Silica-on-Silicon Hybrid Optoelectronic Chip Alignment

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Solution Overview

Problem

The integration of III-V lasers with silicon-based waveguide devices poses challenges due to material property differences, including optical coupling alignment, high-frequency signal transmission, complex processing, high costs, and heat dissipation, necessitating a practical and efficient hybrid integrated chip design.

Innovation Solution

A silica-on-silicon-based hybrid integrated optoelectronic chip is developed, featuring a silicon substrate with lug bosses and grooves, a silica waveguide element, and a metal electrode layer with solder bumps, enabling accurate alignment and efficient high-frequency signal transmission through flip-chip bonding, and utilizing multi-step processes like material growth and hot oxygen bonding for high-efficiency light coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If III-V lasers are integrated with silicon-based waveguide devices, then the functionality and performance of the optoelectronic chip are improved, but the complexity of the manufacturing process and material compatibility issues worsen

Engineering Contradiction:
ImprovefunctionalityVSAvoidmanufacturing process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The chip is divided into distinct functional regions: a silicon substrate area for passive waveguide devices and a separate III-V material area for active laser devices. This segmentation allows each region to be optimized for its specific material system while maintaining overall chip functionality, thereby reducing manufacturing complexity through specialized process zones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A silica-based waveguide structure serves as an intermediary between the silicon substrate and the III-V laser devices. This intermediate layer facilitates optical coupling between different material systems while providing a compatible platform for both silicon and III-V processes, thus reducing direct material compatibility issues.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If alignment structures are added to facilitate optical coupling, then the coupling precision is improved, but the device structure becomes more complex

Engineering Contradiction:
Improvealignment precisionVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Alignment marks and positioning structures are pre-formed on the silicon substrate before III-V laser device fabrication. This preliminary alignment infrastructure is established in advance, allowing subsequent laser devices to be precisely positioned and coupled to the silicon waveguides without adding complex alignment mechanisms during final assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The silica waveguide structures are designed to provide a common optical interface level between silicon and III-V devices. By creating an equipotential optical coupling platform, the system achieves precise alignment without requiring complex mechanical adjustment mechanisms, thus improving precision while limiting structural complexity.

Inventive Principle:
Principle #12Equipotentiality

3Temperature

If flip-chip bonding is used for integrating active devices, then the heat dissipation performance is improved, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveheat dissipationVSAvoidprocess complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The flip-chip bonding process merges the active III-V laser device directly with the silicon substrate's heat dissipation structures. By combining the active device mounting with the thermal management function in a single integrated step, the system achieves improved heat dissipation while consolidating multiple process functions into one operation, thereby limiting the increase in overall process complexity.

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 design facilitates high-efficiency light coupling between waveguide devices of different materials, reduces light reflection, and improves integration levels, enabling chip-level probe testing and subsequent encapsulation for mass production of hybrid integrated chips.

Implementation Method 1

a silica waveguide element (2) is arranged in the groove (10)

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

the surface of the metal electrode layer is provided with solder bumps (4), and an active optoelectronic chip (5) is arranged above the solder bumps

Methodology Applied
Scientific EffectSoldering: Soldering

Data Source

PatentEP2940739B1Silica-on-silicon-based hybrid integrated optoelectronic chip and manufacturing method therefor
Publication Date: 2019.06.12 WUHAN TELECOMM DEVICES
  • EP2940739B1 patent drawingFigure 1~2c
  • EP2940739B1 patent drawingFigure 3a~3d
  • EP2940739B1 patent drawingFigure 3e~4b

AI summary

Provided are a silica-on-silicon-based hybrid integrated optoelectronic chip and a manufacturing method therefor. The hybrid integrated optoelectronic chip comprises a silicon substrate (1), wherein the surface of the silicon substrate (1) is provided with a platform (8), lug bosses (6,7) and a groove (10); a silica waveguide element (2) is arranged in the groove (10), the lug bosses (6,7) are protruded from the surface of the platform (8), and the surface of the platform (8) is provided with a discontinuous metal electrode layer (3); and the surface of the metal electrode layer (3) is provided with solder bumps (4), and an active optoelectronic chip (5) is arranged above the solder bumps (4) and the lug bosses (6, 7). In the manufacturing method, multi-step processes including material growth, hot oxygen bonding, flip-chip bonding, lithography alignment and the like are adopted, thereby guaranteeing the high-efficiency light coupling among waveguide devices of different materials, and reducing the light reflection between waveguide end faces. A high-frequency electrode composed of alternating current electrode areas (26) is manufactured between the alignment lug bosses (6, 7). Due to the fact that flip-chip bonding technology is beneficial to the transmission of high-frequency signals, integration level between devices is improved. Meanwhile, the process design not only can achieve the chip-level probe test, but also can be used for the subsequent gold ball bonding or wedge bonding process, thereby facilitating the achievement of encapsulation and mass production of hybrid integrated chips.