3D Memory Device Slit Trench Structure for Integration Density
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Solution Overview
Problem
Current three-dimensional memory devices face challenges in reducing size and improving integration density due to the structural limitations of their memory cell strings, which hinder efficient data storage and retrieval operations.
Innovation Solution
The proposed solution involves a memory device structure that includes a source line, multiple memory cell strings, a slit trench, and a slit insulating layer, where the memory cell strings are formed vertically over the source line, and the slit trench is filled with a slit insulating layer, allowing for a more compact design and enhanced data storage capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If memory cell strings are arranged in conventional three-dimensional structure, then data storage capacity is improved, but device size and integration density are limited
Solution Approach 1:
The patent divides the memory structure into discrete memory cell strings separated by slit trenches. This segmentation allows for optimized spacing and arrangement of memory cells, improving integration density while maintaining data storage capacity. The slit trenches create distinct regions that can be independently managed and accessed.
Solution Approach 2:
The patent transitions from two-dimensional planar memory structures to three-dimensional vertically stacked memory cell strings. By stacking memory cells in the vertical dimension, the device achieves higher data storage capacity within a smaller footprint area, effectively resolving the contradiction between storage capacity and device size.
2Manufacturing precision
If memory cell strings are closely arranged to improve integration density, then device size is reduced, but manufacturing precision and structural stability become challenging
Solution Approach 1:
The patent introduces slit trenches as intermediary structures between memory cell strings. These trenches filled with insulating material act as spacers and structural supports, maintaining precise spacing between closely arranged memory cell strings. This intermediary structure enables high integration density while preserving structural stability and facilitating manufacturing precision.
3Ease of manufacture
If conventional insulating structures are used between memory cell strings, then manufacturing is simpler, but device size and integration density are suboptimal
Solution Approach 1:
The patent modifies the insulating structure by creating slit trenches with specific geometric parameters (depth, width, shape) and filling them with insulating material. This parameter optimization allows the insulating structures to serve dual purposes: maintaining structural integrity and enabling compact memory cell arrangement, thereby reducing device size without significantly complicating the manufacturing process.
Data Source
AI summary
There are provided a memory device and a manufacturing method thereof. A method of manufacturing a memory device may include forming, on a substrate, a conductive layer, a sacrificial layer, and a stack structure. The method may include forming a plurality of vertical holes by etching a portion of the stack structure. The method may include forming a memory layer and a channel layer along internal surfaces of the vertical holes. The method may include forming a slit trench exposing a portion of the sacrificial layer therethrough by etching a portion of the stack structure between the vertical holes. The method may include exposing a portion of the channel layer and the first conductive layer through a lower portion of the stack structure by removing portions of the sacrificial layer and the memory layer. The method may include forming another conductive layer along surfaces of the exposed portion of the channel layer and the first conductive layer. The method may include forming a slit insulating layer in the slit trench.