Silicon controlled rectifier

A silicon controlled rectifier comprising:

• a semiconductor substrate comprising silicon of a first conductivity type;
• first and second semiconductor wells formed in the semiconductor substrate, and respectively comprising silicon of a second conductivity type and silicon of the first conductivity type;
• first and second semiconductor regions respectively formed in the first and the second semiconductor wells in spaced apart relation, and respectively comprising silicon of the first conductivity type and silicon of the second conductivity type;
• third and fourth semiconductor regions respectively formed in the first and the second semiconductor wells, and respectively comprising silicon of the second conductivity type and silicon of the first conductivity type, wherein the third semiconductor region directly contacts with the fourth semiconductor region;
• a silicide layer formed on the third and the fourth semiconductor regions, wherein the silicide layer extends from the third semiconductor region to the fourth semiconductor region;
• a first insulating region formed in the first semiconductor well and located between the first and the third semiconductor regions;
• and
• a second insulating region formed in the second semiconductor well and located between the second and the fourth semiconductor regions,
• wherein the first insulating region and the second insulating region directly contact with two sides of the silicide layer.