A DEVICE SIMULATION OF THE BBT EFFECT IN FLASH MEMORY CELLS AND IMPLICATIONS FOR THE DEVELOPMENT OF HIGH-RELIABILITY MEMORY CELLS

In order to analyze the BBT (band-to-band tunneling) phenomenon in flash memory cells by simulation, a new model is proposed, which improves on the BBT model by introducing the concept of “average electric field.” This model agrees well with the measured results in a wide drain N-concentration range. Using this model, the reliability of memory cells is analyzed. It is found that the difference of the amount of BBT generation does not directly affect the endurance characteristics but does affect the disturb characteristics. The same model can be used to analyze problem points of the present cells and to estimate the BBT current of next-generation devices accurately.