STAIRCASE FORMATION IN THREE-DIMENSIONAL MEMORY DEVICE

Title:

STAIRCASE FORMATION IN THREE-DIMENSIONAL MEMORY DEVICE

Document Type and Number:

WIPO Patent Application WO/2019/218351

Kind Code:

A1

Abstract:

A method for forming a staircase structure of 3D memory, including: forming an alternating layer stack on a substrate, forming a plurality of staircase regions where each staircase region has a staircase structure having a first number (M) of steps in a first direction; forming a first mask stack to expose a plurality of the staircase regions; removing (M) of the layer stacks in the exposed staircase regions; forming a second mask stack over the alternating layer stack to expose at least an edge of each of the staircase regions in a second direction; and repetitively, sequentially, removing a portion of (2M) of layer stacks and trimming the second mask stack.

Inventors:

ZHAO XIANGHUI (CN)
ZENG ZUIXIN (CN)
HU JUN (CN)
ZHANG SHI (CN)
CHEN BAOYOU (CN)

Application Number:

PCT/CN2018/087519

Publication Date:

November 21, 2019

Filing Date:

May 18, 2018

Export Citation:

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Assignee:

YANGTZE MEMORY TECH CO LTD (CN)

International Classes:

H01L27/11582

Foreign References:

US20170170193A1	2017-06-15
CN107658224A	2018-02-02