Modeling for the 2nd-bit effect of a nitride-based trapping storage flash EEPROM cell under two-bit operation

In this letter, we propose a macromodeling approach for the nitride-based trapping storage Flash EEPROM cell with intriguing 2nd-bit effect. Both unusual I/sub D/-V/sub D/ and I/sub D/-V/sub G/ characteristics of this 2-bit Flash cell can be accurately modeled by the macromodel. It also provides insights into the special device characteristics of the programmed cell. Furthermore, we can use this model to correctly evaluate the read speed degradation resulting from 2nd-bit effect.