Patent ID: 8330195
Filing Date: 2012-12-11
Classification: H01L

Abstract:
1. A method of operating an image sensor, comprising: collecting charge carriers within collection regions disposed within a first P type epitaxial layer in response to light incident on the image sensor; generating a first field at a junction between an N type collector layer and a P type barrier layer to draw excess charge carriers generated within the P type barrier layer away from the collection regions into the N type collector layer, wherein the N type collector layer and the P type barrier layer are disposed between a substrate layer and the first P type epitaxial layer, wherein a second P type epitaxial layer is disposed between the substrate layer and the N type collector layer; generating a second field at a junction between the P type barrier layer and the first P type epitaxial layer to push photo-electrons generated within the first P type epitaxial layer towards the collection regions; and electrically coupling the second P type epitaxial layer to the P type barrier layer via electrical pass-throughs selectively disposed through the N type collector layer.