On-chip electrical coil and three-dimensional on-chip magnetic sensor including on-chip electrical coil

Abstract

An on-chip electrical coil includes a semiconductor substrate; a plurality of metal layers disposed on the semiconductor substrate; a plurality of insulator layers disposed on the semiconductor substrate, each insulator layer disposed between a pair of neighboring metal layers to form an alternating arrangement of metal layers and insulator layers; a plurality of metal vias defined in the insulator layers, each metal via electrically connecting a respective pair of neighboring metal layers; and a planar spiral formed by the metal layers and the metal vias, the planar spiral including a plurality of interconnected loops, each loop including two metal wires disposed in respective metal layers, an intra-loop column that electrically connects the two metal wires of a respective loop, and an inter-loop column that electrically connects one of the metal wires of the respective loop to one of the metal wires in a subsequent loop.