Methods and apparatus for a backside illuminated (BSI) image sensor device are disclosed. A BSI sensor device is formed on a substrate comprising a photosensitive diode. The substrate may be thinned at the backside, then a B doped Epi-Si(Ge) layer may be formed on the backside surface of the substrate. Additional layers may be formed on the B doped Epi-Si(Ge) layer, such as a metal shield layer, a dielectric layer, a micro-lens, and a color filter.