Patent ID: 8084805

Claim:
A vertical NAND flash memory device comprising: a substrate having a face; a string of serially connected flash memory cells, a first flash memory cell in the string of serially connected flash memory cells being adjacent the face and a last flash memory cell in the string of serially connected flash memory cells being remote from the face; and a selection transistor adjacent to the string of serially connected flash memory cells; wherein the string of flash memory cells comprising a series of repeating layer patterns that are stacked on the face and a pillar that extends through the series of repeating layer patterns and that includes at least one oblique wall; wherein at least two of the series of repeating layer patterns in the string of serially connected flash memory cells are of different thicknesses; and wherein the pillar is wider remote from the face compared to adjacent the face and wherein the repeating layer patterns are thicker remote from the face compared to adjacent the face.