Phase Change Memory Cell Programming via Capacitance-Discharge Pulse
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current phase change memory (PCM) programming processes require a separate read operation to determine if a programming pulse is needed, which takes about 100 nanoseconds, including a 50 nanosecond read and 50 nanosecond programming pulse, limiting efficiency.
Innovation Solution
A capacitance-discharge current pulse is applied to the PCM cell with a self-selecting voltage greater than its present voltage threshold, allowing for thresholding and programming, with multiple pulses used to step-increase the material resistivity for multiple bit programming, reducing the total operation time to 25 nanoseconds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate read operation is performed before programming pulse to determine if programming is needed, then programming reliability is improved, but operation time increases to 100 nanoseconds
Solution Approach 1:
The patent combines the read operation and programming pulse application into a single integrated operation. The read pulse and program pulse are merged into one operation sequence, eliminating the need for a separate read step before programming. This integration reduces the total operation time from 100 nanoseconds to 50 nanoseconds while maintaining programming reliability through the self-selecting voltage mechanism that determines whether programming is needed.
Solution Approach 2:
The patent applies a read pulse before the programming pulse as a preliminary action that serves dual purposes: it reads the current state of the memory cell and simultaneously prepares the cell for programming by establishing the self-selecting voltage condition. This preliminary read action eliminates the need for a separate subsequent read operation, integrating two functions into one preliminary step.
2Adaptability or versatility
If multiple programming pulses are applied to program multiple bits, then data storage capacity is improved, but operation time increases
Solution Approach 1:
The patent uses periodic application of programming pulses to program multiple bits. Instead of applying all programming pulses simultaneously, they are applied in a sequential periodic manner where each pulse programs one bit and the cell state is evaluated. This periodic action allows multiple bits to be programmed within a single 50 nanosecond operation window, achieving both high capacity and fast operation.
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 method enables efficient programming of PCM cells by reducing the total operation time and allowing for multiple bit programming within a shorter timeframe, improving data storage efficiency in PCM devices.
Implementation Method 1
The program pulse may alter a phase or material resistivity of the memory cell
Implementation Method 2
determining if the applied voltage is greater than a voltage threshold of the selected memory cell
Data Source
AI summary
Described herein are techniques related to one or more systems, apparatuses, methods, etc. for programming a memory cell through the use of a program pulse.