Suspended of high-Q integrated inductors using wafer level packaging technologies

Thin film multilayer technologies adapted from wafer level packaging offer a very promising approach for the implementation of integrated passive devices, which have become increasingly popular these years. In this paper, we present a novel fabrication technique which combines wafer level packaging (WLP) and Micro-Electro-Mechanic System (MEMS) technologies to prepare suspended inductors with high Q factor. Simulation and measurement of both the proposed suspended inductors and non-suspended ones on low resistivity silicon wafers are done. The measured quality factor (Q) of 5.6nH suspended inductors with optimal strictures fabricated using polyimide (PI)/copper (Cu) thin film technology and two step etching are significantly higher than the traditional PI/Cu inductors.