Charge transferring device and charge transferring method which can reduce floating diffusion capacitance

摘要

A charge transferring device includes a detection MOSFET for detecting a signal charge, a reset MOSFET for removing the signal charge after the signal charge is detected. The reset MOSFET includes a floating diffusion layer to which the signal charge is transferred, an impurity layer to which a reset voltage is applied, and a reset gate electrode to which a reset signal is supplied. The detection MOSFET includes a detection gate electrode connected with the floating diffusion layer. The floating diffusion layer includes a first semiconductor region and a second semiconductor region whose impurity concentration is lower than that of the first semiconductor region. The impurity concentration of the first semiconductor region is set to a concentration such that the first semiconductor region is not depleted in a voltage lower than the reset voltage when the reset signal is supplied to the reset gate electrode.