US Patent 7183612 Semiconductor device having an electrostatic discharge protecting element

In an ESD protecting element, a plurality of source regions and a plurality of ballast resistor regions are formed. A drain region is formed at a region which is in contact with a channel region in the ballast resistor region, and an n+ type diffusion region is formed at a region isolated from the drain region via an STI region. A third contact is provided on the drain region, first and second contacts are formed on the n+ type diffusion region, and the first contact is connected to a pad. The second contact is coupled to the third contact by a metal wire. The first and second contacts are laid out along the widthwise direction of a gate.