Double-level spiral inductors with multiple-via interconnects on GaAs substrates

Abstract

In this letter, we report the electromagnetic characteristics of on-chip double-level square spiral inductors. The inductors are unique in that the double-level spirals are interconnected by multiple vias with one air bridge, instead of the usual "single-via-at-center" interconnect. We show that, in spite of a decrease in resonant frequency, inductance as well as Q factor are greatly improved over those of single-level spiral geometries, and this could be due to the enhancement of electromagnetic coupling between double spirals.