Self-aligned implants to reduce cross-talk of imaging sensors

摘要

A method of preparing self-aligned isolation regions between two neighboring sensor elements on a substrate. The method includes patterning an oxide layer to form an opening between the two neighboring sensor elements on the substrate. The method further includes performing a first implant to form a deep doped region between the two neighboring sensor elements and starting at a distance below a top surface of the substrate. The method further includes performing a second implant to form a shallow doped region between the two neighboring sensor elements, wherein a bottom portion of the shallow doped region overlaps with a top portion of the deep doped region.

主权项

1. An image sensor comprising:
a substrate; two neighboring sensor elements in the substrate; a deep doped region in the substrate between the two neighboring sensor elements and starting a distance below a top surface of the substrate; a shallow doped region in the substrate between the two neighboring sensor elements, wherein a bottom portion of the shallow doped region overlaps with a top portion of the deep doped region; and a shallow trench isolation (STI) feature, wherein the shallow doped region extends from a top surface of the substrate through the STI feature.