Effects of polysilicon shield on spiral inductors for silicon-based RF IC's

Increasing demands for more affordable personal mobile communication equipment have motivated research and development of low cost, high performance silicon-based on-chip inductors. Current silicon technology uses a conductive substrate, which causes unwanted energy dissipation. Inserting a patterned polysilicon shield beneath inductors can help reduce this substrate loss. Effects of the polysilicon ground shield on inductor performance have been investigated. An inductor utilizing a new high resistivity polysilicon floating shield is shown in this paper to have improved inductive characteristics.