Variable Resistance Memory Device Oxygen Migration Control
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Solution Overview
Problem
Non-volatile memory elements with variable resistance layers composed of metal oxide layers of different oxygen content atomic percentages exhibit fluctuations in element characteristics when stacked together, leading to inconsistent performance.
Innovation Solution
A method of manufacturing variable resistance non-volatile memory devices where the thickness and area of the second metal oxide layer with higher oxygen content are controlled to match the first metal oxide layer, ensuring equal initial resistance across all elements by adjusting these parameters during the formation of each non-volatile memory element layer, and optionally forming an oxygen barrier layer to inhibit oxygen migration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple non-volatile memory element layers are stacked together with variable resistance layers including metal oxide layers of different oxygen content atomic percentages, then the memory capacity is increased, but the element characteristics fluctuate and performance becomes inconsistent
Solution Approach 1:
The patent applies parameter changes by systematically adjusting the thickness and area of the second metal oxide layer across different non-volatile memory element layers. By varying these geometric parameters, the patent compensates for fluctuations in element characteristics and achieves equal initial resistance across all layers, thereby maintaining reliability while increasing memory capacity through stacking.
Solution Approach 2:
The patent implements local quality by making each non-volatile memory element layer have different thickness and area parameters tailored to its specific position in the stack. Instead of uniform dimensions, each layer is locally optimized with specific thickness and area values to achieve consistent initial resistance, allowing the overall device to maintain high reliability while achieving high capacity through multiple layers.
2Reliability
If the thickness and area of metal oxide layers are adjusted to achieve equal initial resistance, then element characteristic consistency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent manages manufacturing complexity by systematically varying only two key parameters - thickness and area of the second metal oxide layer - while keeping other layer parameters constant. This controlled parameter change approach achieves equal initial resistance across layers without requiring complex manufacturing processes, as the adjustments can be made through standard deposition and patterning techniques with modified dimensions.
3Manufacturing precision
If the thickness of the second metal oxide layer is increased, then the initial resistance decreases, but the resistance changing characteristics become inconsistent across layers
Solution Approach 1:
The patent resolves this contradiction by simultaneously adjusting two parameters - thickness and area of the second metal oxide layer - rather than changing only thickness. This dual-parameter adjustment allows independent control of initial resistance (primarily through thickness) and resistance changing characteristics (through the combined effect of thickness and area), achieving both manufacturing precision and 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 approach effectively suppresses fluctuations in element characteristics, ensuring uniform resistance changing characteristics across multiple layers, thereby enhancing the reliability and capacity of the memory device.
Implementation Method 1
a second metal oxide layer comprising a second metal oxide having a higher oxygen content atomic percentage than the first metal oxide
Implementation Method 2
a redox reaction is caused to take place selectively in a region of an interface between an electrode and a variable resistance layer with a higher oxygen content atomic percentage, contacting the electrode, and resistance change is stabilized
Data Source
AI summary
In a method of manufacturing a variable resistance non-volatile memory device including non-volatile memory element layers stacked together by repeating the step (S100, S200 . . . ) of forming a non-volatile memory element layer plural times, when a thickness of the second metal oxide layer included in each of the non-volatile memory element layers just after the step of forming the corresponding non-volatile memory element layer is completed is a thickness in formation, and when an area of a portion of the second metal oxide layer included in each of the non-volatile memory element layers and a portion of the first metal oxide layer included in the corresponding non-volatile memory element layer, which portions are in contact with each other, just after the step of forming the corresponding non-volatile memory element layer is completed is an area in formation, at least one of the thickness in formation and the area in formation is made different among the steps of forming the non-volatile memory element layers, to cause all of the non-volatile memory elements in a state in which formation of an uppermost non-volatile memory element layer is completed, to have an equal initial resistance.