Multispectral CMOS sensors with on-chip nanostructures for wavelength monitoring of LED devices

High-end illumination devices based on LEDs require precise color matching, because the dominant wavelength depends on temperature and changes due to aging. We demonstrate the performance of multispectral sensors fabricated using a complementary metal-oxide semiconductor (CMOS) process for color-sensing feedback. Various plasmonic nanostructures were simulated and implemented to achieve band pass and cut-off filters, placed on top of photodiodes. These devices for multispectral sensing can be fabricated in high volume and measurements indicate that a wavelength change of 3 nm yields a relative signal change of more than 20 % due to the steep-edge characteristics of the filters.