Low-leakage JFET

Claim 1

A low-leakage-current JFET comprising: a semi-conductor body comprising a lightly doped layer of one conductivity type having a generally planar surface; a first source/drain region of a conductivity type opposite said one conductivity type in the surface of said body; a second source/drain region of a conductivity type opposite said one conductivity type and surrounding said first source/drain region; a channel region of conductivity type opposite said one conductivity type extending between said first and second source/drain regions at a shallow depth just below said surface; a shield layer of said one conductivity type above said channel region and serving as the top gate for said JFET; said lightly doped layer serving as the bottom gate of said JFET; said bottom gate layer being conductively isolated from said top gate; top gate contact means for said shield layer having an upper portion connectible to terminal means to convey electrical signals to said top gate; said top gate contact means comprising a nonpentrating contact layer over at least a portion of said top gate; said top gate contact means further comprising an interior contact segment in said top gate portion comprising additional impurity of said one conductivity type located wholly above the level of said channel region; said top gate contact means serving to avoid conductive electrical connection from said upper portion thereof through said channel region to said lightly-doped layer.