Semiconductor photo-detection device and radiation detection apparatus

A semiconductor photodetector comprising:

• a semiconductor substrate having a first conductivity type;
• a plurality of pn junction type photodiodes formed on a first surface side of the semiconductor substrate opposite from an incident surface of the semiconductor substrate for receiving light to be detected;
• a separate region including a pn junction, and formed on the first surface side of the semiconductor substrate, the separate region being separate from the photodiodes;
• and
• a high-concentration impurity semiconductor region having the first conductivity type with an impurity concentration higher than that of the semiconductor substrate, and formed on the first surface side of the semiconductor substrate, the high-concentration impurity semiconductor region being separate from the photodiodes and the separate region;
• wherein
• the separate region is formed along a side of a first photodiode in the plurality of photodiodes, and between the first photodiode and a second photodiode adjacent to the first photodiode, and is constituted by a second conductivity type impurity semiconductor region with the semiconductor substrate, the second conductivity type being opposite to the first conductivity type,
• the high-concentration impurity semiconductor region is formed as a region including at least a region near a corner of the first photodiode and a corresponding corner of the second photodiode, and
• an electrode electrically connected to the second conductivity type impurity semiconductor region and the high-concentration impurity semiconductor region is formed on the first surface side of the semiconductor substrate.