Patent ID: 8237225

Claim:
A semiconductor device for electrostatic discharge protection, comprising: a semiconductor substrate; an electrostatic discharge (ESD) protection element disposed in a surface of the semiconductor substrate and connected between an input/output terminal and a ground terminal; a first well region having the same conductivity type as the semiconductor substrate, and surrounding the ESD protection element; a first high concentration substrate region having the same conductivity type as the semiconductor substrate, and surrounding the ESD protection element in the first well region; a second well region having an opposite conductivity type to the conductivity type of the semiconductor substrate, and surrounding an outer side of the first well region; a high concentration anode region having the same conductivity type as the semiconductor substrate, disposed in the second well region separately from the first well region; and a second high concentration diffusion region having the opposite conductivity type to the conductivity type of the semiconductor substrate and disposed in the second well region, the second high concentration diffusion region surrounding the high concentration anode region disposed in the second well region and the first well region as a guard ring of the ESD protection element, the guard ring of the ESD protection element corresponding to a cathode of a latch-up protection diode, wherein: the high concentration anode region is connected to the input/output terminal; the first high concentration substrate region is connected to the ground terminal; and the second high concentration diffusion region is connected to a power supply terminal.