Patent ID: 8440531

Claim:
A method of forming a nonvolatile memory device, comprising: forming a first vertical stack of layers on a substrate, said first vertical stack of layers comprising a composite of at least a plurality of first material layers and a plurality of second material layers arranged as an alternating stack of first and second material layers comprising different materials; forming a first opening extending through at least a plurality of the first material layers and at least a plurality of the second material layers within the first vertical stack of layers; filling at least a portion of the first opening with a composite stack of a bulk sacrificial pattern and a capping sacrificial pattern on the bulk sacrificial pattern, said bulk and capping sacrificial patterns comprising different materials and said bulk sacrificial pattern comprising a polymerized material containing carbon; forming a second vertical stack of layers of different materials on the first vertical stack of layers; forming a second opening that extends through the second vertical stack of layers and exposes the capping sacrificial pattern within the first opening; and removing the capping sacrificial pattern and the bulk sacrificial pattern through the second opening.