3D NAND存储器及其形成方法
By using a wet etching process to control the initial sacrificial layer thickness difference in 3D NAND memory, the problem of damage to the charge storage layer caused by etching deviation is solved, and effective protection of the charge storage layer is achieved to prevent memory failure.
CN114171533BActive Publication Date: 2026-07-17YANGTZE MEMORY TECH CO LTD
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YANGTZE MEMORY TECH CO LTD
- Filing Date
- 2021-10-25
- Publication Date
- 2026-07-17
AI Technical Summary
Technical Problem
In existing 3D NAND memory, the charge storage layer is easily damaged due to etching deviations when forming a multi-layer stacked structure, causing memory failure.
Method used
An initial sacrificial layer is formed using a wet etching process. By controlling the thickness difference of the initial sacrificial layer on the charge storage layer, the characteristics of wet etching—fast etching at the top of the deep hole and slow etching at the bottom—are utilized to protect the charge storage layer from damage.
Benefits of technology
It effectively prevents damage to the charge storage layer at the step, avoids failure of 3D NAND memory, and improves the reliability of the memory.
✦ Generated by Eureka AI based on patent content.
Smart Images
Figure CN114171533B_ABST
Abstract
本发明提供一种3D NAND存储器及其形成方法，所述方法形成初始牺牲层，所述初始牺牲层位于所述第二沟道孔顶部侧壁的的厚度大于位于所述台阶上的厚度，再利用湿法刻蚀工艺对深孔顶部刻蚀快，底部刻蚀慢的特性，采用湿法刻蚀工艺刻蚀所述初始牺牲层，从而在电荷存储层上形成厚度一致的沟道孔牺牲层，则在形成开口的刻蚀过程中，位于第一沟道孔与第二沟道孔交界处(即台阶处)的沟道孔牺牲层不会被完全刻蚀，能够对该处的电荷存储层起到良好的保护作用，防止由于该处电荷存储层被破坏而造成3D NAND存储器失效。
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