BLOCKING OXIDE IN MEMORY OPENING INTEGRATION SCHEME FOR THREE-DIMENSIONAL MEMORY STRUCTURE

摘要

An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. After formation of a memory opening, all surfaces of the memory opening are provided as silicon oxide surfaces by formation of at least one silicon oxide portion. A silicon nitride layer is formed in the memory opening. After formation of a memory stack structure, backside recesses can be formed employing the silicon oxide portions as an etch stop. The silicon oxide portions can be subsequently removed employing the silicon nitride layer as an etch stop. Physically exposed portions of the silicon nitride layer can be removed selective to the memory stack structure. Damage to the outer layer of the memory stack structure can be minimized or eliminated by successive use of etch stop structures. Electrically conductive layers can be subsequently formed in the backside recesses.

主权项

1. A three-dimensional memory device comprising:
an alternating stack of insulating layers and electrically conductive layers and located over a substrate; a memory stack structure extending through the alternating stack and comprising, from outside to inside, a blocking dielectric, memory elements, a tunneling dielectric, and a semiconductor channel; and annular silicon nitride spacers located at each level of the insulating layers, vertically spaced from one another, and contacting an outer sidewall of the blocking dielectric.