RF performances at cryogenic temperatures of inductances integrated in a FDSOI technology

This paper investigates the RF performances of octagonal inductances integrated in a Fully Depleted Silicon On Insulator (FD-SOI) technology. 0.5nH to 4 nH inductors were first characterized vs frequency down to 4.2K and then modelled thanks to lumped elements including induction, coil proximity and skin effects. At low temperature, the quality factor is improved by a factor two because of the metal resistivity reduction, in agreement with DC measurements. Such performances and RF characterizations are mandatory to enable cryogenic CMOS RF integrated circuits design.