String contact structure for high voltage ESD

摘要

The present invention relates to an electrostatic discharge (ESD) protection scheme and particularly to a string contact structure for an improved ESD performance. In an embodiment, the invention provides a method for forming an ESD protection circuit for protecting an internal circuit from damage due to an ESD voltage appearing on a pad coupled to a clamp device including a first terminal and a second terminal. The method includes forming a string contact along the first terminal and the second terminal of the clamp device. The method further includes forming one or more conductive layers on the string contact to couple the first terminal and the second terminal of the clamp device to the pad and a ground pad.