Magnetic Read Head Sensor Self-Aligned Back Edge Fabrication
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Solution Overview
Problem
The existing magnetic read heads in hard disk drives face challenges in precisely defining the stripe height of the free and pinned layers, which affects the accuracy of magnetic signal reading and writing.
Innovation Solution
A method is developed to form a magnetic read head using a single photolithography process with multiple removal processes to define the stripe heights of the free and pinned layers, allowing for precise alignment and alignment of the back edges of the sensors, enabling accurate magnetic signal detection and writing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single photolithography process is used with multiple removal processes, then manufacturing precision of stripe height is improved, but device complexity increases
Solution Approach 1:
The fabrication process is segmented into distinct removal steps (first removal process for capping layer and portions of free layer, second removal process for remaining spacer layer and additional free layer portions) that can be independently optimized and controlled, allowing precise stripe height definition despite increased process steps
Solution Approach 2:
The spacer layer is formed with predetermined thickness and pattern before the sensor layers are complete, serving as a pre-established reference structure that guides subsequent photolithography and removal processes to achieve self-aligned stripe height definition
2Measurement precision
If multiple sensor layers are formed with self-aligned back edges, then measurement precision of magnetic signal is improved, but manufacturing complexity increases
Solution Approach 1:
The spacer layer serves as a self-aligning reference structure that automatically defines the back edge position for multiple sensor layers through its predetermined thickness and pattern, eliminating the need for separate alignment operations and reducing manufacturing complexity despite improved measurement precision
Solution Approach 2:
The problem of aligning back edges in the lateral dimension is transformed into a vertical dimension problem by using the spacer layer thickness as the controlling parameter, allowing precise stripe height definition through vertical layer formation rather than lateral alignment operations
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
This method ensures precise stripe height definition, enhancing the accuracy and stability of magnetic signal detection and writing, improving the overall performance of the magnetic read head in hard disk drives.
Implementation Method 1
A single photolithography process is performed on a resist that is disposed over a portion of the one or more second sensors, the spacer layer and the one or more first sensors
Data Source
AI summary
The embodiments of the present invention relate to a method for forming a magnetic read head having one or more sensors disposed over one or more sensors. The method includes forming one or more first sensors on a shield, forming a spacer layer over the one or more first sensors and forming one or more second sensors over the spacer layer. A single photolithography process is performed on a resist that is disposed over a portion of the one or more second sensors, the spacer layer and the one or more first sensors, and portions of the one or more second sensors, the spacer layer and the one or more first sensors not covered by the resist are removed by multiple removal processes. The stripe heights of the free layers and the pinned layers of the one or more first sensors and the one or more second sensors are defined as a result of the multiple removal processes.