Patent ID: 7875918
Filing Date: 2011-01-25
Classification: H01L

Abstract:
1. An image sensor pixel, comprising: a substrate doped to have a first conductivity type; a first epitaxial layer disposed over the substrate and doped to have the first conductivity type, wherein the first epitaxial layer directly contacts the substrate without an intervening layer; a collector layer selectively disposed over at least a portion of the first epitaxial layer and doped to have a second conductivity type, wherein the second conductivity type is opposite the first conductivity type; a second epitaxial layer disposed over the collector layer and doped to have the first conductivity type; a light collection region for collecting photo-generated charge carriers disposed within the second epitaxial layer, wherein the light collection region is doped to have the second conductivity type, wherein the light collection region is defined to be a doped region having only the second conductivity type; a barrier layer disposed between the second epitaxial layer and the collector layer, the barrier layer doped to have the first conductivity type; and an electrical pass-through disposed through the collector layer and electrically coupling the first epitaxial layer to the barrier layer, wherein the electrical pass-through is doped to have the first conductivity type.