Patent ID: 8164127
Filing Date: 2012-04-24
Classification: H01L

Abstract:
1. A pixel cell comprising: a substrate; an epitaxial layer having a doping concentration profile of an embossing shape, the epitaxial layer including at least one layer stacked on the substrate; and a photo converting device in the epitaxial layer; wherein the epitaxial layer includes, a first epitaxial layer of a first conductivity type on the substrate and having a first doping concentration, a second epitaxial layer of the first conductivity type on the first epitaxial layer and having a second doping concentration that is higher than the first doping concentration, and a third epitaxial layer of the first conductivity type on the second epitaxial layer and having a third doping concentration that is lower than the second doping concentration, and wherein the second epitaxial layer is between the first epitaxial layer and the third epitaxial laver.