Memory Block Threshold Compensation for Mixed Program/Erase Modes
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Solution Overview
Problem
In three-dimensional memory devices, the varying programming methods for sub-blocks within memory blocks lead to discrepancies in threshold voltages due to differences in program and erase operations, affecting reliability and data integrity.
Innovation Solution
A memory device with a control circuit that compensates for threshold voltage changes in sub-blocks by performing compensation operations when a predetermined cycling or program number is reached, adjusting voltages through offsets in program and erase operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different programming methods are used for different sub-blocks, then storage capacity and programming flexibility are improved, but threshold voltage discrepancies and reliability deteriorate
Solution Approach 1:
The patent applies parameter changes by adjusting the cycling number threshold and reference numbers for compensation operations. When the cycling number of program and erase operations reaches or exceeds a reference number, the control circuit performs compensation operations on affected sub-blocks to restore threshold voltages to normal levels, thereby maintaining data integrity while allowing diverse programming methods
Solution Approach 2:
The patent implements feedback through the control circuit that continuously monitors the cycling number of program and erase operations in each sub-block. Based on this feedback, the control circuit determines when compensation operations are needed and applies appropriate voltage offsets to restore threshold voltages, creating a closed-loop system that maintains reliability despite varying programming methods
2Stability of the object's composition
If compensation operations are performed frequently, then threshold voltage stability is improved, but device complexity and operation time worsen
Solution Approach 1:
The patent applies preliminary action by pre-setting reference numbers for cycling counts before operations begin. The control circuit compares the actual cycling number against these pre-established thresholds and only initiates compensation operations when the threshold is reached, avoiding unnecessary operations and simplifying control logic
Solution Approach 2:
The patent uses parameter changes by adjusting the reference number threshold to balance compensation frequency. By optimizing this parameter, the system achieves threshold voltage stability while minimizing the frequency of compensation operations, thereby reducing operational overhead and complexity
Data Source
AI summary
There are provided a memory device and an operating method of the memory device. The memory device includes: a memory block including a plurality of sub-blocks; a peripheral circuit for performing first program and erase operations in a first manner in a first sub-block, among the plurality of sub-blocks, and performing second program and erase operations in a second manner in a second sub-block, among the plurality of sub-blocks; and a control circuit configured to, when a cycling number of the second program and erase operations that are performed in the second sub-block is equal to or greater than a reference number, control the peripheral circuit to perform a compensation operation that compensates for a threshold voltage of memory cells included in the first sub-block.