Multilayer image sensor pixel structure for reducing crosstalk

摘要

An image sensor pixel includes a substrate, a first epitaxial layer, a collector layer, a second epitaxial layer and a light collection region. The substrate is doped to have a first conductivity type. The first epitaxial layer is disposed over the substrate and doped to have the first conductivity type as well. The collector layer is selectively disposed over at least a portion of the first epitaxial layer and doped to have a second conductivity type. The second epitaxial layer is disposed over the collector layer and doped to have the first conductivity type. The light collection region collects photogenerated charge carriers and is disposed within the second epitaxial layer. The light collection region is also doped to have the second conductivity type.