3D integration techniques applied to SiGe power amplifiers

We describe a 0.35 μm SiGe BiCMOS technology that is optimized for power amplifier (PA) applications. The key feature of this technology is a novel low inductance ground to the package by method of through-silicon-via (TSV), offering a competitive solution for future multi-band / multi-mode PA integration. The tungsten filled, multi-finger, bar shaped TSV delivers over 75% reduction in inductance compared to a traditional wire bond, enabling higher frequency applications with roughly 20% die area reduction, and without compromising the technology reliability for use conditions in a low-cost plastic QFN package. In this paper we demonstrate the commercial feasibility of the TSV, its RF performance, and its usefulness in a demanding WiMAX PA application. ©The Electrochemical Society.