Semiconductor device and manufacturing method of semiconductor device

A method of making semiconductor devices, the method comprising:

• a) forming a well region of a first doping type, and a body region of a second doping type in substrate, wherein the second doping type is opposite to the first doping type;
• b) forming a drain region of the first doping type in the well region;
• c) forming a source region of the first doping type in the body region;
• d) forming an isolation structure on the substrate, the isolation structure being located between the drain region and the source region;
• e) forming a gate structure on the isolation structure;
• and
• f) performing ion implantation on a first part of the gate structure to form a first gate region of the first doped type, and performing ion implantation on a second part of the gate structure to form a second gate region of the second doped type.