On Wednesday 28 November 2018 Dirk Van Aken, Senior Project Manager, will present at the CNES workshop on ultraviolet detectors and instruments in Toulouse (France) the paper:
“QE of front side and back side thinned CMOS Image Sensors between 100 and 400nm”
Classical frontside illuminated CMOS and CCD image sensors are suitable for visible light imaging, yet suffer serious degradation in spectral response for wavelengths especially in the near and deep UV.
The underlying reasons (interference, material-specific absorption, coatings, surface treatments) are fairly well understood, and certain measures to enhance the UV response are possible.
We had the occasion to have virtually the same device processed in following flavours of two CMOS image sensor processes:
- Plain frontside illumination, with all dielectric layers including the passivation layer in place
- Frontside illumination with the dielectric stack completely removed
- Frontside illumination with the dielectric stack partially removed
- Backside illumination with 3 combinations of Si layer thickness and anti-reflective coatings.