Infrared Cut Filter Patterning Without Dye Elution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The miniaturization of pixel size in solid-state imaging devices requires a corresponding miniaturization of infrared light cut filters, which is challenging due to the elution of infrared light absorbing dyes during the dry etching process, leading to deterioration of spectral characteristics.
Innovation Solution
A method involving the formation of an infrared light cut layer with a protective layer containing a crosslinked resin structure, which prevents the stripping solution from permeating and eluting the dye, thereby maintaining the spectral characteristics of the filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If dry etching is used to miniaturize the infrared light cut filter, then the pixel size and filter size are reduced, but the stripping solution causes elution of infrared light absorbing dye leading to deterioration of spectral characteristics
Solution Approach 1:
A protective layer is introduced as an intermediary between the infrared light cut layer and the stripping solution. This protective layer prevents direct contact between the stripping solution and the infrared light absorbing dye, thereby preventing elution while allowing the dry etching process to proceed for miniaturization.
Solution Approach 2:
The protective layer is formed on the infrared light cut layer before the dry etching and stripping processes. This preliminary protective action ensures that when the stripping solution is later applied to remove the resist pattern, the infrared light absorbing dye is already protected from elution.
2Area of moving object
If the infrared light cut filter is miniaturized, then it can be integrated with smaller pixel sizes, but the spectral characteristics deteriorate due to dye elution during manufacturing
Solution Approach 1:
The protective layer serves as a mediator that allows the miniaturization process to proceed without compromising the spectral characteristics. It enables the filter to be scaled down while maintaining the integrity of the infrared light absorbing dye during manufacturing.
Solution Approach 2:
The protective layer is selectively applied to specific regions where the infrared light cut layer is present, providing localized protection where needed during the manufacturing process while allowing other areas to be processed normally.
3Reliability
If a protective layer is added to prevent dye elution, then spectral characteristics are maintained, but the device structure becomes more complex
Solution Approach 1:
The protective layer is designed with specific material properties and thickness parameters that allow it to perform its protective function while minimizing its impact on the overall device structure. By optimizing these parameters, the added complexity is reduced.
Solution Approach 2:
The protective layer is designed to serve multiple functions: protecting the infrared light absorbing dye from elution, maintaining spectral characteristics, and potentially serving as part of the final filter structure. This multi-functionality reduces the need for additional separate components.
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 protective layer effectively suppresses the elution of infrared light absorbing dyes, thereby maintaining the spectral characteristics of the infrared light cut filter and ensuring accurate detection of visible and infrared light in solid-state imaging devices.
Implementation Method 1
the protective layer contains a resin having a crosslinked structure in which an epoxy group and a functional group reacting with the epoxy group are crosslinked
Implementation Method 2
the protective layer suppresses the infrared light cut layer from coming into contact with the stripping solution, and thus the stripping solution is suppressed from being permeated into the infrared light cut layer
Implementation Method 3
An infrared light absorbing dye of the infrared light cut filter absorbs infrared light, thereby cutting infrared light that can be detected by each photoelectric conversion element from entering the photoelectric conversion element
Implementation Method 4
The miniaturization of the infrared light cut filter is realized by dry etching using a resist pattern formed on the infrared light cut filter
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
A method for producing an infrared light cut filter includes: forming an infrared light cut layer containing an infrared light absorbing dye; forming a protective layer on the infrared light cut layer for providing protection against a stripping solution; forming a resist pattern on the protective layer; patterning the protective layer and the infrared light cut layer by dry etching using the resist pattern; and removing the resist pattern from the protective layer using the stripping solution.