Single-Photon Detector Structure With Plasmonic Nanopatterns for SWIR
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Solution Overview
Problem
Existing single-photon detection elements struggle to detect photons with energy lower than the bandgap of the semiconductor substrate and are inefficient in detecting short-wavelength infrared rays, while also suffering from noise issues.
Innovation Solution
Incorporation of plasmonic nanopatterns on the substrate surface to enhance light absorption and reduce transit time of carriers, along with a passivation film to improve noise characteristics and a conductive layer to reflect incident light, thereby improving photodetection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional semiconductor substrate is used, then the device structure is simple, but photons with energy lower than the bandgap cannot be detected
Solution Approach 1:
The patent combines semiconductor substrate with plasmonic nanopatterns to create a composite structure. The plasmonic nanopatterns are formed on the semiconductor substrate surface, creating a hybrid system that enables sub-bandgap photon detection while maintaining the underlying semiconductor structure. This composite approach allows the device to detect photons with energy lower than the semiconductor bandgap by utilizing plasmonic resonance effects.
Solution Approach 2:
The device is segmented into distinct functional regions: the semiconductor substrate provides the basic photodetection capability, while the plasmonic nanopatterns are separately formed on the surface to enhance specific wavelength detection. This segmentation allows each component to perform its optimized function independently, with the plasmonic structures targeting specific sub-bandgap wavelengths.
2Reliability
If conventional detection structures are used, then the device is easy to manufacture, but short-wavelength infrared rays cannot be efficiently detected
Solution Approach 1:
The patent modifies the optical parameters of the semiconductor substrate by introducing plasmonic nanopatterns with specific geometries, sizes, and arrangements. These parameter changes in the nanopatterns (such as diameter, spacing, and shape) are optimized to resonate with short-wavelength infrared rays, thereby enhancing detection efficiency for this specific wavelength range while maintaining compatibility with existing semiconductor manufacturing processes.
3Reliability
If conventional photodetection structures are used, then the device structure is simple, but noise characteristics are poor
Solution Approach 1:
The plasmonic nanopatterns act as an intermediary layer between the incident photons and the semiconductor substrate. This intermediary structure enhances the interaction between sub-bandgap photons and the substrate through plasmonic resonance, improving signal generation while the structured arrangement of nanopatterns helps suppress noise by directing and concentrating optical energy in controlled manner.
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 solution enables detection of photons with energy below the bandgap of the semiconductor substrate, enhances detection of short-wavelength infrared rays, and reduces noise, resulting in improved photodetection efficiency and performance.
Implementation Method 1
plurality of plasmonic nanopatterns provided on the second surface... configured to contact the first well
Implementation Method 2
plasmonic nanopatterns... to enhance light absorption
Implementation Method 3
a conductive layer to reflect incident light, thereby improving photodetection efficiency
Implementation Method 4
Additional electron-hole pairs are sequentially generated due to impact ionization caused by the accelerated electrons
Implementation Method 5
A high electric field rapidly accelerates photo-generated electrons toward an anode (+). Additional electron-hole pairs are sequentially generated due to impact ionization caused by the accelerated electrons
Implementation Method 6
When an incident photon with sufficient energy to emit carrier reaches a photodiode, an electron-hole pair (EHP) is generated. A high electric field rapidly accelerates photo-generated electrons toward an anode (+)
Data Source
AI summary
A single-photon detection element comprises a substrate comprising a first surface and a second surface opposite each other, and a plurality of plasmonic nanopatterns provided on the second surface. The substrate comprises a high-concentration doping region provided adjacent to the first surface and having a second conductivity type, and a first well provided between the high-concentration doping region and the plurality of plasmonic nanopatterns and having a first conductivity type different from the second conductivity type. The plurality of plasmonic nanopatterns are configured to contact the first well.