Abstract: A CCD shift register which is improved in the transfer efficiency with a minimal decrease in the amount of electric charge that can be handled. The CCD shift register has an array of transfer electrodes, each comprising a pair of storage and transfer gate electrodes, which are formed on a semiconductor substrate through a gate insulator. A semiconductor region under each storage gate electrode is divided into a plurality of subregions by using impurities.

Abstract: An output circuit for sequentially receiving and converting charge collected in the photoelements of an image sensor and converting such charge into an output voltage. The output circuit includes a buried-channel LDD transistor having gate, source and drain electrodes. The source electrode provides a floating diffusion. When the transistor is turned off, a potential well is provided in the floating diffusion which collects charge. An output source-follower amplifier also employing buried-channel LDD transistors is connected to the floating diffusion and produces the output voltage.