Patent ID: 8410576
Filing Date: 2013-04-02
Classification: H01F,H01L,Y10T

Abstract:
1. A method of forming an inductive structure on a conventional semiconductor structure comprising: providing a conventionally-formed semiconductor wafer with a cavity formed therein, the bottom surface of the cavity lined with a first non-conductive material; providing a first core structure, wherein the first core structure is formed in a conventional manner in a separate process, the first core structure is implemented in a material selected from alloys of (Co)NiFe, NiZn or MnZn; placing the first core structure in the cavity using a conventional pick and place machine and adhesively attaching the first core structure to the bottom of the cavity in the semiconductor wafer; depositing a second non-conductive layer to touch a top surface of the first core structure filling the remainder of the cavity; opening a plurality of openings in the second non-conductive layer to expose the top surface of the first core structure using conventional photolithographic methods; forming a first coil, having ends, to touch the second non-conductive layer and laying over a portion of the first core structure; depositing forming a third non-conductive layer to touch a top surface of the first coil structure, the top surface of the first core structure and the top surface of the second non-conductive layer; forming openings in the third non-conductive layer to expose the top surface of the first core structure using conventional photolithographic methods; providing a second core structure wherein the first core structure is formed in a conventional manner in a separate process, the second core structure is implemented in a material selected from alloys of (Co)NiFe, NiZn or MnZn; placing the second core structure in the openings in the third no-conductive layer to touch the top surface of the third non-conductive layer using a conventional pick and place machine and adhesively attaching the second core structure to the third non-conductive layer, the second core structure may touch, but is not attached to the first core structure; providing conventional back end processing steps, including formation of a passivation layer overlaying the inductive structure and forming openings that expose the top surfaces of the ends of the coil; and depositing a metal selected from the group of aluminum, aluminum-copper or gold on the ends of the coil prior to dicing and wire-bonding.