Lateral Phase Change Memory Cell for Low Reset Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Phase change memory devices face challenges in reducing reset current, particularly due to limitations in electrode confinement and phase change material confinement techniques, which affect scaling and reliability.
Innovation Solution
The implementation of a lateral ultrathin phase change memory cell with a sub-30 nm inner electrode and a 10 nm phase change material layer, utilizing both electrode confinement and phase change material confinement to reduce reset current, while maintaining compatibility with current manufacturing methods and minimizing resistance drift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If electrode confinement is used to reduce reset current, then reset current is reduced, but manufacturing yield deteriorates
Solution Approach 1:
The electrode is divided into two distinct parts: a first electrode and a second electrode, both extending in the lateral direction. This segmentation allows each electrode to have optimized dimensions for confinement while maintaining manufacturing feasibility through simultaneous formation processes.
Solution Approach 2:
The patent transitions from vertical confinement approaches to lateral confinement, where electrodes extend in the lateral direction rather than relying solely on vertical stacking. This dimensional change enables confinement effectiveness while using manufacturing-compatible lateral patterning techniques.
2Loss of energy
If phase change material confinement is used to reduce reset current, then reset current is reduced, but structural integrity deteriorates
Solution Approach 1:
The phase change material layer is configured with specific local thickness characteristics - thinner regions positioned between the first and second electrodes to enhance confinement and reduce reset current, while maintaining overall structural integrity through the layered architecture and support from electrode structures.
Solution Approach 2:
The patent optimizes the thickness parameter of the phase change material layer, creating ultrathin regions (few nanometers) in critical areas to achieve confinement effects. This parameter control enables reset current reduction while the overall layer structure maintains structural stability.
3Loss of energy
If technology scaling is pursued to reduce reset current, then device size is reduced, but manufacturing complexity increases
Solution Approach 1:
The first and second electrodes are formed simultaneously in a single manufacturing step, merging what could be separate fabrication processes into one operation. This reduces manufacturing complexity while achieving the scaled-down device structure needed for low reset current.
Solution Approach 2:
The lateral electrode structure serves multiple functions: it provides electrical contacts, enables phase change material confinement, and facilitates simultaneous formation during manufacturing. This multi-functionality reduces overall device complexity while maintaining scaling benefits.
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 reduces reset current, eliminates RIE damage, and provides tunable resistance, making low-drift phase change materials more practical by enabling higher resistance and reduced resistance drift.
Implementation Method 1
The phase change material may be operated in one of at least two reversibly transformable phases, an amorphous phase and a crystalline phase
Implementation Method 2
In the amorphous phase, the phase change material has a discernibly higher resistance when compared to the crystalline phase
Implementation Method 3
energy is supplied to the phase change material such as, for example, electrical energy, thermal energy
Data Source
AI summary
A structure including an inner electrode and an outer electrode on a substrate and a phase change material layer, the phase change material layer vertically aligned above both the inner electrode and the outer electrode. A structure including an inner electrode and an outer electrode on a substrate and a phase change material layer, the phase change material layer vertically aligned above both the inner electrode and the outer electrode, where the inner electrode and the outer electrode are on the same horizontal plane. A method including forming an inner electrode and an outer electrode simultaneously on a substrate, forming a phase change material layer above both the inner electrode and the outer electrode.