DIODE DEVICE TO PROTECT METAL-OXIDE-METAL CAPACITORS

摘要

An ESD protective clamp device comprised of a two-terminal diode formed in an isolated chip cell. The lower part of this chip cell region contains a buried layer (30) of silicon with P-type dopant, and the upper part is an epitaxial layer (32) also with P-type dopant. An annular (ring-shaped) anode plug segment (34) is formed at the outer reaches of the epitaxial layer with P+ doping. At the interior central region is an N-type plug (42) circular in horizontal cross section and concentric with the annular plug. This central plug serves as the cathode. Electrical connections are made to anode and cathode to provide interconnection with an IC circuit with a MOM capacitor to be protected.