Patent ID: 7244971

Claim:
A solid state image pickup device comprising: a semiconductor substrate of a second conductivity type and having a surface layer of a first conductivity type opposite to said second conductivity type formed thereon; a plurality of charge storage regions of the second conductivity type disposed in said surface layer in a row and column matrix shape, constituting a plurality of photoelectric conversion elements; a plurality of vertical channels of the second conductivity type disposed in said surface layer adjacent to respective columns of said charge storage regions; vertical transfer electrodes formed above the semiconductor substrate, crossing said vertical channels, constituting vertical charge coupled devices; a horizontal channel of the second conductivity type disposed in said surface layer coupled to said vertical channels, having a first portion with a plurality of transfer stages, each including a barrier region and a well region, and a second portion constituting a gate region with gradually decreasing width, and including an upstream region and a downstream region of different effective impurity concentration, establishing a built-in potential; horizontal transfer electrodes disposed above respective transfer stages of said horizontal channel; an output gate electrode disposed above said gate region; a floating diffusion region of said second conductivity type disposed in said surface layer coupled to said gate region of said horizontal channel, constituting an output element for receiving a signal charge and outputting a voltage signal.