A semiconductor structure includes first and second transistors each having a source terminal, a drain terminal, and a gate terminal. The semiconductor structure further includes a program line; a first metal plate over the first and the second transistors; a first insulator over the first metal plate; a second metal plate over the first insulator; a second insulator over the second metal plate; and a third metal plate over the second insulator. The first metal plate, the first insulator, and the second metal plate form a first anti-fuse element. The second metal plate, the second insulator, and the third metal plate form a second anti-fuse element. The source terminal of the first transistor is electrically connected to the first metal plate. The source terminal of the second transistor is electrically connected to the third metal plate. The program line is electrically connected to the second metal plate.