Hybrid Visible SWIR Imaging Sensor with Quantum Dot Integration

The patent combines silicon-based visible light photodetectors and quantum dot-based near-infrared photodetectors into a single hybrid imaging sensor array on a common CMOS substrate. This merging allows the sensor to simultaneously detect both visible and near-infrared wavelengths, resolving the contradiction between visible light sensitivity and NIR detection capability.

The patent uses composite material structures where quantum dot layers (e.g., PbS, PbSe) are integrated with silicon-based photodetector structures. The quantum dots have tunable bandgaps that enable near-infrared detection while the silicon substrate maintains visible light sensitivity, creating a composite photodetector system that achieves both detection capabilities.

The patent designs a universal CMOS readout circuit architecture that can handle signals from both silicon-based visible photodetectors and quantum dot-based NIR photodetectors. The readout circuits are configured to process signals from multiple photodetector types through a unified interface, reducing the complexity that would otherwise arise from having separate processing paths for different material systems.

The patent segments the imaging sensor into distinct regions: silicon-based photodetector regions for visible light and quantum dot photodetector regions for near-infrared. This segmentation allows each material system to be optimized independently while sharing common support infrastructure such as the CMOS substrate and readout circuits, thereby managing complexity through modular organization.

The patent employs preliminary action by first fabricating the silicon-based visible photodetectors and CMOS readout circuits using standard CMOS processes, then subsequently depositing and patterning the quantum dot layers in designated regions. This sequential fabrication approach allows each material system to be processed under its optimal conditions while maintaining compatibility with standard semiconductor manufacturing workflows.

The patent uses intermediary layers and structures, such as transparent conductive oxide layers and dielectric layers, to facilitate the integration of quantum dot photodetectors with the underlying CMOS circuitry. These intermediary elements provide electrical connections, mechanical support, and process compatibility, enabling the hybrid structure to be manufactured using adapted standard semiconductor processes.