Electrostatic discharge protection device for digital circuits and for applications with input/output bipolar voltage much higher than the core circuit power supply

An electrostatic discharge (ESD) device comprising:

• a substrate doped to a first conductivity type;
• an epitaxial layer formed in the substrate and doped to a second conductivity type;
• a first well disposed in the substrate and doped to the first conductivity type, the first well comprising,
• a cathode comprising a first region doped to the first conductivity type and a second region doped to the second conductivity type and separated from the first region by a first isolation region;
• a second well adjacent to the first well and doped to the second conductivity type, the second well comprising,
• an anode comprising a third region doped to the first conductivity type;
• and
• a first trigger contact having a length D1 disposed at a junction between the first well and the second well and between a second isolation region and a third isolation region.

A method of making an electrostatic discharge (ESD) device, the method comprising:

• providing a substrate doped to a first conductivity type;
• forming a first well doped to the first conductivity type in the substrate, the first well comprising,
• a first region doped to the first conductivity type,
• a second region doped to a second conductivity type, and
• a first isolation region disposed between the first region and the second region;
• forming a second well doped to a second conductivity type in the substrate adjacent to the first well, the second well comprising,
• a third region doped to the first conductivity type,
• a fourth region doped to the second conductivity type, and
• a second isolation region disposed between the third region and the fourth region;
• and
• forming a first trigger contact comprising a highly doped region a junction between the first well and the second well.

A method of making an electrostatic discharge (ESD) device, the method comprising:

• providing a substrate doped to a first conductivity type, wherein the substrate comprises an epitaxial layer doped to a second conductivity type;
• forming a first well doped to the first conductivity type in the substrate;
• forming a cathode in the first well, the cathode comprising,
• a first region doped to the first conductivity type,
• a second region doped to the second conductivity type, and
• a first isolation region disposed between the first region and the second region;
• forming a second well doped to the second conductivity type in the substrate adjacent to the first well;
• forming an anode in the second well, the anode comprising,
• a third region doped to the first conductivity type,
• a fourth region doped to the second conductivity type, and
• a second isolation region disposed between the third region and the fourth region;
• and
• forming a first trigger contact comprising a highly doped region disposed at a junction between the first well and the second well.