Integration of self-assembled inductors with CMOS LC oscillators

The quality factor (Q) of integrated inductors is of great importance to radio frequency applications. Monolithic integration of out-of-plane Au inductors with Complementary Metal-Oxide-Semiconductor (CMOS) LC oscillators is reported in this paper. The recently developed self-assembly process involves in-plane fabrication of Au inductors and subsequent rotation of the structure by surface tension forces of a melting Sn hinge. The CMOS compatibility of this process is demonstrated through the integration of an LC oscillator with the self-assembled inductor using post-CMOS processing. At a 1.48 GHz oscillation frequency, a phase noise of -95 dBc/Hz is reported at a 100 kHz frequency offset. Obtained results show this technique to be promising for the integration of high Q inductors with commercial RF systems.