A wafer structure for an image sensor includes a substrate that has a given conductivity type, a given dopant concentration, and a given concentration of oxygen. An intermediate epitaxial layer is formed over the substrate. The intermediate epitaxial layer has the same conductivity type and the same,...http://www.google.com.au/patents/US8173535?utm_source=gb-gplus-sharePatent US8173535 - Wafer structure to reduce dark current
