Multispectral Filter Fabry-Perot Cavities With 3D Resin Patterning
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Solution Overview
Problem
Existing methods for manufacturing multispectral filters require numerous lithography and etching steps, leading to profile deformations and etch non-uniformities, which compromise the aspect ratio and surface quality of dielectric layers.
Innovation Solution
A method involving 3D structuring of a resin layer followed by deposition and planarization of dielectric material, allowing the formation of Fabry-Perot cavities on a temporary substrate, eliminating the need for successive lithography and etching steps, and ensuring precise dielectric thicknesses and improved surface quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lithography and etching steps are used to manufacture multispectral filters, then different dielectric thicknesses can be achieved, but profile deformations and etch non-uniformities occur leading to degraded surface quality and compromised aspect ratio
Solution Approach 1:
The patent applies preliminary action by first depositing the complete dielectric layer to the maximum required thickness before any patterning or etching steps. This ensures that all areas receive the full dielectric material, and subsequent steps only remove material where needed, preventing the profile deformations and surface quality issues that occur when trying to build different thicknesses through multiple deposition and etching cycles.
Solution Approach 2:
The patent inverts the conventional manufacturing approach by depositing the dielectric layer in reverse order: instead of building up different thicknesses through multiple steps, the maximum thickness is deposited first uniformly across the substrate, and then material is selectively removed through etching only in areas where thinner sections are required. This inversion eliminates the cumulative errors and surface quality degradation associated with conventional iterative approaches.
2Adaptability or versatility
If multiple lithography and etching steps are performed to create different dielectric thicknesses, then colour filtering can be achieved, but manufacturing complexity increases significantly
Solution Approach 1:
The patent merges multiple manufacturing operations into a streamlined sequence: a single dielectric deposition step creates the base layer, followed by one lithography step to define patterns, and one etching step to create the final thickness variations. This consolidation of steps maintains the ability to produce multiple color filters while dramatically reducing the overall manufacturing complexity compared to conventional methods that require separate deposition and etching cycles for each thickness variation.
Solution Approach 2:
The preliminary deposition of the complete dielectric layer before any patterning simplifies subsequent manufacturing steps. By having the full thickness material already in place, the lithography and etching steps can focus solely on defining the patterns and removing excess material, rather than needing to coordinate multiple deposition operations with etching steps, thereby reducing overall process complexity.
3Manufacturing precision
If successive lithography and etching steps are used to manufacture multispectral filters, then different dielectric thicknesses can be obtained, but manufacturing time and productivity are reduced
Solution Approach 1:
The patent performs the dielectric layer deposition as a preliminary action before any patterning or etching steps. By depositing the complete thickness of the dielectric layer in a single step upfront, the subsequent lithography and etching operations can proceed in parallel or sequence without waiting for additional deposition cycles, thereby maintaining precise thickness control while significantly improving manufacturing throughput and productivity.
Solution Approach 2:
The manufacturing process is segmented into distinct functional stages: a preliminary deposition stage that establishes the dielectric layer, followed by a patterning and etching stage that defines the final structure. This segmentation allows the deposition process to be optimized for speed and precision independently from the patterning process, improving overall manufacturing efficiency while maintaining the required thickness precision.
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 method enables the production of multispectral filters with enhanced surface quality and maintained aspect ratio, reducing manufacturing complexity and improving the reliability of the filtering process.
Implementation Method 1
Three-dimensionally structuring the resin layer by lithography so as to obtain at least two resin patterns of different heights
Implementation Method 2
Depositing a layer made of the dielectric material intended to form the dielectric patterns of the Fabry-Perot cavities
Implementation Method 3
Transferring the planarised face of the handle substrate to the upper face of a substrate, called the carrier substrate
Data Source
AI summary
A method for manufacturing a multispectral filter for electromagnetic radiation including two colour filters each including a first reflective layer, a second reflective layer, a layer of dielectric material of Fabry-Perot cavity, the thickness of the dielectric layer of both colour filters being different and each of both filters facing a photoelectric transducer. The method includes depositing a resin layer onto a handle substrate, structuring the resin layer to obtain two resin patterns of different heights, at least one of the patterns having a maximum reference height; depositing a dielectric layer to form the dielectric patterns of the Fabry-Perot cavities and planarising; transferring the planarised face of the handle substrate to the upper face of a carrier substrate; removing the handle substrate and the resin and depositing a reflective layer onto the at least two dielectric patterns of Fabry-Perot cavity, forming the second reflective layer.