THREE DIMENSIONAL VERTICAL NAND DEVICE WITH FLOATING GATES

摘要

A monolithic three dimensional NAND string including a stack of alternating first material layers and second material layers different from the first material layers over a major surface of a substrate. The first material layers include a plurality of control gate electrodes (3A, B) and the second material layers include an insulating material (122A, B) and the plurality of control gate electrodes extend in a first direction. The NAND string also includes a semiconductor channel (1), a blocking dielectric (107), and a plurality of vertically spaced apart floating gates (FG). Each of the plurality of vertically spaced apart floating gates or each of the second material layers includes a first portion (109) having a first thickness (W1), and a second portion (209) adjacent to the first portion in the first direction and having a second thickness (W2) which is different from the first thickness.