Samsung patent application US20130015325 "Backside illuminated image sensor" by Jung-Chak Ahn proposes to use relatively thick BSI substrate (10um in an example embodiment) and apply high voltage on the backside to reduce crosstalk. The backside voltage is provided by a charge pump. Unfortunately, the application does not tell what to do with current flow from the backside voltage source (-10V in the example below) through the p-type inter-PD isolation to the front side p+ pinning layer at 0V.
