Resistive Memory Cell With Compensation Device For Resistance Distribution

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Solution Overview

Problem

Current semiconductor memory devices face challenges in maintaining resistance distribution uniformity, which affects the sensing margin and data storage reliability in resistive memory devices.

Innovation Solution

Incorporating a compensation resistive device in series with the resistive device within each memory cell, along with a write driver that adjusts program currents and voltages to compensate for resistance variations, thereby enhancing the sensing margin and data storage accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a resistive memory device uses variable resistive materials without compensation, then the device structure remains simple, but the resistance distribution becomes non-uniform affecting sensing margin

Engineering Contradiction:

Improvesensing marginVSAvoidmemory cell structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The memory cell is segmented into three distinct components: a resistive device for data storage, a compensation resistive device for correcting resistance variations, and a selection transistor for controlling cell access. This segmentation allows each component to perform its specific function independently, resolving the contradiction by adding a dedicated compensation element rather than attempting to fix the entire cell structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The compensation resistive device is configured with specific local properties (higher resistance than the resistive device) to counteract the resistance distribution non-uniformity. By applying local quality enhancement through the compensation device, the patent improves the sensing margin at the specific location where resistance variation occurs without redesigning the entire memory device.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If compensation resistive devices are added to each memory cell, then resistance distribution uniformity improves, but the manufacturing complexity increases

Engineering Contradiction:

Improveresistance distribution uniformityVSAvoidfabrication process

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by configuring the compensation resistive device with a resistance value that is higher than that of the resistive device. This parameter differentiation allows the compensation device to effectively counteract resistance variations. The manufacturing process benefits from this clear parameter specification, as the compensation device can be designed with target resistance values that compensate for known process variations.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If higher program currents are used to overcome resistance distribution issues, then data storage reliability improves, but energy consumption increases

Engineering Contradiction:

Improvedata storage reliabilityVSAvoidprogram current energy

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the mechanical approach of simply increasing program current with an electrical compensation mechanism. Instead of applying higher currents to overcome resistance variations, the compensation resistive device electrically compensates for resistance distribution non-uniformity, allowing reliable data storage at lower, more energy-efficient current levels.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This approach effectively compensates for resistance distribution irregularities, increasing the sensing margin and ensuring reliable data storage and retrieval in resistive memory devices.

Implementation Method 1

resistive RAMs (RRAMs) using variable resistive materials, such as transition metal oxides

Methodology Applied

Scientific EffectVariable resistive material effect: Electrical Resistance

Implementation Method 2

phase-change random access memories (RAMs) (PRAMs) using phase-change materials

Methodology Applied

Scientific EffectPhase-change material effect: Phase Change

Implementation Method 3

magnetic RAMs (MRAMs) using ferromagnetic materials

Methodology Applied

Scientific EffectMagnetoresistance effect: Magnetoresistance

Data Source

PatentUS9165646B2Resistive memory device including compensation resistive device and method of compensating resistance distribution

Publication Date: 2015.10.20 SAMSUNG ELECTRONICS CO LTD

AI summary

A resistive memory device includes a memory cell array, an input/output (I/O) sense amplifier unit, an address input buffer, a row decoder, and a column decoder. The memory cell array includes unit memory cells, and operates in response to a word line driving signal and a column selecting signal, each unit memory cell includes a resistive device and a compensation resistive device. The I/O sense amplifier unit amplifies data output from the memory cell array to generate first data, and transfers input data to the memory cell array. The address input buffer generates a row address signal and a column address signal based on an external address. The row decoder decodes the row address signal and generates the word line driving signal based on the decoded row address signal. The column decoder decodes the column address signal and generates the column selecting signal based on the decoded column address signal.