SOT-MTJ Layout Pattern with Dummy MTJs for Pattern Density Uniformity
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Solution Overview
Problem
The uneven thickness and spacing of SOT-MTJ structures during the etching process lead to quality issues in the manufacturing of semiconductor structures, particularly due to the inclusion of two contact plug structures, resulting in non-uniform pattern density and process defects.
Innovation Solution
Incorporating dummy MTJ structures with varying shapes between the MTJ structures to adjust the spacing and create a more uniform pattern density, ensuring consistent etching parameters by maintaining consistent groove depths for the bottom anti-reflection layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SOT-MTJ structures are arranged with two contact plug structures below each layer, then the device functionality is improved, but the pattern density uniformity deteriorates due to uneven spacing in different directions
Solution Approach 1:
Dummy MTJ structures are introduced as intermediary elements between the actual SOT-MTJ structures. These dummy structures serve as space-fillers that maintain uniform pattern density without requiring functional contact plug structures, thereby resolving the contradiction between device functionality and manufacturing precision
Solution Approach 2:
The patent applies different structural configurations to different regions of the array: actual SOT-MTJ structures with two contact plugs are placed at corner positions where full functionality is needed, while dummy MTJ structures without contact plugs are placed in intermediate positions where only space-filling is required. This local differentiation maintains both device functionality and pattern density uniformity
2Ease of manufacture
If SOT-MTJ structures are arranged in rectangular or elliptical shapes to accommodate two contact plug structures, then the device configuration is optimized, but the spacing between structures becomes non-uniform in different directions
Solution Approach 1:
The patent employs asymmetric arrangement strategies where dummy MTJ structures are strategically positioned to compensate for the asymmetric spacing created by rectangular or elliptical SOT-MTJ structures. This creates a more uniform overall pattern density despite the asymmetric shapes of individual structures
3Area of stationary object
If spacing between SOT-MTJ structures is reduced to increase array density, then the chip area utilization is improved, but the etching process quality deteriorates due to non-uniform groove depths
Solution Approach 1:
Dummy MTJ structures act as intermediary elements that maintain uniform spacing and groove depth patterns across the array. By placing these dummy structures at regular intervals, the etching process encounters uniform resistance and creates consistent groove depths, even when the overall array density is increased
Solution Approach 2:
The patent modifies the structural parameters by introducing dummy MTJ structures with different configurations (no contact plugs, potentially different dimensions) compared to actual SOT-MTJ structures. This parameter differentiation allows for optimized spacing that maintains etching quality while increasing overall array density
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 addition of dummy MTJ structures improves the uniformity of pattern density and enhances the quality of the manufacturing process by stabilizing etching parameters, reducing defects, and ensuring consistent thickness across the semiconductor structure.
Implementation Method 1
SOT(spin-orbit torque) layers arranged in an array
Implementation Method 2
The core principle of STT technology is to use spin-polarized current. When a spin-polarized current passes through a magnetic material, electrons in the current will transfer their spin angular momentum to the magnetic moment of the material, thus changing the direction of the magnetic moment.
Implementation Method 3
the magnetoresistance (MR) effect is the effect that the resistance of a material changes with the change of an external magnetic field
Implementation Method 4
giant magnetoresistance substances have different resistance values in different magnetization states
Data Source
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AI summary
Provided is a layout pattern of a semiconductor structure, which comprises a plurality of SOT(spin-orbit torque) layers (30) arranged in an array and located on a dielectric layer (26), wherein two contact plug structures (16; 18) are connected below each SOT layer (30), and a plurality of MTJ(magnetic tunnel junction) structures (20) are arranged in an array, each MTJ structure (20) is located on each SOT layer (30), wherein each SOT layer (30) comprises one MTJ structure (20) disposed thereon. And a plurality of dummy MTJ structures (40) located between the MTJ structures (20), wherein the shape of each dummy MTJ structure (40) is different from the shape of each MTJ structure (20).