Non-Self-Supporting Crystalline Laser Stress Mitigation in HAMR

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Solution Overview

Problem

In heat-assisted magnetic recording (HAMR) devices, the assembly of read/write heads with lasers and waveguides is challenging due to limited space and mechanical stress issues, which can lead to deformation and degraded performance, and existing manufacturing processes are incompatible with the integration of non-self-supporting crystalline laser layers.

Innovation Solution

The use of two distinct thin film deposition methods, such as chemical vapor deposition and ion beam sputter deposition, to form non-self-supporting crystalline layers that mitigate mechanical stress and are integrated with a waveguide to direct plasmons to a recording medium, along with facet anti-reflective bi-layer coatings to balance stress and maintain optical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If non-self-supporting crystalline laser layers are integrated into HAMR devices, then compact integration and light beam intensity are improved, but mechanical stress and deformation occur

Engineering Contradiction:

Improvelaser integration compactnessVSAvoidmechanical stress in laser

Core Design Contradiction:

Volume of moving objectVSStress or pressure

Solution Approach 1:

The laser structure is divided into multiple non-self-supporting crystalline layers that are separately deposited and then integrated. This segmentation allows each layer to be optimized for specific functions while reducing overall mechanical stress through distributed stress management across multiple thin layers rather than a single thick layer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs different deposition processes (chemical vapor deposition and ion beam sputter deposition) with distinct process parameters to create layers with different stress characteristics. By changing deposition parameters such as temperature, pressure, and material composition, the mechanical stress in each layer can be controlled to compensate for stress in other layers, thereby mitigating overall mechanical stress while maintaining compact integration.

Inventive Principle:

Principle #35Parameter changes

2Stress or pressure

If multiple deposition processes are used to form laser layers, then mechanical stress is mitigated, but manufacturing complexity increases

Engineering Contradiction:

Improvemechanical stress mitigationVSAvoidmanufacturing process complexity

Core Design Contradiction:

Stress or pressureVSDevice complexity

Solution Approach 1:

Multiple deposition processes are merged into a single integrated manufacturing sequence where chemical vapor deposition and ion beam sputter deposition are performed in succession within the same fabrication environment. This merging allows the complex multi-process manufacturing to be executed as a unified workflow, reducing the operational complexity that would otherwise arise from separate processing steps while still achieving stress mitigation through process diversity.

Inventive Principle:

Principle #5Merging (Combining)

3Area of stationary object

If laser layers are made non-self-supporting, then space is reduced and integration is improved, but structural stability deteriorates

Engineering Contradiction:

Improvespace for laser integrationVSAvoidstructural stability of laser layers

Core Design Contradiction:

Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The non-self-supporting crystalline laser layers are nested within a waveguide structure that provides structural support. The laser layers are deposited and then integrated into the waveguide, which acts as a containing structure that maintains structural stability while allowing the laser active region to remain thin and non-self-supporting. This nesting arrangement preserves the space-saving benefits of thin layers while the waveguide provides the necessary mechanical stability.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 mechanical stress, maintains optical performance, and allows for compact, efficient integration of lasers within HAMR devices, enhancing light beam intensity and directional control while minimizing manufacturing complexity and cost.

Implementation Method 1

The waveguide is configured to receive plasmons from the laser and direct the plasmons to a recording medium

Methodology Applied

Scientific EffectPlasmon generation:

Implementation Method 2

A first layer is deposited using a first process

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Implementation Method 3

A second layer is deposited using a second process different than the first process

Methodology Applied

Scientific EffectIon beam sputter deposition: Sputtering

Data Source

PatentUS11404083B1Laser stress mitigation for heat-assisted magnetic recording

Publication Date: 2022.08.02 SEAGATE TECH LLC

AI summary

An apparatus has a substrate. A laser is deposited above the substrate. The laser comprises one or more non-self-supporting layers of crystalline material. A first layer is disposed proximate the laser. The first layer is deposited using a first process. A second layer is disposed proximate the second layer. The second layer is deposited using a second process different than the first process. The first layer and the second layer are configured to mitigate mechanical stress in the laser. A waveguide is deposited proximate the laser. The waveguide is configured to receive plasmons from the laser and direct the plasmons to a recording medium.