Low voltage breakdown element for ESD trigger device

A method of making an electrostatic discharge semiconductor device, comprising the steps of:

• implanting, into a substrate having a first concentration of a first conductivity type, a first region, a second region, and a third region, each of said first region, said second region, and said third region having a second conductivity type that is opposite in polarity to said first conductivity type, wherein said first region is separated from said second region and said third region by an isolation region;
• implanting a fourth region of said first conductivity type adjacent to said substrate and adjacent to said first region;
• implanting a fifth region of said first conductivity type and a second doping concentration into said substrate, said fifth region being separated from said first, said second, said third and said fourth regions by an isolation region;
• forming an insulated terminal across said second and said third well regions;
• electrically connecting said first and said second regions to an input pad of said semiconductor device;
• and
• electrically connecting said insulated terminal, said third region and said fifth region to each other.