Patent ID: 8283725

Claim:
A semiconductor device, comprising: an n-type metal oxide semiconductor transistor for electrostatic discharge protection disposed on a semiconductor substrate, placed between an external connection terminal and an internal circuit region so that an internal element disposed in the internal circuit region is protected from electrostatic discharge breakdown; a p-type region disposed on the semiconductor substrate in contact with a side of a drain region of the n-type metal oxide semiconductor transistor that is opposite to a gate electrode of the n-type metal oxide semiconductor transistor, the drain region is between the gate electrode and the p-type region; an n-type region placed apart from the drain region opposite to the gate electrode of the n-type metal oxide semiconductor transistor, fully isolated from the drain region by the p-type region, having no connection to the drain region through another n-type region, and configured to receive a signal from the external connection terminal; and a shallow trench region surrounding the n-type metal oxide semiconductor transistor, the p-type region, and the n-type region for isolation.