Reliability of copper wirebonds over through-silicon vias for SiGe power amplifiers

SiGe bipolar transistors with through-silicon-vias (TSVs) are widely used for power amplifiers for WiFi front-end modules. Wirebond packages are generally used to minimize cost and maximize heat dissipation from the devices. The die sizes are small (on the order of 1mm × 1mm) so that the bond pads and the TSVs occupy a large fraction of the chip area. It is therefore desirable to place TSVs under bond pads to minimize die size. In this report, we assess the reliability of structures with TSVs under bond pads. It is shown that TSVs can be placed under Cu wirebonds without degrading reliability.