3D NAND memory device and method of forming the same

Abstract

A 3D-NAND memory device is provided. The memory device includes a substrate, a bottom select gate (BSG) disposed over the substrate, a plurality of word lines positioned over the BSG with a staircase configuration and a plurality of insulating layers disposed between the substrate, the BSG, and the plurality of word lines. In the disclosed memory device, one or more first dielectric trenches are formed in the BSG and extend in a length direction of the substrate to separate the BSG into a plurality of sub-BSGs. In addition, one or more common source regions are formed over the substrate and extend in the length direction of the substrate. The one or more common source regions further extend through the BSG, the plurality of word lines and the plurality of insulating layers.

Dependencies are inferred from the claim text.