Patent ID: 6753202
Filing Date: 2004-06-22
Classification: H01L

Abstract:
A method of fabricating a light-sensing diode, having minimal surface-generated junction leakage current, in a high resistivity semiconductor substrate of a first conductivity type comprising the steps of:forming protective isolation regions into the surface of selected portion of said semiconductor; implanting, at high energy, ions of said first conductivity type into said semiconductor to form a well of said first conductivity type shaped as an annulus such that a selected central portion of said semiconductor remains unimplanted; implanting, at high energy, ions of the opposite conductivity type into said central portion to form a well having side walls surrounded by said well of said first conductivity type; implanting, at low energy and high dose, ions of said first conductivity type into at least one selected portion of said well of said opposite conductivity type to form, under and near said surface, a region of compensated conductivity, thereby extending along said surface under said insulator said well of said first conductivity; rapidly annealing said ion implants; depositing over portions of said surface a layer of insulating material suitable as gate dielectric; forming gates of poly-silicon or other conductive material deposited onto said insulating layer; forming source and drain regions to complete said diode; and forming contact metallizations at said source and drain regions.