ABSTRACT
Modern silicon-based processes now feature active devices functioning at very high speeds, with Gigahertz being the standard unit of measurement and state-of-the-art transistors operating with ease above 200 GHz. At such speeds, high-quality on-chip passives are a requirement, not a luxury. Despite filling large swaths of valuable silicon die with seemingly simple metal shapes, on-chip inductors and capacitors are mandatory for even what some now consider “low-speed” applications. For state-of-the-art RF transceivers, mixers, amplifiers, and the like operating in the tens of gigahertz, impedance matching circuitry must be carefully designed as part of the tape-out process, and a well-characterized suite of passive components, or elaborate and computationally intensive EM simulation, can be the difference between a functioning circuit and a wasted effort. Likewise, traditional analog circuitry operating at “only” a few hundred megahertz also may require extensive use of on-chip capacitors and inductors for stable operation. As these advanced processes mature and enter the marketplace, they are being increasingly considered for use in so-called extreme environments—in this context, wide temperature ranges and high radiation fields, or sometimes both. Because of the importance of the passive components of modern circuits, it is critical that the effects of extreme environments on passive components be characterized and understood as part of the design phase—not as part of a troubleshooting phase.
