Protection element and fabrication method for the same

摘要

The protection element of the present invention is constructed of a MOS capacitor composed of a semiconductor substrate, an insulating film formed on the semiconductor substrate and a word line formed on the insulating film. A well region having a conductivity type opposite to that of the semiconductor substrate is formed in a portion of the semiconductor substrate constituting the MOS capacitor. If charge exceeding the breakdown voltage of the insulating film constituting the MOS capacitor is induced in the word line, the induced charge is released into either the semiconductor substrate or the well region depending on whether the induced charge is positive or negative.