What was the motivation for FSI sensors initially? To me the BSI version seems much more intuitive (but I am likely biased because it is also the way I first learned how pixels work)
@franklieeder Totally agree. In class, the professor mentioned that FSI models were easier to make, since the infrastructure to make them were already developed.
What are those metal layers? Why do we need them in the first place?
I think that's just the wires to transport the signal?
The metal layers are the wiring. FSI sensors are much easier to manufacture but the problem is that the wires block some of the light. BSI sensors have better low-light performance because much more light hits the diode. Other advantages are that there is wider angular response and possibly faster readout rates. However, there may be worse response uniformity.