electron reliability of small geometry MOSFETs has been also studied and the results are presented and discussed.