Cascaded diode structure with deep N-well and method for making the same

摘要

A cascaded diode structure with a deep N-well for effectively reducing the leakage current of the P-type substrate by floating the base of a parasitic transistor in the cascaded diode structure. The cascaded diode structure includes a P-type substrate, a deep N-well formed on the P-type substrate, a plurality of elemental diodes formed on the deep N-well, and a plurality of connecting parts for cascading the elemental diodes. Each elemental diode includes a P-well formed on the deep N-well, a heavily doped P-type region formed on the P-well, and a heavily doped N-type region formed on the P-well.