Semiconductor Light Enhancement Structure for Photodetector Absorption
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Solution Overview
Problem
Conventional image sensors face challenges in enhancing light intensity for photodetectors, particularly for infrared and red light, due to limitations in light collection efficiency, leading to reduced absorption and detection capabilities.
Innovation Solution
A light enhancement structure with cone-shaped microstructures is integrated between the photodetectors and the carrier substrate, utilizing a dielectric layer and microstructures to redirect and enhance light intensity through reflection, specifically designed for infrared and red photodetectors, while maintaining flat surfaces for blue and green photodetectors to prevent light leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a light enhancement structure with microstructures is added to enhance light intensity for infrared and red photodetectors, then light absorption capability is improved, but device complexity increases
Solution Approach 1:
The patent applies different surface structures to different regions: cone-shaped microstructures are formed only in first regions corresponding to infrared and red photodetectors, while second regions corresponding to blue and green photodetectors maintain flat surfaces. This local differentiation optimizes light absorption for specific wavelength ranges without unnecessarily complicating the entire device structure.
Solution Approach 2:
The light enhancement structure is segmented into multiple regions with different characteristics. The first region contains cone-shaped microstructures for infrared and red light enhancement, while the second region remains flat for blue and green light detection. This segmentation allows each region to be optimized for its specific function.
2Illumination intensity
If cone-shaped microstructures are formed to redirect and enhance light, then light intensity incident on photodetectors is increased, but manufacturing precision requirements increase
Solution Approach 1:
The patent forms cone-shaped microstructures with a predetermined size that is intentionally designed to be larger than the minimum required for light enhancement functionality. This partial exaggeration of the microstructure size simplifies manufacturing by providing a larger tolerance window, reducing the stringency of precision requirements while still achieving the desired light redirecting effect.
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 light enhancement structure significantly increases the light intensity incident on photodetectors, enhancing their absorption capabilities, particularly for infrared and red light, while maintaining optimal performance for blue and green light detection.
Implementation Method 1
utilizing a dielectric layer and microstructures to redirect and enhance light intensity through reflection
Implementation Method 2
enhancing their absorption capabilities, particularly for infrared and red light
Data Source
AI summary
A semiconductor device includes a carrier substrate, a first color filter, a first photodetector, and a light enhancement structure. The first photodetector is disposed between the carrier substrate and the first color filter. The light enhancement structure is disposed between the first color filter and the carrier substrate and adjacent to the first photodetector for enhancing intensity of light incident the first photodetector.