Patent ID: 7521278
Filing Date: 2009-04-21
Classification: H01L

Abstract:
1. A method for forming the passivation layer for silicon-isolation interface between photosensitive regions of an image sensor, the method comprising: (a) providing a substrate having a plurality of spaced apart to-be formed photosensitive regions that collect charge in response to incident light; (b) etching trenches in the substrate between the to-be formed photosensitive regions; (c) forming a plurality of masks over the to-be formed photosensitive regions so that trenches between the to-be formed photosensitive regions are not covered by the masks; (d) implanting the image sensor with a first low dose to passivate the trenches; (e) filling the trenches with a dielectric to form isolation between the to-be formed photosensitive regions; (f) forming a plurality of masks which cover the to-be formed photosensitive regions but does not cover a surface corner of the isolation trench to permit passivation implantation at the surface corner of the trench isolation; and (g) implanting the image sensor at a second low dose to passivate the surface corner of trenched isolation region.