Patent ID: 8592934

Claim:
A semiconductor photodetector comprising: a semiconductor substrate formed with a plurality of pn junction type photodiodes on a side of the semiconductor substrate opposite from an incident surface of the semiconductor substrate for receiving light to be detected; wherein, on the side of the semiconductor substrate opposite from the incident surface, a separate region including a pn junction, which is separate from the photodiodes, is formed between photodiodes adjacent each other in the plurality of photodiodes, and a high-concentration impurity semiconductor region having the same conductivity type as that of the semiconductor substrate, which is separate from the photodiodes and the separate region, is formed between the separate region and each of the photodiodes closest to the separate region, the separate region is disposed so as to be sandwiched between the high-concentration impurity semiconductor regions, the high-concentration impurity semiconductor region has an impurity concentration higher than that of the semiconductor substrate and is formed so as to surround the photodiode as seen from the side of the semiconductor substrate opposite from the incident surface, the semiconductor substrate and the high-concentration impurity semiconductor region are of a first conductivity type, an electrode electrically connected to a second conductivity type impurity semiconductor region constituting the separate region with the semiconductor substrate, and the high-concentration impurity semiconductor region is formed on the side of the semiconductor substrate opposite from the incident surface, the second conductivity type being opposite to the first conductivity type, a portion of the semiconductor substrate is disposed between the second conductivity type impurity semiconductor region and the high-concentration impurity semiconductor region, and wherein an electrode conductor included in the electrode is formed so as to cover the entirety of the separate region and the high-concentration impurity semiconductor regions disposed so as to sandwich the separate region.