Methods of fabricating back-illuminated imaging sensors

A back-illuminated semiconductor imaging device on a semiconductor-on-insulator substrate is disclosed. The device includes an insulator layer, a semiconductor substrate having an interface with the insulator layer, an epitaxial layer grown on the semiconductor substrate; and one or more imaging components in the epitaxial layer. The semiconductor substrate and the epitaxial layer exhibit a net doping concentration profile having a maximum value at a predetermined distance from the interface which decreases monotonically on both sides of the profile. The doping profile between the interface with the insulation layer and the peak of the doping profile functions as a "dead band" to prevent dark current carriers from penetrating to the front side of the device.