BSI CMOS Biosensor Layout for Fluorescence DNA Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current biosensors for biological or chemical analysis face limitations in effectively detecting and measuring fluorescence or chemiluminescence, particularly in biological or chemical samples, which hampers accurate identification and sequencing of nucleic acid macromolecules.
Innovation Solution
A backside illumination (BSI) complementary metal-oxide-semiconductor (CMOS) image sensor is employed, featuring a photo sensing layer with a substrate and photodiode, along with a color filter material and functionalized spots or wells to receive and analyze light emitted from nucleic acid macromolecules, enabling precise measurement of fluorescent or chemiluminescent labels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional CMOS image sensors with front-side illumination are used, then integrated circuits and amplifiers can be placed on the chip, but light capture area is reduced and light must pass through wiring layers causing destructive interference
Solution Approach 1:
The patent inverts the conventional front-side illumination architecture to back-side illumination. The photodiodes are positioned on the backside of the substrate, allowing light to enter directly without passing through wiring layers and amplifiers. This inversion resolves the contradiction by eliminating the harmful interference from front-side components while maintaining full light capture area.
Solution Approach 2:
The patent transitions from a planar front-side architecture to a three-dimensional back-side illumination structure. By moving the photodiode active region to the opposite side of the substrate and introducing intermediate transfer layers, the design captures light from a different spatial dimension, avoiding obstruction from circuit wiring while preserving area efficiency.
2Measurement precision
If backside illumination is used to place photodiodes closer to light source, then light capture efficiency increases and destructive interference is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent segments the sensor structure into distinct functional layers: a substrate layer, an intermediate layer with transfer openings, and a backside photodiode layer. This segmentation allows each layer to be optimized independently for its specific function while simplifying the overall manufacturing process through modular fabrication steps.
Solution Approach 2:
The patent introduces an intermediate layer with transfer openings as a mediator between the substrate and the backside photodiodes. This intermediate structure facilitates the controlled formation of photodiodes at precise locations while maintaining alignment with underlying circuit elements, thereby reducing manufacturing complexity despite the inverted architecture.
3Adaptability or versatility
If filters are used to divide incident light into wavelength bands, then color detection is enabled, but device complexity and manufacturing steps increase
Solution Approach 1:
The patent merges the filter structure with the color filter array layer, integrating wavelength selection functionality directly into the existing sensor architecture. By combining multiple functions (light filtering, color separation, and structural support) into a single integrated layer, the design achieves versatile wavelength detection without proportionally increasing device complexity.
Solution Approach 2:
The color filter array layer serves multiple functions simultaneously: it acts as a structural support layer, provides wavelength-specific filtering, enables color detection across multiple bands, and maintains alignment with the photodiode array. This multi-functionality achieves spectral versatility without adding separate dedicated components for each function.
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 configuration enhances the ability to detect and analyze light emitted from biological samples, facilitating accurate identification and sequencing of nucleic acid macromolecules, such as DNA, through improved light detection and correlation of emitted light parameters.
Implementation Method 1
The light is received by the photodiodes on a substrate and transformed into electrical signals of different intensity
Data Source
AI summary
Embodiments of the invention provide an improved biosensor for biological or chemical analysis. According to embodiments of the invention, backside illumination (BSI) complementary metal-oxide-semiconductor (CMOS) image sensors can be used to effectively analyze and measure fluorescence or chemiluminescence of a sample. This measured value can be used to help identify a sample. Embodiments of the invention also provide methods of manufacturing an improved biosensor for biological or chemical analysis and systems and methods of DNA sequencing.