FIELD: physics.
SUBSTANCE: solid-state image sensor includes a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type in contact with the bottom surface of the first semiconductor region and operating as a charge accumulation region, a third semiconductor region, which includes side surfaces surrounded by the second semiconductor region, a fourth semiconductor region of a second conductivity type, situated away from the second semiconductor region, and a transfer gate which forms a channel for transferring charges accumulated in the second semiconductor region into the fourth semiconductor region. The third semiconductor region is a region of a first conductivity type or second conductivity type, and concentration of impurities therein is less than that in the second semiconductor region. The third semiconductor region has a top surface in contact with the second semiconductor region.
EFFECT: meeting requirements for the number of charges in saturation state, operating parameters for transfer and sensitivity of the disclosed image sensor.
3 cl, 9 dwg
