Abstract: A sensor having photodiodes whose sensitivity and storage capacity can be increased is provided. The sensor is formed by arranging the photodiodes in an array with first region of second conductivity type is formed on the principal surface of a substrate of a first conductivity type. A pixel separating region of the first conductivity type is formed to penetrate through the first semiconductor region to separate the regions of the adjacent photodiodes. A second region of the second conductivity type used to drain excess charge is formed in substrate at a position away from the junction surface between substrate and the first region and below the junction surface.

Abstract: A semiconductor device that contains photodiodes whose sensitivity and storage capacity can be increased, and a solid-state image pickup device formed by arranging the photodiodes in an array and its manufacturing method. A first semiconductor region 11 of a second conductivity type is formed on the principal surface of a semiconductor substrate 10 of a first conductivity type. A pixel separating region 14 of the first conductivity type is formed to penetrate through the first semiconductor region 11 to separate the regions of the adjacent photodiodes PD. A second semiconductor region 15 of the second conductivity type used to drain excess charge is formed in semiconductor substrate 10 at a position away from the junction surface between semiconductor substrate 10 and the first semiconductor region 11 and below the junction surface.