Image Sensor Anti-Reflection Layer Design for Delamination Prevention
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Solution Overview
Problem
Current image sensors face challenges in reliability due to issues with reflection and delamination, which affect their performance and manufacturing costs, particularly in CMOS image sensors used in various applications.
Innovation Solution
The implementation of an image sensor design that includes a substrate with a light-receiving region and a pad region, featuring an anti-reflection layer with different material compositions for preventing reflection and a delamination-preventing layer to address these issues, improving the overall reliability and manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer anti-reflection layer is used, then the manufacturing process is simple, but reflection is not effectively prevented and reliability is reduced
Solution Approach 1:
The anti-reflection layer is divided into multiple subsidiary layers (first, second, and third subsidiary anti-reflection layers) with different material compositions and thicknesses. Each layer targets specific wavelengths of light, collectively achieving broad-spectrum anti-reflection performance that a single layer cannot provide, thereby improving reliability without excessive complexity
Solution Approach 2:
The patent employs composite material structure where the anti-reflection layer comprises multiple layers with different material compositions (e.g., silicon oxide, silicon nitride, silicon oxynitride). This composite approach enables optimized optical properties across different wavelengths while maintaining manufacturing feasibility through standard semiconductor processes
2Reliability
If the anti-reflection layer and delamination-preventing layer use the same material, then the manufacturing process is simplified, but delamination occurs reducing reliability
Solution Approach 1:
The patent applies different material compositions to different functional layers: the anti-reflection layers use materials optimized for optical performance (silicon oxide, silicon nitride), while the delamination-preventing layer uses silicon oxynitride specifically optimized for adhesion. This local differentiation ensures both optical performance and layer stability without requiring completely separate fabrication processes
Solution Approach 2:
The delamination-preventing layer acts as an intermediary layer between the anti-reflection layer and the underlying substrate or wiring layers. This intermediate layer with silicon oxynitride composition provides optimal adhesion properties, preventing delamination while being compatible with standard semiconductor manufacturing processes
3Object-affected harmful factors
If material composition is optimized for anti-reflection, then reflection is prevented, but the same material may cause delamination issues
Solution Approach 1:
The anti-reflection function is segmented across multiple layers with different material compositions. The first subsidiary anti-reflection layer (silicon oxide) and second subsidiary anti-reflection layer (silicon nitride) handle different wavelength ranges, while the third layer provides additional anti-reflection performance. This segmentation allows each layer to be optimized for its specific optical function without compromising adhesion
Solution Approach 2:
The patent uses a composite material system where silicon oxide, silicon nitride, and silicon oxynitride layers work together. The silicon oxynitride delamination-preventing layer is specifically chosen because it provides both good adhesion to underlying layers and compatible optical properties, creating a composite structure that simultaneously addresses reflection prevention and delamination resistance
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 design enhances the reliability of image sensors by effectively preventing reflection and delamination, leading to improved performance and reduced manufacturing costs, while simplifying the fabrication process.
Implementation Method 1
an anti-reflection layer disposed on the photoelectric conversion layer, wherein a lowermost one of the subsidiary anti-reflection layers of the anti-reflection layer includes a first material composition and the delamination-preventing layer includes a second material composition different from the first material composition
Implementation Method 2
a delamination-preventing layer disposed in the pad region of the substrate... the delamination-preventing layer includes a second material composition different from the first material composition
Implementation Method 3
a photoelectric conversion layer disposed in the light-receiving region of the substrate; wherein the light-receiving region receives light to generate image data
Data Source
AI summary
An image sensor is provided. The image sensor includes, a substrate including a light-receiving region and a pad region disposed around the light-receiving region, wherein the light-receiving region receives light to generate image data, a photoelectric conversion layer disposed on the light-receiving region of the substrate, an anti-reflection layer disposed on the photoelectric conversion layer and including a plurality of subsidiary anti-reflection layers, a microlens disposed on the anti-reflection layer, a delamination-preventing layer disposed on the pad region of the substrate, and a wiring layer disposed on the delamination-preventing layer, wherein a lowermost one of the subsidiary anti-reflection layers of the anti-reflection layer includes a first material composition and the delamination-preventing layer includes a second material composition different from the first material composition.