Phase Change Memory Electrode Protrusion and Sacrificial Etching
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Solution Overview
Problem
Current phase change memory devices face challenges in achieving high integration of phase-change material layers, particularly in reducing the contact area between lower electrodes and memory elements to minimize current density and enhance reliability.
Innovation Solution
A method involving the formation of preliminary electrodes with protruding regions, followed by the creation of sacrificial regions and thin films on these regions, which are then etched to form openings for the integration of phase change memory elements, using materials like titanium, tantalum, and silicon-based compounds to reduce heat transfer and optimize electrode dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contact area between lower electrodes and memory elements is reduced, then current density is minimized and reliability is enhanced, but manufacturing complexity increases due to the need for preliminary electrodes, sacrificial regions, and multiple etching steps
Solution Approach 1:
Preliminary electrodes with protruding regions are formed in advance before the final memory element integration. These preliminary structures serve as templates that guide subsequent sacrificial region formation and etching processes, enabling precise control of contact area dimensions while simplifying the overall manufacturing sequence
Solution Approach 2:
Sacrificial regions are introduced as intermediary structures that temporarily occupy the space between lower electrodes and memory elements. These sacrificial regions are formed on the protruding regions of preliminary electrodes, then selectively removed through etching to create the desired contact area geometry, acting as a mediator that enables precise contact area control
2Manufacturing precision
If preliminary electrodes are formed with protruding regions and treated to form sacrificial regions, then contact area control is improved, but manufacturing steps and time are increased
Solution Approach 1:
The formation of sacrificial regions is merged with the preliminary electrode structure by directly treating the protruding regions of the preliminary electrodes. This integration eliminates separate formation steps and allows simultaneous definition of both the electrode geometry and sacrificial region locations, improving manufacturing precision without proportionally increasing cycle time
Solution Approach 2:
The protruding regions of preliminary electrodes are treated to form sacrificial regions, changing the material parameters and physical state of these regions. This parameter change enables selective removal of sacrificial regions through etching, achieving precise contact area control while utilizing the existing preliminary electrode geometry to minimize additional processing time
3Reliability
If thin films are formed on protruding regions and sacrificial regions, then heat transfer is minimized and structural integrity is enhanced, but device complexity and manufacturing steps increase
Solution Approach 1:
Thin films are deposited selectively on the protruding regions and sacrificial regions rather than uniformly across the entire substrate. This localized film formation provides targeted thermal isolation and structural support exactly where needed at the electrode-memory element interface, enhancing structural integrity while minimizing the total film deposition area and associated manufacturing complexity
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 enables the creation of highly integrated phase change memory devices with reduced contact areas, allowing for lower current densities and improved reliability by minimizing heat transfer and enhancing the structural integrity of memory elements.
Implementation Method 1
the treating includes at least one of oxidation or nitridation
Implementation Method 2
the treating includes at least one of oxidation or nitridation
Implementation Method 3
Phase change memory devices are example devices that store data by changing a state of a phase-change material by applying a current to a phase-change material layer
Data Source
AI summary
Memory devices and methods of forming memory devices including forming a plurality of preliminary electrodes, each of the plurality of preliminary electrodes including a protruding region, protruding from a first mold insulating layer, forming a second mold insulating layer on the first mold insulating layer, removing at least a portion of the plurality of preliminary electrodes to form a plurality of openings in the second mold insulating layer and a plurality of lower electrodes, and forming a plurality of memory elements in the plurality of openings. Memory devices and methods of forming memory devices including forming one or more insulating layers on sidewalls of all or part of a plurality of lower electrodes and/or a plurality of memory elements.