An antifuse is provided having a unitary monocrystalline semiconductor body including first and second semiconductor regions each having the same first conductivity type, and a third semiconductor region between the first and second semiconductor regions which has a second conductivity type opposite from the first conductivity type. An anode and a cathode can be electrically connected with the first semiconductor region. A conductive region including a metal, a conductive compound of a metal or an alloy of a metal can contact the first semiconductor region and extend between the cathode and the anode. The antifuse can further include a contact electrically connected with the second semiconductor region. In this way, the antifuse can be configured such that the application of a programming voltage between the anode and the cathode heats the first semiconductor region sufficiently to reach a temperature which drives a dopant outwardly therefrom, causing an edge of the first semiconductor region to move closer to an adjacent edge of the second semiconductor region, thus permanently reducing electrical resistance between the first and second semiconductor regions by one or more orders of magnitude.