Solid state imaging device

A photoelectric conversion device comprising:

• a semiconductor substrate including a pixel region in which a plurality of pixels are arranged, each of the pixels including a photoelectric conversion unit configured to accumulate charges generated from an incident light, a charge holding portion configured to hold the charges transferred from the photoelectric conversion unit, a transfer transistor including a gate electrode and configured to transfer the charges generated by the photoelectric conversion unit to the charge holding portion, an amplification unit including an input node configured to receive the charges transferred from the charge holding portion, and a boundary region arranged outside the pixel region;
• a light-shielding portion arranged so as to cover at least the charge holding portion, extending over at least two or more of the plurality of pixels, and extending so as to reach the boundary region from the pixel region;
• a first contact plug connected to the light-shielding portion;
• a wiring connected to the first contact plug to supply a fixed potential to the light-shielding portion via the first contact plug;
• a second contact plug connected to the gate electrode, the second contact plug being different from the first contact plug,
• a first semiconductor region arranged in the boundary region and connected to a first well in which each of the plurality of pixels is formed;
• and
• a second semiconductor region arranged in the boundary region and connected to a second well,
• wherein the light-shielding portion, the first contact plug, and the wiring are arranged in order from the semiconductor substrate,
• wherein the light-shielding portion and the gate electrode are electrically separated from each other, and
• wherein the second semiconductor region is connected to the light-shielding portion.