US 2026/0231422 A1 · LATERAL ETCH STOPS FOR ACCESS LINE FORMATION IN A MEMORY DIE

Abstract

Methods, systems, and devices for lateral etch stops for access line formation in a memory die are described. A memory die may be formed with isolation regions that provide an etch stop to limit the extent of voids formed by removing a sacrificial material between layers of a dielectric region. For example, first trenches may be formed through a stack of alternating layers of a dielectric material and a sacrificial material, in which one or more materials may formed. Second trenches may be formed between a first trench and an array portion of the memory die, or between pairs of the first trenches, which may support the removal of at least a portion of the sacrificial material to form voids for access line formation. However, the materials formed in the first trenches may provide a boundary, or a restriction zone, that limits an extent of the material removal operation.

Claims21

Dependent claims

(canceled)

An apparatus, comprising:

an array region of a memory die comprising a plurality of pillars associated with a plurality of memory cells, the plurality of pillars extending through a stack of material layers of the array region comprising alternating layers of a first dielectric material and one or more conductive materials;
a first isolation region extending through the stack of material layers and aligned along a first side of the array region, the first isolation region comprising a second dielectric material in contact with the layers of the one or more conductive materials;
a second isolation region extending through the stack of material layers and aligned along a second side of the array region opposite the first side, the second isolation region comprising the second dielectric material in contact with the layers of the one or more conductive materials;
and
a third isolation region between the first isolation region and the second isolation region and extending through the stack of material layers, the third isolation region comprising a third dielectric material in contact with the layers of the one or more conductive materials, the third dielectric material physically separated from the second dielectric material of the first isolation region and the second dielectric material of the second isolation region.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

19/455,632Filed 21 Jan 2026

Priority

28 Jul 2022

Published

6 Aug 2026

Term ends

Not estimatedThe source records don’t support an estimate.

Classification11 codes

H10B 43/27
With source and drain on different levels, e.g. with sloping channels: the channels comprising vertical portions, e.g. U-shaped channels
H10B 43/35
Characterised by the memory core region: with cell select transistors, e.g. NAND
G11C 16/06
Electrically programmable: auxiliary circuits, e.g. for writing into memory
H10B 41/41
Characterised by the peripheral circuit region: of a memory region comprising a cell select transistor, e.g. NAND

Lateral etch stops for access line formation in a memory die

Life of this patent

Lateral etch stops for access line formation in a memory die

Life of this patent

Abstract

Claims21