Three-dimensional memory device having multi-deck structure and methods for forming the same

Abstract

Embodiments of structure and methods for forming a three-dimensional (3D) memory device are provided. In an example, a 3D memory device includes a substrate, an alternating layer stack on the substrate, and a barrier structure extending vertically through the alternating layer stack. The alternating layer stack includes (i) an alternating dielectric stack having a plurality of dielectric layer pairs enclosed laterally by at least the barrier structure, and (ii) an alternating conductor/dielectric stack having a plurality of conductor/dielectric layer pairs. The 3D memory device also includes a channel structure and a source structure each extending vertically through the alternating conductor/dielectric stack, and a contact structure extending vertically through the alternating dielectric stack. The source structure includes at least one staggered portion along a respective sidewall.