Charge-coupled device having channel region with alternately changing potential in a direction perpendicular to charge transfer

摘要

A charge-coupled device comprises a p type silicon substrate (130), a plurality of n type impurity regions (121) of a high impurity concentration, a plurality of n type impurity regions (140) of a low impurity concentration, a silicon oxide film (150) for defining a channel region (10), a gate oxide film (110), a plurality of gate electrodes (21, 31, 41, 51, 22, 32, 42 and 52) and clock bus lines (70, 80, 90 and 100) for applying a clock signal to the respective gate electrodes. The n type impurity regions (121) and (140) are formed alternately in the channel region (10) along a direction perpendicular to the charge transfer direction, whereby the potential in the channel region (10) changes in the above described perpendicular direction. The change of the potential causes a strong electric field in the channel region (10) in the above described perpendicular direction, which serves to prevent carriers from freezing to an impurity level at a low temperature. Thus, the transfer efficiency of carriers is improved.