Composite Substrate Light Absorption for Photolithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of a desired metal pattern on a composite substrate with a piezoelectric substrate bonded to a supporting substrate using photolithography is hindered by light reflection, causing unintended exposure of the photoresist and preventing precise pattern formation due to the transmittance of light through the substrate layers.
Innovation Solution
A composite substrate is formed with a piezoelectric substrate and a supporting substrate bonded via an organic adhesive layer, where at least one of the adhesive layer or the supporting substrate absorbs light used in photolithography, preventing light from reaching the backside of the photoresist and allowing for precise metal pattern formation through the lift-off process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a piezoelectric substrate and supporting substrate are made transparent to photolithography light, then light transmission through the substrate is improved, but light reflection from the bottom of the supporting substrate causes unintended exposure of the photoresist
Solution Approach 1:
An organic adhesive layer is introduced as an intermediary between the piezoelectric substrate and the supporting substrate. This adhesive layer has light-absorbing properties that prevent reflected light from reaching the photoresist, thereby solving the unintended exposure problem while maintaining the transparency of both substrate layers
Solution Approach 2:
The patent creates a composite substrate structure consisting of three layers: a transparent piezoelectric substrate, a light-absorbing organic adhesive layer, and a transparent supporting substrate. This composite structure combines the advantages of light transmission with the advantage of light absorption to prevent reflection
2Strength
If the supporting substrate is made of a reflective material, then structural support is improved, but light reflection from the substrate surface causes photoresist exposure and prevents precise pattern formation
Solution Approach 1:
The organic adhesive layer is applied locally at the interface between the piezoelectric substrate and supporting substrate. This localized application of light-absorbing material is sufficient to block reflected light without requiring changes to the entire supporting substrate structure
Solution Approach 2:
The organic adhesive layer serves as a mediator that decouples the structural support function of the reflective substrate from the optical interference it causes. The adhesive layer absorbs reflected light while allowing the supporting substrate to maintain its structural integrity
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 approach enables the formation of a desired metal pattern with high precision by absorbing light, preventing unwanted exposure and reflection, thus ensuring accurate pattern formation on the composite substrate.
Implementation Method 1
at least one of the supporting substrate and the organic adhesive layer can absorb the light used for photolithography
Data Source
AI summary
A composite substrate is a piezoelectric substrate that is transparent to light used for photolithography, and a supporting substrate for supporting the piezoelectric substrate are bonded together via an organic adhesive layer. Where at least one of the supporting substrate and the organic adhesive layer of the composite substrate absorbs light used for photolithography.