A new high voltage IC with robust isolation design

A new and robust isolation design for control devices integrated in the high side island region of 250V high-voltage integrated circuits (HVIC) is proposed and verified by numerical calculations, simulations and experiments. The new isolation structure can be realized using micro N-well in the P-type isolation region to achieve a higher breakdown voltage (BV). The measurement and TCAD simulation results prove this new isolation structure's BV is over 350V with negligible leakage current. In the proposed scheme BV is improved by 15% more than the conventional structure without adding additional process steps and photo layers.