Patent ID: 7132702

Claim:
A back-illuminated image sensor comprising: a semiconductor base of a first conductive type; a plurality of charge accumulating units of a second conductive type different from said first conductive type, formed on a second-plane side which is the backside of a first plane of said semiconductor base, said charge accumulating units which accumulate, on a pixel-by-pixel basis, signal charges generated by an energy ray incident from the second-plane side; a charge transfer unit formed on the first-plane side of said semiconductor base facing said charge accumulating units, the charge transfer unit which transfers said signal charges to be read; a charge transport unit which transports said signal charges accumulated in said charge accumulating units to said charge transfer unit; and a depletion prevention layer formed closer to said second-plane side than said charge accumulating units, the depletion prevention layer which prevents a depletion region around said charge accumulating units from reaching said second plane.