Semi-Circular Split-Gate Memory Cells to Reduce Read Disturb
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Solution Overview
Problem
Read disturb in semi-circular memory cells of a memory device is a significant challenge, as it affects the reliability and integrity of data storage.
Innovation Solution
The implementation of split-gate cells with independent first and second memory cells, where reduced pass voltages are applied to unselected word lines to minimize interference during sensing operations, ensuring that current flows primarily through the selected cell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sensing operations are performed in semi-circular memory cells, then sensing speed is maintained, but read disturb increases affecting data reliability
Solution Approach 1:
The memory cell is divided into two separate gates (first gate and second gate) that can be independently controlled. This segmentation allows selective activation of only the required gate during sensing operations, preventing unintended activation of the other gate and thereby reducing read disturb to improve data reliability
Solution Approach 2:
Different voltage levels are applied to different gates based on their specific functional requirements. The first gate receives a first voltage level while the second gate receives a second voltage level, allowing optimized local control to minimize read disturb in specific regions while maintaining sensing performance
2Measurement precision
If higher voltages are applied to unselected word lines to ensure proper sensing, then sensing accuracy is maintained, but interference with unselected cells increases
Solution Approach 1:
The sensing operation is segmented into controlled voltage applications on separate gates. By applying voltage selectively to the first gate or second gate depending on the sensing requirement, the system maintains sensing accuracy while preventing voltage-induced interference in unselected cells through independent gate control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces read disturb, enhancing the reliability and integrity of data storage by minimizing unintended cell activation during sensing operations.
Implementation Method 1
conduct a current through the selected first memory cell to detect a threshold voltage of the selected first memory cell
Data Source
AI summary
The memory device includes an array of split-gate cells with first memory cells and second memory cells that can operate independently of one another and are arranged in first side-strings and second-side strings respectively. Control circuitry is configured to perform a sensing operation on a selected first memory cell to detect its threshold voltage. During the sensing operation, the control circuitry applies a reference voltage to the selected first memory cell, applies a first positive voltage to the second memory cells of a plurality of unselected word lines to partially turn on the second memory cells of the unselected word lines, and applies at least one pass voltage to the first memory cells of the unselected word lines to turn on the first memory cells of the unselected word lines. The control circuitry then conducts a current through the selected first memory cell to detect its threshold voltage.