Polysilicon field ring structure for power ic

摘要

A polysilicon field ring structure is used to eliminate any type of unwanted surface current leakage in an integrated power chip having high voltage and low voltage areas and enclosed in a plastic housing. All P-type diffusions not biased to the ground potential are surrounded by rings biased to the supply potential, and all N-type diffusions not biased to the supply potential are surrounded by rings biased to the ground potential.