Method of making a high efficiency horizontal transfer section of a solid state imager
AssigneeSony Corporation
InventorsJunichi Hojo, Toshiaki Wakayama
Life of this patent
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Abstract
In a horizontal transfer section of a solid state imager, a horizontal transfer efficiency can be improved while other element sections are prevented from being substantially affected. In a solid state imager having a horizontal transfer section comprised of a well-region of a second conductivity type formed on the surface of a semiconductor substrate of a first conductivity type and a signal charge transfer region formed on the surface of the well-region of the second conductivity type, the well-region is formed completely in a depletion state by the implantation of impurities into this well-region. The horizontal transfer efficiency is thus improved.
Claims7
A method for constructing a horizontal transfer section of a solid state image sensor, comprising the steps of:
- providing a substrate of a first conductivity type;
- providing a well-region of a second conductivity type opposite the first conductivity type on said substrate;
- providing a charge transfer region of said first conductivity type on the well-region;
- providing an insulating layer on said charge transfer region;
- providing a first set of electrodes on the insulating layer and each having a connection for supply with a first drive pulse;
- providing a second set of electrodes on said insulating layer with each having a connection for supply with a second drive pulse;
- subjecting said well-region to a first impurity implantation to render a potential of the well-region shallower;
- and
- then subjecting the well-region to a second impurity implantation to form a depletion state therein while maintaining a potential of the charge transfer region.
Dependencies are inferred from the claim text.