34. Through-Silicon via Technology for RF and Millimetre-Wave Applications

This chapter focuses on some of the radiofrequency (RF) and millimetre-wave (MMW) applications that a through-silicon via (TSV) technology can enable. We will first discuss a grounded TSV application for a RF wireless communication power amplifier that is in mass production. A grounded TSV is essentially a metal connection that takes the active device interconnect to a package ground without needing to go through wire bond. A tungsten-filled grounded TSV delivers over 75% reduction in inductance compared to a traditional wire bond, thus enabling higher frequency applications in silicon technology. Such a grounded TSV is seamlessly integrated into a 350-nm SiGe BiCMOS. Next we show feasibility on insulated TSV that is utilised in a digital technology for high speed I/O functions, such as, in an advanced microprocessor. The insulated TSV sits in a 3D-IC carrier silicon chip that is made compatible with standard 90-nm high performance CMOS processing. The TSV arrays are designed to provide minimal resistance and inductance with excellent yield and breakdown voltage characteristics. A commercial application of this concept is for the emerging 100-Gb Ethernet that requires almost 1 Tbps data transmission between ICs. This concept of insulated via in a 3D-IC environment is then extended to a 130-nm MMW SiGe BiCMOS technology. We introduce the concept of a Wilkinson power divider that can be utilised in a 60-GHz phased array radar system.