Three-dimensional memory device including a deformation-resistant edge seal structure and methods for making the same

Abstract

A vertically alternating stack of insulating layers and dielectric spacer material layers is formed over a semiconductor substrate. The vertically alternating stack is patterned into a first alternating stack located at a center region of a memory die and a second alternating stack that laterally encloses the first alternating stack. Memory stack structures are formed through the first alternating stack, and portions of the dielectric spacer material layers in the first alternating stack are replaced with electrically conductive layers while maintaining the second alternating stack intact. At least one metallic wall structure is formed through the second alternating stack. An edge seal assembly is provided, which includes at least one vertical stack of metallic seal structures. Each vertical stack of metallic seal structures vertically extends contiguously from a top surface of the semiconductor substrate to a bonding-side surface of the memory die, and includes a respective metallic wall structure.