Patent ID: 7473973

Claim:
A semiconductor device comprising: a silicon-controlled rectifier to protect an internal circuit from electrostatic discharge damage; and a first metal-oxide-silicon field-effect transistor to apply a trigger voltage to the silicon-controlled rectifier, the first metal-oxide-silicon field-effect transistor including a gate electrode and a substrate which are electrically connected to each other, wherein the silicon-controlled rectifier and the first metal-oxide-silicon field-effect transistor are provided on a common first well region of a first conductivity type, and the first metal-oxide-silicon field-effect transistor has a second well region of the first conductivity type, and the silicon-controlled rectifier has a third well region of the first conductivity type, the second well region of the first conductivity type and the third well region of the first conductivity type being electrically connected to each other through the first well region of the first conductivity type.