Double diffused drain metal-oxide-semiconductor devices with floating poly thereon and methods of manufacturing the same

A metal-oxide-semiconductor (MOS) device comprising:

• a diffused region including a first portion of a second impurity type and a second portion of a first impurity type in the substrate;
• a patterned first dielectric layer including a first dielectric portion over the first portion of the diffused region;
• a patterned first conductive layer on the patterned first dielectric layer, the patterned first conductive layer including a first conductive portion on the first dielectric portion;
• a patterned second dielectric layer including a second dielectric portion directly formed on a first portion of an upper surface of the first conductive portion and along a sidewall of the first conductive portion to the substrate;
• a patterned second conductive layer on the patterned second dielectric layer, the patterned second conductive layer including a second conductive portion on the second dielectric portion, a patterned second dielectric layer and a patterned second conductive layer directly formed on the upper surface of a portion of the patterned first conductive layer, the patterned second conductive layer is formed on the patterned second dielectric layer;
• at least a spacer is formed along at least a sidewall of the patterned first conductive layer and the patterned second dielectric layer;
• and
• isolation structures on the substrate,
• wherein the patterned second dielectric layer and the at least a spacer are used to sustain high operating voltage of the MOS.