Tapered Electrode for Resistance Variable Memory
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chemical vapor deposition (CVD) processes for forming electrodes in resistance variable memory devices result in seams, gaps, and rough surfaces, leading to inconsistent and uncontrollable device performance.
Innovation Solution
A tapered, cone-like first electrode is formed using physical vapor deposition (PVD) techniques with a minimized contact area, enhancing the formation of a conduction channel and improving switching properties by reducing surface area and promoting uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chemical vapor deposition (CVD) processes are used to form electrodes, then the electrode can be formed, but seams, gaps, and rough surfaces are created leading to inconsistent device performance
Solution Approach 1:
The patent changes the deposition method from chemical vapor deposition (CVD) to physical vapor deposition (PVD), fundamentally altering the process parameters to achieve smooth, seam-free electrode surfaces. This parameter change resolves the contradiction by eliminating the surface defects inherent in CVD processes while maintaining electrode formation capability
Solution Approach 2:
The patent replaces the chemical-based CVD process with a physical-based PVD process (such as sputtering or evaporation). This substitution eliminates chemical reactions that cause surface roughness and seam formation, thereby improving both electrode surface quality and device performance consistency
2Reliability
If a conventional plug electrode with large surface area is used, then the electrode can be formed, but the device lacks controllability and consistency
Solution Approach 1:
The patent applies local quality by creating an asymmetric electrode structure where the top surface area is minimized while the bottom remains anchored. This localized reduction in surface area at the critical interface improves controllability and consistency without compromising electrode formation or electrical connection
Solution Approach 2:
The patent introduces asymmetry in the electrode geometry, forming a tapered or conical shape rather than a symmetric cylindrical plug. This asymmetric design concentrates the electric field and current at a smaller top area, enhancing device controllability while maintaining adequate bottom anchoring
3Reliability
If physical vapor deposition (PVD) techniques are used to form a tapered electrode with minimized contact area, then consistency and controllability are improved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent employs curvature by forming a tapered or conical electrode shape rather than a straight cylindrical plug. This curved geometry is achieved through controlled PVD deposition angles and serves to concentrate the electric field at the tip, improving device consistency while the process remains integrated into standard semiconductor manufacturing
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
The solution improves the consistency and controllability of resistance variable memory elements by minimizing electrode contact area and surface roughness, facilitating better control over conduction channel formation and switching operations.
Implementation Method 1
A tapered, cone-like first electrode is formed using physical vapor deposition (PVD) techniques
Implementation Method 2
The resistance of the chalcogenide glass can be programmed to stable higher resistance and lower resistance states based on a voltage controlled movement of the conductive material within or into and out of the chalcogenide glass
Data Source
AI summary
A memory element comprising first and second electrodes is provided. The first electrode is tapered such that a first end of the first electrode is larger than a second end of the first electrode. A resistance variable material layer is located between the first and second electrodes, and the second end of the first electrode is in contact with the resistance variable material. Methods for forming the memory element are also provided.