MTJ Top Electrode Structure to Prevent Interconnect Voids
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MRAM devices face issues such as high chip area, high cost, high power consumption, limited sensitivity, and susceptibility to temperature variations, which affect their performance and efficiency.
Innovation Solution
A method for fabricating a semiconductor device involving the formation of a magnetic tunneling junction (MTJ) with asymmetrical top electrodes and spacers, achieved through controlled etching processes to create a planar and inclined top electrode surfaces, minimizing voids and seams in metal interconnections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If conventional MRAM devices are fabricated with symmetrical electrode structures, then manufacturing process is simpler, but chip area is larger and sensitivity is limited
Solution Approach 1:
The patent applies asymmetry by designing the top electrode with different surface heights at different locations. Specifically, the top electrode has a first surface at a first height and a second surface at a second height, creating an asymmetrical structure that reduces the overall chip area while maintaining functional performance. This asymmetrical design allows for more efficient space utilization compared to conventional symmetrical electrode structures.
Solution Approach 2:
The patent introduces dimensional variation by creating a top electrode with multiple surface heights rather than a single planar surface. This dimensional change from a two-dimensional planar electrode to a three-dimensional asymmetrical electrode enables reduced chip area while preserving the magnetic tunneling junction functionality.
2Manufacturing precision
If conventional planar top electrode surfaces are used, then fabrication is simpler, but voids and seams form in metal interconnections
Solution Approach 1:
The asymmetrical top electrode structure with different surface heights prevents the formation of voids and seams in metal interconnections by creating a gradient structure that facilitates uniform material deposition and reduces stress concentration points during the interconnection formation process.
Solution Approach 2:
The patent employs curved or inclined surfaces on the top electrode rather than sharp edges or completely flat surfaces. This curvature helps in reducing stress concentration and prevents the formation of voids and seams during metal interconnection deposition, improving the overall manufacturing precision of the interconnection structures.
3Measurement precision
If magnetic field sensor technologies are used, then data storage capability is achieved, but power consumption is high and sensitivity is limited
Solution Approach 1:
The patent utilizes composite material structures in the magnetic tunneling junction, combining different magnetic layers (fixed layer, free layer), barrier layers, and electrode materials. This composite structure enhances the sensitivity of the magnetic field detection while maintaining low power consumption by optimizing the magnetic anisotropy and tunneling magnetoresistance effects in each layer.
Solution Approach 2:
The patent optimizes various parameters including the thickness of magnetic layers, the composition of barrier layers, and the magnetic anisotropy of the free layer to enhance sensitivity. By carefully controlling these parameters, the device achieves high sensitivity magnetic field detection with reduced power consumption compared to conventional magnetic field sensor technologies.
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 enhances device performance by reducing chip area, lowering power consumption, and improving sensitivity while maintaining robustness against temperature variations.
Implementation Method 1
Magnetoresistance (MR) effect has been known as a kind of effect caused by altering the resistance of a material through variation of outside magnetic field
Data Source
AI summary
A method for fabricating semiconductor device includes the steps of: forming a magnetic tunneling junction (MTJ) on a substrate and a top electrode on the MTJ; forming a first inter-metal dielectric (IMD) layer around the MTJ and the top electrode; forming a stop layer on the first IMD layer; forming a second IMD layer on the stop layer; performing a first etching process to remove the second IMD layer and the stop layer; performing a second etching process to remove part of the top electrode; and forming a metal interconnection to connect to the top electrode.