Development of scalable models for patterned-ground-shield inductors in SiGe BiCMOS technology

摘要

This paper presents the characterization and modeling of a group of monolithic spiral inductors with various patterned ground shield structures fabricated in a 0.18 /spl mu/m SiGe:C RFBiCMOS process. A direct comparison of two different types of ground shields, center-grounded (CGS) and perimeter-grounded (PGS), each fabricated in two different conductor levels, polysilicon and metal-one, is made. Fabricated inductors are characterized using on-wafer measurement with de-embedding of pad parasitics. A 36% improvement in the inductor quality factor over the unshielded inductor is realized using the CGS in polysilicon and metal-one, and using the PGS in polysilicon. Finally, a scalable lumped-element model that accounts for the effects of the different ground shield structures is proposed, and preliminary results of model extraction are presented.