Magnetic Shield Structure for MRAM Data Retention
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Solution Overview
Problem
Magnetoresistive Random Access Memory (MRAM) devices are susceptible to errors due to interference from external magnetic fields, which affects their data retention and reliability.
Innovation Solution
A magnetic shield structure is implemented around the magnetoresistive semiconductor device, comprising top and bottom shields made of high permeability metals like nickel-iron alloy, which are strategically positioned to redirect external magnetic fields away from the device, thereby enhancing its immunity to external magnetic disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MRAM devices are used for data retention, then speed and non-volatility are improved, but susceptibility to external magnetic field interference increases
Solution Approach 1:
A magnetic shield layer comprising a first magnetic shield layer and a second magnetic shield layer is introduced as an intermediary between the external environment and the MRAM device. The shield layers redirect external magnetic fields around the device, preventing direct interference while maintaining the device's magnetic storage functionality. This resolves the contradiction by adding a protective intermediary that blocks harmful magnetic fields without affecting data retention performance.
Solution Approach 2:
The magnetic shield layers are designed with specific material properties and geometric parameters (thickness, spacing, orientation) to optimize magnetic field redirection. By adjusting these parameters, the shield effectiveness is maximized while maintaining compatibility with the MRAM device's operational requirements, thus improving reliability without excessive susceptibility to external fields.
2Object-affected harmful factors
If magnetic shield layers are added around the MRAM device, then immunity to external magnetic fields is improved, but device complexity increases
Solution Approach 1:
The magnetic shielding function is divided into multiple discrete layers (first magnetic shield layer and second magnetic shield layer) with distinct orientations and positions. This segmentation allows each layer to be optimized for specific directional protection and simplifies the manufacturing process compared to a single complex shield structure, thereby reducing overall device complexity while maintaining high immunity.
Solution Approach 2:
The magnetic shield layers serve multiple functions: they redirect external magnetic fields, provide structural support, and can be integrated with existing packaging processes. This multi-functionality reduces the need for additional separate components, thereby improving magnetic immunity without proportionally increasing device 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
The shielding arrangement provides magnetic field immunity of at least 100 Oe along various axes, significantly reducing the impact of external magnetic fields on the MRAM device, thus improving data retention and reliability.
Implementation Method 1
A magnetic shield structure is implemented around the magnetoresistive semiconductor device, comprising top and bottom shields made of high permeability metals like nickel-iron alloy, which are strategically positioned to redirect external magnetic fields away from the device
Data Source
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AI summary
Structures and methods are disclosed for shielding magnetically sensitive components. One structure includes a substrate, a bottom shield deposited on the substrate, a magnetoresistive semiconductor device having a first surface and a second surface opposing the first surface, the first surface of the magnetoresistive semiconductor device deposited on the bottom shield, a top shield deposited on the second surface of the magnetoresistive semiconductor device, the top shield having a window for accessing the magnetoresistive semiconductor device, and a plurality of interconnects that connect the magnetoresistive semiconductor device to a plurality of conductive elements.