3D Memory CSL Driver Segmentation for Noise Skew Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The variation in size of the common source line (CSL) in flash memory devices leads to CSL noise skew, making it difficult to control voltage distribution across memory cell arrays, resulting in a widened threshold voltage distribution.
Innovation Solution
A memory device with a CSL driver that connects to the CSL through multiple networks, allowing independent control of each network based on the physical location of the CSL, enabling adjustment of the number of activated networks to reduce CSL noise skew.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single CSL driver is used to discharge the CSL, then the device complexity is reduced, but the CSL noise skew cannot be controlled due to variation in CSL size across different physical locations
Solution Approach 1:
The CSL driver is divided into multiple independent CSL driving units (first CSL driving unit, second CSL driving unit, etc.), each connected to different regions of the CSL through separate networks. This segmentation allows independent control of discharge operations in different physical locations, enabling precise control of CSL noise skew while maintaining overall system reliability.
2Adaptability or versatility
If the CSL size varies to accommodate different physical locations in the memory cell array, then the adaptability is improved, but the CSL noise skew increases making threshold voltage control difficult
Solution Approach 1:
Different CSL driving units are configured with different discharge characteristics tailored to their specific physical locations in the memory cell array. Each driving unit can be independently controlled to compensate for local variations in CSL size and capacitance, ensuring uniform threshold voltage distribution across the entire array despite physical location differences.
Solution Approach 2:
The CSL driving units can be dynamically activated or deactivated based on the specific operation requirements and physical location being accessed. This dynamic control allows the system to adapt to varying CSL conditions in different regions, maintaining precise threshold voltage control while accommodating the necessary CSL size variations for adaptability.
Data Source
AI summary
A memory device includes a stack structure, in which a common source line is formed, and a peripheral circuit structure overlapping the stack structure when viewed in plan view and comprising a common source line driver configured to discharge the common source line. The common source line driver includes a first common source line driving unit, electrically connected to the common source line through a first network and configured to discharge the common source line, and a second common source line driving unit electrically connected to the common source line through a second network, different from the first network, and configured to discharge the common source line. The first common source line driving unit and the second common source line driving unit are controlled independently of each other.