Patent ID: 8829591

Claim:
A monolithic three dimensional NAND string, comprising: a semiconductor channel located over a substrate, at least one end of the semiconductor channel extending substantially perpendicular to a major surface of the substrate; a plurality of control gates extending substantially parallel to the major surface of the substrate, wherein the plurality of control gates comprise at least a first control gate located in a first device level and a second control gate located in a second device level located over the substrate and below the first device level; a charge storage material located in the first device level and in the second device level; a blocking dielectric located between the charge storage material and the plurality of control gates; and a tunneling dielectric located between the charge storage material and the semiconductor channel; wherein: the tunneling dielectric has a straight sidewall; portions of the blocking dielectric have a clam shape; and each of the plurality of control gates is located at least partially in an opening in the clam-shaped portion of the blocking dielectric.