Chalcogenide Memory Cell Adhesion via Ion Implantation
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Solution Overview
Problem
Chalcogenide materials used in memory cells face challenges with adhesion to adjacent materials, leading to delamination issues that can affect the performance and reliability of memory cells.
Innovation Solution
Ion implantation is used to enhance the adhesion of chalcogenide materials to electrode materials by introducing a dopant across their interface, which creates a boundary region characterized by damage-producing ions, improving the intermixing and bonding between the materials, and subsequent thermal annealing reinforces these bonds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chalcogenide materials are used as memory elements and select devices, then memory cell functionality is achieved, but adhesion to adjacent materials deteriorates leading to delamination
Solution Approach 1:
A buffer layer comprising silicon nitride is introduced between the chalcogenide material and adjacent materials (electrode materials, dielectric materials, or other chalcogenide materials). This intermediary buffer layer improves adhesion and prevents delamination while maintaining the memory cell functionality. The buffer layer acts as a mediator that resolves the adhesion incompatibility between chalcogenide materials and other materials in the memory cell structure.
Solution Approach 2:
The memory cell structure is transformed from using chalcogenide materials directly in contact with other materials to a composite structure where a silicon nitride buffer layer is interposed between different material layers. This composite approach combines the functional properties of chalcogenide materials with the adhesion properties of silicon nitride, achieving both memory functionality and improved structural stability.
2Device complexity
If chalcogenide material is deposited directly on electrode materials, then device complexity is reduced, but adhesion strength deteriorates
Solution Approach 1:
The silicon nitride buffer layer serves as an intermediary between the electrode material and the chalcogenide material, or between different chalcogenide material layers. This additional layer improves interfacial adhesion and prevents delamination during memory cell operation, while the overall structure remains relatively simple and compatible with standard fabrication processes.
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 method effectively prevents delamination and enhances the adhesion of chalcogenide materials to electrode materials, improving the stability and performance of memory cells by increasing the concentration of dangling bonds and altering crystallinity, which can persist through multiple read/write cycles.
Implementation Method 1
Dopant is implanted through the protective material into the outer electrode material and the programmable material and across the interface to enhance adhesion of the outer electrode material and the programmable material relative one another across the interface
Implementation Method 2
subsequent thermal annealing reinforces these bonds
Data Source
AI summary
A method of forming a memory cell includes forming an outer electrode material elevationally over and directly against a programmable material. The programmable material and the outer electrode material contact one another along an interface. Protective material is formed elevationally over the outer electrode material. Dopant is implanted through the protective material into the outer electrode material and the programmable material and across the interface to enhance adhesion of the outer electrode material and the programmable material relative one another across the interface. Memory cells are also disclosed.