Imaging device and method for driving the same

An imaging device comprising:

• a first pixel provided on a semiconductor substrate;
• and
• a second pixel provided on the semiconductor substrate and adjacent to the first pixel, wherein
• each of the first pixel and the second pixel includes
• a first transistor provided on the semiconductor substrate and including a first gate electrode, a source, and a drain,
• an amplification transistor provided on the semiconductor substrate and including a second gate electrode,
• a first well region of a second conductivity type, the first well region being positioned in the semiconductor substrate,
• a second well region of a first conductivity type different from the second conductivity type, the second well region being positioned in the semiconductor substrate,
• a first impurity region of the first conductivity type, the first impurity region being positioned in the first well region, being one of the source and the drain, holding charges generated by photoelectric conversion, and being electrically connected to the first gate electrode,
• a second impurity region of the second conductivity type, the second impurity region being positioned in the second well region and electrically connected to the other of the source and the drain,
• a first contact hole,
• a first contact plug connected to the first impurity region through the first contact hole,
• a third contact hole, and
• a third contact plug connected to the second gate electrode through the third contact hole, and
• the second well region of the first pixel, the first well region of the first pixel, the first well region of the second pixel, and the second well region of the second pixel are arranged in this order in a direction from the first pixel toward the second pixel in plan view.

A method for driving an imaging device including a first transistor, a first PN junction, a second PN junction, and a third PN junction, the method comprising:

• increasing a reverse bias voltage applied to the first PN junction by storing charges generated by photoelectric conversion when the first transistor is off;
• turning on the first transistor by storing the charges;
• and
• applying a forward bias voltage to the second PN junction after reducing the reverse bias voltage applied to the second PN junction by storing the charges when the first transistor is on, and discharging the charges, wherein
• when the first transistor is on, the charges are stored in the third PN junction, and
• the second PN junction is connected to the third PN junction through wiring.