US 2019/0103410 A1 · 3D NAND WITH INTEGRAL DRAIN-END SELECT GATE (SGD)

Abstract

A 3D NAND storage device includes a plurality of layers containing doped semiconductor material interleaved with a plurality of layers of dielectric material. Each of the pillars forming the 3D NAND storage device includes a plurality of memory cells and a drain-end select gate (SGD). The pillars are separated by a hollow channel in which a plurality of film layers, including at least a lower film layer and an upper film layer have been deposited. The systems and methods described herein remove at least the upper film layer proximate the SGD while maintaining the film layers proximate the memory cells. Such an arrangement beneficially permits tailoring the film layers proximate the SGD prior to depositing the channel film layer in the hollow channel. The systems and methods described herein permit the deposition of a continuous channel film layer proximate both the memory cells and the SGD.

Claims25

Dependent claims

A method of fabricating a three-dimensional NAND (3D NAND) structure, the method comprising:

disposing a plurality of film layers across at least an interior surface of a hollow channel, the hollow channel having an open first end and a closed second end and including:
a plurality of memory cells disposed along at least a portion of a length of the hollow channel;
and
at least one drain-end select gate (SDG) disposed proximate the first end of the hollow channel;
disposing a sacrificial material in the hollow channel;
selectively removing the sacrificial material to a first defined depth measured from the first end of each of the plurality of hollow channels to expose an upper film layer included in the plurality of film layers;
selectively removing at least the exposed upper film layer to the first defined depth;
and
removing the sacrificial material from the hollow channel.

6 more elements

Dependencies are inferred from the claim text.

3d nand with integral drain-end select gate (sgd)

Life of this patent

3d nand with integral drain-end select gate (sgd)

Life of this patent

Abstract

Claims25