Columnar Member Support for 3D NAND Electrode Uniformity
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Solution Overview
Problem
Three-dimensional semiconductor memory devices face issues with warping and deformation of electrode films due to remaining openings after removing sacrificial layers, leading to non-uniform electrode film resistance and variations in memory cell operating characteristics.
Innovation Solution
The integration of columnar members and plate-shaped members embedded in the silicon substrate helps maintain a uniform shape of electrode films by preventing warping during the replacement of sacrificial films with metal electrode films, ensuring consistent resistance and memory cell performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If sacrificial films are removed and replaced with metal electrode films, then the electrode films can be formed in the stacked body, but openings may remain and cause warping and deformation of the electrode films
Solution Approach 1:
Columnar members are formed in the stacked body before the sacrificial films are removed and electrode films are deposited. These columnar members serve as preliminary structural supports that prevent warping and deformation during the subsequent film formation process, ensuring uniform electrode film shape and resistance.
2Ease of manufacture
If openings are left remaining after removing sacrificial films, then the electrode film formation process can be completed, but the stacked body may warp and electrode films may deform
Solution Approach 1:
Columnar members act as intermediary structural elements between the stacked body layers and the electrode films. They are positioned at specific locations (including in openings where sacrificial films were removed) to provide mechanical support and maintain the structural integrity of the stacked body during electrode film formation, preventing warping and ensuring consistent electrode film resistance.
3Manufacturing precision
If columnar members are added to prevent warping, then electrode film uniformity is improved, but device complexity increases
Solution Approach 1:
Columnar members are not uniformly distributed throughout the entire stacked body but are strategically positioned at specific locations where structural support is most needed, such as in openings formed by sacrificial film removal and at regions prone to warping. This localized approach provides necessary support to prevent electrode film deformation while minimizing the overall addition of structural elements and associated complexity.
Data Source
AI summary
According to one embodiment, a semiconductor memory device includes a substrate, a stacked body, a semiconductor pillar, a charge storage film, and at least one columnar member. The stacked body is provided on the substrate. In the stacked body, a plurality of insulating films and a plurality of electrode films are layered together alternately. The semiconductor pillar is provided in the stacked body and extends in a stacking direction of the stacked body. The charge storage film is provided between the semiconductor pillar and the stacked body. The columnar member is provided in the stacked body and extends in the stacking direction. A lower portion of the columnar member is provided in the substrate.