Strained Ge Photodetector Layout for Broad C- and L-Band Reception
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Solution Overview
Problem
Existing silicon photonics devices struggle to efficiently detect optical signals across the entire C-band and L-band wavelength ranges due to limitations in optical signal absorption and bandwidth, necessitating improved mechanical strain mechanisms for germanium-based photo detectors.
Innovation Solution
A silicon photonics receiver is designed with a germanium layer mechanically strained by tensile and compressive stressor components, including silicon nitride and silicon dioxide films, to modify the band gap and enhance optical signal detection across the C-band and L-band wavelengths, while inhibiting dark current through lateral current conduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional silicon photonics devices are used, then device simplicity is maintained, but optical signal detection across C-band and L-band is insufficient
Solution Approach 1:
The patent applies parameter changes by mechanically straining the germanium layer through tensile and compressive stressor components to modify the band gap energy. This parameter modification enables the photo detector to detect optical signals across the entire C-band and L-band wavelength ranges, resolving the contradiction between detection range and device simplicity.
Solution Approach 2:
The patent employs composite materials by integrating germanium layer with silicon photonics substrate and combining tensile stressor components (e.g., silicon nitride) with compressive stressor components (e.g., silicon dioxide). This composite structure achieves broad spectral detection while maintaining reasonable device complexity through established material systems.
2Productivity
If germanium layer is strained to extend detection range, then bandwidth is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the stress application into separate tensile stressor components and compressive stressor components. Each component can be independently fabricated and optimized, making the manufacturing process more manageable while achieving the desired bandwidth extension through combined stress effects on the germanium layer.
Solution Approach 2:
The patent uses parameter changes in the stressor components (such as adjusting the composition and thickness of silicon nitride and silicon dioxide layers) to control the mechanical strain on the germanium layer. This enables optimization of bandwidth while maintaining fabrication feasibility through standard semiconductor manufacturing techniques.
3Reliability
If stressor components are added to modify band gap, then optical detection efficiency is improved, but device structure becomes more complex
Solution Approach 1:
The patent applies parameter changes by introducing stressor components that modify the band gap parameter of the germanium layer. This enables improved optical detection efficiency across C-band and L-band while keeping the structural complexity manageable through the use of conventional stressor materials and fabrication methods.
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 solution increases the optical signal detection range to cover the entire C-band and L-band wavelengths, enhancing bandwidth and reducing noise, thus improving the efficiency and spectral utilization of optical communication networks.
Implementation Method 1
the tensile stressor component configured to mechanically strain the epitaxial germanium layer to modify an optical signal absorption attribute of the epitaxial germanium layer
Implementation Method 2
mechanically strain the epitaxial germanium layer to modify a band gap of the epitaxial germanium layer to detect optical signals having a wavelength in a range of at least 1530 nanometers to 1565 nanometers
Implementation Method 3
The epitaxial germanium layer is configured to operate as a high-speed photo diode for detection of optical communication signals
Implementation Method 4
the compressive stressor component configured to mechanically strain the epitaxial germanium layer to modify an optical signal absorption attribute of the epitaxial germanium layer
Data Source
AI summary
A receiver for receiving optical signals transmitted over a communications network includes a silicon photonics substrate including multiple regions with respectively different doping, an epitaxial germanium layer extending at least partially over at least two or more of regions with different doping, and at least one of a tensile stressor component and a compressive stressor component in contact with the epitaxial germanium layer. The tensile stressor component and the compressive stressor component are respectively configured to mechanically strain the epitaxial germanium layer to modify an optical signal absorption attribute of the epitaxial germanium layer. The receiver includes a receive circuit including at least one electrode component in electrical contact with the epitaxial germanium layer. The receive circuit is configured to generate an electrical output in response to an optical signal received from a network interface of the communications network by the epitaxial germanium layer.