3D Memory Word Line Pick-Up Structure Without Staircase Contacts
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Solution Overview
Problem
Planar memory cells face density limitations and fabrication challenges as feature sizes approach a lower limit, making 3D memory architectures necessary to increase density.
Innovation Solution
A 3D memory device design that integrates word line pick-up structures without staircase structures, using a single process to merge word line pick-up and fan-out functions, reducing manufacturing complexity and cost by eliminating dummy channel structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If complex staircase structures and word line contacts are used to achieve word line pick-up/fan-out functions, then the device functionality is improved, but the manufacturing cost and process complexity increase significantly
Solution Approach 1:
The patent merges the word line pick-up function and fan-out function into a single integrated word line pick-up structure. This structure combines the electrical connection function (pick-up) and the signal distribution function (fan-out) that were previously separated into staircase structures and word line contacts, thereby reducing device complexity while maintaining the required adaptability for word line control
Solution Approach 2:
The word line pick-up structure is designed to perform multiple functions simultaneously: it provides electrical connection to word lines, enables signal fan-out to multiple channels, and maintains mechanical support. This multi-functional design eliminates the need for separate staircase structures and word line contacts, reducing overall device complexity while preserving full functionality
2Strength
If dummy channel structures are included to support the word line pick-up structures, then the mechanical support is improved, but the manufacturing cost increases
Solution Approach 1:
The patent extracts the mechanical support function from the dummy channel structures and transfers it to the real channel structures themselves. The channel structures are designed to provide mechanical support to the word line pick-up structures directly, eliminating the need for separate dummy channel structures and reducing manufacturing complexity and cost
Solution Approach 2:
The channel structures are designed to serve dual purposes: their primary function of data storage and their secondary function of providing mechanical support to the word line pick-up structures. This self-service approach eliminates the need for additional dummy channel structures, reducing manufacturing cost while maintaining the required mechanical strength
3Ease of manufacture
If the word line pick-up structures are integrated directly into the dielectric portion, then the fabrication process is simplified, but the manufacturing precision requirements increase
Solution Approach 1:
The word line pick-up structures are formed within the dielectric portion during the dielectric layer formation process itself, before subsequent processing steps. This preliminary integration approach simplifies the fabrication process by combining multiple steps into one, while the dielectric material provides a stable matrix that facilitates precise positioning and integration
Data Source
AI summary
In certain aspects, a three-dimensional (3D) memory device includes channel structures in a first region, word line pick-up structures in a dielectric portion of a second region, and word lines each extending in the first region and a conductive portion of the second region. The first region and the second region are arranged in a first direction. The dielectric portion and the conductive portion of the second region are arranged in a second direction perpendicular to the first direction. The word lines are discontinuous in the dielectric portion of the second region and are electrically connected to the word line pick-up structures, respectively.