Patent ID: 8643136

Claim:
A high voltage device, comprising: a first conductive type substrate in which isolation regions are formed for defining a device region; a gate which is formed on the first conductive type substrate; a source and a drain, which are formed in the device region and located at both sides of the gate respectively, and are doped with second conductive type impurities; a second conductive type well, which is formed in the first conductive type substrate, and surrounds the drain from top view; at least a first deep trench isolation structure, which is formed in the first conductive type substrate, and is located in the second conductive type well between the source and the drain from top view, wherein the first deep trench isolation structure has a depth deeper than the second conductive type well from cross-section view; and a first surrounding region, which is doped with first conductive type impurities, and completely surrounds the first deep trench isolation structure from top view, the first surrounding region being shallower than the second conductive type well from cross-section view.