Biased Plasma Oxidation for Metal Oxide RRAM Memory
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior methods for forming metal oxide-based RRAM memory cells result in a rough oxidized surface, leading to non-uniform electrical fields and inconsistent resistance, affecting device reliability and performance.
Innovation Solution
A biased plasma oxidation process is applied to smooth and round the surface of the metal oxide layer, improving oxygen distribution and creating a more uniform interface with the top electrode, thereby enhancing the electrical field and consistency of resistance across memory cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rapid thermal oxidation is used to form the metal oxide layer, then the oxidation process is fast and efficient, but the resulting surface is rough and creates non-uniform electrical fields
Solution Approach 1:
The oxidation process is divided into two distinct stages: first, rapid thermal oxidation to quickly form the metal oxide layer and achieve high productivity; second, plasma oxidation to smooth the surface and create uniform electrical fields. This segmentation allows each process to optimize for its specific function without compromise.
Solution Approach 2:
Plasma oxidation is introduced as an intermediary process between rapid thermal oxidation and top electrode deposition. This intermediate step modifies the rough oxidized surface by smoothing it and rounding edges, creating an ideal interface for subsequent electrode deposition while maintaining the benefits of rapid oxidation.
2Device complexity
If rapid thermal oxidation is used to form the metal oxide layer, then the process is simple and fast, but the resistance consistency across memory cells is low
Solution Approach 1:
The formation process is segmented into rapid thermal oxidation followed by plasma oxidation. The plasma oxidation stage specifically addresses resistance consistency by uniformly oxidizing the metal surface and creating consistent oxygen distribution, resulting in more uniform resistance characteristics across all memory cells in the device.
Solution Approach 2:
The oxidation process parameters are changed from purely thermal to include plasma treatment. This parameter change introduces ion bombardment and reactive species that enhance oxygen incorporation and distribution uniformity, leading to improved resistance consistency without significantly increasing overall process complexity.
3Productivity
If the oxidized surface is rough, then the oxidation process is efficient, but the electrical field uniformity during operation is poor
Solution Approach 1:
Plasma oxidation serves as an intermediary treatment that processes the rough surface created by rapid thermal oxidation. It smooths the surface and rounds edges through controlled ion bombardment and oxidation, creating a uniform interface that ensures even electrical field distribution during device operation while preserving the efficiency benefits of rapid oxidation.
Solution Approach 2:
The plasma oxidation process performs preliminary surface conditioning before top electrode deposition. By pre-smoothing the oxidized surface and rounding edges in advance, it prepares an ideal interface that ensures uniform electrical field formation during subsequent device operation, preventing field concentration at sharp edges.
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 biased plasma oxidation process results in a more uniform electrical field and increased, consistent resistance across memory cells, improving device reliability and performance by reducing surface roughness and enhancing oxygen distribution.
Implementation Method 1
A biased plasma oxidation process is then performed which reduces the volume of oxidized material in the metal oxide layer and further oxidizes at least some portion of the remaining metal oxide in the metal oxide layer. Further, this biased plasma oxidation process creates a smooth and rounded arcuate surface
Data Source
AI summary
The present invention relates to metal oxide based memory devices and methods for manufacturing such devices, and more particularly to memory devices having data storage materials based on metal oxide compounds fabricated with a biased plasma oxidation process which improves the interface between the memory element and a top electrode for a more a uniform electrical field during operation, which improves device reliability.