Nonvolatile Memory Device Program Voltage Control

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Solution Overview

Problem

Nonvolatile memory devices face challenges in reducing program time, leading to inefficiencies and potential E-UPPER phenomena that affect threshold voltage distributions and operational performance.

Innovation Solution

The nonvolatile memory device employs a control circuitry and verification circuitry to manage program voltage application through multiple loops, verifying success or failure within each loop to terminate the program at optimal time points, thereby reducing overall program time and minimizing the E-UPPER phenomenon.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the program voltage is applied for a longer duration to ensure complete programming, then the programming reliability is improved, but the program time increases and E-UPPER phenomenon worsens

Engineering Contradiction:

Improveprogramming reliabilityVSAvoidprogram time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements a verification circuitry that continuously monitors the programming status of memory cells and provides feedback to the control circuitry. Based on this feedback, the control circuitry dynamically adjusts the program voltage application duration, terminating the program operation early when verification succeeds, thus reducing program time while maintaining reliability.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent employs dynamic program time adjustment where the program voltage application duration is not fixed but varies based on real-time verification results. The control circuitry adapts the programming process by extending or shortening the program time according to the actual programming status, optimizing both reliability and speed.

Inventive Principle:

Principle #15Dynamics

2Reliability

If the program voltage is applied for a longer duration to ensure complete programming, then the programming reliability is improved, but the E-UPPER phenomenon worsens

Engineering Contradiction:

Improveprogramming reliabilityVSAvoidE-UPPER phenomenon

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The verification circuitry provides real-time feedback on programming status, enabling the control circuitry to terminate the program operation as soon as successful programming is detected. This prevents excessive program voltage application that would cause E-UPPER phenomenon, while still ensuring reliable programming through continuous verification.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent allows the programming process to be completed and terminated early by skipping the remaining program time when verification succeeds. This rushes through the necessary programming steps without unnecessary extensions, preventing E-UPPER phenomenon caused by prolonged voltage application.

Inventive Principle:

Principle #21Skipping (Rushing through)

3Productivity

If the program time is reduced to improve speed, then the program speed is improved, but the programming reliability may deteriorate

Engineering Contradiction:

Improveprogram speedVSAvoidprogramming reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The verification circuitry continuously monitors programming status and provides feedback to determine when programming is complete. This allows the system to use shorter program times while maintaining reliability by accurately detecting successful programming and terminating early, preventing both under-programming and over-programming.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The verification process operates in parallel or preliminary to the full program time completion, allowing the system to detect successful programming before the allocated program time expires. This enables confident early termination, improving speed without sacrificing reliability.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If multiple verification checks are performed to ensure programming success, then the programming reliability is improved, but the overhead time increases

Engineering Contradiction:

Improveprogramming success verificationVSAvoidverification overhead time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The verification circuitry performs verification checks continuously or in overlapping fashion with the programming process rather than sequentially after completion. This continuous verification approach detects successful programming as early as possible, minimizing verification overhead time while ensuring reliability through multiple check opportunities.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS11482288B2Nonvolatile memory device and method for operating with varying programming time

Publication Date: 2022.10.25 SAMSUNG ELECTRONICS CO LTD

AI summary

A nonvolatile memory device is provided. A nonvolatile memory device comprises a word line, a bit line, a memory cell array including a first memory cell at an intersection region between the word line and the bit line, a word line voltage generating circuitry configured to generate a program voltage, the program voltage to be provided to the word line, a row decoder circuitry configured to receive the program voltage from the word line voltage generating circuitry and configured to provide the program voltage to the word line, a verification circuitry configured to generate a verification signal in response to verifying a success or a failure of programming of the first memory cell, and a control circuitry configured to apply the program voltage to the first memory cell in response to the verification signal, and configured to cut off the program voltage in response to the verification signal.