Three-dimensional memory device containing bridges for enhanced structural support and methods of forming the same

Abstract

A three-dimensional memory device includes vertical layer stacks that are laterally spaced apart by backside trenches that laterally extend along a first horizontal direction, where each of the vertical layer stacks includes a respective alternating stack of insulating layers and electrically conductive layers, memory openings vertically extending through the alternating stacks, memory opening fill structures located in the memory openings and including a respective vertical stack of memory elements and a respective vertical semiconductor channel, and backside trench fill structures located within a respective one of the backside trenches. Each of the backside trench fill structures includes a plurality of dielectric bridge structures laterally spaced apart along the first horizontal direction and dielectric fin portions located at levels of a plurality of the electrically conductive layers. The dielectric fin portions laterally protrude outward relative to sidewalls of the insulating layers within the respective neighboring pair of alternating stacks.