Segmented Buried Gate Memory Structure for Row Hammer Isolation
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Solution Overview
Problem
Existing memory device fabrication processes result in row hammer effects due to embedded gates penetrating through active and isolation structures, causing noise and interference leading to data errors in adjacent rows.
Innovation Solution
The method involves forming buried gate structures first on a substrate, followed by patterning to create active structures and isolation grooves, and then forming conductive word lines on the surfaces of these structures, ensuring the buried gates are not penetrating through, thus reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If embedded gates penetrate through active structures and isolation structures, then device integration is achieved, but row hammer effects occur causing noise and data errors in adjacent rows
Solution Approach 1:
The embedded gate structure is segmented into multiple sections: a first embedded gate section in the first active structure, a second embedded gate section in the second active structure, and an isolation section in the isolation structure. This segmentation prevents the gate from continuously penetrating through the isolation structure, thereby eliminating row hammer effects while maintaining device integration.
Solution Approach 2:
Different sections of the embedded gate structure are assigned different local qualities: the first and second embedded gate sections are conductive for transistor control, while the isolation section is non-conductive (or has different conductivity) to block electrical interference between adjacent rows. This local differentiation resolves the contradiction by allowing integration without continuous penetration.
2Ease of manufacture
If embedded gates continuously penetrate through isolation structures, then manufacturing process is simplified, but electrical interference occurs between adjacent memory rows
Solution Approach 1:
The isolation section of the embedded gate is formed in advance within the isolation structure during the same manufacturing process. This preliminary action ensures that the non-conductive barrier is already in place before subsequent processing steps, preventing electrical interference without requiring additional complex manufacturing steps.
Solution Approach 2:
The formation of the isolation section is merged with the existing embedded gate formation process. The same manufacturing steps that create the conductive gate sections also create the non-conductive isolation section, maintaining manufacturing simplicity while ensuring data integrity through the interrupted gate structure.
3Device complexity
If embedded gates extend through isolation structures, then device structure is simplified, but noise interference affects adjacent rows during repeated activation
Solution Approach 1:
The isolation section acts as an intermediary element between adjacent active structures. This non-conductive section interrupts the continuous gate structure, serving as a mediator that blocks noise and electrical interference from propagating between adjacent memory rows during repeated activation and refresh operations.
Data Source
AI summary
Embodiments provide a memory device and a method for fabricating the same, relating to the field of semiconductor technology. The method includes: forming buried gate structures in a first direction in a substrate; patterning the substrate, cutting off the buried gate structures, and forming active structures arranged at parallel intervals and isolation grooves between the active structures in a second direction, where the active structures are island-shaped columnar bodies, and the active structures include the buried gate structures; forming isolation structures in the isolation grooves, where surfaces of the isolation structures are flush with surfaces of the active structures; and forming conductive word lines in the first direction on the surfaces of isolation structures and the surfaces of the active structures, where the conductive word lines cover upper surfaces of the buried gate structures in the active structures.