Memory Program Resume Verify for Suspend-Induced Cell Misclassification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Memory devices face issues with misclassification of memory cells during program suspend-resume operations, leading to overprogramming and increased programming time due to charge loss and voltage overshoot, which degrades the programming efficiency.

Innovation Solution

Implementing selective slow program convergence (SSPC) techniques with modified program verify and pulse mechanisms to restore correct classification and adjust bitline voltages for misclassified memory cells upon resume, avoiding overprogramming and reducing programming time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If program suspend-resume operations are implemented in memory devices, then programming flexibility and host system responsiveness are improved, but misclassification of memory cells occurs leading to overprogramming and increased programming time

Engineering Contradiction:

Improveprogramming flexibilityVSAvoidmemory cell classification accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent performs a program verify operation before resuming programming to detect and correct misclassified memory cells. This preliminary verification step identifies cells that have been incorrectly classified due to charge loss during suspend, allowing the system to restore correct classification and prevent overprogramming before continuing the programming sequence.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the state of memory cells is re-evaluated after suspend by performing program verify operations. Based on the verification results, the system adjusts the classification of memory cells, restoring those that were misclassified due to charge loss, and uses this corrected classification information to guide subsequent programming operations.

Inventive Principle:

Principle #23Feedback

2Ease of operation

If program suspend-resume operations are implemented, then host system responsiveness is improved, but programming time increases due to additional verify operations and corrections

Engineering Contradiction:

Improvehost system responsivenessVSAvoidprogramming time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The patent performs program verify operations on selected subsets of memory cells rather than all cells, focusing verification efforts on cells that are most likely to have been misclassified. This partial verification approach corrects the critical misclassification issues while minimizing the time overhead compared to verifying every cell.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent dynamically adjusts programming parameters such as pulse voltage and pulse duration based on the classification state of memory cells. By modifying these parameters according to the verified classification, the system optimizes programming speed while maintaining accuracy, reducing overall programming time despite the suspend-resume interruptions.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If memory cells are reclassified after suspend, then overprogramming is avoided, but device complexity increases due to additional control logic and operations

Engineering Contradiction:

Improveprogramming accuracyVSAvoidcontrol logic complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent utilizes existing program verify circuitry and control logic for the suspend-resume functionality, making these components serve multiple purposes: both the standard programming verification and the post-suspend classification correction. This multi-functional use of existing hardware reduces the need for additional dedicated circuitry for misclassification correction.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own existing verification and classification mechanisms to detect and correct misclassified cells after suspend, rather than requiring external correction circuits or complex additional control logic. The memory device self-corrects the classification errors using its built-in capabilities.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS20250364062A1Program suspend-resume operations in a memory device

Publication Date: 2025.11.27 MICRON TECHNOLOGY INC

AI summary

A memory device includes a memory array of memory cells and control logic operatively coupled with the memory array. The control logic causes a program verify operation to be performed on a set of memory cells of the memory array in response to receiving a suspend command while programming the set of memory cells. The control logic reduces a target pre-program verify voltage or increases a target pre-program verify boost voltage for the set of memory cells in response to receiving a resume command. The control logic causes the program verify operation to again be performed on the set of memory cells before resuming programming the set of memory cells.