Recessed Silicon Microlens With AR Coating for Low Insertion Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical devices face challenges with polymer-based microlenses that are prone to deformation and require stringent fabrication conditions, leading to poor light focusing and high insertion loss due to lack of antireflection films.
Innovation Solution
Fabrication of silicon microlenses integrated with multi-layer antireflection coatings on silicon wafers to enhance mechanical integrity, reduce deformation, and minimize light reflection and refraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polymer-based microlenses are used, then fabrication flexibility is improved, but mechanical stability deteriorates due to deformation under stringent fabrication conditions
Solution Approach 1:
The patent changes the material parameter from polymer to silicon, fundamentally altering the mechanical and thermal properties. Silicon's inherent rigidity and stability prevent deformation during fabrication, while still allowing microlens formation through standard semiconductor processing techniques like photolithography and etching.
Solution Approach 2:
The patent creates a composite structure by integrating the silicon microlens with multi-layer antireflection coating films. This composite approach combines the mechanical stability of silicon with the optical performance enhancement from the ARC layers, achieving both structural integrity and optical efficiency.
2Device complexity
If conventional fabrication methods are used, then manufacturing simplicity is improved, but optical performance deteriorates due to poor light focusing
Solution Approach 1:
The patent applies multi-layer antireflection coating films over the silicon microlens. This composite structure reduces light reflection and refraction at the air-silicon interface, significantly improving light focusing capability and reducing insertion loss while maintaining compatibility with conventional fabrication processes.
Solution Approach 2:
The antireflection coating is applied specifically to the microlens region where optical performance is critical. This localized treatment targets the exact area needing improvement for light focusing, leaving other device regions unchanged and maintaining manufacturing simplicity.
3Device complexity
If no antireflection coating is applied, then manufacturing complexity is reduced, but energy loss increases due to high insertion loss from light reflection
Solution Approach 1:
The patent integrates multi-layer antireflection coating films as a composite structure with the silicon microlens. This addition minimizes light reflection and refraction losses at the optical interface, reducing insertion loss while the entire structure remains fabricable using standard semiconductor manufacturing techniques.
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 silicon microlenses with antireflection coatings improve light focusing and reduce insertion loss, providing more robust and efficient optical devices.
Implementation Method 1
one or more antireflection coating layers disposed over the first side of the silicon substrate, including over the silicon microlens
Implementation Method 2
minimize light reflection and refraction
Data Source
AI summary
A sacrificial component over a first side of a substrate. The sacrificial component has a curved profile. First etching processes are performed to the sacrificial component and the substrate from the first side, which remove the sacrificial component and defines a first portion of the substrate below the sacrificial component as a microlens. The microlens has a second curved profile. A mask layer is formed over the first side of the substrate to surround the microlens. The mask layer and the substrate have different material compositions. Second etching processes are performed to the mask layer and the substrate from the first side. The mask layer is etched at a slower rate than the substrate, such that the microlens has a smaller height than a second portion of the substrate below the mask layer after the second etching processes have been completed. The mask layer is then removed.