Electrostatic discharge protection circuit with silicon controlled rectifier characteristics

摘要

An ESD protection circuit based on a modification of conventional silicon controlled rectifier (SCR) for preventing integrated circuits from ESD damage. A first N-well, which has a second N-type doped region and third P-type doped region, is formed in a P-type substrate. A fourth N-type doped region and fifth doped region are formed adjacent to the first N-well in the substrate. A first conducting structure is formed on the second N-type doped region and connected to an anode. A second conducting structure is formed on the fourth N-type doped region and fifth P-tape doped region and connected to a reference potential. Since the third P-type doped region is floated from connecting with the anode, the ESD protection circuit would thus have a higher trigger current than the conventional SCR