Channel doping concentration and fin width effects on self-boosting in NAND-type SONOS flash memory array based on bulk-finFETs

In performing the program operation of the NAND-type flash memory array, the program inhibition is made possible by self-boosting of the channel potential. However, the high program voltage may cause the unwanted program operations in the vicinity: charge redistributions in the adjacent cells sharing either the same bit-line (BL) or the same word-line (WL). In this work, the dependences of self-boosting of the channel potential on process variable and device dimension have been investigated by a 3-D device simulation. Channel doping concentration and fin width have been controlled as the variables. The self-boosting effect has shown an optimum point at a channel doping concentration of 6×1017 boron atoms/cm ³, and it decreases monotonically as the silicon fin width becomes thicker.