Phase Change Memory Adaptive Programming Pulse Adjustment

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Solution Overview

Problem

Conventional phase change memory devices face challenges in increasing data storage density and meeting device performance specifications due to limitations in configuring memory cells to achieve optimal resistance states for data storage.

Innovation Solution

The development of a memory device with phase change memory cells that utilize programmable phase change materials, such as GeSbTe, to achieve various resistance states by adjusting the amplitude and transition time of programming signals, allowing for precise control of resistance values to represent different data values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional phase change memory devices use fixed programming approaches, then device structure is simple, but data storage density and performance specifications cannot be optimized

Engineering Contradiction:
Improvedata storage densityVSAvoidprogramming control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic programming by adjusting pulse amplitude and transition time parameters during the programming process. The system dynamically modifies these parameters based on real-time feedback from resistance measurements, enabling adaptive control to achieve optimal resistance states for higher data storage density while managing the increased control complexity through intelligent parameter adjustment rather than fixed approaches

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes physical parameters (amplitude and transition time of programming pulses) to achieve different resistance states in the phase change material. By varying these parameters, the system can precisely control the resistance state to represent different data values, thereby increasing data storage density through more effectively utilized memory states

Inventive Principle:
Principle #35Parameter changes

2Productivity

If programming pulses have fixed amplitude and transition time, then device operation is simple, but convergence to target resistance values is slow

Engineering Contradiction:
Improveprogramming speedVSAvoidprogramming control complexity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent implements feedback control by measuring the resistance of the phase change memory cell during programming and using this information to adjust subsequent programming pulses. This feedback mechanism accelerates convergence to target resistance values by continuously correcting deviations, while the complexity of feedback control is managed through automated parameter adjustment based on measured resistance states

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts pulse amplitude and transition time during the programming process based on real-time resistance measurements. This dynamic adaptation significantly improves programming speed and convergence to target values compared to fixed pulse approaches, with the control complexity managed through algorithmic parameter adjustment

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If memory cells are programmed to achieve optimal resistance states, then data storage density increases, but programming precision requirements become more stringent

Engineering Contradiction:
Improveresistance state precisionVSAvoidprogramming control complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The feedback mechanism measures actual resistance states and compares them with target values, automatically adjusting programming parameters to achieve precise resistance states. This feedback approach ensures high programming precision for optimal data storage density while managing control complexity through automated correction based on measured deviations

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system precisely controls resistance states by dynamically adjusting pulse amplitude and transition time parameters. This parameter control enables achievement of optimal resistance states for high data storage density, with the complexity managed through systematic parameter variation based on feedback information

Inventive Principle:
Principle #35Parameter changes

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 enhances data storage density and device performance by enabling precise programming of resistance states, improving data retention and reliability while allowing for faster convergence to target resistance values.

Implementation Method 1

The memory element may have a material that can change between different phases (e.g., crystalline and amorphous phases) when programmed. Different phases of the material may cause the memory cell to have different resistance states with different resistance values.

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

In some phase change memory devices, configuring the memory cells to increase data storage density or programming the memory cells to meet some device performance specifications may pose a challenge.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS9093142B2Phase change memory adaptive programming including pulse transition time adjustment
Publication Date: 2015.07.28 MICRON TECHNOLOGY INC
  • US9093142B2 patent drawing
  • US9093142B2 patent drawing
  • US9093142B2 patent drawing

AI summary

Some embodiments include methods and apparatus having a module configured to program a memory cell using a signal to cause the memory cell to have a programmed resistance value, to adjust a programming parameter value of the signal if the programmed resistance value is outside a target resistance value range, and to repeat at least one of the programming and the adjusting if the programmed resistance value is outside the target resistance value range, the signal including a different programming parameter value each time the programming is repeated.