Retention reliability enhanced SONOS NVSM with scaled programming voltage

Abstract

We describe progress in the design and scaling of SONOS nonvolatile memory devices. The deterioration of the Si-SiO/sub 2/ interface is associated with the degradation of long term retention in SONOS nonvolatile semiconductor memory (NVSM) devices. Two-step, high temperature deuterium anneals improves the endurance characteristics and retention reliability over traditional hydrogen anneals. We have realized -9 V +10 V (1ms) programmable SONOS devices ensuring 10 years retention time after 10/sup 7/ erase/write cycles at 85/spl deg/C. We introduce scaling considerations and process optimization along with experiments and SONOS device characterization. An FPGA-based measurement system is described for the dynamic characterization of SONOS nonvolatile memory devices.