Semiconductor device capable of high-voltage operation

A semiconductor device, comprising:

• a semiconductor substrate having a first conductivity type;
• a first well region formed in a portion of the semiconductor substrate, having a second conductivity type that is the opposite of the first conductivity type;
• a second well region formed in a portion of the first well region, having the first conductivity type;
• a first gate structure formed over a portion of the second well region and a portion of the first well region, wherein a dielectric layer of the first gate structure has constant thickness;
• a first doped region formed in a portion of the second well region, having the second conductivity type;
• and
• a second doped region formed in a portion of the first well region, having the second conductivity type;
• and
• a second conductive layer formed over a portion of the first gate structure, a portion of the first well region, and a portion of the second well region.

A semiconductor device, comprising:

• a semiconductor substrate having a first conductivity type;
• a first well region formed in a portion of the semiconductor substrate, having a second conductivity type that is the opposite of the first conductivity type;
• a second well region formed in a portion of the first well region, having the first conductivity type;
• a first gate structure formed over a portion of the second well region and a portion of the first well region, wherein a dielectric layer of the first gate structure has constant thickness;
• a first doped region formed in a portion of the second well region, having the second conductivity type;
• and
• a second doped region formed in a portion of the first well region, having the second conductivity type;
• and
• a second structure formed over a portion of the first gate structure, a portion of the first well region, and a portion of the second doped region.