Reconfigurable Cell String Having FET and Super-Steep Switching Diode Operation in 3D NAND Flash Memory

A new reconfigurable cell string based on 3D NAND flash cell string is proposed and investigated by using TCAD simulation tool. By adapting ambipolar contact, the cell string has switchable characteristics between diode-type and FET-type. The diode-type operation has a steep subthreshold swing (SS) less than 1 mV/dec and the FET-type operation has comparable performances to conventional 3D NAND flash cell string.