3D Nonvolatile Memory Page Programming Voltage Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Nonvolatile memory devices face challenges in maintaining read margins due to electrical disturbances between memory cells, particularly in 3D arrays where program and read operations can lead to reduced reliability and performance.

Innovation Solution

The implementation of a method and structure for nonvolatile memory devices that adjust program and read schemes based on the location and order of string selection lines, using voltage generators and control logic to manage program and read voltages, ensuring sufficient threshold voltage distributions and preventing read failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If memory cells are arranged in 3D arrays to increase storage capacity, then storage capacity is improved, but program disturbances between memory cells increase causing reduced read margins

Engineering Contradiction:

Improvestorage capacityVSAvoidread margin

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies preliminary action by determining the program order of pages based on their string selection line locations before actually programming. Pages are sorted and assigned a program sequence in advance, allowing the system to proactively manage program disturbances rather than reacting to them after they occur. This preliminary ordering ensures that pages are programmed in an optimal sequence that minimizes interference.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of program voltage level dynamically based on the program order and location. Different voltage levels are applied depending on the page's position in the program sequence and its string selection line location. This parameter adjustment allows the system to compensate for program disturbances by using higher voltages for pages more susceptible to interference and lower voltages for pages less affected, thereby maintaining read margins while preserving storage capacity.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If program voltage is applied to selected pages, then data programming is achieved, but electrical disturbances affect adjacent memory cells reducing read margins

Engineering Contradiction:

Improveprogramming capabilityVSAvoidprogram disturbance

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by treating different pages with different program voltage levels based on their specific locations and program orders. Instead of using a uniform voltage for all pages, the system assigns localized voltage characteristics to each page according to its string selection line location and position in the program sequence. This localized approach allows programming capability to be maintained while minimizing program disturbances to adjacent cells by applying appropriate voltage levels locally.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the program voltage parameter dynamically based on the page's program order and location. The control logic determines different voltage levels for different pages in the program sequence, adjusting the electrical parameters to optimize between programming effectiveness and minimizing disturbance to neighboring memory cells.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If multiple pages share a common word line, then device complexity is reduced, but determining program order and voltage levels increases control complexity

Engineering Contradiction:

Improveword line structureVSAvoidcontrol logic complexity

Core Design Contradiction:

Device complexityVSExtent of automation

Solution Approach 1:

The patent manages control logic complexity by systematically changing parameters (program order and voltage levels) based on well-defined rules related to string selection line locations. The control logic automates the determination of program sequences and voltage assignments using algorithms that consider the spatial arrangement of pages, thereby handling the increased control requirements through structured parameter management rather than ad-hoc control mechanisms.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8942046B2Method of programming a 3-dimensional nonvolatile memory device based on a program order of a selected page and a location of a string selection line

Publication Date: 2015.01.27 SAMSUNG ELECTRONICS CO LTD

AI summary

A nonvolatile memory device comprises cell strings formed in a direction substantially perpendicular to a substrate and is configured to select memory cells in units corresponding to a string selection line. The device selects a page to be programmed among pages sharing a common word line, determines a level of a program voltage to be provided to the selected page according to a location of a string selection line corresponding to the selected page, and writes data in the selected page using the determined level of the program voltage.