Photo-detection apparatus and photo-detection system

A photodetection apparatus comprising:

• a substrate having a first surface and a second surface opposite to the first surface;
• a first semiconductor region of a first conductivity type including a majority carrier of a polarity of a signal charge, the first semiconductor region being arranged in a first depth of the substrate;
• and
• a second semiconductor region of a second conductivity type having different conductivity from the first conductivity type, the second semiconductor region being arranged in a second depth greater than the first depth from the first surface;
• a third semiconductor region of the first conductivity type, the third semiconductor region overlapped with the first semiconductor region in a plan view and being arranged in a third depth greater than the second depth from the first surface;
• a fourth semiconductor region of the second conductivity type, the fourth semiconductor region overlapped with the third semiconductor region in the plan view and being arranged in a fourth depth greater than the third depth from the first surface;
• and
• a fifth semiconductor region of the second conductivity type,
• wherein,
• in a cross section passing through the first semiconductor region, the second semiconductor region, the third semiconductor region, and the fourth semiconductor region, the fifth semiconductor region is arranged in one end side of the first semiconductor region and the other end side of the first semiconductor region,
• the fifth semiconductor region is formed from the first depth to the third depth, and
• in the second depth, a sixth semiconductor region is arranged in a region overlapping the first semiconductor region in the plan view, the sixth semiconductor region being a semiconductor region of the second conductivity type having an impurity concentration lower than that of the second semiconductor region or being a semiconductor region of the first conductivity type.