Multi-Photon Lithography With Real-Time Fluorescence Verification
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Solution Overview
Problem
Existing multi-photon lithography (MPL) processes require extensive post-process characterization, such as scanning electron microscopy (SEM), which can deform and damage small structures, and take significant time, making real-time verification and control of the fabrication process challenging.
Innovation Solution
A real-time controlled MPL process using a light-emitting photoresist that emits signals during polymerization, allowing for on-the-fly adjustment of fabrication parameters and 3D digital reconstruction based on fluorescence intensity, minimizing post-process characterization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If post-process characterization using SEM is performed to verify fabrication quality, then measurement precision is improved, but the fabricated structures are deformed and damaged
Solution Approach 1:
The patent implements real-time verification during the MPL fabrication process using a camera to capture images of the photoresist layer as it is being written. This preliminary action allows fabrication parameters to be adjusted before the process completes, eliminating the need for post-process SEM characterization that causes structural damage.
Solution Approach 2:
The patent introduces an intermediary verification system consisting of a camera and image processing algorithm that mediates between the fabrication process and final characterization. This intermediary allows non-invasive monitoring of fabrication quality in real-time, replacing the need for invasive post-process SEM analysis.
2Reliability
If extensive post-process characterization is performed to ensure fabrication quality, then reliability is improved, but loss of time increases significantly
Solution Approach 1:
The patent implements a feedback loop where images captured during MPL fabrication are processed in real-time to verify fabrication quality. This continuous feedback allows immediate detection of issues and parameter adjustments, eliminating the need for time-consuming post-process characterization and significantly reducing total fabrication time.
Solution Approach 2:
The patent makes the verification process continuous by capturing and analyzing images during the MPL fabrication process itself, rather than performing separate post-process characterization. This continuous verification maintains fabrication quality assurance while eliminating idle time between fabrication and characterization.
3Productivity
If real-time verification is implemented during MPL process, then productivity is improved, but device complexity increases
Solution Approach 1:
The patent implements a self-service verification system where the MPL process automatically captures images and processes them in real-time without requiring external intervention. The system self-verify fabrication quality and automatically adjusts parameters, improving productivity while keeping the verification system relatively simple and integrated into the existing MPL workflow.
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
Enables reliable, real-time verification and control of the MPL process, reducing structural deformation and deformation, and providing precise 3D reconstruction of fabricated structures.
Implementation Method 1
scanning the volume of the photoresist which has been affected by the beam of the excitation laser and its vicinities, between 0 and 10000000 μs, preferably 100 and 400000 μs, most preferably between 200 and 100000 μs after excitation with the excitation laser, with a second laser, thereby triggering the emission of light signals
Implementation Method 2
directing and guiding a beam of an excitation laser into and through a volume of a photoresist in order to trigger the polymerization process in the volume of the photoresist which has been affected by the beam of the excitation laser
Implementation Method 3
The method relies on a multi-photon absorption process in a material that is transparent at the wavelength of the laser used for creating the pattern
Data Source
AI summary
The present invention relates to an improved multi-photon lithography process, which allows verification and control of the result of the lithography process while the process is running (real-time verification and control) and optionally full 3D digital reconstruction of the final fabricated structure. The invention further relates to multi-photon lithography equipment and systems used to implement the foregoing processes.