Solid state image sensor with signal amplification

Claim 1

A solid state image sensor comprising: a semiconductor substrate having a high impurity concentration of a first conductivity type, an epitaxial layer of a low impurity concentration formed on said substrate, a plurality of first regions of high impurity concentration of a second conductivity type formed in a two-dimensional disposition on said epitaxial layer and electrically in a floating state, said epitaxial layer and said first regions forming photo-electric converting region, plural charge transfer means for transferring first-type charges along a row direction of said first regions, said charge transfer means including second regions of said first conductivity type and a transfer electrode on an insulating layer which is disposed on said second regions, and being formed corresponding to respective rows of said first regions and electrically in a floating state, said second regions being depleted and used as a charge transfer channel, a charge multiplication means for producing said first-type charges multiplied in proportion to second-type charges generated in said photo-electric converting region by incident light and accumulated in said first regions, said charge multiplication means including said substrate, said epitaxial layer, said first regions and said second regions which form static induction transistors, and voltage controlling means for controllably generating a voltage between said substrate and said first regions, said voltage controlling means establishing a controllable potential barrier with respect to said first-type charges in said substrate for cutting off said static induction transistor when said first-type charges are transferred in said charge transfer region.