To address the needs to detect or track near infrared signals that should not be visible to human eyes, Imec introduces an image sensor with integrated colour (RGB) and narrow-band near-infrared (NIR) filters. This optical filter integration platform is designed for many different fields from medical, industrial, security surveillance, automotive to virtual and augmented reality, where near-infrared signals need to be extracted and overlaid on top of colour images.

Imec’s RGB-NIR multispectral platform demonstrates the possibility to integrate together standard RGB colour filters, NIR-cut filter, NIR narrow band-pass filters and on-chip microlenses technology, down to small pixels as 5μm. The NIR band-pass filter and design pattern implementation can be tuned to match requirements of a specific application, e.g. the wavelength of a particular laser or LED light.

 
RGB-NIR spectral channel graph (cr) Figure 1: Measured QE responses of RGB+NIR spectral channels (microlenses array post-processed on top of each filter).  

Imec designs and manufactures interference based optical filters at wafer level, deposited and patterned directly on top of the CMOS image sensor pixels. This infrastructure provides integrated, clean (class 1 – particle free) and high yield optical filter integration with strong potential for scalability in high-volume.