Hardened MNOS/SOS Electrically Reprogrammable Nonvolatile Memory

A random access 256 × 4 MNOS/SOS nonvolatile memory has been designed, processed, and characterized. Significant advances have been made in radiation hard low power MNOS/SOS technology by the development of nitride-oxide memory devices and high voltage p-enhancement and n-depletion mode devices used in complementary symmetry circuits. This CMOS compatible memory dissipates less than 300 mW with a read access time of less than 400 nsec at total dose levels near 500K rads (Si). The balanced memory detection and read enhancement features help assure long term data retention through total dose and transient radiation environments. Temperature-bias stability has been demonstrated.