A three-dimensional AND flash memory device includes a stack structure, a channel pillar, a first conductive pillar and a second conductive pillar, and a charge storage structure. The stack structure is located on a dielectric substrate and includes gate layers and insulating layers alternately stacked with each other. The channel pillar extends through the stack structure. The first conductive pillar and the second conductive pillar are located in and electrically connected with the channel pillar. The first conductive pillar includes a first metal silicide pillar, and the second conductive pillar includes a second metal silicide pillar. The charge storage structure is located between the gate layers and the channel pillar.