Flash Memory Leakage Detection via Driving Line Floating

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Solution Overview

Problem

The increasing integration density in flash memory devices leads to reduced reliability due to leakage currents between memory cells, necessitating an accurate detection method to maintain device performance.

Innovation Solution

A memory device with a leakage detecting circuit and an operation method that involves precharging and floating driving lines to sense voltage variations, allowing for the detection of leakage currents through word lines, enabling accurate leakage current detection and improved reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the degree of integration of the flash memory device is improved, then storage capacity increases, but leakage current between memory cells increases causing reliability to decrease

Engineering Contradiction:
Improvestorage capacityVSAvoidreliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The detection process is segmented into multiple distinct phases: a first detection phase that measures total leakage current through the driving line, and a second detection phase that measures leakage current through the word line only. This segmentation allows isolation and accurate measurement of the specific leakage component affecting reliability while maintaining high integration density.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A capacitor is introduced as an intermediary element to store the voltage variation corresponding to the first leakage current. This capacitor acts as a mediator that holds the measured value for later comparison, enabling the subtraction of driving line leakage from total leakage to isolate the word line leakage component that impacts reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If leakage current detection accuracy is improved by measuring voltage variations, then reliability detection improves, but device complexity increases due to additional circuit operations

Engineering Contradiction:
Improveleakage current detection accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The capacitor is precharged to a reference voltage level before the detection phases begin. This preliminary action establishes a known baseline that simplifies the subsequent measurement process, allowing direct comparison of voltage variations without requiring complex real-time reference management during the actual leakage detection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The same driving line and leakage detecting circuit are used for both phases of detection (total leakage and word line leakage). The circuit serves itself by reusing existing components rather than introducing entirely separate measurement paths, thereby improving measurement precision while minimizing the increase in device complexity.

Inventive Principle:
Principle #25Self-service

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

The solution effectively detects leakage currents in flash memory devices, enhancing the reliability and accuracy of memory operations by isolating and measuring leakage currents, thereby improving the overall performance and longevity of the devices.

Implementation Method 1

floating the first driving line from the first voltage to sense a first voltage variation of the first driving line, storing the first voltage variation in a first capacitor of the leakage detecting circuit

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP4113521A1Memory device detecting leakage current and operation method thereof
Publication Date: 2023.01.04 SAMSUNG ELECTRONICS CO LTD
  • EP4113521A1 patent drawingFigure 1
  • EP4113521A1 patent drawingFigure 2
  • EP4113521A1 patent drawingFigure 3

AI summary

Disclosed is an operation method of a memory device which includes floating a first driving line corresponding to a first word line from the first word line and precharging the first driving line with a first voltage, floating the first driving line from the first voltage to sense a first voltage variation of the first driving line, storing the first voltage variation in a first capacitor, electrically connecting the first driving line to the first word line and precharging the first driving line and the first word line with the first voltage, floating the first driving line and the first word line from the first voltage to sense a second voltage variation of the first driving line and the first word line, and outputting a first detection signal corresponding to a first leakage current through the first word line based on the first voltage variation and the second voltage variation.