Photosite with pinned photodiode

摘要

A photosite is formed in a semiconductor substrate and includes a photodiode confined in a direction orthogonal to the surface of the substrate. The photodiode includes a semiconductor zone for storing charge that is formed in an upper semiconductor region having a first conductivity type and includes a main well of a second conductivity type opposite the first conductivity type and laterally pinned in a first direction parallel to the surface of the substrate. The photodiode further includes an additional semiconductor zone including an additional well having the second conductivity type that is buried under and makes contact with the main well.

主权项

1. A photosite, comprising:
a semiconductor substrate of a first conductivity type and having an upper surface; and a photodiode confined in a direction orthogonal to the upper surface of the substrate, comprising:
a first well in the substrate and having a second conductivity type opposite the first conductivity type;a semiconductor zone configured to store charge comprising a second well of the first conductivity type that is formed in the first well and laterally pinned in a first direction parallel to the surface of the substrate by the first well;a third well in the substrate and having the second conductivity type placed between the first well and a first conductivity type region in a lower part of the substrate; andan additional semiconductor zone configured to store charge comprising a fourth well of the first conductivity type that is formed in the third well and laterally pinned in the first direction by the third well, the fourth well buried under and making contact with the second well.