Nonvolatile Memory Word-Line Leakage Detection

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Solution Overview

Problem

Nonvolatile memory devices with three-dimensional structures, such as vertical NAND memory devices, face issues with leakage current in word-lines, leading to abnormal operations during program, read, and erase operations, necessitating effective detection methods to ensure reliable data storage and retrieval.

Innovation Solution

A method and device for simultaneously detecting word-line leakage by applying specific voltage sequences to precharge driving lines and detect voltage drops at a sensing node, allowing for the identification of leakage in word-lines during the program operation and terminating the program loop if leakage occurs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If nonvolatile memory devices use three-dimensional structure to increase integration degree and memory capacity, then memory capacity is improved, but leakage current occurs in word-lines causing abnormal operations

Engineering Contradiction:

Improvememory capacityVSAvoidoperation reliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies preliminary action by performing leakage detection before completing the program operation. The method detects leakage current in word-lines during the program operation and terminates the operation early if leakage is detected, preventing data corruption before it occurs. This early detection mechanism resolves the contradiction by maintaining operation reliability without sacrificing memory capacity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by continuously monitoring leakage current during program operation and using this information to control the operation flow. The leakage detection result feeds back to the control circuit, which decides whether to continue or terminate the program operation. This feedback mechanism ensures that high memory capacity operations do not compromise reliability.

Inventive Principle:

Principle #23Feedback

2Reliability

If leakage detection is performed during program operation, then operation reliability is improved, but detection time and operation time increase

Engineering Contradiction:

Improveoperation reliabilityVSAvoiddetection time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies continuity of useful action by performing leakage detection concurrently with the program operation rather than sequentially. The detection process utilizes the same program operation timeline, detecting leakage current while the programming is ongoing. This approach maintains operation reliability without adding significant detection time, as the detection occurs during the existing operation duration.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent implements skipping by rapidly detecting leakage current at critical points during the program operation and immediately terminating the operation if leakage is detected. This rushing through the detection process at key moments prevents time-consuming sequential checks while maintaining reliable leakage detection, thus resolving the time-reliability trade-off.

Inventive Principle:

Principle #21Skipping (Rushing through)

Data Source

PatentUS11798626B2Nonvolatile memory device and method of operating a nonvolatile memory

Publication Date: 2023.10.24 SAMSUNG ELECTRONICS CO LTD

AI summary

A method of operating a nonvolatile memory device which includes at least one memory block is provided. The method includes providing a plurality of word-lines with a voltage during a word-line set-up period, precharging a plurality of driving lines with a voltage during a word-line development period, detecting a voltage drop of a sensing node during a sensing period, and detecting leakage based on the voltage drop.