Fabry-Perot Interference Filter Wafer Cutting with Thinned Mirror Layers
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Solution Overview
Problem
The manufacturing of Fabry-Perot interference filters faces challenges in improving both efficiency and yield due to the complexity of the fine structure involved.
Innovation Solution
A method is developed that includes forming thinned regions on the mirror layers and a stress adjustment layer to prevent damage during the cutting process, using laser light to create a modified region within the wafer, and employing an expanding tape to extend cracks for precise cutting, thereby enhancing manufacturing efficiency and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional manufacturing methods are used for Fabry-Perot interference filters, then the manufacturing process can be completed, but both manufacturing efficiency and yield are low due to the fine structure complexity
Solution Approach 1:
The patent segments the manufacturing process into distinct sequential steps: forming thinned regions in mirror layers, creating modified regions via laser irradiation, and performing cutting operations. This segmentation allows each step to be optimized independently, improving overall manufacturing efficiency despite the complex fine structure
Solution Approach 2:
The patent applies preliminary actions by forming thinned regions in the mirror layers and stress adjustment layers before the cutting process. This preliminary thinning prevents damage during subsequent cutting operations, thereby improving yield without compromising the fine structure integrity
2Ease of manufacture
If the wafer is cut into multiple substrates without preliminary thinning, then cutting can proceed directly, but damage occurs to the mirror layers, sacrificial layer, and stress adjustment layer
Solution Approach 1:
The patent performs preliminary thinning of the mirror layers and stress adjustment layer along the cutting lines before the actual cutting process. This preliminary action creates a weakened path that guides the crack during cutting, ensuring clean separation without damaging the delicate mirror layers or stress adjustment layers
Solution Approach 2:
The patent introduces a modified region as an intermediary between the intact wafer structure and the final separated substrates. This modified region, created by laser irradiation, acts as a controlled fracture path that enables clean cutting while protecting the surrounding delicate structures from damage
3Device complexity
If laser light is irradiated without forming thinned regions first, then the process can be simplified, but scattering occurs and the modified region cannot be reliably formed within the wafer
Solution Approach 1:
The patent performs preliminary thinning of the mirror layers along the intended cutting paths before laser irradiation. This preliminary thinning creates regions with reduced optical absorption, allowing laser light to penetrate deeper and form modified regions precisely within the wafer interior without excessive scattering, thereby improving manufacturing precision
Solution Approach 2:
The patent applies local quality by creating thinned regions specifically at the locations where cutting is needed, while leaving the rest of the mirror layers intact. This localized thinning optimizes laser penetration and modified region formation precision only where required, without unnecessarily complicating the overall device structure
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
This method effectively improves manufacturing efficiency and yield by preventing damage to the mirror layers and stress adjustment layers, allowing for the reliable formation of the modified region and precise cutting of the Fabry-Perot interference filters.
Implementation Method 1
a modified region is formed within the wafer along each of the lines through irradiation of a laser light
Data Source
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AI summary
A method of manufacturing a Fabry-Perot interference filter includes a forming step of forming a first thinned region, in the forming step, a first mirror layer having a plurality of first mirror portions, a sacrificial layer having a plurality of portions expected to be removed, and a second mirror layer having a plurality of second mirror portions are formed on a first main surface of a wafer, and the first thinned region in which at least one of the first mirror layer, the sacrificial layer, and the second mirror layer is partially thinned along each of a plurality of lines is formed; a cutting step of cutting the wafer into a plurality of substrates along each of the plurality of lines by forming a modified region within the wafer along each of the plurality of lines through irradiation of a laser light, after the forming step; and a removing step of removing a portion expected to be removed from the sacrificial layer through etching, between the forming step and the cutting step or after the cutting step.