Inductance device formed on semiconductor substrate
View Patent ↗According to a first aspect of the present invention, a plurality of PN junctions are formed at the surface of a semiconductor substrate under a belt-like conductive film having a spiral shape which constitutes an inductance device. An inverted bias voltage is applied to the PN junctions, and the surface of the substrate is completely depleted. Since the inverted bias voltage is applied to the PN junctions, even though the impurity density of the surface of the substrate is high and the adjacent PN junctions are separated to a degree, the extension of the depletion layers can be increased and complete depletion of the surface of the substrate can be achieved.
1. An inductance device formed on a semiconductor substrate comprising:
an insulating film formed on a surface of said semiconductor substrate; and belt-like conductive films formed on said insulating film,
wherein said belt-like conductive films form a coil and constitute said inductance device; said belt-like conductive films are made of a material having an anisotropic conductivity; and the anisotropic conductivity in the belt-like conductive films is arranged along the coil so that in each of the belt-like conductive films a conductivity in the direction of coil winding is larger than a conductivity in the direction perpendicular to said direction of coil winding and parallel to said surface of said semiconductor substrate.
2. An inductance device according to claim 1 , wherein said belt-like conductive films are made of an oxide superconductive material or an organic conductive material.