Reduced crosstalk sensor and method of formation

摘要

Isolation methods and devices for isolating regions of a semiconductor device are disclosed. The isolation methods and structures include forming an isolating trench among pixels or other active areas of a semiconductor device. The trench extends through the substrate to the base layer, wherein a liner may be deposited on the side walls of the trench. A conductive material is deposited into the trench to block electrons from passing through.

主权项

1. An image sensor comprising:
a substrate formed over a base layer; a plurality of pixel cells formed within said substrate, each pixel cell comprising a photo-conversion device having a charge collection region of a second conductivity type for accumulating photo-generated charge formed in said substrate below a first layer of a first conductivity type; and a plurality of trenches, each trench being provided along a perimeter of a respective pixel cell, each trench extending at least to a surface of the base layer and below a lower level of said photo-conversion device, each trench having sidewalls, and being at least partially filled with a conductive material that inhibits electrons from passing through said trench, wherein each of said plurality of trenches prevents diffusion of photo-generated charge generated by said photo-conversion device in one pixel cell to an adjacent pixel cell, and wherein the conductive material is sufficiently biased to form one of a hole rich or electron rich accumulation layer along the sidewalls of the trench.