Magnetic Transducer Pole and Side Shield Fabrication

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Solution Overview

Problem

Conventional methods for fabricating magnetic recording transducers are complex, time-consuming, and prone to errors, leading to compromised performance due to multiple processing steps and material polishing issues, which can result in asymmetries and variations in transducer geometry.

Innovation Solution

A method that simplifies the fabrication process by forming a pole trench with a yoke region and external protrusion, using a hard mask to cover the protrusion, and performing a single chemical mechanical planarization step to form both side shields and the main pole, reducing the need for additional masks and minimizing material variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional methods are used to fabricate magnetic recording transducers with separate CMP steps for pole and side shields, then the transducer can be formed with side shields, but the processing time increases and fabrication complexity increases

Engineering Contradiction:

Improvetransducer geometry symmetryVSAvoidfabrication process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the CMP steps for the pole and side shields into a single simultaneous planarization process. The pole and side shields are formed from a combined structure that undergoes one CMP step rather than separate steps, reducing fabrication complexity while maintaining geometric precision.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The combined pole-side shield structure serves multiple functions: it forms both the main pole and side shields in one fabrication sequence, and the single CMP step planarizes both components simultaneously, eliminating the need for multiple processing steps and masks.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple separate CMP steps are performed for pole and side shields, then each component can be planarized, but the processing time increases

Engineering Contradiction:

Improvesurface flatnessVSAvoidfabrication speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges the CMP operations for the pole and side shields into a single simultaneous planarization step, maintaining surface flatness for both components while eliminating the time required for separate CMP steps and intermediate handling.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If α-carbon hard mask is used during wet etch, then the pole is protected during trench formation, but material polishing issues occur and asymmetries are introduced

Engineering Contradiction:

Improvepole protection during etchVSAvoidtransducer symmetry

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent removes the α-carbon hard mask step from the fabrication process. Instead of using the mask during wet etch, the method relies on the combined pole-side shield structure and single CMP approach, eliminating the source of material polishing issues and asymmetry introduction.

Inventive Principle:

Principle #2Taking out (Extraction)

4Manufacturing precision

If separate CMP steps are performed for pole and side shields, then each component can be planarized independently, but material variations and flatness issues increase

Engineering Contradiction:

Improvecomponent flatnessVSAvoidmaterial variation

Core Design Contradiction:

Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent combines the pole and side shields into a single structural unit that undergoes one CMP step. This ensures both components are planarized under identical conditions, eliminating material variations introduced by separate processing and ensuring consistent flatness across all components.

Inventive Principle:

Principle #5Merging (Combining)

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 approach reduces processing time, minimizes errors, and enhances the flatness and symmetry of the transducer components, improving overall performance and reducing material consumption and costs.

Implementation Method 1

The side shield and the pole undergo a chemical mechanical planarization (CMP) process. The CMP removes the portion of the pole material external to the trench in the nonmagnetic layer.

Methodology Applied

Scientific EffectChemical mechanical planarization:

Data Source

PatentUS8980109B1Method for providing a magnetic recording transducer using a combined main pole and side shield CMP for a wraparound shield scheme

Publication Date: 2015.03.17 WESTERN DIGITAL TECHNOLOGIES INC

AI summary

A method fabricates a magnetic transducer having a nonmagnetic layer and an ABS location corresponding to an ABS. A pole trench is provided in the nonmagnetic layer. The pole trench has a pole tip region and a yoke region. At least one pole material is provided. The pole material(s) have an external protrusion that is above and external to the pole trench. A hard mask that covers at least the external protrusion is provided. A portion of the nonmagnetic layer adjacent to the pole trench is removed to form a side shield trench. At least one side shield material is provided. A portion of the side shield material(s) are adjacent to the hard mask and fill at least a portion of the side shield trench. The side shield material(s) and the pole material(s) are planarized to form at least one side shield and a main pole.