3D NAND Insulating Layer Geometry for Word Line Isolation
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Solution Overview
Problem
Existing semiconductor memory devices face challenges in achieving high performance due to structural limitations in the stacking and insulation of word lines and columnar bodies, which affect the efficiency and reliability of data storage.
Innovation Solution
A semiconductor memory device design featuring a specific configuration of insulating layers and word lines with a 90-degree crossing angle and columnar insulating portions, along with charge storage structures, to enhance insulation and data storage capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional stacking structures are used for word lines and columnar bodies, then device fabrication is simpler, but insulation efficiency and data storage performance deteriorate
Solution Approach 1:
The patent introduces a specific geometric configuration where the first insulating layer is inclined relative to the columnar insulating portion, creating a three-dimensional angular relationship (alpha angle between 30-60 degrees). This dimensional change in the insulating layer arrangement improves insulation efficiency between word lines while maintaining structural feasibility through defined angular parameters.
Solution Approach 2:
The patent applies different insulating layers with distinct properties at different locations: a first insulating layer with specific inclination angle for enhanced insulation between word lines, and a second insulating layer with different characteristics. This local differentiation of insulating layer properties optimizes insulation efficiency in critical areas without uniformly complicating the entire structure.
2Productivity
If conventional insulating layer configurations are used, then manufacturing process is simpler, but data storage efficiency deteriorates
Solution Approach 1:
The patent specifies precise parameter ranges for the first insulating layer, including inclination angle alpha between 30-60 degrees and thickness ratios, to optimize data storage efficiency. These parameter definitions provide clear manufacturing targets while the ranges allow for process variability, balancing performance requirements with manufacturing feasibility.
Solution Approach 2:
The patent forms the first insulating layer with the specific inclination angle before subsequent processing steps. This preliminary configuration of the insulating layer geometry establishes the foundation for high-density data storage while allowing later steps to complete the structure without requiring rework of the critical angular configuration.
3Quantity of substance
If word lines are closely stacked to increase density, then storage capacity increases, but insulation between word lines deteriorates
Solution Approach 1:
The patent resolves inter-word line interference by introducing a vertical dimension solution: the first insulating layer is inclined at angle alpha relative to the columnar insulating portion, creating a stepped or tiered insulation structure. This three-dimensional arrangement provides enhanced insulation between closely stacked word lines without increasing horizontal spacing, thereby maintaining high storage capacity while reducing interference.
Solution Approach 2:
The first insulating layer acts as an intermediary structure between adjacent word lines and columnar bodies. By positioning this insulating layer at a specific inclination angle, it mediates the electromagnetic interaction between closely spaced word lines, providing effective insulation that enables high-density stacking without suffering from inter-word line interference.
Data Source
AI summary
A semiconductor memory device includes a first wiring, a second wiring, a columnar insulating portion, and a first insulating layer. The first insulating layer includes a first edge. When it is assumed that a position closest to the columnar insulating portion on the first edge is a first position, a position of the first insulating layer, which is different from the first edge and is closest to the columnar insulating portion, is a second position, a virtual line along the first edge is a first virtual line, and a virtual line connecting the first position and the second position is a second virtual line, a crossing angle between the first virtual line and the second virtual line as seen from an inside of the first insulating layer is 90 degrees or more.