A new self-convergent programming and erase tightening by substrate-hot-electron injection for ETOX cells in triple-well

A new self-convergent programming technique for ETOX cells fabricated in a triple-well process is proposed using substrate hot-electron (SHE) injection. The programming efficiency is at least 100X higher than channel-hot-electron (CHE) injection. The cell threshold voltage (V/sub t/) after programming saturates with self-convergence. The SHE re-programming can tighten the Vt spread after erase. The NOR array architecture is codified with individual p-wells for each column so that it is possible to implement single-bit program and erase operations. The ETOX cells in triple-well with the new NOR array can perform as a full EEPROM as well as a flash memory.