Semiconducor International publishes Chipworks' Ray Fontain's article on Sony BSI sensor reverse engineering findings. The article reveals:
- Sony BSI uses SOI process - meaning it's not cheap.
- The sensor's backside has AR layer
- The backside uses aperture grid made of tungsten
- Assuming the pixel size of 1.75um, the silicon layer thickness is about 2.8um
- It appears there is 0.8-0.9um thick spacer between microlens and color filter, so the distanse from microlens to the silicon surface is about 2um
The picture below shows the sensor cross-section:
Update: It appears that Sony uses an additional conforming AR layer on top of microlens (should I say on bottom of microlens?).