Tapered ReRAM with Interface Dipoles
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Solution Overview
Problem
Resistive random-access memory (ReRAM) devices face challenges with random filament placement leading to higher variability and higher forming voltage, as well as abrupt SET programming due to Joule heating during filament formation and rupture.
Innovation Solution
The development of tapered resistive memory devices with interface dipoles, featuring a thermally conductive core dielectric, oxide resistive memory cells with tapered edges, and a top electrode that wraps around the cell, which geometrically constrains filament formation towards the inner edges and reduces Joule heating by directing electric fields and flux density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ReRAM cells with straight oxide resistive memory cells are used, then device structure is simple, but filament formation is random leading to higher variability and higher forming voltage
Solution Approach 1:
The patent applies asymmetry by transitioning from straight oxide resistive memory cells to tapered oxide cells with angled sidewalls. This asymmetric geometry creates a non-uniform electric field distribution that guides filament formation toward the inner edge, achieving controlled and uniform filament placement while managing the increased structural complexity through deliberate geometric design
2Reliability
If high voltage is applied to form filaments, then filament formation is achieved, but Joule heating increases causing abrupt SET programming
Solution Approach 1:
The patent applies local quality by creating a non-uniform electric field within the tapered oxide cell structure. The electric field is concentrated at the inner edge where the oxide thickness is greatest, localizing filament formation to this specific region. This localized field distribution enables controlled filament growth with reduced overall Joule heating, achieving reliable and controlled SET programming
3Manufacturing precision
If straight oxide cells are used, then device fabrication is straightforward, but filament formation voltage is high and variable
Solution Approach 1:
The patent implements asymmetry through tapered oxide cells with angled sidewalls formed by patterning at specific angles (e.g., 45 degrees). This asymmetric geometry creates consistent electric field distribution that lowers and stabilizes forming voltage across devices. While the patterning process becomes more complex, the resulting voltage consistency improves manufacturing precision and device reliability
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 design achieves more localized and uniform filament formation, reducing Joule heating and resulting in less abrupt SET programming, thereby improving the reliability and efficiency of ReRAM devices.
Implementation Method 1
a core dielectric that is thermally conductive disposed on the bottom electrode
Implementation Method 2
the outer edges of the oxide resistive memory cell that are tapered geometrically constrain formation of the filaments toward the inner edges of the oxide resistive memory cell
Data Source
AI summary
Tapered resistive memory devices with interface dipoles are provided. In one aspect, a ReRAM device includes: a bottom electrode; a core dielectric that is thermally conductive disposed on the bottom electrode; an oxide resistive memory cell disposed along outer sidewalls of the core dielectric, wherein the oxide resistive memory cell has inner edges adjacent to the core dielectric, and outer edges that are tapered; an outer coating disposed adjacent to the outer edges of the oxide resistive memory cell; and a top electrode disposed on the core dielectric, the oxide resistive memory cell, and the outer coating. A method of forming a ReRAM device as well as a method of operating a ReRAM device are also provided.