A thyristor is formed from a vertical stack of first, second, third, and fourth semiconductor regions of alternated conductivity types. The fourth semiconductor region is interrupted in a gate area of the thyristor. The fourth semiconductor region is further interrupted in a continuous corridor that extends longitudinally from the gate area towards an outer lateral edge of the fourth semiconductor region. A gate metal layer extends over the gate area of the thyristor. A cathode metal layer extends over the fourth semiconductor region but not over the continuous corridor.