The IMEC research institute has developed an innovative pixel architecture with the potential to significantly impact image sensor design and performance. This breakthrough will be showcased at the 2023 International Electron Devices Meeting in San Francisco. IMEC has extended an invitation to industry partners to collaborate on creating a camera demonstrator for this new technology. Notably, the pixel architecture appears to be adaptable for event-based image sensors.
Traditionally, image sensors for visible light within the range of 400nm to 700nm have utilized pixels with dimensions of several microns to capture sufficient light. However, higher resolution image sensors necessitate larger and more costly die.
While reducing pixel dimensions to sub-micron levels can offer cost and energy efficiency benefits, it introduces challenges related to interference, diffraction, photon collection, and color sensitivity. IMEC researchers are set to present a novel approach to achieving color fidelity in relation to sub-micron pixels, which can be manufactured using standard back-end-of-line processing on 300mm-diameter wafers. This technology promises higher spatial resolutions, improved signal-to-noise ratios, and enhanced color quality, according to the institute.
To address color fidelity, diffraction-based color splitting has been proposed as an alternative to conventional color filters. However, this method has historically neglected the issue of image resolution. IMEC has asserted that their sub-micron pixel architecture not only enhances image resolution but also effectively captures photons and ensures accurate color rendition. Researchers have constructed an array of vertical Si3N4 multimode waveguides on an SiO2 matrix, enabling high color sensitivity and diffraction-limited performance in a cost-effective and scalable manner.
IMEC has demonstrated the production of silicon with waveguides on a 1-micron pitch, showcasing the practicality of this technique on a microscale. Furthermore, the institute has expressed its openness to industry collaboration in advancing this innovative approach towards full camera demonstration and establishing diffraction-limited resolution as the future standard for color imaging.
