Abstract: A metal oxide semiconductor device comprising a substrate, at least an isolation structure, a deep N-type well, a P-type well, a gate, a plurality of N-type extension regions, an N-type drain region, an N-type source region and a P-type doped region is provided. The N-type extension regions are disposed in the substrate between the isolation structures and either side of the gate, while the N-type drain region and the N-type source region are respectively disposed in the N-type extension regions at both sides of the gate. The P-type well surrounds the N-type extension regions, and the P-type doped region is disposed in the P-type well of the substrate and is isolated from the N-type source region by the isolation structure.

Abstract: A metal oxide semiconductor device comprising a substrate, at least an isolation structure, a deep N-type well, a P-type well, a gate, a plurality of N-type extension regions, an N-type drain region, an N-type source region and a P-type doped region is provided. The N-type extension regions are disposed in the substrate between the isolation structures and either side of the gate, while the N-type drain region and the N-type source region are respectively disposed in the N-type extension regions at both sides of the gate. The P-type well surrounds the N-type extension regions, and the P-type doped region is disposed in the P-type well of the substrate and is isolated from the N-type source region by the isolation structure.