Patent ID: 9331093
Filing Date: 2016-05-03
CPC Classification: H01L

Claim Text:
1. A monolithic three dimensional NAND string, comprising: a semiconductor channel, at least one end part of the semiconductor channel extending substantially perpendicular to a major surface of a substrate; a plurality of control gate electrodes extending substantially parallel to the major surface of the substrate, wherein the plurality of control gate electrodes comprise at least a first control gate electrode located in a first device level and a second control gate electrode located in a second device level located over the major surface of the substrate and below the first device level, wherein the first control gate electrode is separated from the second control gate electrode by an insulating layer located between the first and second control gates; a blocking dielectric located adjacent the plurality of control gate electrodes; at least one charge storage region located adjacent the blocking dielectric; and a tunnel dielectric located between the at least one charge storage region and the semiconductor channel, wherein a second portion of the semiconductor channel comprises silicon and germanium and contains more germanium than a first portion of the semiconductor channel which is located closer to the tunnel dielectric than the second portion.