Patent ID: 6849918

Claim:
A miniaturized, dielectrically isolated, solid state, integrated circuit device comprising, in a vertical cross-section through the device: a semiconductor material substrate of a first conductivity type; an oxide region formed entirely by in-situ oxidation of an upper portion of the substrate, wherein the oxide region has a lower surface that, below a selected level extending laterally, is continuously convex and continuously rounded, without any straight portion, and tapers in width continuously and progressively, and wherein the oxide region has an upper surface that does not extend below the selected level and is non-concave, said oxide region being solid throughout between its upper and lower surfaces; two semiconductor material pockets of a second conductivity type that are formed in-situ from an upper portion of the substrate, wherein one of the pockets has a side surface that is in continuous physical contact with a portion of a left side of the lower surface of the oxide region and is continuously concave and rounded, and the other pocket has a side surface that is in continuous physical contact with a portion of a right side of the lower surface of the oxide region and is continuously concave and rounded, said side surfaces of the two pockets being substantially mirror images of each other relative to a vertical line extending centrally through the oxide region; wherein the pockets have respective upper surfaces that substantially conform to said selected level at least for portions of the pockets that are adjacent to the oxide region, and the concave and rounded side surfaces of the pockets extend below the selected level; a respective PN junction at an interface of each of the pockets with the substrate, each of the PN junctions extending to and meeting the oxide region at the convex and rounded lower surface thereof, below said selected level, and the oxide region laterally spacing the two PN junctions from each other, each of the PN junctions being substantially non-conductive electrically under an electrical bias of a selected polarity applied between the substrate and the respective pocket; and said oxide region physically separating and electrically isolating the two pockets from each other laterally, each of the pockets being at least a part of a respective active electrical device and the respective active electrical devices being physically a part of the same integrated circuit device but being electrically isolated from each other laterally by the oxide region and being operable as electrically independent active devices.