Patent ID: 8278170

Claim:
A method of forming a nonvolatile memory device, comprising: forming a first stack of layers on a substrate, said first stack of layers comprising a first plurality of interlayer dielectric layers and a first plurality of sacrificial or word line layers arranged vertically in an alternating sequence; selectively etching through the first stack of layers to define a first opening therein; forming a first active region of a first plurality of nonvolatile memory cells and at least one dummy memory cell in the first opening; forming a second stack of layers on the first stack of layers, said second stack of layers comprising a second plurality of interlayer dielectric layers and a second plurality of sacrificial or word line layers arranged vertically in an alternating sequence; selectively etching through the second stack of layers to define a second opening therein that is aligned with the first opening; and forming a second active region of a second plurality of nonvolatile memory cells in the second opening.