Photoelectric conversion device and imaging system

A photoelectric conversion device comprising:

• a photoelectric conversion element provided in a semiconductor substrate and including a first semiconductor region of a first conductivity type;
• a second semiconductor region of the first conductivity type which is provided in contact with the first semiconductor region;
• a third semiconductor region of the first conductivity type which is provided at a position apart from the second semiconductor region;
• a fourth semiconductor region of a second conductivity type different from the first conductivity type which is provided between the second semiconductor region and the third semiconductor region;
• a fifth semiconductor region of the first conductivity type which is provided at a position apart from the third semiconductor region;
• a sixth semiconductor region of the second conductivity type which is provided between the third semiconductor region and the fifth semiconductor region;
• a first gate electrode provided on an insulation film on the fourth semiconductor region;
• and
• a second gate electrode provided on an insulation film on the sixth semiconductor region,
• wherein an impurity concentration of the third semiconductor region is lower than that of the fifth semiconductor region, and a depth of a lower-edge of the third semiconductor region from a surface of the semiconductor substrate is larger than a depth of a lower-edge of the fifth semiconductor region from the surface of the semiconductor substrate.