Pinned photodiode (PPD) pixel architecture with separate avalanche region

摘要

Described herein is a pinned photodiode pixel architecture having a p-type substrate that is independently biased with respect to a pixel area to provide an avalanche region between an n-type region and a p-type region formed on the substrate. Such a pinned photodiode pixel can be used in imaging sensors that are used in low light level conditions.

主权项

1. A pinned photodiode pixel architecture comprising:
a first doped region formed over a second doped region, wherein the first doped region is internally biased to a first potential; and a third doped region formed over the first doped region, wherein the third doped region is externally biased to a second potential, wherein at least the second doped region is externally biased to a third potential that is independent of the second potential to create an avalanche region between the first doped region and the second doped region, and wherein each of the first doped region, the second doped region, and the third doped region has a different bias.