A vertical solenoid inductor for noise coupling minimization in 3D-IC

This paper presents the use of an integrated solenoid inductor in three dimensional integrated circuits (3D-IC) for improved noise mitigation. The structure is fabricated in a two-tier, stacked 28nm CMOS using through silicon vias (TSV). The structure is implemented as part of an LC voltage-controlled oscillator (VCO), and exhibits 6dB improvement in phase noise and 14dB less coupling from adjacent digital clock lines compared to a planar two-turn inductor.