Heated AFM Layer Deposition for TMR Sensor Pinning Field
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Solution Overview
Problem
In magnetic storage devices, the reduction in size of tunneling magnetoresistance (TMR) readers to meet increasing track density and linear density leads to reduced blocking temperature distribution and pinning magnetic field strength, compromising the thermal stability of the pinned layer, as existing processes fail to effectively improve these parameters.
Innovation Solution
Heating the substrate prior to depositing the antiferromagnetic (AFM) layer and controlling the temperature during the deposition of subsequent layers to enhance the pinning field strength and blocking temperature distribution, resulting in a bi-layer structure with improved coercivity and pinning magnetic field strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the volume of the AFM layer is reduced to meet increasing track density and linear density requirements, then the reader dimensions decrease, but the blocking temperature distribution and pinning magnetic field strength are reduced, worsening the thermal stability of the pinned layer
Solution Approach 1:
The patent applies parameter changes by heating the substrate to elevated temperatures (e.g., 100-300°C) during AFM layer deposition. This temperature parameter modification enhances the pinning field strength and blocking temperature distribution of the AFM layer, allowing the use of thinner AFM layers while maintaining thermal stability. The thermal processing during deposition alters the magnetic properties of the AFM layer, resolving the contradiction between reduced volume and maintained reliability.
2Force
If heating is applied after AFM layer deposition to improve the pinning field, then the pinning field strength increases, but the blocking temperature is not improved
Solution Approach 1:
The patent implements preliminary action by heating the substrate to elevated temperatures before and during the AFM layer deposition process, rather than heating after deposition. This preliminary thermal treatment ensures that the AFM layer forms with enhanced pinning field strength and improved blocking temperature distribution from the outset. By performing the thermal action before and during deposition rather than after, both parameters are improved simultaneously.
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 proposed method enhances the pinning strength, blocking temperature distribution, and thermal stability of TMR readers, reducing the thickness of the AFM layer and minimizing the impact of wafer degas pressure, leading to improved reliability and performance characteristics such as higher magnetoresistance and exchange bias.
Implementation Method 1
Heating the substrate prior to depositing the antiferromagnetic (AFM) layer
Implementation Method 2
depositing the antiferromagnetic (AFM) layer
Data Source
AI summary
Systems and methods are provided for manufacturing a magnetic recording sensor for use in a magnetic reader, such as a tunneling magnetoresistance (TMR) readers. The magnetic recording sensor can be manufactured by heating a substrate in a first chamber and depositing an antiferromagnetic (AFM) layer on the heated substrate. Additionally, a first pinned layer is added onto the AFM layer, and the substrate is subsequently cooled.