STT-MRAM Rectangular Bottom Electrode Area Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Spin Transfer Torque Magnetoresistive Random Access Memory (STT-MRAM) bit cells with hexagonal bottom electrodes have inefficiencies in area usage due to differing widths of the bottom electrode, active layer, and metal layers, leading to limitations in cell size and design symmetry, which affects the mechanical properties and performance of the magnetic tunnel junction storage element.
Innovation Solution
Implementing a rectangular bottom electrode plate with equal widths for the bottom electrode, active layer, and metal layers to improve area efficiency, reduce cell size, and enhance mechanical properties by aligning with the rectangular shape of the magnetic tunnel junction storage element, thereby simplifying cell design and improving current density and symmetry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a hexagonal bottom electrode plate is used in conventional STT-MRAM bit cells, then the spacing requirements between adjacent BE plates are reduced, but the area efficiency of the bit cell array is decreased and the cell size is increased
Solution Approach 1:
The patent transitions from a symmetric hexagonal BE plate to an asymmetric rectangular BE plate design. This asymmetry in shape allows for optimized spacing arrangements in the bit cell array, enabling reduced cell area while maintaining adequate spacing between adjacent structures for proper functionality and manufacturing tolerances.
Solution Approach 2:
The patent changes the geometric parameters of the BE plate from hexagonal to rectangular configuration. This parameter change in shape and orientation allows for more efficient packing arrangements in the bit cell array, improving area efficiency while maintaining the necessary spacing between adjacent plates through optimized dimensional relationships.
2Area of stationary object
If the bottom electrode plate, active layer, and metal layers have different widths in conventional designs, then the cell area is increased, but the design symmetry and mechanical properties are compromised
Solution Approach 1:
The patent implements homogeneous width dimensions across the BE plate, active layer, and metal layers. This uniformity in dimensional parameters creates design symmetry that enhances mechanical properties and structural stability, while the optimized homogeneous configuration actually reduces the overall cell area compared to conventional designs with varying widths.
3Length of moving object
If the corners of the bottom electrode plate are removed to form hexagonal shape, then the spacing between adjacent cells is reduced, but the area efficiency is decreased and manufacturing complexity increases
Solution Approach 1:
Instead of removing corners from a rectangular plate to create a hexagonal shape, the patent inverts the approach by using a complete rectangular plate configuration. This inversion simplifies the manufacturing process by eliminating complex corner removal steps while maintaining optimized spacing between adjacent cells through the rectangular geometry itself.
Data Source
AI summary
A Spin Transfer Torque Magnetoresistive Random Access Memory (STT-MRAM) bit cell is provided. The STT-MRAM includes a rectangular bottom electrode (BE) plate, and a storage element on the rectangular bottom electrode (BE) plate. A difference between a width of the rectangular bottom electrode (BE) plate and a width of the storage element is equal to or greater than a predetermined minimum spacing requirement. A width of the bottom electrode (BE) plate is substantially equal to a width of an active layer or a width of a plurality of metal layers.