Authors: Y.Z. Xu and J.T. Watt
Affilation: Altera Corporation, United States
Pages: 674 - 677
Keywords: RF, Spiral inductor, Compact Model
Spiral inductors fabricated using a 90nm CMOS process have been characterized and analyzed. The extracted series resistance increases with frequency and temperature. The extracted resistance temperature coefficient exhibits a strong dependence on operating frequency. It gradually decreases with frequency and is different from the results using DC temperature coefficients. A single $\pi$-model is used to model the measured high frequency characteristics. Two resistors and a transformer are used to model the observed temperature coefficient. One resistor has temperature coefficient around DC value, while the other one is less dependent on temperature and connected through the other side of the transformer. The model shows good fitting to all parameters, such as series resistance, temperature coefficient, inductance, quality factor and s-parameters across a wide frequency range and from room to high temperature. Discussion of process variation and corner models is also given.