SEMICONDUCTOR MEMORY STRUCTURE AND METHOD FOR FORMING THE SAME

A semiconductor memory structure includes a plurality of gate layers and a plurality of insulating layers alternately stacked over a substrate, and at least an active column disposed over the substrate. The gate layers and the insulating layers are alternately stacked along a first direction. The active column extends along the first direction and penetrates the gate layer and the insulating layer. The active column includes a central portion, a charge-trapping layer surrounding the central portion, and a channel layer between the central portion and the charge-trapping layer. The central portion of the active column includes an isolation structure, a source structure and a drain structure. The source structure and the drain structure are disposed at two sides of the isolation structure.