Silicon Photonics Trench Edge Coupler for SOI
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Solution Overview
Problem
Current methods for coupling external light sources to silicon-on-insulator (SOI) devices require additional wafer bonding steps, increasing manufacturing complexity, cost, and device size, leading to lower production throughput and yield due to the need for thicker dielectric layers and potential misalignment issues.
Innovation Solution
An optical device with an integrated trench in the substrate provides optical isolation between waveguides and the substrate, using a thinner dielectric layer for highly-confined modes and a thicker layer for low-confined modes without additional wafer bonding, reducing material usage and production complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If wafer bonding is implemented to provide additional dielectric layers and insulation, then optical isolation between light signals and substrate is improved, but device size increases and manufacturing complexity increases
Solution Approach 1:
The patent segments the substrate interaction by creating a trench structure that physically separates the waveguide region from the substrate, eliminating the need for thick dielectric layers and wafer bonding while maintaining optical isolation
Solution Approach 2:
The patent extracts the problematic substrate interaction by removing material to form a trench, thereby eliminating optical interference without adding complex bonding layers or increasing device size
2Object-affected harmful factors
If wafer bonding is implemented to provide additional dielectric layers, then optical isolation is improved, but production throughput decreases
Solution Approach 1:
The trench structure segments the optical path from the substrate, enabling optical isolation through a single-layer dielectric without requiring time-consuming wafer bonding processes
Solution Approach 2:
The trench is formed preliminarily in the substrate before waveguide fabrication, establishing optical isolation upfront and eliminating subsequent bonding steps that would reduce production throughput
3Object-affected harmful factors
If thicker dielectric layers are used to provide optical isolation, then optical interference is reduced, but device size increases
Solution Approach 1:
The patent transitions from increasing vertical thickness to creating horizontal separation through a trench, providing optical isolation without increasing the overall device footprint
Solution Approach 2:
By removing substrate material to form a trench, the patent eliminates optical interference pathways without requiring additional thick dielectric layers, thereby maintaining compact device dimensions
4Object-affected harmful factors
If additional wafer bonding steps are implemented, then optical isolation is improved, but manufacturing cost increases
Solution Approach 1:
The trench structure provides optical isolation through geometric segmentation rather than material addition, eliminating costly wafer bonding steps while maintaining isolation effectiveness
Solution Approach 2:
The trench structure enables the single dielectric layer to perform both its primary function and the optical isolation function that would otherwise require additional bonding layers, reducing manufacturing cost
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 integrated trench approach enables efficient optical mode matching and low loss coupling directly from external light sources, reducing stress management concerns and production complexity while maintaining optical isolation, resulting in smaller, more efficient SOI devices with improved yield and throughput.
Implementation Method 1
the light transmitted in the coupling layers is optically isolated from the substrate
Implementation Method 2
coupling between a light source such as optical fiber or laser and an optical device, such as a photonics chip and/or a silicon-on-insulator (SOI) device
Data Source
AI summary
A method includes defining a first waveguide in a first region of an optical device over a first dielectric layer over a silicon on insulator (SOI) substrate of the optical device and disposing a second dielectric layer on the first waveguide and the first dielectric layer of the optical device. The method also includes defining a second region on the second dielectric layer, the first dielectric layer, and the SOI substrate. The second region includes an integrated trench structure defined in the SOI substrate. The method further includes etching the second region to form an etched second region, disposing a third dielectric layer in the etched second region, and disposing a second waveguide on at least the third dielectric layer. The second waveguide is disposed to provide an optical coupling between the second waveguide and the first waveguide.