Optical Interference Filter Layer Stack for Singulation Durability
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Solution Overview
Problem
Optical filters with alternating layers of aluminum nitride (AlN) and other materials face durability issues at the interface, leading to singulation defects and degraded performance during the singulation process, which reduces the yield and reliability of optical filters.
Innovation Solution
Incorporating layers of silicon dioxide (SiO2) between layers of aluminum nitride (AlN) and hydrogenated silicon (Si:H) to enhance durability, preventing the formation of low durability interfaces and reducing singulation defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If alternating layers of aluminum nitride (AlN) and other materials are used in optical filters, then optical filtering performance is improved, but durability at the interface deteriorates leading to singulation defects
Solution Approach 1:
The patent introduces a silicon oxide (SiO2) layer as an intermediary between the aluminum nitride (AlN) layer and the hydrogenated silicon (Si:H) layer. This intermediate SiO2 layer acts as a buffer that prevents direct contact between the AlN and Si:H layers, thereby eliminating the formation of low-durability interfaces while preserving the optical filtering performance of the AlN layer.
Solution Approach 2:
The patent creates a composite layered structure consisting of AlN, SiO2, and Si:H layers. By combining these different materials with complementary properties, the filter achieves both the desired optical performance from the AlN layer and improved mechanical durability through the SiO2 intermediate layer that prevents interface degradation.
2Reliability
If alternating layers of aluminum nitride (AlN) and other materials are used in optical filters, then optical filtering performance is improved, but singulation defects increase during the singulation process
Solution Approach 1:
The silicon oxide (SiO2) layer serves as a protective intermediary during the singulation process. It prevents direct mechanical stress and damage at the AlN-Si:H interface, thereby reducing singulation defects and improving manufacturing precision while maintaining the optical filtering performance of the AlN layer.
Solution Approach 2:
The SiO2 layer is deposited beforehand to provide a cushioning effect that protects the AlN-Si:H interface from mechanical stresses during subsequent singulation processing. This pre-established protective layer prevents defect formation before the singulation process occurs.
3Reliability
If alternating layers of aluminum nitride (AlN) and other materials are used in optical filters, then optical filtering performance is improved, but yield decreases due to degraded performance during singulation
Solution Approach 1:
The SiO2 intermediate layer protects the AlN-Si:H interface from degradation during singulation, ensuring that the optical filtering performance is maintained in the final product. This reduces the number of defective units and improves manufacturing yield while preserving the high-performance characteristics of the AlN-based filter.
Solution Approach 2:
The composite structure of AlN-SiO2-Si:H layers combines the optical performance benefits of AlN with the mechanical protection benefits of SiO2, resulting in filters that maintain high yield by preventing interface-related failures during the singulation process.
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 inclusion of SiO2 and Si:H layers improves the durability of optical filters, increasing yield and reliability by minimizing defects and maintaining performance during the singulation process.
Implementation Method 1
Optical interference filter
Data Source
AI summary
An optical interference filter includes one or more sets of layers. Each set of layers includes a first layer that includes at least aluminum and nitrogen (e.g., an aluminum nitride (AlN) material), a second layer that includes at least silicon and oxygen (e.g., a silicon dioxide (SiO2) material), and a third layer that includes at least hydrogen and silicon (e.g., a hydrogenated silicon (Si:H) material). The second layer is disposed between the first layer and the third layer.