Method and Apparatus for Low Resistance Image Sensor Contact

摘要

A method and apparatus for a low resistance image sensor contact, the apparatus comprising a photosensor disposed in a substrate, a first ground well disposed in a first region of the substrate, the first ground well having a resistance lower than the substrate, and a ground line disposed in a region adjacent to the first ground well. The first ground well is configured to provide a low resistance path to the ground line from the substrate for excess free carriers in the first region of the substrate. The apparatus may optionally comprise a second ground well having a lower resistance than the first ground well and disposed between the first ground well and the ground line, and may further optionally comprise a third ground well having a lower resistance than the second ground well and disposed between the second ground well and the ground line.

主权项

1. A method of forming a semiconductor device, the method comprising:
forming a first ground well in a substrate, the first ground well having a first dopant concentration of a first conductivity type, the first dopant concentration being greater than a dopant concentration of first conductivity type in an underlying region of the substrate; forming a photosensor in a first region of the substrate and separate from the first ground well; forming a dielectric layer on the substrate; and forming a metal trace ground contact directly over the first ground well, the metal trace ground contact extending through the dielectric layer and into the substrate.