3D Nonvolatile Memory Charge Storage Layer Segmentation
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Solution Overview
Problem
Current methods for manufacturing nonvolatile memory devices with three-dimensional structures face challenges in enhancing reliability due to charge diffusion and data disturbance, particularly in high-density storage applications.
Innovation Solution
A method involving alternately stacking material layers with different etching selectivity on a semiconductor substrate, forming openings, and conformally depositing a charge storage layer to create patterns that are isolated between conductive layers and semiconductor pillars, preventing charge diffusion and improving data retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If charge storage layer is continuously formed along the opening surface, then data storage capacity is improved, but charge diffusion and data disturbance occur between adjacent memory cells
Solution Approach 1:
The continuous charge storage layer is segmented into discrete charge storage layer patterns by removing portions between adjacent openings. This segmentation prevents charge diffusion between adjacent memory cells while maintaining sufficient charge storage capacity within each isolated pattern, thereby resolving the contradiction between storage capacity and data retention reliability.
Solution Approach 2:
The charge storage layer patterns are locally formed only in specific regions between sidewalls of conductive layers and semiconductor pillars, rather than continuously along the entire opening surface. This local quality approach concentrates charge storage functionality in isolated regions, preventing charge diffusion while maintaining effective storage capacity.
2Productivity
If three-dimensional structure is adopted for high integration, then device density is improved, but charge diffusion and data disturbance increase
Solution Approach 1:
In the three-dimensional stacked structure, charge storage layer patterns are segmented and isolated between conductive layers and semiconductor pillars. This segmentation prevents vertical and lateral charge diffusion in the high-density three-dimensional configuration, maintaining data retention reliability while achieving high integration density through multiple stacked layers.
Solution Approach 2:
The charge storage layer patterns are formed in a three-dimensional configuration between conductive layers and semiconductor pillars, utilizing vertical stacking to achieve high integration. The isolation mechanisms work in multiple dimensions to prevent charge diffusion, resolving the contradiction between three-dimensional integration and data retention reliability.
3Manufacturing precision
If material layers with different etching selectivity are stacked, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
Material layers with different etching selectivity are stacked and processed to form charge storage layer patterns with precise local geometry. The different etching selectivities enable selective removal of materials to create the specific pattern configuration between conductive layers and semiconductor pillars, achieving high manufacturing precision for the charge storage layer patterns.
Solution Approach 2:
Material layers with different etching selectivity are prepared and stacked in advance before the charge storage layer formation process. This preliminary preparation of the layered structure with controlled etching properties enables precise pattern formation in subsequent steps, improving manufacturing precision while the layering is established beforehand.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the reliability of nonvolatile memory devices by isolating charge storage layers, preventing charge diffusion, and maintaining data integrity over time, especially in three-dimensional structures.
Implementation Method 1
conformally forming a charge storage layer along a surface of the opening and the extended portions
Implementation Method 2
alternately stacking a plurality of first and second material layers having a different etching selectivity
Data Source
AI summary
A method of manufacturing a nonvolatile memory device having a three-dimensional memory device includes alternately stacking a plurality of first and second material layers having a different etching selectivity on a semiconductor substrate; forming an opening penetrating the plurality of first and second material layers; removing the first material layers exposed by the opening to form extended portions extending in a direction perpendicular to the semiconductor substrate from the opening; conformally forming a charge storage layer along a surface of the opening and the extended portions; and removing the charge storage layer formed on sidewalls of the second material layers to locally form the charge storage layer patterns in the extended portions.