1. A microelectronic device comprising:a semiconductor integrated circuit, wherein said semiconductor integrated circuit comprises a multilevel wiring network, wherein said semiconductor integrated circuit operates with a plurality of DC supply voltages; and
a DC to DC voltage converter which delivers at least one of said DC supply voltages for said semiconductor integrated circuit, said DC to DC voltage converter comprising an inductor, and wherein said inductor is integrated thereinto said multilevel wiring network, wherein said inductor comprises a planar magnetic core and a conductive winding, wherein said conductive winding turns around in generally spiral manner on the outside of said planar magnetic core, said planar magnetic core having a laminated configuration comprising at least one magnetic layer and at least one current rectifying layer, wherein the at least one magnetic layer comprises a ferromagnetic alloy having an iron composition of about 10 atomic percent to about 90 atomic percent,
the at least one current rectifying layer comprises a p-type semiconductor, the p-type semiconductor having a first work function less than a second work function of the ferromagnetic alloy, and
the laminated configuration further comprises an interface metal layer disposed on said p-type semiconductor, the interface layer having a work function less than said first work function of said p-type semiconductor.