Magnetic Core Inductor Integrated with Multilevel Wiring Network

Abstract

An inductor is integrated into a multilevel wiring network of a semiconductor integrated circuit. The inductor includes a planar magnetic core and a conductive winding. The conductive winding turns around in generally spiral manner on the outside of the planar magnetic core. The conductive winding is piecewise constructed of wire segments and of VIAs. The wire segments pertain to at least two wiring planes and the VIAs are interconnecting the at least two wiring planes. Methods for such integration, and for fabricating laminated planar magnetic cores are also presented.

What is claimed is: 
     
         1 . A structure comprising:
 a semiconductor integrated circuit comprising a multilevel wiring network disposed on a substrate; and   a first inductor integrated into said multilevel wiring network of said integrated circuit, said first inductor comprising a first planar magnetic core and a first conductive winding, said first conductive winding turned around said first planar magnetic core in a generally spiral manner;   a second inductor integrated into said multilevel wiring network of said integrated circuit, said second inductor comprising a second planar magnetic core and a second conductive winding, said second conductive winding turned around said second planar magnetic core in a generally spiral manner;   said first and second conductive windings further being electrically coupled to one another on one side of said inductors but not electrically coupled to one another on another side of said inductors,   wherein at least one of the first and second planar magnetic cores has a laminated configuration comprising at least one layer of a magnetic material and at least one insulator layer, wherein said insulator layer comprises a reactive deposition-formed oxide of said magnetic material.   
     
     
         2 . The structure of  claim 1 , wherein said multilevel wiring network is arranged into wiring planes, said planar magnetic cores having a principal plane which is parallel with said wiring planes, said conductive windings being piecewise constructed of respective wire segments and of Vertical Interconnect Accesses (VIAs), and said wire segments disposed respectively in at least two of said wiring planes and said VIAs are interconnecting said at least two wiring planes. 
     
     
         3 . The structure of  claim 2 , further comprising:
 planar couplers for magnetic coupling between said planar magnetic cores of said plurality of said inductors, wherein said planar magnetic cores and said planar couplers are arranged in said principal plane in the manner of a ladder having rungs and stringers, wherein each of said planar magnetic cores corresponds to one of said rungs and each of said planar couplers corresponds to one of said stringers and wherein said conductive windings are electrically coupled to one another proximal to one such stringer.   
     
     
         4 . The structure of  claim 3 , wherein said planar magnetic cores and said planar couplers are of the same chemical composition, and wherein said planar magnetic cores and said planar couplers are differing portions of a single planar structure thereof. 
     
     
         5 . The structure of  claim 1 , said magnetic material comprising Co x Zr y Ta 1-X-Y . 
     
     
         6 . The structure of  claim 2 , said non-magnetic layer constructed and arranged to prevent electrical current circulation in said planar magnetic cores perpendicularly to said principal plane. 
     
     
         7 . The structure of  claim 1 , said planar magnetic core having a hard-axis of magnetization, said hard-axis aligned substantially in parallel with a magnetic field that is induced when an electrical current is flowing in said conductive winding. 
     
     
         8 . The structure of  claim 1 , wherein said insulator layer consists essentially of said reactive deposition-formed oxide of said magnetic material. 
     
     
         9 . A structure comprising:
 a multilevel wiring network arranged into wiring planes of an integrated circuit disposed on a substrate; and   a plurality of inductors integrated into said multilevel wiring network,   each of said inductors comprising a planar magnetic core and a conductive winding, said planar magnetic core having a laminated configuration comprising at least one layer of a magnetic material and at least one insulator layer, wherein said insulator layer comprises a reactive deposition-formed oxide of said magnetic material,   said conductive windings turned around their respective inductors' planar magnetic core in a generally spiral manner   each of said planar magnetic cores having a principal plane which is parallel to said respective wiring planes,   said conductive windings further being piecewise constructed of wire segments and of Vertical Interconnect Accesses (VIAs), said wire segments pertain to at least two of said wiring planes and said VIAs are interconnecting said at least two wiring planes, and   said conductive windings further being electrically coupled to one another on one side of said inductors but not electrically coupled to one another on another side of said inductors.   
     
     
         10 . The structure of  claim 9 , further comprising:
 planar couplers for magnetic coupling between said planar magnetic cores of said plurality of said inductors, wherein said planar magnetic cores and said planar couplers are arranged in said principal plane in the manner of a ladder having rungs and stringers, wherein each of said planar magnetic cores corresponds to one of said rungs and each of said planar couplers corresponds to one of said stringers and wherein said conductive windings are electrically coupled to one another proximal to one such stringer.   
     
     
         11 . The structure of  claim 10 , said planar magnetic cores and said planar couplers being of the same chemical composition, and said planar magnetic cores and said planar couplers comprise differing portions of a single planar structure thereof. 
     
     
         12 . The structure of  claim 11 , wherein said insulator layer consists essentially of said reactive deposition-formed oxide of said magnetic material. 
     
     
         13 . The structure of  claim 9 , said magnetic material comprising Co x Zr y Ta 1-X-Y . 
     
     
         14 . The structure of  claim 9 , said non-magnetic layer constructed and arranged to prevent electrical current circulation in said planar magnetic core perpendicularly to said principal plane. 
     
     
         15 . The structure of  claim 9 , said planar magnetic core having a hard-axis of magnetization, said hard-axis being aligned substantially in parallel with a magnetic field that is induced when an electrical current is flowing in said conductive winding.