Back illuminated sensor with low crosstalk

A method for producing a back-illuminated image sensor, comprising:

• providing a sensor layer having a frontside and a backside opposite the frontside;
• situating an insulating layer adjacent the backside;
• situating a circuit layer adjacent the frontside;
• providing a plurality of photodetectors of a first type conductivity for converting light incident on the backside into photo-generated charges, the photodetectors having a depletion region, wherein the plurality of photodetectors are disposed in the sensor layer adjacent the frontside;
• forming a region of a second type conductivity in at least a portion of the sensor layer adjacent the frontside;
• biasing the second type conductivity region at a predetermined voltage;
• forming a well of the second type conductivity in the sensor layer adjacent the backside;
• and
• providing trench isolations in the sensor layer starting at the frontside and extending beyond the depletion region of the photodiodes.

An image capture device, comprising:

• a lens configured to receive light;
• a back-illuminated image sensor including:
• a sensor layer having a frontside and a backside opposite the frontside;
• an insulating layer adjacent the backside;
• a circuit layer adjacent the frontside;
• a plurality of photodetectors of a first type conductivity for converting light from the lens incident on the backside into photo-generated charges, the photodetectors having a depletion region, wherein the plurality of photodetectors are disposed in the sensor layer adjacent the frontside;
• a region of a second type conductivity formed in at least a portion of the sensor layer adjacent the frontside and connected to a voltage terminal for biasing the second type conductivity region at a predetermined voltage;
• a well of the second type conductivity formed in the sensor layer adjacent the backside;
• and
• trench isolations in the sensor layer starting at the frontside and extending beyond the depletion region of the photodiodes.