Junction varactor for ESD protection of RF circuits

摘要

An ESD protection device includes a first well of a first semiconductor type disposed in a substrate of a second semiconductor type forming a first diode. A second well of the second semiconductor type is formed in the substrate to form a second diode with the first well. A first plurality of doped regions of the first semiconductor type are formed in an upper surface of the first well. A second plurality of doped regions of the second semiconductor type are formed in the upper surface of the first well forming a third diode with the first well. A plurality of STI regions are formed in the upper surface of the first well. Each STI region is disposed between a doped region of the first and second semiconductor types. The third diode provides a current bypass when an ESD voltage spike is received at one of the first or second plurality of doped regions.