High voltage device and high voltage device for electrostatic discharge protection circuit

A high voltage device for an electrostatic discharge protection circuit, comprising:

• a first type substrate;
• a first type epitaxial silicon layer disposed in the first type substrate;
• a first type well disposed in the first type epitaxial silicon layer;
• a second type well disposed in the first type epitaxial silicon layer, wherein the second type well comprises a second type lightly doped region and a second type heavily doped region, the second type lightly doped region is located next to the first type well and the second heavily doped region is located underneath a portion of the first type well and the second type lightly doped region, wherein the first type well adjoins with the second heavily doped region;
• a gate structure disposed on a portion of the first type well and the second type lightly doped region;
• a second type first doped region and a second type second doped region disposed in the second type lightly doped region and the first type well on each side of the gate structure respectively;
• a first isolation structure disposed in the second type lightly doped region and between the gate structure and the second type first doped region;
• a first type doped region disposed in the first type well and adjacent to the second type second doped region;
• and
• a second isolation structure disposed in the first type well and between the first type doped region and the second type second doped region.